EMRFD Message Archive 2035

Message Date From Subject
2035 2008-09-09 09:55:51 Chris Craig Feed thru caps use on VFO
I need some advice on sealing up my VFO for a Willamette 20, a DC

It's my first time build using Manhattan construction. I just plan on
building a box using copper clad boards. I want to remote mount the
pots that control the main tuning and RIT. I bought some 1500pf feed
thru's from Dan's. So, is it as simple as passing the wires thru the
caps to the externally mounted pots? One wire is ground as these are
just voltage divider pots. Should I 'feed thru' the ground also? I
read somewhere (Chap. 8?) that running ground connections are a good
idea. Or maybe I dreamed it. My original plan was to use a shielded
cable (small audio type) but I think feed thru's are better. Just
trying to keep the RF (+12dBm) inside the box.

Most of the ones I see, have the pots mounted in the VFO with the
shafts extending out, as on page 8.10. I would like to avoid that and
I would like the flexibility of mounting them where I want.

Thanks for your support,

Chris, KE6GS / XE3
2041 2008-09-09 15:11:32 kerrypwr Re: Feed thru caps use on VFO
It depends on how far you want to go at the start.

One approach would be try it & see; if you have problems, apply remedies.

My approach with most things is to try to get it right in the
design/construction phase. I expect things to work at first switch-on
and I dislike trouble-shooting.

If I were doing what you propose I would enclose the pots in small PCB
housings with feedthroughs and possibly RFCs in the shielded DC lines.

But I have a habit of over-designing!!