SBL1 Balanced Mixer Ideas ?

[Skywave]

O.K. Lawrence, fine, fine. I did pick up on one bit of that post: 'a project for sometime later'. So well do I know that! Several years ago I produced a conceptual drawing with a few 'initial' circuits for a home-brew ssb transmitter based on a modified Racal RA-17 2nd. VFO . . . . and actually managed to produce some functional hardware. I got as far as modifying the VFO, building a hetrodyning crystal osc., a balanced mixer and filter and the first R.F. DBM for freq. translation - made with discrete diodes and toroids. And that's when things got a bit sticky . . . on two counts: (a) the output spectrum of my R.F. DBM wasn't 'clean' enough and (b) problems with designing a wide-band H.F. filter. One day I'll get back to it - and what I now know about these Mini-Circuits DBMs has actually given me some inspiration.

Trouble is, of course, that in the meantime between then and now I've accumulated a whole raft of other 'things to do': a CR.100 to restore, an AR88 that needs a final check-out, a Marconi TF2002B that needs a repair, a replacement ATU for the new general-purpose H.F. aerial (this is actually W-I-P) and a host of other things - plus a few domestic sets that Lady Skywave wants me to restore for her antiques and collectables business. And then there are all the other numerous, non-electronic / domestic jobs - which includes doing the daily washing-up, housework & emptying the bins. How, once upon a time (a few years ago), I managed also to keep full-time employment running remains a mystery. In fact, when I last did a 'job stock-take' - and assuming that nothing more gets added to 'the list' - I estimated that I'll need to live to about the age of 150 years to get it all done! Just as well that longevity runs in my family: looks like I'm gonna need it! Me, bored? Don't know the meaning of the word!

Anyway, I've just looked at the clock: whoa! it's bed-time - so I'll wish you a good-night.

Al.

[pwdrive]

Cheers Al, yes me too, can't now imagine how I managed to do everything I did in the past or even a couple of years ago, my wife bought a new lamp shade for the living room the other day, yep I'll do that tommorow....it's still on the floor waiting...back to the simple receivers, the plan is to have a crack at the double balanced mixer job and the Regenerodyne which I posted earlier in this thread, like you I have various comms. receivers that need finishing off.

Lawrence.

[pwdrive]

Been doing a bit of searching on the web regarding the double balanced mixer of the SBL1 orADE1L type, to stand a better chance of matching the ports to the rest of the circuits so far as diy/homebrew is concerned, the concensus seems to be to terminate the ports with a resistive attenuator pad in order to help produce a better match at the ports themselves, in my case it would have to be by experimental methods. There will be a loss of input/output but this could be compensated for to a certain degree possibly.

Lawrence.