I'm surprised the LO filter can be peaked as low down in frequency as
5.5MHz.
The schematic I'm looking at has fixed 10pF capacitors across T1
secondary and primary which means they are about 7uH when peaked for the
10m LO of 19MHz.
To get T1 to tune down to 5.5MHz would then require an extra 110pF to be
switched in parallel; but those padding trimmers are only 5-60pF.
Steve G3TXQ
On 05/09/2016 22:24, Katz Ajamas wrote:
I think I know the problem.
I strongly suspect that upon closer examination, rick will find that his
515, in addition to having an inverted sideband on 80 is also tuning
backwards!
Someone has peaked the LO filter for the 80m band on the VFO(5-5.5mc)
frequency instead of the VFO mixed with crystal frequency of 12.5-14mc.
Easy to do on the 515.
73, -Bob ah7i/w4
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