This is a very basic VXO for the NS-40 from the
Simple Simon VXO
or 2 Crystals for More Range
The range is approximately 2 to 3.5 khz around the crystal frequency.
By adjusting the trimmers on the back of the Polyvaricon, the range may
be increased to about 5.5 to 6 khz with 2 crystals. But, the tuning is very
sensitive at the high frequency end. The greatest range is usually when
the trimmers appear to be in the ‘ full moon ‘ position or plates fully open.
A brief video of the Simple Simon VXO
Click here for schematic pdf : Simple_Simon
A few Build Photos :
2 stacked SIP pins installed at each corner
Polyvaricon super glued to perf board
Polyvaricons are available from QRPme
also from QRPkits – Pacific Antenna
This particular one is from QRPkits .
SIP sockets are available from : Dan’s Small Parts
( use ctrl-F search for SIP )
The mini perfboard is from All Electronics .
SIP pins used as a socket
Bottom View
Polyvaricon – 2 Sections together for 220 pf
The center pin of the Polyvaricon is forward on the perf board and connects to the
crystal sockets. The two outward pins are rearward and are connected together.
Simple Simon with Sudden Stacker
This is a temporary solution that adds crystals to provide more range.
The excellent SAVXO from 4SQRP provides a more permanent solution.
Inexpensive crystals are available :
QRPme.com : http://www.qrpme.com/?p=parts
N4ESS : http://www.expandedspectrumsystems.com/prod4.html
More information later.
Thanks for viewing.
72, 73,
Dick, N4UN
N4UN Radio 
Comments on: "Simple Simon VXO" (2)
Hi Dick: Excellent, Dick! I guess it could be called a None Simpler VXO. Could you sketch a schematic and post it here? Thanks for sharing.
73, Fred
k6kub
Hello, Fred. Thanks for your nice comments. I have included
a brief schematic and a few more details. 73, Dick, N4UN