Re: OT: High Frequency coax?? Copper tubing??


I'm not at all familiar with this type of coax. What is the core material, and what makes it so good at the higher frequencies?

----- Original Message -----
From: "Dennis Tillman W7PF" <@Dennis_Tillman_W7PF>
To: <>
Sent: Sunday, November 03, 2019 1:46 PM
Subject: Re: [TekScopes] OT: High Frequency coax?? Copper tubing??

These two sizes of Semi-Rigid Copper Coax cable are very common:
RG-402 which is 3.58mm OD (0.141" OD)
RG-405 which is 2.20mm OD (0.0865" OD)

Working with it is very different compared to typical coax we are all used to. Tools to cut it properly and to bend it properly are expensive. Using common tools to cut it like a pipe cutter, and to bend it like an inexpensive bending jig, will almost certainly affect the high frequency performance of whatever you make.

Dennis Tillman W7PF

-----Original Message-----
From: Reginald Beardsley
Sent: Sunday, November 03, 2019 9:01 AM

Here's a representative link for the information you're looking for:

There's lots more. This was simply the first one google tossed up. It is great stuff provided you don't want to bend it more than once. Though rebending used cables is OK. The solder filled braid "RG402" has become my standard cable for anything above 1 GHz. I've made a couple of H field probes from a used piece of high grade stuff.

Connector quality on Chinese ebay jumpers is rather variable. I've been documenting my efforts in this thread:

I will be supplementing the TDR results with 8753B/85046A testing soon now that I have an APC-7 cal kit and adapters.
Have Fun!

Dennis Tillman W7PF
TekScopes Moderator

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