At 12:09 AM 3/4/97 -0700, Steve Hurst,KA7NOC wrote:
>Gang,
>
> Rx'ed my new xtal for the 38er, rig seems to work FB now !! :-)
>
> Tuning range on mine is now, 10.090 to 10.119 approx. Any ideas on how
>
> to bring her up to 10.100 ?? BTW, first station I HEARD was a ZL at
>approx.
Steve...I didn't see anybody answer the question of tuning range for
you, so I'll take a swipe at an answer. There are three ways to change
the low end frequency. 1) Use a smaller choke for L1, which will move
the whole thing up a bit, and reduce the frequency range some, due
to the overall inductance being reduced. 2) Increase the voltage on
D3 by adding a resistor in series with the bottom end of the tuning pot.
This raises the minimum voltage on the tuning diode, thus, lowering its
capacitance, and raises the lower band edge. This approach also reduces
the tuning range a bit, since some of the tuning capacitance range can
not be used. 3) Add a small trimmer capacitor (5-45pF) in series with
the diode end of the present inductor. This allows you to adjust the
lower frequency band edge, and preserves the maximum tuning range,
afforded by the inductor/tuning diode combination that your rig has.
This is the approach that I posted to the group a while back. Besides
working well, it lets you retune the rig to cover a different part of
the band, in case you hear someone toward the top end that you just have to
work, and can't quite get to the way you had it adjusted.
Maybe someone else has another suggestion also.
72....Jim
Jim Kortge, K8IQY (ex NU8N) | BMHA, NorCal, QRP-L
jokortge@tir.com | __o Cascade 17/40 SSB
Fenton, MI |_`\<, Mizuho 17/40 SSB
.... .. .. . . .. . (*)/(*) . . . . . ..
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