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Author Topic: Amp Tube Snobbery  (Read 33401 times)
K0RS
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Posts: 1109




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« Reply #15 on: August 20, 2014, 11:17:45 PM »

I know I, for one, am sure glad Eimac got rid of those 500 ad men writing jingles.  It would drive me crazy, especially around Xmas time when you couldn't seem to get away from them.

"Eimac tubes, Eimac tubes, they're the ones to be had!
Don't use Russian tubes, they'll make you sad!
And Chinese tubes are most assuredly bad!"

Now I can't seem to get the lyrics out of my head...almost worse than the Chia Pet thing.  Or the Clapper.
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ZENKI
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« Reply #16 on: August 21, 2014, 06:49:58 AM »

Now hams want to call technical ignorance "tube snobbery"  All of sudden for reasons of wanting to be cheap we turn a blind eye to the fact that many of these cheap tubes
were meant for Class C and Radar pulse service and not meant for linear service use.

Its easy being a  ignoramus by burying your head in the sand and saying all is  good and these tubes  are good because they are cheap. Going on to say that hams that dont use tubes are  snobs is a ridiculous contention.  Maybe some hams forget that  we require linear amplifiers for SSB, not non-linear cheap class C tubes  with poor IMD performance  for SSB operation. Since most hams operate on SSB we can ignore the requirements of CW linears.

If you live in Europe and hear the crud on a band like 40 meters,  anger is the first thing that comes to mind when operating next door to these hams who only considered the price of their tubes rather than how clean their signal is  that these cheap  tubes are producing. I suppose this is no different to the ignorant hams who use garbage class C CB amplifiers on the ham bands on SSB because they think they being smart by being cheap.   Technical ignorance is not a defense nor can bending the truth for convenience change the fact that  many hams are doing the wrong thing.

The majority  of hams who use  good tubes like 3-500's, 3cx800's and 8877s and the many good linear SSB tubes are not really snobs, they just hams  who  are considerate of other users of the ham bands and have a greater technical understanding of the issue. I supposed the next argument we will be having is  that hams are snobs for not using cheap CB class C amplifiers on the ham bands and we should  ignore the technical requirements just  so that the dummies can own a amplifier regardless of what they do to the band. I suppose the technical stupidity of this kind of technical stupidity can be seen and heard on the CB band  24/7. Why would anyone  want to degrade the ham service to this level when its good affordable clean linear tubes like 3-500's are readily available?

I dont buy this argument and will stick with linear tubes meant for SSB linear service regardless of where they are made. Its simply a technical requirement thats called doing the right thing. Its not about being a arrogant snob.  There are numerous SDR receivers around the world, listen to the crud that these tubes produce, you can hear and the see the damage "cheapness" produces  on the waterfall  QED!
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KG9SF
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Posts: 282




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« Reply #17 on: August 21, 2014, 01:02:12 PM »

Zenki, you use a lot of words but you don't say anything.

Are you telling us that you look at the spec sheets for a GU74B and somehow think it was designed for class C nonlinear use? Forgive me, but you must be nuts. l suppose that everyone on this forum knows already that your prime focus is on IMD products.  We've heard you ramble on and on about that.

But to characterize 4CX800As as cheap, nonlinear, class C radar tubes is just laughable.

Oh, and I'd go easy on using "ignorant" very often when referring to others and trying to pawn off crud as knowledge like your last post.

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N9AOP
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« Reply #18 on: August 21, 2014, 02:02:56 PM »

One thing I noticed is that Alpha will sell an 8877 in either Eimac or Chinese flavor.  The Eimac is twice the price but the
Eimac is guaranteed for only one year while the Chinese one is for two years.  Is there some cryptic message in this?
Art, N9AOP
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W3RSW
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« Reply #19 on: August 22, 2014, 07:50:30 AM »

Eimac has stood by a one year guarantee for many years.  It is to catch an errant tube or even batch that somehow slipped through the cracks. "That assembler, that tool or that thorium supplier is now longer with us.."  Grin .  However the vast majority of Eimac tubes last for the commercial 24/7 usage period, say 8k to 10k hours, of hard riding and for many years in amateur service provided operating limits are followed in amplifiers of good design.

In past years CPI Eimac has even stood by good tubes that commonly went bad because of bad amp design and even worse, uninformed amateur operating practice, e.g., the 8875's in Dentrons.  A few dollars worth of components and an idiot shutdown or two potentially would have saved the discontinuance of a darn good tube.  8873's, 4's, 5's and 7's were never comparatively cheap tubes even back when the design was new and shiny if one wants to use that argument for the lack of decent amp design in those days.

************

Not to many years have yet transpired for Chinese tubes so we'll see. They do seem to be getting somewhat better.  A little searching about various Chinese factories, failure of certain Chinese tube types more than others and early build problems of Chinese tubes should answer your question.

It looks like one reputable outfit, RF Concepts/"Alpha" has decided to capitalize on the need for reasonably priced Chinese tubes along with double testing, etc, but again, ...we'll see.
They may saturate the market so another boom/ bust cycle may occur.

The market (you) can simply decide if you think the price difference is worth taking the gamble; either the Chinese tubes are good enough to match the warranty ( at the end  of which the bulk of the run doesn't run out of emission from under thoriation, etc,? ) vs. Eimac's perceived gouging but with proven reliability.

It may very well be that medical Eimac pulls with no or slightly reduced emission have far more value than newly made Chinese tubes.  Time will tell.

Of course shipping will also weed out the better manufactured tubes before you even get them.
 Grin. I could go on and on but will only be repeating numerous threads.
« Last Edit: August 22, 2014, 07:56:01 AM by W3RSW » Logged

Rick, W3RSW
K6AER
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Posts: 5726




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« Reply #20 on: August 22, 2014, 08:22:30 AM »

I am curious. Which triode or tetrode chinise tube in the 800-1500 watt range is designed for class C only? I went looking and did not find any. Possibly Wouxun is coming up with one for their little FM HT’s.

In that all linear tubes can be biased for class “C” including the 8877, maybe I missed the “CLASS C OPERATION ONLY” on the side of the heatsink fins. The Balance between class A (highly linear but inefficient) and class AB (less linear but more efficient) has always been just that, a balance.

Do hams want a highly efficient amplifier and are willing to pay a bit of IMD penalty for less fan noise and heat or do we want the best IMD possible only to have the amplifier putting out 1500 watts of heat even when the driver is off but the amplifier is keyed.

To a larger question how much IMD is bad? 20 dB better than the driver, 30 dB better than the driver? What will be buried in the noise floor with a dipole, will not a 4 element beam at 100 feet. At this point big station hams have to run larger amplifiers for more head room and a cleaner signal. All the IMD performance is lost if the amplifier is over driven.

At this time I would like to see schematics of these phantom class “C” HF amplifiers.

I know this is a hot topic for some hams that don’t or can’t get on the air but just once I would like to see a real technical design article with their test results for all to see.
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N3QE
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« Reply #21 on: August 22, 2014, 09:31:22 AM »

It looks like one reputable outfit, RF Concepts/"Alpha" has decided to capitalize on the need for reasonably priced Chinese tubes along with double testing, etc, but again, ...we'll see.
They may saturate the market so another boom/ bust cycle may occur.

There are several reputable places that are known for being able to effectively screen out the bad Chinese tubes (I suspect they also cajole the manufacturer to not send them the crap.) I strongly recommend both RF Parts and Ameritron for these tubes.
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KX2T
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Posts: 1068




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« Reply #22 on: August 22, 2014, 10:44:31 AM »

Well I think this post was used to flush out ZENKI  and it did, here is a guy who uses NO CALL SIGN which makes me laugh, knows everything that needs to be known about anything radio at least in his own mind, and also comments about how companies should re build most all of there radio's and who has never worked in manufacturing at least to what I have seen him post. Its a joke but tubes from our good ole famous Eimac are going to the way side as far as the ham market is concerned, many years ago when Eimac brought out the 8877 they used the ham market to promote these tubes, they didn't cost an arm and a leg and then something happened, companies started building MRI's and boy these tube and there larger brotherin were being use much more than than the ham market used them plus they could charge a hell of allot more money to the medical market so the ham's got the shaft. Were an 8877 went for $300 to $400 then it went up to $800 then over $1K plus range and the medical market pays these prices and the tubes were labeled Eimac/Varian now. The amateur market is soo small compared to the medical field and maybe we got used in the beginning as to stroke the fire of many tube that Eimac brought out that are used in many other market not just ours. The Chinese tube if you get a handle with the companies over there can be made to better standard but you gotta work with then and this takes time. The Russian tube that are NOS Svetlana tube will deplete there supply and believe me when Svetlana starts up there production again they will cost as much as the Eimac tubes. As far as IMD well when you run your mic gain at the ALC peaks or over on your meter don't expect whatever tube you have in your amp to be clean if your overdriving your radio's PA, use less ALC range, maybe 2/3rds and maybe a slight bit more with your processing if you think you need it. IMD starts in most cases with what's driving your amp then if your exciter is overdriven then the amp will produce those nasty IMD's.
Jim
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KD0REQ
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« Reply #23 on: August 22, 2014, 12:57:23 PM »

you think the Russian tube vendors will restart big bottles, eh?  I rather suspect if you get out of the business for some time, you are going to be knocking your head against the fall for at least half as long.  the important part of the production cycle, once it's been shooed out the door, the workers, isn't coming back.

I don't think so.  instead of needing 500 watts to talk tank to base, they're going to be using satellite radios, just like us.  if they need a few land stations retubed, I suspect Russia will buy a half-year of Chinese production tubes as cheaper and faster, and then figure out a new way.  maybe 10,000 MRF150s in parallel...

I strongly suspect that once the market dwindles, nobody else is coming in to try and satisfy a boutique market in sorta-power tubes.  heck, shortwave worldwide is going away, too, and there goes the reason for the 30KW filament-burners.
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KD8MJR
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« Reply #24 on: August 22, 2014, 12:59:17 PM »

Not to many years have yet transpired for Chinese tubes so we'll see. They do seem to be getting somewhat better.  A little searching about various Chinese factories, failure of certain Chinese tube types more than others and early build problems of Chinese tubes should answer your question.

I don't know a lot about tubes but I do know a fair bit about how the Chinese industrial sector works.   So let me give you some advice and suggest that you throw out any trend charts or thoughts that you may have that show that it's better in August 2014 than it was in Aug 2010 so it will be even better in 2015.

 Nope the Chinese don't work that way, it may be better in 2015 or it may be worst than the day they started up!   Chinese companies have Zero built in Pride, they operate solely on profits.  If it makes sense to cut corners next year and make the tubes less reliable to increase profits they will do it without hesitation.   It's only under the lash of a foreign investor demanding certain standards that a Chinese Manufacturer will make products of a consistently high standards.

This is not racism talking, this is what I have seen with my own eyes and have had to deal with for years.
When you see huge investors like Apple say no more over working people or using child Labor and they get ignored and have to go down there and personally do the monitoring, you know how bad it is.   When you see independent Chinese companies dump toxic chemicals into baby formula just so they can pass the protein standards test at the bureau of standards, you get a pretty good idea of what your dealing with.
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“A lie can travel half way around the world while the truth is putting on its shoes.”  (Mark Twain)
W8JX
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« Reply #25 on: August 22, 2014, 01:23:19 PM »

Not to many years have yet transpired for Chinese tubes so we'll see. They do seem to be getting somewhat better.  A little searching about various Chinese factories, failure of certain Chinese tube types more than others and early build problems of Chinese tubes should answer your question.

I don't know a lot about tubes but I do know a fair bit about how the Chinese industrial sector works.   So let me give you some advice and suggest that you throw out any trend charts or thoughts that you may have that show that it's better in August 2014 than it was in Aug 2010 so it will be even better in 2015.

 Nope the Chinese don't work that way, it may be better in 2015 or it may be worst than the day they started up!   Chinese companies have Zero built in Pride, they operate solely on profits.  If it makes sense to cut corners next year and make the tubes less reliable to increase profits they will do it without hesitation.   It's only under the lash of a foreign investor demanding certain standards that a Chinese Manufacturer will make products of a consistently high standards.

This is not racism talking, this is what I have seen with my own eyes and have had to deal with for years.
When you see huge investors like Apple say no more over working people or using child Labor and they get ignored and have to go down there and personally do the monitoring, you know how bad it is.   When you see independent Chinese companies dump toxic chemicals into baby formula just so they can pass the protein standards test at the bureau of standards, you get a pretty good idea of what your dealing with.

Many are quick to attack Chinese on tubes yet they offer no viable alternative. They should be darn glad that Chinese or Russians even make the tubes in question because without them there would be no options. Even if tubes have a 30% or greater failure rate that is still 70% good and 70% good tube is far better than 100% of no tubes. Simple math. There is no reason for China to spend a lot of money perfecting obsolete technology with a very limited market. If you look around your house pretty much everything short of food comes from or was made in part or whole in China. Complaining will not change a thing. Get over it.
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Ham since 1969....  Old School 20wpm REAL Extra Class..
KD8MJR
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« Reply #26 on: August 22, 2014, 01:44:02 PM »

My point has nothing to do with that.  All I am saying is that unlike most companies that will typically improve or at least maintain the quality of a device as time passes.  The Chinese on a whole are totally unpredictable, they have no long term out look on quality or pride in the product like you find with German, Japanese, American and Korean companies.  
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“A lie can travel half way around the world while the truth is putting on its shoes.”  (Mark Twain)
W8JX
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« Reply #27 on: August 22, 2014, 01:53:07 PM »

My point has nothing to do with that.  All I am saying is that unlike most companies that will typically improve or at least maintain the quality of a device as time passes.  The Chinese on a whole are totally unpredictable, they have no long term out look on quality or pride in the product like you find with German, Japanese, American and Korean companies.  

There is no profit in refining a obsolete product for a very limited market. We have to work with what we have. As far as "German" quality, Pfaff a old german company that makes sewing machines acquired Huskvarna Viking sewing machines built in Sweden like finely jeweled watches on their top end models. Pfaff promptly sold off all old machines and moved production of them to China. Morale is Germany cuts corners and has been building VW's in Mexico for some time too.  
« Last Edit: August 22, 2014, 02:34:06 PM by W8JX » Logged

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Ham since 1969....  Old School 20wpm REAL Extra Class..
KD0REQ
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« Reply #28 on: August 22, 2014, 03:17:16 PM »

the repairmen who lost their Husqvarna ticket, who got a look at the Chinese machines before new management decided they can outsource their sales and service as well, found the difference right away.  the guy my wife had servicing her machines went to work at the gas company.
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W8JX
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« Reply #29 on: August 22, 2014, 03:24:33 PM »

the repairmen who lost their Husqvarna ticket, who got a look at the Chinese machines before new management decided they can outsource their sales and service as well, found the difference right away.  the guy my wife had servicing her machines went to work at the gas company.

Such a sad fate for a once fine brand.
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Ham since 1969....  Old School 20wpm REAL Extra Class..
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