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Posted to sci.electronics.repair
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What Shielded wire to use for RF Test Leads
Jeff Liebermann wrote:
On Tue, 14 Mar 2017 11:39:39 -0500, wrote:
On Tue, 14 Mar 2017 09:19:52 -0700, Jeff Liebermann
wrote:
On Tue, 14 Mar 2017 00:45:43 -0500, wrote:
To make a shielded test lead for use on a RF device, such as a Signal
generator, Oscilloscope, or other, I have seen recommendations for TV
coax (RG59), CB/Ham antenna wire (RG58) and microphone cable. Which is
best?
(...)
So what is normally used?
I use RG-58c/u for 50 ohm test leads. The stranded center wire is
more flexible than the rather stiff RG-58a/u.
A/U is stranded center too. Rg58 is solid. Au cu difference seems to be
outer covering difference.
Greg
For 75 ohm RF, I use RG-6/u double shielded CATV cable with F
connectors on both ends. If I need to plug into test equipment, I
have female F to Male BNC adapater.
I've never heard of RG58 C/U.
http://www.ebay.com/sch/i.html?_nkw=rg-58c%2Fu
Also known as Belden 8262.
30ft for $36 including shipping and BNC connectors on the ends.
http://www.ebay.com/itm/191993013419
A little pricey but about what I would expect for a long test lead.
It's what's used on test leads and mobile antenna coax cables. Bend
the solid center conductor RG-58a/u a few times and it will break. Try
to get the type that has both foil and wire braid shields.
Where would someone buy a small amount of
it (Online)? Looking on Ebay, I see the A/U type. And that stuff is
mostly pre-made cables with either Pl-259 , or BNC connectors on it, OR
large rolls of the bulk wire. (25 ft is the shortest).
I could buy a 12ft with BNCs, and cut it in half to make two leads, but
that's the A/U type.
Kindly disclose how many feet of the stuff you want and I'll find it
for you. How many feet in a "large roll of bulk wire"? eBay is a
good place to get short lengths, but not high quality cables.
I'm thinking this is something that might need to be ordered from a
store that sells Ham Radio stuff, but do they sell small lengths and do
they ship it?
How many feet and I'll find you a source. It's quite common.
Also, you'll need mating BNC, UHF, whatever connectors. I avoid
solder type connectors because they like to fall apart. Crimp type
are stronger and more reliable. You'll need a crimper:
http://802.11junk.com/jeffl/antennas/Misc/slides/crimpers.html
100ft for $42 plus shipping:
http://www.l-com.com/coaxial-rg58c-u-bulk-coaxial-cable-stranded-center-conductor-50-ohm-cable
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