[Johnson] Ranger/Valiant with Xtals

[Sherrill Watkins]

Dear Fabio: Both of the transmitters you name were specifically designed to
operate on 20 meters by using 40 meter crystals. The following suggestions
may help. First try to determine if the crystal will oscillate on its
fundamental frequency. Try a different transmitter, etc. If still no luck, I
suggest to VERY CAREFULLY disassemble the FT-243 holder and clean the quartz
waffer and all of the contact surfaces with denatured alcohol using a clean
cotton swab such as a "Q-tip", etc. However, make sure your hands are washed
with a strong soap or detergent so as to keep fingerprints (oil) off of the
internal components. The internal parts should only be handeled while wearing
surgical (thin rubber) gloves. Check to determine if the crystal was
assembled correctly. The thin quartz wafer is sandwitched between two shiney,
small metal plates and that all the contact electrodes are in place and
connected to the terminals and that the spring is in place and putting proper
compression on the internal plates and wafer. Make sure there is no dirt,
oxidation or fingerprints on any of the internal components or the crystal
will not oscillate. If the quartz wafer is not square, make sure it is
orented uniformly with the two supporting pressure plates. Also, be sure to
reassemble everything in proper order including the rubber sealing gasket and
be careful NOT to overtighten the cover screws as they are very easy to
strip. Check the gasket for cracks that will allow moisture to enter and
cause the crystal to quit working. Use ONLY a jewelers Phillips type
screwdriver to disassemble and assemble to protect the screw head from
damage. I have had partial success in getting older FT-243 type crystals to
oscillate using this technique. If it still does not work, disassemble the
crystal and invert (flip over) the quartz wafer. Extreme caution must be
excertised at all times to avoid breaking the crystal wafer or damaging the
components. - 73- Sherrill W. k4own.     

-----Original Message-----
From: Fabio Liberatori [mailto:liber.fab at iol.it] 
Sent: Friday, December 03, 2004 3:24 PM
To: johnson at mailman.qth.net
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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