[TowerTalk] RG-6 Coax For Receive Loop?

[Grant Saviers]

Some comments-

RG6 is a good choice, I use it for bidirectional Beverages and for feeds 
to all Rx antennas.

For 80 and below VLF avoid the steel core RG6 since the Cu flash is 
designed for VHF/GHz skin depths.  So the solid Cu center wire is 
available and read the fine print on ebay.

The Thomas & Betts and other premium cable crimp connectors are a must 
with the appropriate prep and crimp tools.

For chassis F female connectors the Amphenol ones with 4 screws are 
highly advised.  The mount won't loosen and the pin grip is solid.  Not 
cheap but chasing noise or faults in phased Rx antennas has not been 
fun. Any knockoffs of these I've found are not well made.

Flooded cable is pretty messy to work with, I prefer burying in a conduit.

IIRC, W8JI made some measurements on shield effectiveness.  Quad shield 
is the standard and again known brands might be advisable.

The usual binocular core transformers which are easy and cheap to make 
are one way to kill CM.  RG316 micro TFE coax wound on smaller #31 
ferrite toroids can yield a compact cheap CM choke also.  Crimp BNC 
connectors are available. I use the large #31 clamp ons on the RG6 at 
each Rx antenna feedpoint if I haven't built in a transformer and/or 
RG213 choke.

Also, I am not a fan of using the RG6 as the means to deliver DC power 
if needed to the Rx elements, especially for home QTH antennas.  Any 
even very high R leakage paths for -xxDbm signals will cause noise, 
likely intermittent, (ask me a how I know) which is super hard to find.

Grant KZ1W

On 1/25/2023 20:10, Tony wrote:
> All:
> 
> I need coax for an amplified receive loop and I'm considering RG-6 as a 
> cheap alternative to the more expensive coax. I'm concerned with 
> common-mode noise and was wondering if quad-shield RG-6 would be better 
> than standard? Also wondering what type of choke to use i.e., material 
> turns etc. The loop is designed for VLF to HF but primary use will be 
> for 160 and 80.
> 
> Thanks, Tony
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