On 8/7/2016 12:01 PM, Jim Brown wrote:
Not long after moving here in 2006, I found a partial
spool of a Pasternak RG6 in a surplus outlet. It has a copper center and
TWO rather dense copper braid shields.
I'll call your two braided shields and raise you two more shields:
http://www.showmecables.com/product/belden-1617a-rg11-coax-cable-quad-shield-per-ft.aspx
That's two braided and two shielded. However, both the braids and
the shields are aluminum, not copper.
I picked Pasternak for my example of copper shielded RG11 cable because
they had a simple web page and an obvious rendering of the copper braid.
Unless I need something exotic or unusual, I can't afford their prices.
Another limitation of CATV coax is that only CATV crimp connectors work,
The assumption is that if it's 75 ohms, it must be for CATV.
That's not the case as there are data cables that are 75 ohms
and which usually use crimp on 75 ohm BNC connectors. DS3/T3
data is one example:
https://en.wikipedia.org/wiki/Digital_Signal_3
http://www.connectworld.net/syscon/t3-ds3.html
https://www.google.com/search?q=ds3+t3+connectors&tbm=isch
and the only ones that are widely available to fit it are F-connectors
or BNCs.
There are also compression type RCA phono plugs, which are widely
used for home theater interconnects:
https://www.google.com/search?tbm=isch&q=rca+compression+connector
Most are for RG6 size coax cable, but a few are RG59, which is not
interchangeable.
I find the Snap'N Seal branded connectors to be quite good, but
> they 1) must physically match the cable dimensions;
Agreed. I use the red T&B/Belden SNS1P6U connectors, which fit
the largest variety of cable types. About $0.50/ea
2) stripping and
crimp tools that match the coax must be used for a good connection;
Here's parts of my collection:
http://802.11junk.com/jeffl/antennas/Misc/slides/CATV-tools.html
The one's with the orange handles come with dies for BNC, F, and
phono and cost about $20 on eBay. It's fairly universal, but some
of the others will only work with a specific manufacturers F connectors.
More crimpers:
http://802.11junk.com/jeffl/antennas/Misc/slides/crimpers.html
I think my collection has roughly doubled in size since the pictures
were taken.
3) F-connectors require adapters to connect to our antennas, and most
F-connector adapters I've seen are of highly questionable quality.
I guess I should have mentioned adapters. Most are RG6 size coax as
F to whatever. Many are junk and will fall apart if flexed.
However, they usually fail first due to water incursion. The flexible
joint between the connectors is not rigid and will rotate on most
adapters. This causes my Teflon and electrical tape layered connector
embalming method to fail as the Teflon tears and the tape unravels
when the adapter is rotated. I've tried securing the assembly with
ty-wraps onto tower legs and masts, but the adapters still manage to
somehow rotate. I will confess to owning a few F to whatever adapters,
but I no longer use them for permanent antenna installation.
--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
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