Dear Stefan,
Yes. xtal 7,02 MHz will run stable, and xtal 6,5536 MHz must be pulled
down by 12,6 kHz to 6,5410 MHz. A coil in series to the crystal and the
tuning capacitor will do this, in its simpiest form by using a molded rf
choke.
Or 7,0200 MHz is adjusted for 7,0256 MHz, then 6,5536 Mhz will deliver a
difference frequency of 472 kHz. And when 6,5536 MHz is pulled down to
5.6466 MHz, the difference will be 479 kHz.
OK?
73 Ha-Jo, DJ1ZB
"Stefan Schäfer" <[email protected]> schrieb:
> Hello Ha-Jo,
>
> Can you pull one of the xtals to cover the whole band?
>
> 73, Stefan
>
> Am 05.07.2012 20:57, schrieb [email protected]:
> > Dear all,
> >
> > the only parts I have bought so far for MF (still beeing engaged in
> > other developments) are two crystals: 6,5536 MHz and 7,0200 MHz, to be
> > mixed with each other. The mixer is another bipolar transistor, and its
> > emitter current is being keyed. A final source follower after the
> > low-pass filter will deliver the output to 50 ohms.
> >
> > The same solution I have also used on LF.
> >
> > 73 Ha-Jo, DJ1ZB
> >
> >
> >
>
>
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