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@att.net>
> To: <amps@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@amsat.org
>>http://
>>home.att.net/~alan.kaul/index.html
>>
>>
>>
>>_______________________________________________
>>Amps mailing list
>>Amps@contesting.com
>>http://lists.contesting.com/mailman/listinfo/amps
>>
>>
>>--
>>No virus found in this incoming message.
>>Checked by AVG Free Edition.
>>Version: 7.1.375 / Virus Database: 268.1.2/274 - Release Date: 2006-03-03
>>
>>
>
>
>
--
++++++++++++++++++++++++++
Joe DiPietro, N2UF
http://www.joeham.net
N2UF@joeham.net
++++++++++++++++++++++++++
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|