[Boatanchors] outboard power supply for EF Johnson VFO 122

[Rob Atkinson]

It's not too hard to build a small supply for a 122 and this is a
great starter project for homebrewing.   It just needs to supply
around 100 ma (to run cool for long periods) 250 v. DC and 6.3 v. AC.
1 amp for the filaments is probably more than enough.  There are two
advantages:  You can power the VFO separately and leave it on to avoid
warm up drift when you operate.  I usually power mine up an hour
before I fire everything else up and I used to leave it on all weekend
when I was working before I retired.  You can't do that with a rig
that has a VFO built in or running of the rig's supply unless you like
having your DX100 sit there all on all day.   This also allows you to
run more than one rig with the 122 if you want to.  Powering the VFO
off the rig is fine...for AM.  On CW, it might get chirpy without
being on its own separate supply, but a lot depends on how it is
keyed.  CW chirp from the VFO can be avoided by letting it free-run on
CW.


73

Rob
K5UJ