[Amps] testing 572 B tubes

[Joe DiPietro, N2UF]

I have April 1978 HR right here.  Testing Power Tubes is Page 60-63.

Joe, N2UF

Karl-Arne Markström wrote:
> In "Ham Radio Magazine"April 1978 there was an article titled  "Testing Power Tubes"
> by Joe Carr K4IPV (SK). It covered the basics in transmitting tube testing and evaluation.
> Recommended reading.
> 
> 73/
> 
> Karl-Arne
> SM0AOM
> 
> ----- Original Message ----- 
> From: <alan.kaul at att.net>
> To: <amps at contesting.com>
> Sent: Saturday, March 04, 2006 11:33 AM
> Subject: [Amps] testing 572 B tubes
> 
> 
> 
>>Does anyone know if there is a way to test 572 B's?
>>
>>I recently acquired this AMP.  It had "fairly new tubes" -- according to the previous
>>owner perhaps 20-30 hours on them.  I found I was unable to load it up to more than 400-600W
>>output and suspected the 500 pf plate bypass cap (which a couple of you mentioned as a possible
>>problem).  I replaced the plate bypass cap, with a .001 mfd and added a .01 mfd in parallel.
>>Then I replaced the plate RF choke with  a new choke from RF parts designed for use in
>>Ameritron and other amps (it specs at 1.5A, 225 uH, 4 KV max).  Then I put it all back
>>together and fired it up and the power output is pretty much the same as before I
>>made the changes.
>>
>>So I am wondering if the TUBES might be a little soft. 
>>
>>Anyone  have any other ideas??
>>
>>Please and thanks and best 73 de alan
>>
>>--
>>Alan Kaul W6RCL LaCanada, CA 91011
>>e-mail:  w6rcl at amsat.org
>>http://
>>home.att.net/~alan.kaul/index.html
>>
>>
>>
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>>Amps at contesting.com
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>>
>>
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>>
> 
> 
> 

-- 
++++++++++++++++++++++++++
Joe DiPietro, N2UF
http://www.joeham.net
N2UF at joeham.net
++++++++++++++++++++++++++