[ARC5] Capacitor Types

[Kenneth G. Gordon]

On 24 Jan 2015 at 11:03, Mark K3MSB wrote:

> 
> When replacing capacitors I thought it was recommended to use mica for the
> RF sections, and for all sections downstream of the IF (towards the audio)
> to use orange drops.

IMHO, mica for RF, but I hate orange-drops: they are too big, too ugly, and 
don't really fit well. There are better, far less "intrusive", capacitors available 
now. Disc ceramics are a much better choice in most places you would have 
used orange-drops in earlier days. Metal film jobs are also less ugly and 
work better.

Orange drops were useful when they first came out, but there are better 
choices now.

> Is it advisible to use mica or orange drop type caps for IF stages?

It depends on WHERE in the IF stages you want to use caps: the only real 
difference between IF and "RF" is the frequency. Use caps, other than mica, 
for cathode or screen bypass, and mica to couple an "RF" signal from stage 
to stage.

>  I'm
> working on an HQ-129-X and I was planning on using mica for the RF and 1st
> IF stages and my supply of orange drops for all the other stages.

Yes.

> I've typically just used orange drops for everything (as I have them "in
> stock"), but I'm wondering if it's better to go mica for the RF side of the
> house.

Yes, it is. At least in my opinion and experience...

Ken W7EKB