[Johnson] Ranger/Valiant with Xtals

[Ed Worst]

Hello Fabio,

When you ordered the crystals, did you specifically state that they were for
the Ranger (or Valiant)?  Most crystals from that era were made to work on
the frequency specified with a "correlation capacitance" of - in the case of
the Ranger - 23pf.  This is the total capacitance that appears in parallel
with the crystal to form a high  Q resonant circuit.  I picked the values of
the capacitors (24pf and 200pf) off my schematic for the Ranger.  I no
longer have a Valiant, so I can't tell if it's the same or not.  If the
crystal wasn't fabricated with that correlation capacity, it could be off
frequency, or not even oscillate at all in that circuit.  You might be able
to return the crystals since everything (housing, blank, cover, springs) is
re-usable.

Does everything work OK on 20m when you're in the VFO position?

Will the crystals oscillate in the 40m position?

Hope this is of some help.

73,
ed - k9ew

----- Original Message -----
From: "Fabio Liberatori" <liber.fab at iol.it>
To: <johnson at mailman.qth.net>
Sent: Friday, December 03, 2004 14:23 PM
Subject: [Johnson] Ranger/Valiant with Xtals


>
>      Hello,
>               I recently bought two 7.143 MHz xtals for 14.286 MHz use
> in my Johnson transmitters, but no luck...
> Both do not oscillate, even if they are of new production (fitted
> into the old FT-243 case).
> I checked the correct position on the xtal socket, of course...
> I did any other attempt I was able to imagine...  Cleaning contacts,
> changing position, and so on...).
>
> Is my 7.143 xtal frequency choice  wrong for 20 meters use ?
> Do I need actually 14.286 MHz xtals ?
>
> Does anybody use Rangers and Valiants with xtals here on this reflector ?
>
>      Any suggestion will be very appreciated,
>
>                 Fabio, I0LBE
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