[Amps] FYINFO--3-500z PROBLEM

[ALEX AIMETTE]

I AM POSTING THIS FOR YOUR COMMENTS AND INFO.  i HAVE HEARD THAT  
AMERITRON HAS HAD A PROBLEM--NO PERSWONAL KNOWLEDGE!!!!
ALEX W2OX

-------- Original Message --------
Subject: 	Re: [FRC] Eimac 3-500Z tube
Date: 	Thu, 20 Dec 2007 21:24:35 -0500
From: 	fainsbert <cmfainsbert at verizon.net>
To: 	<frc at gofrc.org>, <bob at applegate.org>
References: 	<200712210145.lBL1jYml029354 at buzz.applegate.org>



Bob:

Thanks for your almost instantaneous response. I did buy two matched RF 
Parts 3-500ZG's. And that may be part of the problem!

I have an old Henry 2K Classic X amp and in the SSB position, it runs at 
about 3800 volts key down and 800 ma. Theoretically, that's within the 3-500 
specs.

I did insert the RF Parts 3-500ZG tubes in the Henry and it appeared to run 
perfectly until I had a extended QSO [10 minutes] and both tubes began to 
oscillate and glow cherry red.  This same thing started to happen more 
frequently destroying some of the amps internal components. I sent the tubes 
back to RF Parts [they were still under warranty] and they tested OK.

Finally, with the efforts of NO2R, the Henry was "revitalized" and the RF 
Parts tubes were reinserted. Within 10 minutes into a QSO, the oscillating 
repeated itself. The Henry was turned off and the RF Parts tubes were 
removed and replaced with a pair of used Eimac 3-500Z's.

I have my suspicions that the RF Parts 3-500's may work fine under a lower 
plate voltage lower than 3800 v. Made in China? Maybe they used inferior 
internal parts to save a few pennies.

I have had this Henry for over 20 years and it helped me with 337 of my 338 
[ yes, even FJ] DXCC contacts.
Oh yes, I also have a QRO HF-2500DX.

I love my Henry!!!!!

Best Wishes to all for the Holiday Season/

Chuck Fainsbert
KC2NB

----- Original Message ----- 
From: "Bob Applegate" <bob at applegate.org>
To: "fainsbert" <cmfainsbert at verizon.net>
Sent: Thursday, December 20, 2007 8:45 PM
Subject: Re: [FRC] Eimac 3-500Z tube


> RF Parts has really good 3-500ZGs; I've used them for a number of contests 
> in my
> amp with great luck, despite lots of REALLY BAD things being done to them!
>
> 73
>
> Bob - K2UT
>
>
>
> Fainsbert <cmfainsbert at verizon.net> wrote :
>
>> Does anyone have a new Eimac 3-500Z tube that they
>> would like to sell?
>> &nbsp;
>> If so, please email to
>
> ___________________________________
> NOCC, http://nocc.sourceforge.net
>
>
> 


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