On Tue, 26 Aug 2014 16:43:15 EDT, Steve Bonine wrote:

On 8/25/14, 10:54 PM, Jeff Liebermann wrote:

RG-213/u is good stuff. Double shielded and 95% coverage. However,
I've seen some RG-213 "style" coax, which is basically junk
counterfeit coax. If it's not from a known name brand manufactory, it
might become a problem.

I expect that this is a story most of you have heard in one form or
another and/or experienced.

Yep. I've seen plenty of counterfeit cables of all types. Usually
the cable leaves out something, such as insufficient shielding, or
lack of tin or silver plating. Sometimes they substitute copper
plated steel wire for solid copper. Others have outer jackets that
fall apart in the sun, or are full of holes.

It's an all too common problem:
http://www.belden.com/blog/datacenters/5-Things-You-Need-to-Know-About-Counterfeit-Cable-and-Connectivity.cfm
http://mpddigital.us/lmr-coaxial-cable-counterfeiting-rises/

In about 2011, UL instituted and anti-counterfeiting move that
required anything with a UL label to include a holographic label on
the box, and very specific labeling on the cable:
http://www.cablinginstall.com/articles/2011/02/counterfeit-cable-exposed.html
At the time, I went through my bulk cable inventory and discovered
that about 25% of the cable I had in stock was counterfeit, mostly
CAT5e and CAT6 cable.

I haven't seen any counterfeit RG-213/u but did run into a
malfunctional UHF duplexer that used RG-214/u. The previous owner had
built and installed new phasing lines in order to move it onto ham
frequencies. It would tune to frequency, but the isolation (i.e.
notch depth) was insufficient. I eventually took apart one of the
phasing lines and immediately noticed that the shielding was not
plated. RG-214/u is suppose to be silver plated. Although this was
well past the return date for an eBay purchase, I contacted the
seller, who was sufficiently horrified to send me a replacement set of
cables. That fixed the tuning problem.

So perhaps more important than the price is the source.

Generally true. However, I suspect that some vendors are unaware that
they're selling counterfeit products.

Caveat Emptor.
--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Some can work at 2Thz. I have a HENE gas laser that connects to the
handpiece via a PL-259.

--
Fool me once, shame, shame on you.
Fool me twice, fool me, won't get fooled again.

On Thu, 28 Aug 2014 10:08:12 EDT, Barry OGrady
wrote:

Some can work at 2Thz.

I suspect you might mean 2 GigaHz. The PL-259 is only rated to 300
MHz:
http://www.amphenolrf.com/products/uhf.asp

Tests of the PL-259/SO-239 connectors:
http://www.hamradio.me/subjects/connectors/

I would say that it's potentially a problem above about 300 MHz:
http://www.hamradio.me/wp-content/uploads/2011/10/UHFvsOtherConnectors.png

Mo
http://www.wa1mba.org/UHFconn.htm
http://en.wikipedia.org/wiki/UHF_connector

However, lousy performance above about 300 MHz doesn't have any effect
on HF operation from 2 to 30 MHz, so they're perfectly acceptable for
use with the OP's SDR radio.

I have a HENE gas laser that connects to the
handpiece via a PL-259.

Ummm... PL-259 connectors are only rated to 500 VDC:
http://www.amphenolrf.com/products/uhf.asp
How many volts (peak) are you using to drive your laser?
1400v is typical.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On Wed, 27 Aug 2014 13:06:05 EDT, just as I was about to take a herb,
Jeff Liebermann disturbed my reverie and wrote:

However, I suspect that some vendors are unaware that
they're selling counterfeit products.
If they charge enough some people might think they are good quality.
--
Cheers,

DrT

** You've never known happiness until you're married;
** but by then it is too late.