17 meters seems to me to be the most useful WARC band to add to a transceiver.
Here are the highlights of my Receive modification.
Omni D 17m receive modification. The basic mod is done on the 15 meter band
because the VFO tuned circuits can be padded down to 17m with trimmers and the
digital readout will read the 18 Mhz Frequency OK. Remove the 6.99 MHz
(15meter) mixer crystal. Put a correct size pin in the crystal holder to go to
a miniature relay which will switch between the 17m (4.00 MHz) crystal and the
15m crystal. I put the 2 crystals with there pins up, on the crystal block, one
each side of the bandswitch shaft. Soldered 60 pf trimmers with stiffer wire
to band switch wafers G and H that go to trimmers C11 and C12. The ground side
of the extra trimmers are grounded by a relay to activate 17m when the band
switch is set to 15 M I used 2 relays one for the crystals and one for the
trimmers. Drill out the rivet in the lower right rear ( facing the front of the
Omni) for a minature toggle switch, this is next to a 12 volts dc to operate
the relays. Adjust trimmers for noise signal and reduced
phase noise?and digital readout. when listening. Look at oscillator signal on
the VFO amp board if you have a scope. Pictures available.
Adding transmit capability was not yet sucessful so I am still addressing that
design.
Best regards,el Rob
K6BUE rabbueche@dslextreme.com
On May 23, 2007, at 10:31 AM, rob bueche wrote:
>
> > I receive 17m on my Omni D ser.B Thusly.
> > Set band to 20m.
> > Use SB-R, Tune from 14414 to 14434.
> > Tune resonator near 21m until noise increases and tune for signals.
> > I estimate the mixer is using the 5th harmonic of the PTO
> > which for the 17m band is at 27.068 minus 9 MHz is 18.068.
> > On 20m the PTO tunes from 5.0 to 5.5 MHz.
> > This worked on my 315 Rx and suppose it will work on any of the
> > similar
> > 9 MHz rigs, Triton, Argos.
> > Best regards, el Rob
> > KI6FZF Now K6BUE
> > rabbueche@dslextreme.com
> >
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