On Sat, 17 Oct 1998 22:16:11 EDT KA2YKC@aol.com writes:
>
>Hello All,
>
>
>
> I'm in the process of repairing an Alpha 76CA for a friend. For some
>reason
>he fried the plate choke (maybe out of band operation).
They do not like 17M with the stock choke.
Replaced the
>plate
>choke, all else visually looked good and tested good. Upon firing it
>up I
>noticed that I had no output although there was plate current. After
>close
>visual inspection, I discovered the braided staps used to connect the
>band
>switch to the LOAD cap was very brittle and had broken away from the
>variable
>cap. ( Is it possible a No-Load condition could have fried the plate
>choke ?)
Crystalized solder is a norm in high power amps. I always suggest that
solder joints in the output section be regularly checked....better still
suck out the old solder and reflow new every few years if the amp gets
heavy use.
Anything is possible...usually pyrotechnic....under the above conditions.
>
> Since it is too short to simply re-attach to the screw stud of the
>cap, I was
>wondering what the best type of conductor would be to replace the
>strap and
>re-connect the circuit. I was planning on using a piece of 12ga. solid
>copper
>conductor from a piece of Romex. Anyone have a better idea?
Braid is a poor choice for RF. The #12 copper will work altho a better
choice at least for appearance would be silver plated strap.
I like to use #12 or #14 stranded and silver plated with Teflon
insulation. Looks good and seems to hold up better on 10-15M.
GL with the amp, it is one of the great ones.
73 Carl KM1H
>
>Thanks & 73
>Eric
>
>--
>FAQ on WWW: http://www.contesting.com/ampfaq.html
>Submissions: amps@contesting.com
>Administrative requests: amps-REQUEST@contesting.com
>Problems: owner-amps@contesting.com
>Search: http://www.contesting.com/km9p/search.htm
>
>
___________________________________________________________________
You don't need to buy Internet access to use free Internet e-mail.
Get completely free e-mail from Juno at http://www.juno.com
or call Juno at (800) 654-JUNO [654-5866]
--
FAQ on WWW: http://www.contesting.com/ampfaq.html
Submissions: amps@contesting.com
Administrative requests: amps-REQUEST@contesting.com
Problems: owner-amps@contesting.com
Search: http://www.contesting.com/km9p/search.htm
|