> Re tube changes for the AL-1200:
>
> 1.) See N9ADG's website. About four years ago, several hams put the GS-35b
> into their
> AL-1200's. This seems to work ok except that the cooling is below
> minimums and a
> bigger (noisier) blower is required along with a different filament
> transformer and bias
> circuit;
>
> 2.) Another workable option is to put in an 8877. You will need a filament
> transformer
> change, socket, and chimney, and you will need the timer and grid
> current trip curcuit to
> protect the 8877. You might need to tweak the tuning/ and or components
> of the tuned
> input circuit;
>
> 3.) IMHO, swapping to a pair of 3-500's is a great option although they need
> more drive than
> the 3CX1200A7. However, you will retain the "quick on" feature of the
> amp and the tubes
> are cheap! You will need a new filament transformer, sockets, chimneys,
> and
> suppressors;
Honestly i didnt think the cost of a pair of 3-500Z's was cheap copmpared to a
single GS-35B. I dont know what is in a AL1200 but i did not replace the
3-500Z's in my Yokagawa PL960( its a THP HL-2K) but instead did some sheet
metal work and installed a GS-35B.
Mike
KC7NOA
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|