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Is That Amp Really Worth It?
Alan Applegate (K0BG)
on
January 14, 2008
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Is That Amp Really Worth It?
Over the years, there have been some really well designed power amplifiers, some of which have stood the test of time. The Heathkit SB200 comes to mind. While it doesn't directly support the WARC bands, it is nonetheless serviceable. The 572B finals are still available, as are upgrade kits to modernize the keying and rectifier circuitry. If they haven't been abused, or improperly modified, they're still a decent buy. Street prices vary across the board, but are typically $250 to $350 in good working condition.
A few, like the Dentron MLA2500b (and its little brother the MLA1200) weren't worth the effort the day they were introduced. For example, the meter circuitry was suspect, and it didn't have a tuned input unless you purchased the ATI-6. If you own(ed) one of these, and the bleed resistors haven't flamed, count yourself lucky! What's more, it had no grid protection for the rather expensive 8875 finals (even back then). The last NOS (New, Old Stock) 8875s sold for nearly $650 each, and nowadays, they're extinct! Yet, I've seen MLA2500s being sold for nearly $1,000.
Dentron, along with Swan and a few others, made amplifiers which used inexpensive sweep tubes as finals. Whether the finals were 6KD6s, 6LQ6s, D50As, or what have you, the finals for these amplifiers are nonexistent. That is to say, I haven't seen any NOS units for several years. Even if you pay $100 for one of these relics, you've thrown your money away!
That last sentence sort of explains the subject of this article; Is That Amp Really Worth It? Well, I suspect that's in the eyes of the beholder, but if you don't know what you're up against, you're liable to get took! I certainly don't have all the answers, but a few things sort of stand out if you do a little research. As I alluded to above, probably the most important is the final tubes in question.
I have no idea how many different tube types have been used as finals in the myriad of commercial HF amplifiers sold over the years. A few of the more popular ones included; 4-400, 4-1000, 3-400, 3-500, 811A, 813, 572B/160L, 8875, 8877, PL172, 3CX800, 3CX1200A7, 4CX250B, and even the 1625. I know this, some of these types haven't been made in 50 years!
Here's one site you might want to visit. Dr. David Kirkby, G8WRB, has put together a list of the more popular finals, albeit some of them have never been used (legally) in any amateur HF amplifier. Unfortunately, it doesn't list their current availability, or if they've been discontinued, recently or otherwise. It doesn't include any sweep tubes, but suffice to say, they're long-gone-johnson anyway.
The bottom line here is glaringly evident; Amplifiers which use discontinued finals aren't worth the effort, no matter how good a bargain they appear to be. You may argue that your MLA2500b (or what have you) is still operational, but when it does fail (it will sooner or later), you're sunk (pun intended).
I can hear it now; I modified mine to use XXXX finals. All this means is, the amplifier has been modified. And that too, can be a really big problem. Contrary to popular belief, there is more to substituting finals than replacing the tubes and/or sockets. Adding insult, most of the modification articles posted on the Internet are suspect at best.
I recently worked on a 10 year old AL1200. One of it's previous owners had replaced the meter lights with LEDs. Nothing wrong with that, had it been done correctly. It was obvious that a soldering gun had been used, and the LEDs were mounted on swizzle sticks! The various connections were insulated with Scotch mending tape! Yes it worked, but how much longer is the question?
In all fairness, I have seen some really good mod jobs (no pun here). A couple of years ago, I purchased a non-working SB200 for $125. The capacitor bank had been replaced with a very-well made home-brewed PCB, and the cooling fan had been replaced. The only problem I could find was an open grid resistor. The finals appeared original, and it easily delivered 600 watts out once repaired. The handicapped amateur I gave it to has used it nearly everyday since. Caveat Emptor.
That last sentence tells it all. Unless you know exactly what you're doing, and you have the tools and knowledge to use them, buying a questionable amplifier isn't advisable. If you're not in the aforementioned category, here are a few tips.
1). Don't buy any amplifier with discontinued finals, even if it comes with spares. Remember this; glass enveloped tubes do not store well unless they are used regularly. Even some of the ceramic ones are notorious leakers.
2). Don't buy any amplifier you can't play with first hand.
3). Don't listen to the seller's description of how good it looks and/or operates. Reread number 2).
4). Don't buy any amplifier that doesn't have a tuned input. I don't care if your transceiver is a TS520. Some day, you might want to upgrade your radio, and solid state transceivers don't like reactive mismatches.
5). Don't buy any amplifier without a manual. If it comes with a xeroxed copy, make sure you can read the fine print on the schematic. Fact is, some of the pdf, on-line versions can't be read either.
6). As a general rule of thumb, anything made before 1995 is suspect. There are a few exceptions, but once an amplifier reaches middle age, it may be more costly than just the selling price. Again, refer to numbers 1). and 2).
7). Always ask if the seller smokes. You'll already know this if you paid attention to number 2). If you yourself are a smoker, and you're selling an amplifier, have the courtesy to tell a potential buyer.
8). Any amplifier made before 1995 may or may not have low voltage keying. If the one you're interested in doesn't have, or your radio doesn't have a built-in keying relay (IC-706, FT857, etc.), factor in the cost of a keying interface (about $50).
9). Whatever amplifier you buy (new, used, or home brew), don't try to drive it past its nominal input (typically 55 to 85 watts of drive). This is especially important if you didn't pay attention to number 1). If you want more power out, buy a bigger amplifier!
10). Don't pay too much. You can buy a new, tube-type amplifier for about $1.25 per watt output. Top of the line ones, can cost upwards of $2 per watt. So the question remains, why would you buy a used one for the same amount? Especially when you didn't pay attention to number 1)?
11). Before you spend your hard-earned money on an amplifier, take a long look at your antenna system. Dollar for dollar, you'll get more out of a decent antenna, than you'll ever get with an amplifier.
12). You'll probably need more than just the amplifier, as I mentioned in number 8). If you don't have a dummy load and requisite antenna switch, a decent directional wattmeter, a few coax jumpers and interface cables, and perhaps a 240 volt outlet, maybe you should invest in those first.
Digressing for a moment or two. It is difficult to say how much longer some tube types will be with us. Eimac is still making 8877s and 3CX1200A7s, so you're fairly safe with them. Certainly 572Bs, 811As, and 3-500Zs will be around for some time to come, but they aren't made in the US any longer. Svetlana has stopped production on some of the GU styles, and at least one GS style. Whether any of this presents a problem, remains to be seen.
Certainly the future is in solid state amplifiers. Currently, they're selling for $2.50 to $4 per watt, but that price line will eventually fall. Some of the older solid state amplifier finals are in the discontinued category, and the same caveats should be followed, especially number 9). Finally (no pun here either)...
Patients is a virtue not all of us have, but you need it if you're in the market for a used amplifier. The world's oldest marketing adage is very apropos at this point; if the deal sounds too good to be true, it most certainly is.
Alan, KØBG
www.k0bg.com
This article has expired. No more comments may be added.
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Is That Amp Really Worth It?
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by W9AC on January 14, 2008
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"Certainly the future is in solid state amplifiers."
Alan,
Solid-state amps have their own set of issues and they can be more prone to component obsolescence than tube-based amplifiers. Moreover, unless the output transistors are bolt-mounted for easy replacement, replacement of a set of final transistors can be a nightmare-ish experience.
You raise some excellent points, but as long as one knows about the potential for component scarcity, I would have no issues with the purchase of an amp where tubes are no longer available.
I own an original Alpha 70V amp and purchased it ten years ago from someone who rarely used it and it included two new spares. I knew very well that the last tube was manufactured in the late '70s. The amp is still on the original vapor-cooled tube from 1970 and emission has not changed one bit. That's not to say that it won't fail tomorrow, but there are some instances like mine where if I keep a reasonable spare parts inventory, I should be good up until the time I become SK.
Another point is that some older equipment is actually easier to maintain with an adequate parts supply than is the case with newer equipment. With the exception of the tube, I can secure every single new part on the Alpha 70V amp, including all the original OEM plumbing parts for the water cooling system.
Look at transceivers made in the past 10-15 years. Many of them are using mission-critical semiconductors that have gone out of production long ago. In these cases, I can actually count on parts being available longer for my Drake C-line than a Yaesu FT-2000. The same is true for a Heath SB-220 when comparing future parts availability for a new microprocessor-based amp. Ten years from now, that new amp may be nothing more than a heavy door stop.
So, I wouldn't necessarily let "old age" dictate my amp buying decisions. There are certainly others factors to consider.
Paul, W9AC
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RE: Is That Amp Really Worth It?
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by KE4WLE on January 14, 2008
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I think rule 11 should be rule number 1.
In addition, any amateur radio operator who is considering an amp should read:
http://www.arrl.org/tis/info/pdf/9811054.pdf
Words to live by right there.
R
KE4WLE
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RE: Is That Amp Really Worth It?
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by LNXAUTHOR on January 14, 2008
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- excellent link to the ARRL pdf - good, solid advice! tks!
- and gee, listening to all the hams on 20M i thought that using an HF amplifier was required to operate on that band?
:-)
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Is That Amp Really Worth It?
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by N3QE on January 14, 2008
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The thought of looking on a web page for final tube data seems very counterintuitive to me! I've looked for it, and found everything I needed, elsewhere for the past half-century!
I know it might be sacrilege to mention it, but all of the ARRL Handbooks since time began have listed commonly-used ham final tubes with suggested operating parameters in several different classes of service.
It's true if it's the 2008 edition or the 1948 edition. The 2008 edition has been trimmed down quite a bit but reflects all commonly available tubes of today.
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RE: Is That Amp Really Worth It?
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by N3QE on January 14, 2008
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Oh, even better, the handbook tables from years past are available through the ARRL TIS:
http://www.arrl.org/notes/1921/pwrtubes.pdf
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RE: Is That Amp Really Worth It?
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by W4VR on January 14, 2008
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9 times out of 10 you get what you pay for. I've had Heath amplifiers and they were good products with reasonably good-quality parts that lasted for decades. I had a new MLA-2500B for about two years in the early 80's...I paid $700 for it and I got what I paid for...I had a tube failure within 6 months. When I sent the tube back to Eimac for a replacement they told me that the tube base appeared to have been inadequately cooled...although they made good on the replacement. I understand that Eimac got smart later on and refused to replace tubes free of charge for that particular amplifier.
Solid State is the future for linear amplifiers, but they have their own problems too. Unless you buy a good brand, such as Icom, you have to be very careful how you use it...I own two Icom PW-1's and they have been operating flawlessly for many years putting out a clean signal. I think these Icom amplifiers cost too much, but if you want something that will give you good service for many years you have to be willing to pay the price.
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RE: Is That Amp Really Worth It?
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by WB2WIK on January 14, 2008
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Nice article!
The bottom line is, there's a lot of junk out there -- including many amplifier models that really were designed and built specifically for legal amateur service -- that just isn't worth buying at any price, today.
I always advise:
-Stick with stuff you can fix yourself or you know can be fixed at reasonable cost by someone qualified to do so, using parts that are actually available today.
-Don't buy something like an amplifier without seeing it first, and preferably testing it out on the air to confirm it works.
The "it worked last time used" stories are tiresome and usually mean "no hope of this working when you turn it on, so good luck."
WB2WIK/6
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RE: Is That Amp Really Worth It?
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by KE4MOB on January 14, 2008
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I don't think that amps are different than anything else we buy anymore. Programmed obsolescence is an accepted norm in the global manufacturing environment. Technology is moving so fast that usually an item is outdated no more than two years from initial release, and is replaced by a newer, cheaper model.
The fact that hams regularly use devices that are decades old is either an indicator of our resourcefulness or an indicator of our irrelevance in the modern world. I'd like to hope it's the former!!!
On the other hand, when selecting equipment, do we really want to jump on the "latest and greatest" bandwagon and find ourselves holding an empty bag full of "unobtanium" five years down the road?
Taking a completely logical approach to the problem leads one to the conclusion that since everything is either disposable or obsolete, then why have any of it?
It's definitely something to kick back and think on, for awhile at least...
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RE: Is That Amp Really Worth It?
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by AB7E on January 14, 2008
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"11). Before you spend your hard-earned money on an amplifier, take a long look at your antenna system. Dollar for dollar, you'll get more out of a decent antenna than you'll ever get with an amplifier."
Absolute statements like this are pretty silly, KE4WLE's endorsement of same notwithstanding. Thousands of hams have space or neighborhood aesthetics restrictions that preclude putting up a more effective antenna, and an amp can dramatically improve their signal with no visual impact. For thirty years I was limited to simple ground plane verticals for all bands, and the Henry 2K-4 I bought used for $600 dramatically expanded my country totals. I also like chasing DX with QRP, so it wasn't totally horrible operating skills that held me back before I got the amp.
The claim becomes just plain false when it comes to the lower bands, though. Small wire loops can really improve reception for a very low cost, but I don't think anyone is going to add 10 db of gain to their 80m transmitting antenna for anything even close to the few hundred dollars it would take to buy a used amplifier.
This antenna versus amplifier claim is made way too often by folks who like to think in terms of generalities, and for really weak signal DX when no one else is calling it might even be true. But in most cases an amp coupled with a decent vertical or a couple of dipoles hung from a tall tree is going to be far more cost effective in db/$ for breaking pileups than a tower and yagi.
Dave AB7E
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RE: Is That Amp Really Worth It?
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by KG6WOU on January 14, 2008
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Dave:
While I agree with you that for transmit output, an amp is going to be cheaper than big antenna - I think the point of the general statement is that you should not ignore the possiblity of what an antenna can do first. That, and of course, an Amp is of little use on receive.
But I'm sure I'm not the only space limited ham who is contemplating a small amp since a tower is rather not possible.
Hams fit into a small bubble in the business - between the 100 watt mobile type radio used for land-mobile service and the 5 KW and up broadcast users. Our relatively limited market makes for some interesting compromises.
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RE: Is That Amp Really Worth It?
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by WX1F on January 14, 2008
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I snickered when I read the prices Alan quoted that "He" paid for each amp. As long as Ebay exists, us poor hams will never plug a coax into our own amp. It goes like this...amp goes up for sale on the eham classified....rich ham snaps it up and puts it on Ebay for resale...dumb rich ham buys it...us poor hams just look at the ads and wish. I have NEVER owned a max limit amp. Anyone out there who's running a 3rd or 4th hand HF rig ever owned one? I don't think so...not unless it's willed to you by a your rich ham friend. And don't tell me to save my pennies. I get $100 saved and WHAM...car breaks...furnace breaks....Don't get me wrong, I don't hate rich hams. I just hate rich hams telling me how many amps THEY'VE owned or how many towers they have. Whoopie-doo....put a sock in it...
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Is That Amp Really Worth It?
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by K2DC on January 14, 2008
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Among some of the fairly popular finals you missed are 4CX1000 and 4CX1500 (Collins), 3CX1200D7 (Henry), 8873 (Henry and Heathkit), 8874 (Alpha) and 3CX3000 (Henry).
And I disagree on the Dentron MLA-1200. I bought one 3 years old in 1981. I had to replace the old twist-solder caps in the power supply with screw terminals. But it took me 18 years to go through a tube. And that includes being stupid occaisionally, band switch in the wrong place once in a while, etc. And I was able to find agood pull for only $200 - but that was seven or eight years agao - good luck today.
It's all Alphas now, a 78 and an 86 with spares for both, so I'm set for quite a while.
73,
Don, K2DC
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RE: Is That Amp Really Worth It?
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by WR8D on January 14, 2008
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Mine certainly are. I still use my alpha 76ca. It has three 8874's and a hypersil. I bought it new in 82 and have "tried" to run the guts out of it from time to time through the years. What else can i say, it's an alpha. I do have one of their new models too but just love the looks and the feel of the old 76. This is it's third solar cycle it's going into. Looking inside it still looks new and since buying it new i've never had a problem with it in all these years. If you can pick one of these up that some cber has not had then in my opinion you'll not go wrong.
It is infact the center piece of my shack running with one of icoms new rigs. I gave it a face lift a few years back with one of those new black front panels, sprayed the cabinet high gloss black and it is a monster. The new alpha gets played too on another station setup i have but you can't beat these old 76's and i see recently the price for them is going back up.
As for tubes, well i never allow mine to see anything other than a 0 reflected power at what ever freq i'm operating at. The old 76 was built for 1kw brick on the key "forever duty" and it runs 1.5k output about the same. I have a buddy in Tenn that uses the 8874 tubes in his radio station and i have a full round of good pulls but the old tubes are still at full output. With the ceramic tubes for me that's been the key to life. I drive them sometimes just a little over specs and it does'nt seem to hurt them at all. Same with a pair of 1200A7's i have in another amp. Keep the reflected power out of them and be nice to them and they'll last a life time. Mine have so there's your proof.
All i can say about an amplifier keying buffer is save your money. Go to radio shack buy a 9 volt relay, a small project box, two rca jacks and a 9volt battery and build your own like i have. It'll take under thirty minutes to throw the parts together.
Go to dayton and walk over to the alpha booth. They're still playing them 24 hours a day and all three days at legal limit and continuous duty. The rest of the manufacturers of amplifiers will let you look at theirs sitting there...but alpha is still putting it on the line for all to see.
Are they worth the price??? If you want the best there is with years and years of built like a tank quality backed by a service team that is unmatched in the amateur field...you betcha!!!
John WR8D
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RE: Is That Amp Really Worth It?
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by G3LBS on January 14, 2008
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I have found it best to use only one 'big' tube. If you need more power, design for a bigger single tube.
If you have to use more than one, monitor the currents in each one.
W2/G3LBS
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RE: Is That Amp Really Worth It?
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by KT4WO on January 14, 2008
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"Certainly the future is in solid state amplifiers."
yep...and look at my Ten Tec 444..and find a final for
it....600 watt door stop...but..I do have a nice
50VDC 24 Amp pwr supply for that "one day project" with
MRF150's.. hee hee
Nice write!
Trip - KT4WO
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RE: Is That Amp Really Worth It?
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by K6AER on January 14, 2008
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While Alan has several good posts I disagree with several of his assertions. I repair a lot of used amplifiers and with the exception of rare tubes, most can be brought to functioning condition fairly easily. Flat tubes, dry capacitors and burned band switches are the biggest replacement items.
Older amplifiers when treated properly will last for many, many years. Quality construction does last forever.
“Amplifiers made before 1995 do not have low voltage keying”. All the Alpha models 86,89 and 91B’s have low voltage keying. As for adding a low voltage keying relay that is about a $3 purchase at Radio Shack for a reed relay.
As for tubes being used illegally in amplifiers I have no idea what that means unless you are referencing power out (Maybe the tubes were stolen). It is up the amateur to run the proper output level for his license. Amplifiers are being built that will do double the limit in order to have very good IMD numbers which the older amplifiers 30 years ago did not do.
Speaking if IMD numbers, most solid state amplifier have very poor IMD numbers for they have no power head room. The THP 2.5KL can only produce 1800 watts out maximum. For nice linearity and good IMD numbers you should limit the amplifier to about 1000 watts PEP SSB. When hams try to run the amplifier at 1500 watts out, the finals roll over and die. Many of the amps have been returned for real tube amplifiers.
Ham duty amplifiers most commonly use triodes but the Russian 4CX800 is still popular. The Russian tube is getting harder to find for new tubes are not being released commercially. I expect the tube prices to float to $250 by the end of 2008. This is still cheaper than the 3CX800A7’s, 3CX1200 and the 8877’s. I would be wary of Russian tubes that have a low production run. They can vanish overnight.
I have bought several used amplifiers with out trying them out but you have to ask hard questions and get a good feel for the type of ham selling the amplifier. You need to ask questions about his operating conditions and why they are selling the unit. What are the operating numbers, grid and plate currents and wattage out along with how they are measuring the output. Will he take it back if your not satisfied (you pay shipping for the return)? If your gut feeling is bad, walk from the deal. There is always another deal down the road.
Bottom line is an amplifier cost is not what you pay for it but what it depreciates. A used Alpha 99 at $3400 is a great deal for 5 years down the road you will be able to sell it for more than you paid for it. Alpha still supports its amplifiers going back to the Alpha 374.
Paying $4000 for a marginal 1.8KW solid state amplifier will be a false economy if the manufacture is using limited production transistors (ARF-1500) with no second source or the amplifier turns out to be rather fragile.
Don’t let the age of a product blind you to its quality. New is not always better.
Mike K6AER
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RE: Is That Amp Really Worth It?
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by WI7B on January 14, 2008
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I'm reflecting on both AB7E's and WX1F's comments. I live in a condo, and have a 15.5 foot vertical on the balcony. I don't have options for more antenna real estate.
My relatively cheap little AL-811 has brought me fun and DX for three years. I used it to work Argentina, Morocco, and Ukraine. I could not have done so without it.
My 811As were down to 350Wout SSB after much abuse, so I got the more expense 572B. So far so good.
We can't all live in 10-20 acres lots with plenty of space for antenna, or afford 5-10 HF amplifiers.
So we make do...and listen to those who can. so to you, just remember that quote form Spiderman. "With great power comes great responsibility".
73,
---* Ken
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RE: Is That Amp Really Worth It?
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by NL7W on January 15, 2008
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I will second the comments of WR8D and K6AER. Older, quality amps, such as the various ETO Alpha models, can be solid investments. The 8874's placed into service are truly amazing -- lasting decades in considerate and service. I'm still running the original pair in my amp; they are not soft.
I recapped my legacy 374A about two years ago, and fully expect it to last, with a spare set of tubes on-hand, for another 2 to 3 decades. The QSK mod comes next.
A quality RF deck can be made serviceable for a really long time -- given the availability of tubes.
73.
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RE: Is That Amp Really Worth It?
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by WY7I on January 15, 2008
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Nice article, and very informative.
Except for this line :
"Patients is a virtue not all of us have, but you need it if you're in the market for a used amplifier."
Needless to say, "**Patience** is a virtue not all of us have..."
especially for correct spelling!
WY7I
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RE: Is That Amp Really Worth It?
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by KF4HR on January 15, 2008
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Good article Alan, and I definitely agree with you about looking to antenna improvements first (if possible), to improve station performance. A plus-up of a few db from a better antenna helps both the receiving and transmitting side. A Power Amp can get you heard (in certain situations), but you're still in the same boat receiving wise.
A couple of other things you didn't touch on:
* Running barefoot (100/200W), versus Power Amp power levels, and what that amp cost is actually buying the user (S-meter wise, at the receiving end).
* And the cost of a full legal limit amp versus a 1KW amp, and what that extra 500 watts really buys the user. Again, at the receiving end (s-meter wise).
Can an amp help? Yep, a bit. But in both these cases above, the law of diminishing returns (cost and performance) rears its ugly head.
You bring up a good point about power tubes being a key decision making factor for purchase of a Power Amp. I'm curious if anyone knows of a web site that provides a list of power tubes are still being manufactured, and those that aren't. And those that are scheduled to be on the hit-list soon, or manufactured overseas?
Older ham gear from the 70's and 80's,and 90's have a similar problem in that certain components (IC's, etc) that eventually stop being manufactured. This causes manufactures to eventually drop repair support as the remaining stockage of spare parts dry up. Buyer's beware of equipment in this era! Should your older unit break and you return it to the manufacture for repair, you may find the manufacture returns it to you stating the defective component(s) are no longer available. Now you have a nice door-stop, or you're off hunting the bone-yard for spare parts. Just like some older Power Amplifiers not being a good deal at any price; the same can hold true for some of the older ham gear.
KF4HR
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RE: Is That Amp Really Worth It?
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by KC2GUY on January 15, 2008
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I considered a transistor amp...ever see how many are for sale? wonder why? even the newer ones? just follow ebay. ever see an alpha on ebay? almost never..unless a ham is retired from the hobby and is selling his shack. You never see a new one. I have an alpha 99. Sent it in once to get checked over and replace a warm-up board that was acting up. Alpha went over everything. Returned as new, and purs along. I dont follow S units.. I just listen to the delight at the other end when i put the amp on line at 1kw. THEN,people who otherwise had a tough copy are there for a long, pleasant QSO. Amps also help cut thru QRN quite a bit. If you never tried one, do so, and use it responsibly. Having said that, I agree to concentrate on your antenna FIRST, and make the best set-up for the space you have. Then its time for an AlPHA...ask anyone.
Ken
KC2GUY
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Is That Amp Really Worth It?
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by K6YE on January 15, 2008
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Alan,
Good article. WB2WIK/6 and K6AER made some interesting comments.
For the buck, ease of servicing, and tube availability (IMHO), the Heath SB-200 and SB-220 are hard to beat.
More often than not I run my FT-1000D and IC-775DSP barefoot and work just about everything that I can hear. Two Hundred (200) watts ouput works really well. On 160, 80, and 40 meters, an amplifier is sometimes needed (160 = all of the time).
Using the very best antenna one can and always using the very best feedline will produce great results with or without an amplifier. QRP folks really shine in this area.
Have fun and enjoy the hobby.
Semper Fi,
Tommy - K6YE
DX IS
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Is That Amp Really Worth It?
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by KC1QF on January 15, 2008
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Apart from all that great pro and con technical discussion, about dBs, about tubes and about lifetimes, one of the things you forgot to mention is why people really buy amplifiers.
The casual hams, with a bit of pocket money, buy linears because of the aura associated with owing an amplifier. Ebay and ham fleamarkets are like candy stores. We fulfill a desire to own a linear amplifier.
I have always dreamed of owing an Alpha (who hasn't), but it is just too much money for me. Who hasn't dreamed of having a 77DX in the shack, or a Collins 30S-1, a Henry 3K, or a BTI (remember this one?).
We don't all need to have linears that run 24/7, whose tubes will survive brick down operation. We just like to own them.
Over the past 20 years I have collected quite a few linears, most of them for few dollars (one of my TenTec Titans was given to me), and even though I don't use them all the time, I am happy I have them. And I still would get more.
I own two SB-200 (bought for $180 and $200) that run great (new capacitors in one of them), a HA-14 (a great little amp that takes very little space in the shack for $220), two Ten Tec Titans, one TL-922 (given), and one GLA-1000 (which I use).
I have found tubes for a few dollars and having two Titans guarantees spare parts (such as the pricey 3CX800A7 tubes).
There is no ham that doesn't dream to own the real big guns, whether there is a large antenna in the back lot or not. I wish I could afford a 8877/3CX1500 based linear, but unfortunately I will have to wait for a few more years until the prices come down.
For me, owing a linear is a desire fulfilled, nothing to do with operating practice, increased dBs or contest operation.
Peter, KC1QF
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by K4PDM on January 15, 2008
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I'm afraid I must disagree with most of what is in this article. Take it to heart and you probably won't buy anything under $2500 or so. We are not outfitting a broadcast station here; just trying to enjoy ourselves.
Sweep tubes are still available as New, Old Stock. They are more expensive but they are there. My Amp Supply LA-1000A lasted 20 years on the original sweep tubes. It's all in how you treat them. Yes, the old sweep-tube amps are junk compared with Alphas. Buy them for $100 and have fun.
The author has a very regimented point-of-view. He demonstrates much technical knowledge but needs to open his mind a little. There's room for all equipment, old and new, as long as you know what you're getting and it is priced right. Just my opinion.
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by WA3SKN on January 15, 2008
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Good article!
The only issue is that certain power transistors are becoming extinct faster than tubes, and with NO replacements!
-Mike.
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by KD5SFK on January 15, 2008
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Amplifiers remind me of 300+HP cars. You don't really need all that horsepower, but driving it sure is fun! ;)
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by K5UJ on January 15, 2008
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With Peter Dahl going or out of business another thing to think about is the availability of the amp's transformer(s). (Some are more reliable than others ; )
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by N5XM on January 15, 2008
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The ONLY reason I have an amp is to get out a better signal. I have a modest tri-band Yagi, and vees for the low bands, and the amp is an AL-80A that I run at 500 watts. I've been able to work most of the DX I want at this level of power, and the 3-500Z is loafing at that output. Yes, I'd love to have wonderful antennas, but most of us in the middle of the financial pack, actually most of us period have compromise antennas, so we just do the best we can. Very good opinions, Alan, and great effort on your part. Nothing is written in stone.
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by K5UJ on January 15, 2008
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I sense this is going to devolve into another ham class war (a.k.a. amp users v. amp have-nots).
<<The casual hams, with a bit of pocket money, buy linears because of the aura associated with owing an amplifier. Ebay and ham fleamarkets are like candy stores. We fulfill a desire to own a linear amplifier.>>
I'm not sure how we define "casual ham" but assuming I, and every ham I know, are casual hams, then I can safely report that casual hams own amps for one reason: to not have crappy ragchews. You may get some kind of aura; we get armchair copy comfortable above the noise level.
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by KA1MDA on January 15, 2008
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"Patients is a virtue not all of us have"
Patients are people who are under a doctor's care because they are ill. Poor health is not a virtue. Perhaps you meant PATIENCE(no pun intended).
KA1MDA
www.ka1mda,org
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by RADIOGUYR2 on January 15, 2008
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I fail to see why they quit making the 3-500z tube. It was the most popular amp tube made so far. Yet they abandon it. WHY?
When I called they told me that they have a new replacement tube the 3CX1500D7
It was an idea that languished for a period of time, the individual that
suggested this tube was a ham I have known for many years. We promised to sell
him a tube for his moneymaking idea, namely conversion of existing amplifiers
such as the Drake L4B, to replace the 3-500Z that Eimac no longer makes. I
guess I finally convinced engineering to make a tube sometime last January. It
was just completed last month but the effort to check it was put off for one
reason or another. Finally it was sent to the lab engineers to check out. RF
test data indicates it is a good tube where 80 to 100 Watts of drive power is
available. It likes to be run at 4000 Volts (more so than 3000 V as grid
current tends to drop with increasing plate voltage). The 3CX1500D7 is
"bulletproof" compared to the smaller oxide cathode tubes presently being used
in amplifiers made for the amateur radio market. I brought in an old Drake L4B
and we see that it will work in that equipment as long as the air flow is
increased by adding a blower to the air intake opening on the back of the
linear. Also a gasket must be added between the OD of the plate cooler on the
tube and the ID of the glass chimney on the existing amplifier, and the unused
socket covered over. The gasket can be made of silicone rubber and stuck on
with RTV or silicone rubber. Teflon might be useable if one can keep it from
slipping down (it can't be glued to the chimney!) but no one has figured out
how to use that material yet. Something needs to reduce the loss of air from
the top of the chimney around the anode cooler on the tube. A special pyrex
chimney would be nice but too costly (besides we don't have glass making
equipment any longer). Last week my boss decided to send out a press release,
announcing this tube. Unfortunately we have not built up a stocking level yet,
therefore delivery is going to be rather lengthy, I presume it will be between
60 and 90 days. (That should make one available for a late summer project,
right?) You may be delighted to know that we are introducing a new
"buy-direct" plan whereby Hams can pay us directly (we plan to accept Visa or
Mastercard sales only) and we ship this tube directly from the factory, thereby
keeping the price manageable. If distributors were selling this tube their
normal 35% markup would make it much less desirable. This plan will not apply
to other products already established as distributor items. Selling for $599
per tube, it is obvious that a single 3CX1500D7 will cost somewhat more than
two 3-500ZG. But we believe the reliability will be superior to some of the
Chinese 3-500Z that are on the market (did you ever wonder why they sell
matched pair of 3-500Z?) Also if you take into account the extra headroom this
tube has it starts to show virtues that are worth the investment. I just spoke
with one individual who feels this way to the extent that he plans to call our
customer service tomorrow and order one.
But do they work?
I still can't understand why they quit making, what I consider to be the best amp tube when this tube, while it will replace the other two, is not much more effecent. Nor is it ready on instantly.
Eimac... go back to making the 3-500z tubes.
It would not be hard for them to improve on them and make the 3-600 driect replacement that has more power ability, cheaply.
A pair of these keep my shack warm and dry in the winter.
Now that we have these damm glow lights I get no heat out of 'em so were freezing out here. Not to mention that when its cold you can't see a thing till they warm up. Thanks Al Gore.
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by KT0DD on January 15, 2008
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I wish Elecraft would get off their duff and get the kpa800 and the kpa 1500 into production. these have finals board mounted so changing finals is as easy as changing tubes. I just wish Elecraft would do do or get off the pot. 73.
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by KG6TT on January 15, 2008
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I'm in the midst of a conundrum of my own... older amplifier wise. There are three amps in the shack here. 1. A Ten-Tec Centaur with three 811As and a fan that begs for ear protection... but it is relatively new and 811s are still plentiful and cheap. 2. My pride...a beautiful Alpha 76A (modified by me for silent QSK with vacuum relays... not a hack job). 3. Most recent addition an Ameritron AL-80A. Each amp is on a different transceiver... a luxury of sorts but consistent with my operating style. Now my conundrum is the Alpha. My pair of original 8874s is running hard these days to put out 600 watts so I've been looking for replacements.... replacements that a 'hobby' ham with other responsibilities can actually and realistically afford. So far... (sigh). Even now there are three separate auctions going for single tubes... by past results these will sell for nearly $500 each!. And there is an auction for a pair of 8874 'pulls' listed as 'working' beginning at $400.... and finishing who knows where. Now what exactly does "working" mean? Heck I can pull my 8874s and sell them as working as they do... just not very well.
So the conundrum is at what point do you give up and retire an otherwise beautiful amp? I bought the single tube AL-80A for less than the price of a barely working pair of 8874s and that amp provides an excess of 1kW output with a tube that can be replaced for under $200 (today... but tomorrow?).
Still how do you determine whether or not an amp is worth it? At what point do you say it has paid for itself in service? Personally if your only choice is to buy new then a ham with resources like myself would be buying AL-811A type amplifiers (sadly I have repaired four of those 'entry' level amps for other hams over the past two years alone).
My last thought on this matter relates to the issue of obsolete parts withing the 'worth it' equation. Technology today is moving faster than ever... progress... change... and yes change which means much of what was used even a few years ago is now obsolete. If you are going to stop ourselves from investing in ham gear because of part obsolescence guess we had better dump whatever we own as soon as the manufacturers stop selling it as new. But what would be the fun in that? :)
Be aware... be informed... make the best choice that fits your needs... your resources... and what's available. Hopefully in the end most of our choices will provide us years of service and enjoyment.
73,
Jerry, KG6TT
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by K6AER on January 15, 2008
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I suspect Elecraft realized the market for a $6000 kit, solid state amplifier is very limited. Most hams lack the skill and technical equipment to build the amplifier and the servicing would be a nightmare.
They made a much better discussion to table the project and concentrate on the K3 vision.
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by AI2IA on January 15, 2008
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11). Before you spend your hard-earned money on an amplifier, take a long look at your antenna system. Dollar for dollar, you'll get more out of a decent antenna, than you'll ever get with an amplifier.
Certainly the future is in solid state amplifiers. Currently, they're selling for $2.50 to $4 per watt, but that price line will eventually fall. Some of the older solid state amplifier finals are in the discontinued category, and the same caveats should be followed, especially number 9). Finally (no pun here either)...
This was a good, sincere article that can go a long way in helping hams enjoy the endeavor without getting burned (pun intended).
I like the above two quotes best of all.
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by W9PMZ on January 15, 2008
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Transistor amplifiers are the answer?
Could be, but the biggest issues are the high current requirements and mechanical installation.
With regards to headroom, with DSPs being cheap, I wonder if anyone has tried digital predistortion? Might be able to reclaim 10dB of IMD performance.
73,
Carl - W9PMZ
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by W3HR on January 15, 2008
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Tubes no longer available? No problem.
Make your own!
http://dailymotion.alice.it/video/x3wrzo_fabrication-dune-lampe-triode_tech
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by NXET on January 15, 2008
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transistor amps are the solution
right-- and you can doubble the power supply for a arc welder too.
Ever see the current flux on solid state amps when the antenna is blowing in the breeze outside. Transistors/FETS don't take to moving the SWR around to well. Then again it should get real fun to watch the 200 amp power supply do some tig welding inside the box when it starts backing up. the connections might be a bit difficult to get that 00 cable attached to the little fet amp leads) And what about the super sized regulator chips. Now that is some serious regulation going on with that amp. (will a 723 still work here) Why in linear mode you could heat the whole house. At least a 1 hp blower motor to keep it cool.
About the only good thing about solid state amp is that its instant on (mind you you need a BIG soft start or you will swing every compass that will point at you for miles around) with a bid surge of the contactor relay. Shutting it off should be just as much fun when the arcing starts. Talk about spiking the utility.
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by K7PEH on January 15, 2008
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It seems from the exchanges here and from other things I have read that the big deciding factor on the kind of amp a person buys is cost. In fact, it seems that a lot or maybe most hams strive to buy the cheapest amplifier that money can buy. This is probably a used Heathkit or other 811 or 572 or 3-500 based amplifier. Often it is not a solid-state amplifier.
Therefore, I think that the choice of tube based amp has a lot to do with cost and not as much do to the technology choice of a tube based amplifier. Now, I know that this is a supposition and an opinion but it sure seems that way from the things I have read here on eHam.
Solid state amplifiers seem to be expensive. Of course, there is the Ameritron 600 watt amplifier (I briefly forgot the name) which is not bad but for 600 watts it is still expensive. Then, there is my amplifier of choice, the Icom PW-1. I have to admit that the $4600 cost, new, that I paid was a bit of a stumbling block but after I wrote out the check to HRO in Tigard Oregon, I was OK with the purchase.
Is it worth the money? Probably not from the viewpoint of what the other guy hears. He doesn't know I have a PW1 unless I tell him. So, given that perspective, it is probably not worth the money. But, I have a tendency to buy toys. And, I really like Icom. I don't know why. I know it is not because I have analyzed the technical merits of Icom versus other products, I just like Icom. OK, I admit that Icom America headquarters in Bellevue, Washington is just a 15 minute drive from my home but maybe that is not the reason either.
If you have the money, my suggestion or recommendation is to buy solid-state. Join the 23rd century (all tubes will be dead and gone by then).
Oh, and thanks Alan for yet again another nice article. You really should consider writing a book. I would also like to see Tom, W8JI write a book on amplifier design and technology. It should be easy, a lot of the stuff is already on his web site. These would be great books, I would buy a copy. ARRL is would definitely publish them.
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by G6NJR on January 16, 2008
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the ultimate answer is DONT BUY AN AMP in the first place it is all these amps that are along with over wide Heil assited transmissinos that are turning the Ham bands into an noise farm full of rubbish signals from 3 main locations USA Italy Russia get off the igot a big amp hook 100 watts works very well thank you you do not need more .
I have heard of and seen mention of stations bragging about running in excess of 10 Kilo watts yes 10 Kilo watts .
I often listen to stations bragging about their Heil mics and the compression and this and that gizmo and at the end of the day all you are doing is making an un needed mess out of the HF bands If you want Broadcast quality audio then go pay for a commercial broadcast license and operate in the broadcast bands where you can be as fat as you wish and not cause QRM to others there is no place in Ham radio for these signals ..
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by WV4I on January 16, 2008
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I don't chime in on many threads like this, but exception for this one. I also agree almost 100% with K6AER, NL7W, other similar replies, so won't repeat their points.
Two questions seem to be posed by this thread title? Do you NEED an amp n/w price, and is it worth the $$??
I've owned many hf amps, all tube. I have owned 2 QRO vhf amps, one SS and one tube. I operate a lot, including contests when I'm off work that weekend. Bottom line, if you want to get thru most pileups, poor band condx, nearby qrm, etc., it simply takes an amp. More antenna won't help whether you have HOA Gods or city bldg codes to deal with or not.
Worth the $$? Look at what's for sale. Biggest market is in Alphas and Ameritron, for buyers and sellers. Easier to get market prices, parts, knowledge (i.e. Yahoo Groups) etc.. The older the amp, the higher chance of past abuse, misuse, lack of use, hacker mods, component aging failure, etc. Better get it cheap if you must. If seller can't recite the numbers after saying it works perfect, forget it. Ditto for ownership, operational history. You won't buy a new legal limit amp at $1.25/watt, as the tubes, ps, etc., are just too expensive.
The rich ham, poor ham, post hit on something that has really changed ham radio for most of us. It's the equipment flippers that live on this site, QTH, QRZ, etc., and snag all the fair/good deals on amps, higher end gear, in minutes, and then resell on EBAY, etc.at a quick profit. Usually the seller is trying to give another ham a fair/good deal, and is unknowingly being taken advantage of by these flippers. Just biz some might say? Nope, it's a hobby for most of us.
Back to operating.....
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by WB2WIK on January 16, 2008
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The "rich ham/poor ham" story hasn't changed a bit in the 42 years I've been licensed, and I suspect well before that.
When I was a kid, some hams had multiple S-lines which at the time cost "equivalently" more than anything on the market today -- anything -- and some had homebrew stuff or old surplus junk.
This concept hasn't changed at all.
Amplifiers aren't for the rich, they're for those who want to be heard better and naturally should be added after all possible antenna improvements are made.
Not a day goes by that I don't work somebody using an old SB-220, TL922, L4B, Swan Mark-II, etc, etc. Many of these can be found for well under $1000 and work fine.
WB2WIK/6
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by W4LGH on January 16, 2008
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Basically a pretty article to pay attention to. I do AMP repairs, and a lot of parts are getting harder and harder to find. I thing in question tho, Eimac has not made any 8877's (3cx1500's) for sometime now, at least over a year. 8877's are still available, but the prices are going up daily. Their main use was in the medical field, but most of that equipment has been retired, so Eimac retired their production line.
Either Heatkit, the SB-200 or the SB-220 are probably the best bang for the buck these days. Parts are easy to come by, 572B's used in the 200 are easy to get, altho they will be made in China, and can be bought for about $35 each. The SB-220 uses 3-500Z, which is my GLASS TUBE of choice. These also are coming out of China for about $150 each, but if taken care of will last a life time!
My Amp of choice is Drake. I have both the L4B and the L7. Both use 3-500's, and other parts are found pretty easy. The L4B is made like a Battleship and will easily make 1350watts without any mods. Mine still has the original 3-500Z Eimac tubes in it, that are over 35 yrs old, and with 80watts of drive will do 1340watts!! Would love to put a pair of 3-500ZG grafite tubes in it, as they are really 3-600's, but it isn't worth the money.
My L7 has an upgraded power supply and puts 3200volts on the plates of the 3-500's. With this increased voltage, and 100watts of drive, this amp will do right at 2000watts, into a dummyload of course. However I usually run it around 1400watts and its loafing. Both amps also use external power supplies making them easy to put on the desk, keeps all the extra heat out of the amp, which make plastic part brittle etc. The L7 is still built tough, but not as tough as the L4B.
Amps using the 811A tube, like the Ameritron AL-811 and its bigger brother the AL-811H are still pretty good buys too. The 811A is very easy to find and can be had for $12 a piece. By the way, the 572B is a direct replacement for the 811A, but changing out the 811A with 572B's will NOT gain you any increase in POWER! It will give you a much tougher tube that can withstand a lot more abuse.
600watts is the first magic number on HF, you will not hear much, if any difference in 600 going to 1500watts. Remember that power has to go up 4 times to really hear any difference. Using the 600 watt figure, makes the AL-811-H a nice buy, if you arel looking new. Altho Ameritron rates the standard AL-811 @ 600watts...that is pushing the tube to its limits, as the 811A is good for about 165watts each.
165x3= 495watts, 165x4= 660watts on the H model.
Enjoy your amp, LEARN how to TUNE it properly and it will work for you.
73 de W4LGH - Alan
http://www.w4lgh.com
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by NXET on January 17, 2008
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the other side of the coin is the QRP guys. They will tell you that they can do just about the same thing as the big amp boys. My personal, life is to short for QRP. Yet which has more fun? Which is the least expensive, complex and enjoyable?
I have had several amps. solid State is nice and lots of people point to the constant power of the filliments in amp tubes as being waistful. (85-150 watts just to light 'em up and keep 'em warm n ready) While they suggest that the solid state amps only draw power when under demand or excited--true.
However, solid state amps have their own set of problems that the FCC and others are quite aware of. ( reasion your not allowed to make one) Tube amps on the other hand are simple, rugged and cheap.
What one uses voltage to achieve the other uses current as stated by others.
voltage kills. Current welds
new technology is always going to be more expensive until enough of them are produced. Yet we find that makers of tubes are dropping out due to lack of profitablitiy even after they have met the break even point due to lack of commercial application.
Yes best to improve the antenna first and then look at the amp second. No doubt about it though, amps have always been a status issue.
As to old amps vs new ones, their are plenty of amps out their that will still haul the mail. Yes they need to be upgraded so as to match the new solid state trancievers but a simple addition is all that is required and you have a perfictly useable dependable (after all they did stand the test of time) amps - chucked aside - sold by the previous owner for pennies on the dollar-- so that they can go invest in something new...a need for status and ego of having the newest and best on the block. (both appear to be happy and content with their purchases)
The issue is do you need one-- and not how new a amp do you need. If you you feel the need, their are plenty of good ones that still use tubes which heat/light up the shacks up that can be had for 1/10 the price of the latest greatest. Therein it the economics between the two. (heck you have to run a space heater in the winter time anyway out in the shack... because new sold state ones don't give off heat till you start talking... hmmm) where as the tube ones you don't need the space heater.. you have one already--
Even though these amps are not as effecent as the new technology stuff; in the end they are more economical to buy (pennies on the dollar, worth their weight in copper wire inside) and perform as good or better under extream conditions than the high tech ones costing mega bucks.
Until the cost of the FETS or transistors come down, the tube amp still will be with us for many years and not likely to be going away anytime soon.
Remember its only a hobby and not a lifestyle requireing a second mortgauge on the house. The competition and challenge is knowing how and using what you have. If the guy on the other end hears you then your in. Throwing all the power in the world by using a amp to override the others is a somewhat conseated attitude. The use of a amp should be done respectfully with reguards to others who don't have one. Which would you rather be known as--- a competitive ham or one that is only out for their own self gratification by steping on or blowing the others away with brute power. I know a lot of DXpedition statons who will not answer the loudest signal first off... snagging the little ones first and then coming back to the big guns. You can tell on the scope which ones are running amps by the bandwidth most of the time.
someone once said, if everyone had a 2KW amp what a mess we would be in. shortly thereafter you would find others running 4 kw amps, then 6, then 10 and where would it stop? Is that the true sprit of ham competition or a pissing contest?
I for one would like to see the ARRL restrict field day to the basic 100 watts. then we would see how operator tech. comes into play and who makes the big scores without the big gun amps. think of the fun everyone would have including the QRP guys that now could be heard.
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by G3LBS on January 17, 2008
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As you get older you can't cope with heavy antenna engineering and maintenance but you can build amps - the warmer the better.
Buffalo Gil W2/G3LBS
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Is That Amp Really Worth It?
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by K1VSR on January 17, 2008
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This article is obviously tailored towards HF ops, but just to give another take...
On HF, the bands are generally really noisy and because of that, an extra one or two S units isn't really going to help you much. When you go higher in frequency and get into the quieter bands, like 1.25m for example, that extra 1 or 2 S units can make all the difference.
In the end, I use the "repeater analogy" with my home station. When setting up a repeater, you want to follow two rules:
1. If you can hear the repeater, it can hear you.
2. The repeater should hear you exactly as well as you hear it.
If you use a 300 watt amp on your repeater, you risk people hearing it all over creation but not being able to get into it. If you just run exciter power, you risk having people with a full-quieting signal that have a hard time hearing the machine.
In the end, you try different power levels with distant stations until you find the happy medium. If you have a repeater that's 500 feet up on a commercial tower, you know it's going to hear every little signal, so maybe that 100-watt amp is what you need to get the extra saturation so that the distant stations receive the repeater as well as the repeater receives them. If your repeater is in your back yard on a 50 foot tower, then chances are 25 or 30 watts is all you'll need to equalize the transmit and receive.
Use that same logic for your station. Use enough power to make sure that you can hear people as well as they hear you, and you'll be good. Sometimes that involves amplifiers, sometimes it doesn't. Simple as that.
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RE: Is That Amp Really Worth It?
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by KB2FCV on January 17, 2008
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Pretty good article, I don't know if I necessarily agree with everything in it. I used to own an SB-220 for a number of years. It did need some major work done once (new caps, rewired a choke by peter dahl), but for the most part it gave me good service for 8 or 10 years until I sold it to buy something else. It was nice to use to go after DX. I felt it made a difference... getting them in 2-3 shots (sometimes the 1st!) versus taking a good hour to get em'. When I moved out I discovered QRP as I was reduced to improvised antennas (magnet wire up into the trees). I built a K2 and was very successful working into europe, africa and south america.
I really believe with a GOOD antenna you can do alot just running barefoot or even QRP. The amp will certainly help but won't do much if you can't hear em'. I own another amp now. I bought it to use eventually but more for my collection to match up with my sx-101a, ht-32a... it's the ht-33a. It will be used semi-regularly just to make sure it still works but not really for serious day-to day work. If I ever decide I need something serious I'll get something relatively newer.
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Is That Amp Really Worth It?
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by KR9D on January 17, 2008
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Your Rule 2 is what I would call a risk factor more than a rule. It's more risky buying an amp you haven't seen or had demonstrated to you. In return for that risk, the seller should expect a lower price.
I bought an Ameritron AL-811A from an ebay seller for about the going rate for that amp in claimed working condition. For that price, I expected at least some issues, and it was worth the risk. The price was low enough so that even if there were major issues, it would not be a total loss for me even as a learning experience.
Caveat emptor, indeed. But that doesn't mean we should never take a risk if the price is right.
In the end, my amp had a flaky solder joint on the coax going into the T/R relay PCB, and it would arc when the tuning wasn't right. After some testing, I noticed intermittent operation, and heard the arcing. That made it easy to find, and a dab of solder fixed the problem. I ended up with a reliable small amp for far less than a gain antenna on the lower bands.
When solar conditions are good, we don't need power. It's when conditions are bad that a little power might provide the edge. Remember that it's the guy on the receiving end that demonstrates skill when we provide him a signal down in the noise. I'd rather make his life a bit easier, unless both of us are enjoying low power operation by agreement. I rarely use my amp, but I'm glad I have it, even with my too-low wire in the trees.
Rick
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RE: Is That Amp Really Worth It?
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by W9OY on January 17, 2008
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This article is kind of silly. You can buy a good used current amp like an AL-80B, AL-1500 or TT Titan for 700 to 2000, run the heck out of it for 20 years and throw it away and know you had a great time with your toy. If you buys something with a PL-172 or an 8875 in it you deserve what you get, but there is no excuse for the gloom and doom in this article.
Sure the tubes may blow or the transformer may fry. An asteroid my fly up your butt also or you may win the lotto or drop dead from a heart attack. You just can never tell what is going to happen so pays yer money and have some radio fun.
73 W9OY
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RE: Is That Amp Really Worth It?
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by N6HPX on January 18, 2008
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Nice article but I have no use for a Amp in my area, my neighbors would kill me over the TVI as many don't use Cable TV. But still good info.
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RE: Is That Amp Really Worth It?
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by N7YA on January 18, 2008
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I have never owned an amp, but i plan on it...i only want to run no more than 400w though, but more like 300, and only on occasion. Ive done quite well on the first 200+ countries without one, i think all i need is just a little kick now and again to get the last 100.
1.5 kw is no substitute for operating skill...there IS life outside the linear.
73...Adam, N7YA
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by N6HPX on January 18, 2008
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I have used only a 100 watts at my station and from my home in DU1 I worked the east coast of USA but again it could come in handy at times like when a African station comes on but the TVI would kill me alot. My neighbors have home madwe TV antennas and you can't convince them of the filters.
73's from Japan
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by G3LBS on January 19, 2008
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Have confidence in yourself - Your programs are better than theirs.
Shame on you if your antennas are not home-made too.
Buffalo Gil AKA Dr Gil W2/G3LBS
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RE: Is That Amp Really Worth It?
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by N6HPX on January 19, 2008
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No problem with the homemade antennas but the TVI is my problem there. As I get alot of it from the neighbors. Mostly I operate at night when the bands are open there. And thats on 20m but also in the mornings on 40m.
Home made for me isnt a problem either as I have done many when I can find the parts.
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RE: Is That Amp Really Worth It?
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by G3LBS on January 19, 2008
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Maybe you could knock-up a 6-band spider quad and beam your signal away from the neighbors?
I suspend mine from the trees.
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by W4LGH on January 19, 2008
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No problem with the homemade antennas but the TVI is my problem there. As I get alot of it from the neighbors. Mostly I operate at night when the bands are open there. And thats on 20m but also in the mornings on 40m.
Home made for me isnt a problem either as I have done many when I can find the parts.
=====================================================
If its not getting into your TV , then tell the neighboors its their problem! Fire in the hole!
73 de W4LGH - Alan
http://www.w4lgh.com
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by N6HPX on January 19, 2008
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I would love to hook up a trbander had one offered for 20,000 peso's but maybe next year as the kids need money for school soon. I had planned on several beams and my idea was a 2m,6m and triband or 5 bander type. But the winds get up 100 plus during typhoon season. My current antennas are 20m dbz and a g5rv/lite but wanna get a better antenna on 40 m and also 80m as thats where we spend our time at the most
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RE: Is That Amp Really Worth It?
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by N6HPX on January 20, 2008
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My TV is on Cable BTW and I havent seen any TVI as of yet. In fact I have a small TV in the room and there isnt any flickers as of yet. I use an old Drake TVI filter on the HF side and have purchased many smaller HP filters like those at Radio Shack for the TV. So far I am clean on myside. One neighbor doesnt say anyting but I did notice it flickering on his set one time and that was when I was on 6m working Malaysia.
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RE: Is That Amp Really Worth It?
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by WR8D on January 20, 2008
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The main thing to remember is when dealing with rf...
Never and i mean never try to be good hearted and ask a neighbor if you're killing his tv.
Believe me i learned this from hard earned experiance. If they're not throwing rocks at ya then don't say a word till they do.
I got the cable company here in a big mess several years ago. There were some cbers running illegal power tearing up all creation. Seeing towers and big antennas i got pulled into the ruckus. It took a direct call from the fcc to the cable company on my behalf..and then it took them seven straight days to fix their mess. Needles to say they never called me a cber running illegal power again..hi hi and it even fixed the cable problem the chickenbanders were having.
Neighbors will blame any little thing they see on their screens on "you".
An yes my alphas were worth every moment i saw those guys climbing the cable tv poles. hi hi.
WR8D
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RE: Is That Amp Really Worth It?
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by N6HPX on January 20, 2008
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the call was 9m6baa so he wasn't a pirate and he confirmed the QSO I got his card in a few weeks, he was a British ham at the time.
I never ask the neighbors about any TVI but they suspect it could be me, none have seen me transmit yet but they usually understand pretty much.
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Is That Amp Really Worth It?
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by KA5ROW on January 20, 2008
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I have owned both the Heathkit SB-220 and currently own a Kenwood TL-922 A and I like my Kenwood. Like it or not we will be forced to go solid state. And as any ham will tell you there is no forgiveness with solid state. My TS-Systems amp failed because I keyed it up into the wrong antenna and just for a Second or Two at the most. As far as sweep tube amps run from them as if they were the plague. But you are correct, Some once very good amplifiers it's best to stay away from like the Heathkit SB-230 the 8873 used in the SB-230 is a $600 + tube but you can find the amp on e-bay for $350 if you are the unfortunate one and get one with a week tube and buy a new one the money you spent would have bought you a brand new Ameritron 811 H with money left over.
Be very careful about buying amplifiers on e-bay. Amps are heavy and require special packing. Transformers and tubes should be shipped separate. I heard horror stories of amps not packed properly.
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by N4PAL on January 21, 2008
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A question to all that are "pro tube" amplifier users and anti solid state, is there anything glowing inside you current HF transceiver? "Oh my” you have a solid state transceiver connected to that tube amp.
So, what is the the future for the tube amps? Or did we forget tubes did not win out for HF transceivers?
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RE: Is That Amp Really Worth It?
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by K5UJ on January 21, 2008
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No one is pro-tube anti-solid state for any reason other than simple economics.
Once you get to power levels above around 500 or 600 watts, solid state amps start becoming expensive for hams. There are a number of reasons for this. A couple are the power supply which almost has to be very high current and higher than typical DC voltage (usually 48 v.), and that on the antenna side of the PA, you have to have a lot of band pass filtering and a matching network and other protection which at QRO involves expensive components. Even if the cost of transistors comes down, the costs for these other parts of the amp are probably going to remain high. Right now, high power FETs are also pretty expensive.
The advantage of s.s. is low mean time between failure and higher efficiency (less electricity cost) but in amateur service, these economic advantages are not all that alluring, compared to broadcasting where the rig is on continually for months or even years.
On the other hand, tube amps, while being not as technically sophisticated, are attractive to hams for just that reason: Easier to repair. A clean output and match of the plate Z to 50 ohms can be had with a relatively simple tank circuit. There are certainly some expensive components but fewer than 10 (B+ transformer, tubes, couple of air variable caps, bandswitch....) and most hams run their amps for probably no more than 2 hours / week and are transmitting at low duty cycles for no more than half that time so the operating cost savings of sold state don't really apply.
Hams who buy 1 kw s.s. amps usually do so for the ease of operation and quick band changes and are willing to pay for that, not because they believe the solid state design is inherrently superior. Its advantages will hold sway however, if legal limit s.s. amps can ever compete with tube amps on price.
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Is That Amp Really Worth It?
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by K1DA on January 21, 2008
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Yea old boy it is a Kenwood made before '86 and
works fine. This article sounds like a "how to by a good used car" piece from "People" magazine.
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by K1DA on January 21, 2008
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I agree with those who point out that unless you are
real weak signal (the far east on 80 for example)dxer or a "this is HIFI SSB 'cause I said so" type, 600 watts is the break point. Given all the home entertainment devices loaded with solid state junctions out there using 600 or less often keeps one under the radar.
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RE: Is That Amp Really Worth It?
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by KD8EZU on January 22, 2008
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AS a new ham I found the article very informative. I have absolutely no plans for an amp as with just a properly tuned G5RV and a long wire antenna I've talked to many different hams in close to 50 countries.
I use old , restored boatanchors and very much enjoy being heard by DX stations running barefoot over the "big boys" running power. I take pride in saying " "rig here is a TS-820S running 95 watts"
I've heard ham stations with lots of power but with overly processed and deep bass audio that cannot be understood by a DX station. These ops have forgotten to turn off the ESSB and equalize for DX purposes. Whats good for ragchewing doen not always work for DX chasing
Other hams have terribly garbled audio from overdriving their expensive microphones. EIther way they cannot make contacts no matter what they're power level is. Efficiency should be the name of the game . Good clean audio without the DSP enhanced "false mid bass" plus an efficient resonant antenna system seem to work most of the times.
One day I'll buy one for sure, but I'm pleased to say I do not have the interest in one for now. As others have said, too much money and lack of a well running stati will not be made up for with an Amp.
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RE: Is That Amp Really Worth It?
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by N6HPX on January 23, 2008
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I too feel that when the time is right maybe I will own one, I had that chance many years ago when a friend of mine went SK and I was allowed to inventory his stuff for sale to the Public. But his AMP had no tubes inside and I figured needed repair..the owner of the apartment tossed it out before I could findout. I wish my neighbors all had Cable but I am not that lucky..maybe some day but have to wait
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Is That Amp Really Worth It?
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by K3MD on January 25, 2008
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I would have to say that to me this article does not make much sense.
6KD6 or equivalent are readily avaiable at Antique Radio Supply or RF Parts.
I have had old sweep-tube linears that were very portable and useful (SBE-LA I got for $50 and re-capped, used for years on vacation). It weighed around 22 pounds or so.
There a number of nice old sweep tube linears on EBay.
8873's are obsolete, it is difficult to convert any of the old Heathkit 8873 units to 8874's. but it can be done and has been done.
There are wonderful "obsolete" tube type linears available (most old Henry VHF, Alpha linears run 8874's. These tubes seldom wear out.) I ran a 76 PA for 16 years with no problems and no new tubes.
A lot of newer linears are junk.... my Ameriton 3-500ZG linear (AL-82) melted the entire bandswitch. All top-of-line Amertron linears use the same bandswitch and HV power supply.
A lot of older "top of line" linears are not good... I had a Ten-Tec 3CX800A7 unit, bought new, which broke 4 times, sold it.
It is fun and games to get an old Drake L-4 or L-7 and re-cap it and you are good to go. Have seen them running 1700 watts out... tubes orange with non-ZG finals. For many years the Mt. Airy VHF Club, with whom I operate the June VHF contest, ran a totally obsolete Swan 6 meter linear, 3-400's in the final, very reliable and puts out around 1 KW. The replacement is less reliable.
What fun can we have in the world without buying and restoring old linears? Not a week goes by that I don't see at least 1 old Henry linear I want on EBay.... one day I am going to get one.
The new keying unit from Ameritron makes amp key line voltage issues a thing of the past... I have 3, they are extremely useful.
Has anyone who has not converted an SB-220 to 6 meters really been a ham? A very easy conversion, gets 500 watts out. I never saw any plans, N3LL told me he did it on an SB-200, so I did it.
I inherited (literally, he passed away and willed it to me) a Harris 3-1000Z shipboard linear from a friend, weight 246 pounds, had to give it away when I moved. The linear, designed for 700w, would put out 1500w easily, and vibrate the entire building in the process. 4000 volts on the plate! No interlock, kind of like the old Henry VHF linears. Not for the stupid.
I restored my current SB-200 for around $30 in parts... you can also use Harbach!
I love my AL-811 beat-to-hell linear, has gone on at least 4 DXPeditions, no knob on tuning cap, dents all over, works fine. Has 2 572B's in final... this IS a direct substitution!
Yes, I have 1 transitorized DXPedition linear/ power supply, 500w out, 15 pounds, but is this really "fun?"
My first linear equired a lot of work, it was a Hallicraftere HT-44 converted to 572B's. Tubes were left on in standby, had to rewire the control circuit in mid-DX contest. MV rectifiers.
Consult "My Linear Problem" in National Contest Journal.
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by N6HPX on January 25, 2008
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Wonder about your electric bill wonder if it goes up when you push higher power at say 600 watts, that would be something my spouse would be curious on as well
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Is That Amp Really Worth It?
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by N6TZ on January 27, 2008
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Hey Hams, is it possible to improve our English?
"Having recently gotten a used AL-811H and put 4 new tubes from Ameritron into it"
I think you mean:
Having recently "obtained", "purchased", or maybe "received" a used AL-811H
Look up "gotten" in the dictionary - please!
Also, how about this:
and "installed" four new tubes from Ameritron
Good English takes a little more thought and is well worth the effort. My English is not perfect but I try to proof read carefully for any possible improvements in my text.
Hal, N6TZ
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RE: Is That Amp Really Worth It?
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by WA2HIP on January 27, 2008
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I strongly disagree with some of the things said.
I HAVE a sweep tube amp (6LQ6's) by Swan. It is a good performer. I got it for a song and had NO PROBLEM finding replacement tubes on eBay. There are substitutes too! Just do a Google Search for info before you buy.
Some of us are on a limited budget and need to buy Heating Oil and Food first. The solid state amps that go for $1000 or more is beyond our reach.
BTW, my Swan 1200-W cost less than $100 and for about $70 I got new tubes. It puts out about 600 watts PEP. ALso, I have 1 1/2 extra sets of finals for it that I got on eBay also.
There is a great personal satisfaction in making these old radios work well. I use my heathkit SB-101 all the time too and it is a great radio & I get many compliments.
So - don't be a nay-sayer, be more open minded & supportive of those of us who work on a limited budget!!
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Is That Amp Really Worth It?
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by N6CIC on January 30, 2008
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Nice article with thought provoking ideas. I own a FL-2100B which I bought on eBay. It is built like a tank and the 572B's are easy to buy (made in China of course). However, I only use the amp. at 400 watts on 80 and 40 SSB when needed. Otherwise I run barefoot CW and 50 watts PSK31 and make many contacts with a simple vertical. I like having the amp. when I need it, but otherwise go lower power.
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by N6HPX on January 30, 2008
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As for proof reading well it might be good but on the computer I am using it don't have that connected to the system. Sorry but agree I have said a few misprinted words.
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by WD4CHP on February 1, 2008
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I had a Dentron MLA2500b.
Used it for 6 months.
Sold it for what I paid.
Not worth the increased cost of electricity.
100 watts is all that is needed.
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RE: Is That Amp Really Worth It?
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by WA0FDV on February 13, 2008
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Obviously the only way to go is 'homebrew'. You get exactly what you want, the tube of your choice and save the labor expenses. Myriad is never followed by 'of' , e.g., ...myriad commercial HF amplifiers..
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