[hpsdr] Ideas for Munin Picked up at Dayton Hamvention

[Bob Mahrenholz]

Sent this out a few days ago and didn't get any comments. Thought 
maybe it did not go.
Bob


Hello Everyone,

I really enjoyed Dayton this year. After looking at all of the booths 
in the Exhibit Hall,
I scoured the outdoor flea market looking for a small diameter 
co-axial cable to use in
winding T1 for the output stage of Munin.

I found my answer at several of the places selling microwave 
components. It is RG-178,
(Belden 83265). It has an outside diameter of only 0.71 inches (1.803 
mm). The center
conductor is 30 AWG, insulation is Teflon, and the shield is silver 
plated copper braid.
Outer jacket is FEP. It's impedance is 50 ohms rather 25 but I do not 
think that this would
be a problem with the short length involved. Mouser's price is 
$364.62 for a 100' spool.
(See below)

It is a true co-axial cable rather than the "Control and 
Instrumentation Cable" that Belden
83705 is. (Incidentally the 83705 is listed as "obsolete" in the 
Belden Catalog.)

The RG-178 may be found in Belden's Catalog:

         https://edeskv2.belden.com/Products/#s=rg-178&r=0

Click on the cable number and then click on "Detail".

I purchased some 50' of the RG-178 at the Hamfest ($10  for a 25 foot 
roll). if someone
would like to try out a piece. I don't know what length it would take 
for a single board
but maybe some one of you knows.

At the TAPR presentation at Dayton by Steven Bible, N7HPR, the TAPR president,
I learned that one of the functions of TAPR is to assist in the 
development of new
boards. I propose that we get TAPR to purchase a 100 foot roll of 
Belden 83265 and
then sell it in appropriate lengths to those of us putting together a 
Munin board.

73,
Bob, K4QQK

p.s. Kjell, thanks for the info on the current measuring pins of J1.