Re: Valve frequency multipliers

legg <legg@nospam.magma.ca> wrote:

[...]

 
I'd be more selective of the crystal frequency. Two triplers might get
you there with a lot less grief.

I regret to say I think you are right   :-(

Quintuplers just don't seem to work in those circuits so I have placed
an order for a 16.656 Mc/s crystal, which will triple-triple to 149.904
Mc/s.  That will mean bringing the VFO down to a range of 3.904 to 5.904
Mc/s, which should be relatively easy. 

Revised block diagram at:
http://www.poppyrecords.co.uk/other/Transceiver/BlockDiag6a.gif

It will make image rejection in the second receiving mixer a little more
difficult  The transmitting mixer is intended to be balanced, so
rejecting 149.904 Mc/s instead of 150.000 Mc/s from the output will not
be any more difficult but I may require an extra tuned circuit in the
later part of the transmitting chain to reduce the level of image
frequency.

I just hope the new crystal will work in the same circuit as the old one
and I won't have all the hassle of redesigning it.


--
~ Liz Tuddenham ~
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