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eHam Forums => Amplifiers => Topic started by: AD4DZ on April 20, 2014, 10:28:24 AM



Title: Which Amp To Buy?
Post by: AD4DZ on April 20, 2014, 10:28:24 AM
I currently have two amps.The first is a THP 1.5KFX and I love it It is tied in with a THP tuner and it is as smooth as butter, always ready and puts out a nice easy 900 watts with no problems. The amp and tuner follow the transceiver automatically.
My other amp is a Ameritron ALS-600 that is supposed to be automatic but isn't, makes a lot of noise, and only gives me about 450 watts.
Tokyo Hy Power is no longer available so what Automatic Solid state 1000 watt amp would you recommend that wouldn't bankrupt me?
I really prefer a no tune amp but maybe I should consider a tube amp to save some $ $. Your advice is appreciated.
Dave  W9DEC


Title: RE: Which Amp To Buy?
Post by: N1UK on April 20, 2014, 10:37:46 AM
Take a look at the Acom 1000. It is really easy to tune. - 160m thru 6m


Mark N1UK


Title: RE: Which Amp To Buy?
Post by: K6AER on April 20, 2014, 12:45:55 PM
First question is what is your budget?

The larger question is no one will hear the extra 600 watts from 900 watts now. Just what are you looking for?

On a side note the ACOM 1000 is a very nice amplifier but I would put the money in an up graded antenna and tower. More bang for the buck.


Title: RE: Which Amp To Buy?
Post by: K2CBI on April 20, 2014, 01:44:02 PM
Why get rid of the THP 1.5Kfx, if you love it?  Repairs (if needed) are still available from Audio Visual Service Labs in Virginia Beach.  THP equipment is terrific - why replace it?


73, Mike
K2CBI


Title: RE: Which Amp To Buy?
Post by: K7JQ on April 20, 2014, 04:17:20 PM
I know your reservations about keeping the THP amp. I had an HL-1.5kfx for almost 7 years, without the slightest glitch or problem. I know AVSL still will repair them, even at component level, but the problem is...for how long, and what will the resale value eventually depreciate down to, especially if parts become no longer available? Tough choice, as it's a great amp. Odds are "something" will eventually fail, requiring a future repair. Could be a gamble to assume that it will work forever.

With the exception of the Ameritron ALS-1300 (personally have no confidence in its' long term reliability), all the other 1,000 watt solid-state amps are well in excess of $3,500, and have built-in tuners, which I don't need. I recently sold the THP amp, and have an Acom A1000 on order, basically a dollar-for-dollar swap. I'm not concerned about having to tune an amp, and the Acom is probably the easiest and fastest tune on the market. Just my opinion on your question.

Good luck on your decision.

 73,  Bob, K7JQ


Title: RE: Which Amp To Buy?
Post by: N4ATS on April 20, 2014, 04:22:30 PM
ALS-600 and ALS-1300

I would stand clear of both as they are very overrated as far as power output. If you want a "real" solid state amplifer , look at the Prometheus line. I have a friend who has one and it is well worth it...

http://www.dishtronix.com/prometheus.html


Title: RE: Which Amp To Buy?
Post by: AD5ZC on April 20, 2014, 04:53:23 PM
ALS-600 and ALS-1300

I would stand clear of both as they are very overrated as far as power output. If you want a "real" solid state amplifer , look at the Prometheus line. I have a friend who has one and it is well worth it...

http://www.dishtronix.com/prometheus.html

My entire family (Easter get together) just looked at me as I howled in disbelief at your post.  Thanks for the laugh!!!

Honestly, I've read many of your posts and for the most part respect the help you try to give other hams but your hatred and concerted effort to undermine MFJ have reached the point of ridiculosity.  That's right.  Ridiculosity.

The Prometheus is without a doubt a better amp than the Ameritron but it ain't 8 thousand dollars better.
The OP asked not to be bankrupted.  Please stay on topic. :)


Title: RE: Which Amp To Buy?
Post by: W9GB on April 20, 2014, 05:23:51 PM
Quote from: W9DEC
I currently have two amps.The first is a THP 1.5KFX and I love it It is tied in with a THP tuner and it is as smooth as butter, always ready and puts out a nice easy 900 watts with no problems. The amp and tuner follow the transceiver automatically.
I would keep the THP 1.5KFX amplifier, there is NO commercial solid-state equivalent in that power / price class.

You asked about the Ameritron ALS-600 HF amplifier (which you own).
I can only give 2 specific observations:
From my Elmer (SK, 2011) who was a Korean vet (Ft. Benning), later broadcast engineer.
He was a very early owner of Ameritron ALS-600, and
A RTTY contester that I have known in the area for a long time.  Neither are EE.

In BOTH Cases, the ALS-600 made FIVE Trips to Mississippi (Ameritron) to repair.
My Elmer commented that QA was poor, but not surprising for the MFJ price point targets.
He reduced his usage to 75 meter nets, after the last FET replacement and Ameritron updates (5th trip back).

The RTTY contester sold his Ameritron ALS-600 as soon as it returned the Fifth time --
 he purchased the Elecraft KPA-500 amplifier / matching tuner and has had NO issues, at this point.
--
How can a company make $$, with this many trips back for service?  It doesn't.
My personal observations are aligned to your experience.
The Ameritron ALS design is now a bit dated.
Freescale has new RF transistors that would be more suitable -- but at a higher cost for the resulting HF amplifier.


Quote from: AD5ZC
Honestly, I've read many of your posts and for the most part respect the help you try to give other hams but your hatred and concerted effort to undermine MFJ have reached the point of ridiculosity.  That's right.  Ridiculosity.
I don't know what this statement has to do with W9DEC question in this thread.
eHam.net use to have Moderators to reduce personal attacks in these forums.


Title: RE: Which Amp To Buy?
Post by: W8VVE on April 20, 2014, 05:32:47 PM
Are you looking for another HL 1.5KFX?   Drop me an email.
Sam. W8VVE.  nwsam@ntelos.net


Title: RE: Which Amp To Buy?
Post by: K3GC on April 20, 2014, 06:41:16 PM
Another vote for keeping the THP.  It is a great amp and should give you years of service.  I love mine and would not consider replacing it.  I rather expect that they will appreciate in value over time.
73,
Gene K3GC


Title: RE: Which Amp To Buy?
Post by: K9OJT on April 20, 2014, 06:51:02 PM
http://www.dishtronix.com/prometheus.html

The Prometheus is without a doubt a better amp than the Ameritron but it ain't 8 thousand dollars better.

Trust me..if I had the bucks I would own the Prometheus. It is made less then 40 miles from my QTH...that aside I have studied their information. The headroom alone is enough to justify the cost. I believe the Prometheus is most likely the next generation in solid state amplification. It may take awhile but I am convinced the Prometheus will eventually become the state of the art.

Time will tell.

Mike K9OJT


Title: RE: Which Amp To Buy?
Post by: N4ATS on April 21, 2014, 03:53:07 AM
"Honestly, I've read many of your posts and for the most part respect the help you try to give other hams but your hatred and concerted effort to undermine MFJ have reached the point of ridiculosity.

Nahh , the ALS-600 and ALS-1300 are ok amps for the money plus you don't have to take a loan out to get one. I used an ALS-600 for years , my point was if you want to sail at 1000 watts as he described and the amplifier stay working afterwards, the Prometheus is the way to go. Most Hammy's can't afford one though.

The original poster is looking to advance and seems like he may be able to afford it.


Title: RE: Which Amp To Buy?
Post by: W8JX on April 21, 2014, 05:55:36 AM
but I would put the money in an up graded antenna and tower. More bang for the buck.

That depends on what you are looking for. On 20m and above DX a tower and beam can a lot but 40 and below were noisy can be higher a amp can help a lot. I have had many QSO's on 40  that would no have been pleasant or possible without a amp on both ends during poor conditions.


Title: RE: Which Amp To Buy?
Post by: K2GWK on April 21, 2014, 06:25:52 AM
What about the Expert Amps 1K-FA? It is in the same ballpark as the THP as far as price and I have heard a lot of good things about the amp. The new legal limit 1.3K-FA will be available soon also and it seems the price without the built-in tuner won't bee too bad.

Forum Thread: SPE Expert 1K-FA vs 1.3K-FA (http://www.eham.net/ehamforum/smf/index.php/topic,96129.0.html)

http://www.expertampsusa.com/ (http://www.expertampsusa.com/)

(http://www.expertampsusa.com/css/images/sliderTWO002.jpg)


Title: RE: Which Amp To Buy?
Post by: KH6DC on April 21, 2014, 01:20:37 PM
Why get rid of the THP 1.5Kfx, if you love it?  Repairs (if needed) are still available from Audio Visual Service Labs in Virginia Beach.  THP equipment is terrific - why replace it?


73, Mike
K2CBI

I second the response from Mike.  Keep the THP and if it ever needs repairs, AVSL is the repair center for all THP products.


Title: RE: Which Amp To Buy?
Post by: SA2CER on April 22, 2014, 10:35:30 AM
A quality automatic amp will "bankrupt" you as you probably know. Take a good look at ACOM, Military quality AND v e r y quick and simple to tune. They are quiet also, not to forget.
ACOM also has an automatic, the ACOM-2000. And it is coming a smaller automatic soon as well.  I have the ACOM 1010 and are deeply impressed!


Title: RE: Which Amp To Buy?
Post by: SA2CER on April 22, 2014, 10:45:58 AM
K6AER wrote:
"On a side note the ACOM 1000 is a very nice amplifier but I would put the money in an up graded antenna and tower. More bang for the buck."

I say: ...Eh, Then one gonna get an heck of antenna!!!


Title: RE: Which Amp To Buy?
Post by: NC8T on April 23, 2014, 07:44:51 PM
I'm surprised no one has mentioned QRO Tech made right here in Ohio.


Title: RE: Which Amp To Buy?
Post by: N6AJR on April 24, 2014, 10:12:48 AM
Neither is it solid state or cheap BUT look at a nice used Alpha 87 A.  They are tubed and have a 3 minute war up cycle, BUT they are fully automatic in operation and have so many built in protects, that even I can not break it. A beautiful amp, around 4k to 5k used, and are a real star.

 Check with RF concepts/ ALPHA and see what they have in the used bin. They are  the absolute BEST amp I have ever owned. I have had the als 600, the als 500 a bunch of sweep tube amps, an ALS 1200 a TL922, several Clipperton L's, an IC 2 KL ( great if you are running Icom stuff),  the ameritron 811 and 811 H and many more. The absolute best is the alpha 87 A, bar none.


Title: RE: Which Amp To Buy?
Post by: W8JX on April 24, 2014, 01:02:38 PM
Alphas are the pricey and in my book spending 4 or 5k for a used no warranty amp is a bit foolish because while it more might be okay it could cost big $$$ to repair or be a very expensive door stop. When you spend that my you want new amp and new tubes.


Title: RE: Which Amp To Buy?
Post by: KA4WJA on April 24, 2014, 01:53:20 PM
Dave, W9DEC, the original poster, never answered what his budget was, nor what bands/modes he desired to run, nor what antennas he has (or can afford / fit in his yard), etc..
And, since he mentioned possibly buying a tube amp to save $$$, and asked for advice....
 
1)  So, here is just my advice/opinion here...
ALPHA...Used Alpha's will give you years and years of service...



2)  I agree with John, W8JX, regarding the Alpha 87a, as this is microprocessor controlled amp, and some 87a's have been known to be a bit temperamental (not to mention expensive to repair)...
But, this is not the case for all Alpha's!!!
Alphas are the pricey and in my book spending 4 or 5k for a used no warranty amp is a bit foolish because while it more might be okay it could cost big $$$ to repair or be a very expensive door stop. When you spend that my you want new amp and new tubes.
Spending $1500 - $2000 on a used Alpha "legacy" amp, such as an Alpha 76, 374a, 78, etc. is not out-of-the-question, if the 8874's are good (or you get spares)

And, $4000 - $5000 will get you a Alpha 77dx, in very nice shape...and probably with a good (new?) 8877...
(the only problem here is finding one....those that own 'em, usually keep 'em 'til they die.....I got lucky and found one in the 90's....but I'm not dying anytime soon...sorry...:)

Non-microprocessor-controlled amps are fairly easy to troubleshoot/repair, so warranty is not a big issue (in my opinion).....



3)  And on a side note, regarding tubes / tube life...
Here are my personal experiences (take 'em for whatever you think their worth!!!)

--- My mid-1970's Henry 2002 (still has 1100 watts out at 144.1mhz), still has the original Eimac 8874's in her...I've owned her for 30+ years now, and she has worked 2m EME, etc. without issue....and I'm the second owner (the original owner used it on 2m FM service @ 400+ watts out, for years)
[ONLY maintenance/repair:  I replaced the filter caps, once in 35 years...]


--- My late 70's, Alpha 77 had some upgrades done in the early 80's (and I think new tubes at that point), but the still the same Eimac 8877 tubes for 30 years....and she still works great, full output and very clean IMD-wise....
[ONLY maintenance/repair: I had to re-solder one wire on a relay in the power supply, after shipping it from the original owner, and that was in the 1990's]


--- My 1979 Heathkit SB-221, of which I'm the original owner (which I built myself, about 35 years ago), still has its original Eimac 3-500z's....
(I loaned this SB-221 to my best friend about 10 years ago, as I didn't want it sitting around unused, and he and his wife use it almost daily....and she still puts out 1100+ watts PEP, with no signs of any issues....)
[ONLY maintenance/repair:  replaced the filter caps once, and cleaned/lubed the fan, once....]

--- I've also homebrewed a few (an 811-a amp, a 2x-572b amp, and a couple solid-state 25watt amps, a couple vhf solid-states, etc.), and have never had a tube / device failure (although I did have a problem with a spur/oscill from a vhf amp once...)

--- Also a few Mirage vhf and uhf solid-state amps.....and no device failures...


So, if you don't abuse your amp (keep from improperly tuning it, and from  overdriving / overheating it), and you buy/build a decent quality amp to start with....tube life is a fairly moot argument....


Just my 2 cents...


73,
John,  KA4WJA
  


Title: RE: Which Amp To Buy?
Post by: N4ATS on April 24, 2014, 02:44:54 PM
"Alphas are the pricey and in my book spending 4 or 5k for a used no warranty amp is a bit foolish because while it more might be okay it could cost big $$$ to repair or be a very expensive door stop."

That's the beauty of an Alpha , in MOST cases they don't go bad. My Alpha 89 has been slamming legal limit for many many years. In all my years of amplifier repairs, and I repair piles, I could count the number of busted Alpha's on one hand....BUT the number of "other" brands I get in for repairs are countless....


Title: RE: Which Amp To Buy?
Post by: W8JX on April 24, 2014, 06:04:47 PM
"Alphas are the pricey and in my book spending 4 or 5k for a used no warranty amp is a bit foolish because while it more might be okay it could cost big $$$ to repair or be a very expensive door stop."

That's the beauty of an Alpha , in MOST cases they don't go bad. My Alpha 89 has been slamming legal limit for many many years. In all my years of amplifier repairs, and I repair piles, I could count the number of busted Alpha's on one hand....BUT the number of "other" brands I get in for repairs are countless....

You have had good luck but I have had good luck with lessor amps too. Again the problem is if it goes belly up you can be out big $$$ for repairs. You can get a NEW Acom for same or less depending on model and it is a solid amp too.


Title: RE: Which Amp To Buy?
Post by: AD4DZ on April 24, 2014, 06:09:50 PM
Thank you very much for all your input. My antennas are a hex beam at 25 feet and a Stepp IR big r vertical. I'm a fairly new ham so I'm experimenting and enjoying a lot of different bands. I like to chase DX and do so mainly on 10, 12, 15, 17, and 20 meters. I really enjoy my Tokyo high power as it's completely automatic and I can change bands and frequencies at will so I don't think I'd be satisfied with anything less than a solid-state automatic amp. I guess at this point in time I'm leaning towards the expert but I'm going to research some of the others before  I pull the trigger. I'm really in no hurry and although I'd rather not spend that much money for an amp I will probably do so. Thanks again for all your input.

Dave
W9DEC

73

W9D EC


Title: RE: Which Amp To Buy?
Post by: N0PQK on April 24, 2014, 06:56:29 PM
Here is one.

http://www.hamradio.com/detail.cfm?pid=H0-008643&oi=1076421191


Title: RE: Which Amp To Buy?
Post by: K7JQ on April 25, 2014, 08:37:38 AM
That's a lot of money for an open item (used) THP HL-1.5kfx, with no warranty. I've recently seen (claimed) mint condition units for around $2,500 on the online classifieds. Since the bankruptcy, more of these have been popping up, whereas previously used ones were very scarce.


Title: RE: Which Amp To Buy?
Post by: KH6DC on April 25, 2014, 02:15:24 PM
Here are my 2 choices:

1. ACOM 1000 or,

2. Alpha 8410 if I ant to go legal limit


Title: RE: Which Amp To Buy?
Post by: KT0DD on May 26, 2014, 09:47:06 AM
Acom is out with a Solid State 600 watt amp. If you are dedicated to 110-120v this is about the best you can do. Besides, you have to go from 600 to 2400 watts (4X power change) to gain 1 S-unit on the other end.


Title: RE: Which Amp To Buy?
Post by: W5HEH on May 27, 2014, 09:38:34 PM
Take a look at Ten-Tec /Alpha Amps they merged and i imagine will be around for many years to service from Tennessee, USA , both great quality .


Title: RE: Which Amp To Buy?
Post by: W8JX on May 29, 2014, 10:24:16 AM
Take a look at Ten-Tec /Alpha Amps they merged and i imagine will be around for many years to service from Tennessee, USA , both great quality .

I would not bet farm on that. They merged to just to try to survive a bit longer. Both are seeing serious competition that is squeezing market share.


Title: RE: Which Amp To Buy?
Post by: W3RSW on May 30, 2014, 11:38:52 AM
Fun thread.
Not an original thought but we all seem to pick our currently owned or more/easily used amps.
So I'll throw in my pre-owned, "certified" Alpha 89 gotten from rF Concepts via HRO for a little over $3k.  Existing 3cx800a7's yield 1.5 k with very little grid drive as they were spec'd from low grid drive lots.

Agree with others. --yes it's a tank, manually tuned and safety controlled by good "old fashioned" 7400 series chips, etc., no microprocessor or complicated logic trail. R.F. C. keeps just about spare everything for this amp, and even the bulk of those components are available from Mouser, et. al. If company goes out of business.

Back lit dials, full light show from reasonably stepped and calibrated LED's along with the already mentioned heavy duty construction. Mine came with strapping P. Dahl xformer.

And yeah, I do run it at around 1.2 kW pep out using two tone set up. The amp is simply designed to be reasonably efficient at 1.0 to 1.5 or so kW output.

Like many I seem to run it in one band that usually needs it the most, hence other than modest changes, tuning isn't too much an issue.

I do like the Acom rigs though and if going for a new amp would seriously consider one of their 1kw or a little more powerful tube models other than having some misgivings about the complications of having tetrodes and potential problems of Mother Russia's ex satellites manufacturing the amplifier, (especially these days redux) not to mention the additional control and power supply complexity of using tetrodes, heh, heh.

Yeah, I know Ian, Wm3SEK and others like tetrodes but I am simply fascinated with the oxide cathode, focused anode, high mu Eimac series as being the epitome of tube evolution.  Sorry they dropped the 8873, 8875 and hope for continued production of the 8874, 8877 and 3cx800 a7. Won't have to worry in my lifetime or for next generation however, given that amp manufacturers seem have finally put decent operating and safety limit circuitry in new amplifiers along with the exceeding long lifetime of these types of tubes when properly used.

Well OSHA types and legal harpies effectively eliminated the beryllium oxide 8873's ( like We were going to sit and file down to dust the heat sink all day.)  Dentron et. al. Burned Eimac to death over their 8875's with over usage of warranty replacement by hoping hams were smart enough not to full wick every knob and by dumb full scale grid meter design.  So I wish long life to the remaining series of 88's.

My Alpha 89 will definitely be pre-owned by another one of these days at reasonable cost to him and with reasonable reimbursement to me, unless my family has dumpster or yard sale thoughts. ;D


Title: RE: Which Amp To Buy?
Post by: KA4WJA on May 30, 2014, 12:47:50 PM
Yes, a fun thread!!
And, I seem to recall a "caution" about that Beryllium (?) oxide in the SB-230 construction manual...and we all laughed and said, "the guy who runs too high power using that, might DIE".... :)

If we could figure out a way for the new radios to spray Beryllium oxide dust out the front panel if you turn the mic gain too high, it wouldn't take too long before the on-air splatter issues would be reduced... :) :)




Speaking of tubes...:)

I have a Tempo 2002 (running a pair of 8874's on 144mhz) and a Alpha 77sx (running a pair of 8877's on HF).....and I have spare pairs of 8874's (NOS) and 8877's (working FB pulls)...
(and my old SB-221 w/ a pair of almost 35 yr old Eimac 3-500z's)
All still working fine...

I have no worries myself....but some have asked me...
So, here's my question...

We know that there are sources (China) for 8877's, etc. and plenty of NOS Eimac 8877's...
But, isn't Eimac still manufacturing 8877's / 3CX1500's?  and 3CPX-1500's?
....I am simply fascinated with the oxide cathode, focused anode, high mu Eimac series as being the epitome of tube evolution.  Sorry they dropped the 8873, 8875 and hope for continued production of the 8874, 8877 and 3cx800 a7. Won't have to worry in my lifetime or for next generation however, given that amp manufacturers seem have finally put decent operating and safety limit circuitry in new amplifiers along with the exceeding long lifetime of these types of tubes when properly used.
The reason I ask this directly is just last month I had a conversation with an MRI service technician (who had no clue about ham radio), and he said he still services MRI's, etc. "with tubes in 'em"....and said all he does, is "un-plug everything...remove the old tube, put in the new one....and hook everything back up....and then do a re-cal"...
I described the 8877 and he said "yep, that sounds like it" (although, I assume he was using the 3CPX-1500, pulse-rated tube)
When I asked him about the source of the tubes, he said he didn't know....but remarked that his boss "orders a case or two every month or so"....
I have no way of knowing whether any/all of what he said was factual....we were all just sitting waiting on a delayed flight, killing time talking....

So, what is the straight dope here...
Is Eimac still making 3CPX-1500's??  and 8877/3CX-1500's??
Anyone know for sure?



73,

John, KA4WJA


Title: RE: Which Amp To Buy?
Post by: KF4R on May 30, 2014, 01:35:20 PM
Just a FYI, Ameritron has now announced ALS- 1306 at Dayton, to be available next month. The same amp as the 1300 but with 6 meters.
Bob KF4R


Title: RE: Which Amp To Buy?
Post by: W3RSW on May 30, 2014, 04:16:06 PM
John,
Yep, still making them.  I said "hope they continue" for those three. It's the 8873 and 8875 that they quit making.  Also meant to say the spacer (heat conductive but HV insulated, amazing material) between the tube and heat sink is the piece that contained the BeO2 (or whatever the valence combo is.). The 8873 is fine, just like all the others, silver plated, but with a finless cylindrical anode, as you know.

You can buy the three series, 8877, etc. still made from Richardson Electronics, CPI's favored outlet. ...but h'ain't cheap no mo.
$890 per 3cx800a7 last quote I got with a month or so wait until production run is made.

Ought to sell them by the Troy ounce.  Hey, not to far out of the realm due to the silver and gold in them, not to mention the extremely close tolerances and very small dimensions of the components, especially the grid to cathode spacing with the grid wires critically spaced between cathode emission bands. The better centered, the lower the grid current requirements since theoretically the grids only provide a voltage field to direct and control the electron stream on its way to a much farther away spaced anode.  If spacing is perfectly equidistant then the current required is small. Gain is greatly determined by the ratio of the grid to anode spacing over the grid to cathode spacing.  With a gain of 200, that's quite an achievement.

Can't imagine how Eimac produced them so relatively cheaply in the 70,s, for Hams no less. We sure killed the goose on that one.  Denny should've been lynched from Eimac's perspective. We had a great ride from our perspective, but da train was comin' down de tracks.

I'm enjoying them while I can.



Title: RE: Which Amp To Buy?
Post by: W8JX on May 31, 2014, 05:31:58 AM
The realty is that is does not cost anywhere near 900 to make a 3cx800. It's a captive market with one supplier controlling most of it and they squeeze out as much profit as possible.


Title: RE: Which Amp To Buy?
Post by: W3RSW on May 31, 2014, 06:25:25 AM
"Everybody knows that."
Left you some room. ;D



Title: RE: Which Amp To Buy?
Post by: K8KVN on May 31, 2014, 07:33:03 PM
I'm surprised no one has mentioned QRO Tech made right here in Ohio.

You know, those look like nice amps.


Title: RE: Which Amp To Buy?
Post by: KA5PIU on June 01, 2014, 09:07:21 PM
Hello.

What I look for are old marine radio amps.
They are commercial grade and FCC type accepted, and frequently CHEAP!
Most will run on 100 to 260 volts, with something like 30 taps on the transformer.
And the transformer is very forgiving, and well protected.
The tubes are run well within the ratings, well within the ratings.
For example, the RCA Radiofone super10 has a 4cx5000 tube in it.
At 1.5 kW, the thing will last forever!
Oh, and did I say A 4cx5000?
No, it has 2!
There are switches to drive 1 or 2 tubes, and you can pick witch one.
I got it for scrap value.
It will happily dim your house lights on 220.
True, it is the size of a gun safe, but it does work.
Quiet? not with the normal fans, but at 1.5 kW, you can slow things down, way down.
The power supply is normally always on, and can provide a host of voltages for your radio.
But, that is but another avenue.
Whatever the case, look at what has the highest value for you.
In my case, $100 for an old marine box was what I went for.


Title: RE: Which Amp To Buy?
Post by: W3RSW on June 02, 2014, 05:39:03 AM
Yeah, fire that baby up on 500kHz ! Just don't send SOS unless the FCC's at the door.  ;D


Title: RE: Which Amp To Buy?
Post by: KA5PIU on June 02, 2014, 05:47:29 AM
Yeah, fire that baby up on 500kHz ! Just don't send SOS unless the FCC's at the door.  ;D


That was my first thought, test the auto alarm sender.
There is this fire alarm like pull station. :-X


Title: RE: Which Amp To Buy?
Post by: N3QE on June 02, 2014, 06:21:20 AM
For example, the RCA Radiofone super10 has a 4cx5000 tube in it.
At 1.5 kW, the thing will last forever!
Oh, and did I say A 4cx5000?
No, it has 2!

Do you have a picture? All the "RCA Radiophone" trademarked units I remember seeing were truly crufty CB sets marketed for marine use. They were crufty beyond belief even compared to other early tube CB sets, the microphone I remember coming with the set was a perfectly square box.

What you are describing sounds more like the "RCA Ampliphase" which I know were used shipboard for SW broadcasting.

Tim.


Title: RE: Which Amp To Buy?
Post by: KA5PIU on June 02, 2014, 06:30:47 AM
For example, the RCA Radiofone super10 has a 4cx5000 tube in it.
At 1.5 kW, the thing will last forever!
Oh, and did I say A 4cx5000?
No, it has 2!

Do you have a picture? All the "RCA Radiophone" units I remember seeing were truly crufty CB sets marketed for marine use. They were crufty beyond belief even compared to other early tube CB sets, the microphone I remember coming with the set was a perfectly square box.

What you are describing sounds more like the "RCA Ampliphase" which I know were used shipboard for SW broadcasting.

Tim.

RCA used "Carfone" for its mobile applications.
And, the marine model was "Radiofone".
This has nothing to do with what is inside, it is just a marketing name.
http://vintageadsandbooks.com/radio-corporation-america-1962-super-carphone-150-2-way-vintage-ad-y107.html
As you can see, not an average RCA carfone, but a Super Carfone 150!
And, why pictures? there is a youtube of it.


Title: RE: Which Amp To Buy?
Post by: N3QE on June 02, 2014, 06:42:48 AM
As you can see, not an average RCA carfone, but a Super Carfone 150!

RCA Carfone 150 was a decent high-band mobile FM radio of its era. The ones I recall used 6146's in the finals and a lot were converted to mobile or fixed ham use by the 70's.