>Subject: [AMPS] al-1200
>Sent: 3/29/1997 11:19 AM
>Received: 3/29/1997 1:38 PM
>From: stratto, stratto@tiac.net
>To: amps@contesting.com
>
>Last year at Dayton, I went by the MFJ booth to look at the al 1200. I
>noticed a difference in the al 1200 parasitic suppression choke
>coil/resisitor and also a small parastic suppresion metal strip besides the
>tube, about 1 inch long.
The person who designs MFJ-Ameritron amplifiers sincerely believes that
he (alone) can neutralize a single-ended g-g amplifier. (see Eimac's
*Care and Feeding of Power Grid Tubes*)
>What is the difference, anyone no why? I did inquire about the difference,
>and MFJ sent me a new choke assembly, and told me to cut down my present 3"
>metal strip to about 1 inch after the new assebly was in...
I know a fellow who owns two AL-1200s. One is old, the other is
"neutralized". The old one was more stable than the new improved
version--until the owner installed an unapproved VHF
parasitic-suppressor, which happily licked the problem. .
R. L. Measures,ag6k,805-386-3734
--
FAQ on WWW: http://www.contesting.com/ampfaq.html
Submissions: amps@contesting.com
Administrative requests: amps-REQUEST@contesting.com
Problems: owner-amps@contesting.com
|