Re: a simple spur fix

AndyH
 

Not 'revising' but 'revisiting'.  soz

Two other bits.  Earlier in this thread Farhan reports the benefit of changing R26 and R46 to 220 Ω from 470 Ω.  This is for the stock amps, though - no idea if this is a necessary swap if the transistors are changed to BFR106.
https://groups.io/g/BITX20/message/61586

If you replace Q20/21/22, you want about 6 VDC at the collector of Q20.
https://groups.io/g/BITX20/message/61414

73, Andy


On Sat, Dec 8, 2018 at 04:23 AM, AndyH wrote:
No worries Nick - nothing wrong with circles.  hi hi  Revising the thread I see that you were part of it - sorry for the redundant link.

Here are Allison's suggestions for the two RF amps:
45mhz IF replace (Q20, Q21, Q22) with BFR106.  Change R23 to 18ohms.  Change R27 to 39 ohms.
12mhz IF amp change R43 to 18 ohma and put a .1uf in series with 680 ohms across R41.
https://groups.io/g/BITX20/message/51448

Cheers,
Andy

On Mon, Nov 12, 2018 at 08:36 PM, Nick VK4PP wrote:
Thanks Andy.
I have read that, but its all over the place a bit. Probably easy enough if you have a thorough working knowledge of electronics, But for a NOOB like me, I get some of what is said., but really a step by step
replace this with that. and maybe a commoners explanation of what is happening. Could be a good lesson on how these amps work.

My apologies if I seem to be going round in circles. but hey.

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