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Neil Purling · 12th Nov 2018, 6:52 pm

The Future kit is a pair of BC458's for audio amplification wheras the 'Electronics Australia' circuit had only one. I am wondering what will serve as the power amp

TDA2822M or a LM386?
It depends on if you can change the gain by any means, as you can with the LM386. I certainly have a bunch of TDA2822m & there are some LM386 somewhere.
I need to get my 'scope & sig gen out to do some testing.
Perhaps I ought to make amends by amplifying one of these boards with hot bottles, rather than cold Silicon?
I could power the radio section from a pair of LR44 shirt button cells (in parallel) & they'd last for ages.
But'i'd need to do something about the impedance mis-match.

12th Nov 2018, 6:52 pm	#33
Neil Purling Nonode Join Date: Jul 2005 Location: Hull, East Yorkshire, UK. Posts: 2,087	Re: ZN414 and TA7642 radios The Future kit is a pair of BC458's for audio amplification wheras the 'Electronics Australia' circuit had only one. I am wondering what will serve as the power amp TDA2822M or a LM386? It depends on if you can change the gain by any means, as you can with the LM386. I certainly have a bunch of TDA2822m & there are some LM386 somewhere. I need to get my 'scope & sig gen out to do some testing. Perhaps I ought to make amends by amplifying one of these boards with hot bottles, rather than cold Silicon? I could power the radio section from a pair of LR44 shirt button cells (in parallel) & they'd last for ages. But'i'd need to do something about the impedance mis-match.