> Thanks for looking over the design. I didn't consider the impedance change
> of
> the relay, maybe somehow tune it out?
>
>>I've wondered before if you could use the two halves in parallel
>>at lower frequencies, with the rf in and out from the centre tap
>>of the transformer primaries.
>
> I think what you describe is similar to this example, which is used in the
> THP
> HL-2.5Kfx
> http://www.arrl.org/qex/2006/09/qx9ohsawa.pdf
Sort of. The rf path in that amp is push pull all the way. I was
thinking of feeding rf into the centre tap of the low Z side of the
input transformer (where R9/10 connect in the article), and taking it
out at the centre point of the low Z winding on the output end - you'd
have to use E/I cores with semi rigid or binocular cores rather than the
transmission line types used in the QEX article.
I think that Tempo did a similar sort of thing with the 6N2, and there
was a lovely amp using a pair of 3CX800s on the amps projects web site
(the address escapes me) using the same idea.
I've no idea how well/if it might work. You might be much better off
building a low bands amp from some cheap plastic fets. Kill a MRF141G in
the experimenting and it's a big hole in your pocket.
Steve
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|