On 7/3/2011 3:30 PM, Edmund H. Ramm wrote:
snip Instead you might have posted
something interesting about boatanchors, like what could be the reason
for my Ranger VFO's frequency jumps on 7MHz and higher. The jumps persisted
even after I replaced all components, only now I had frequency drift, too,
which was to be expected. So I re-installed the original parts.

Hi,

You might try improving the grounding of the final plate tune capacitor,
to elliminate an rf feedback path, as pointed out by Tom Rauch, W8JI:

http://www.w8ji.com/johnson_vfo_chirp_jump.htm

Tom is the designer of various amps in the Ameritron line.

73,
Ed Knobloch

On 7/5/2011 7:04 PM, Edmund H. Ramm wrote:
snip
Hi Ed, nice to read from you again. I did this long since. Looks like
our namesake VE3CUI had about the same idea. Any sources for 1/4" phenolic
(or PTFE) shafts? That's what I'd like to try in addition.

But the jumps I mentioned further up are irreglular, which IMO
doesn't indicate a stray feedback path.


Hi, Eddi

Nice to hear from you, as well.

Here's a source for 1/4" diameter PTFE rods:

http://www.smallparts.com/small-part...qid=1309915938

73,
Ed Knobloch