HELP - Unmarked RG8-type coax

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chief21

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I recently received a small spool of completely unmarked coaxial cable...

RG8-size and outward appearance
solid copper conductor
what appears to be a white foam dielectric, covered with silver foil
silver, high-coverage braid
black, unmarked jacket - filled with a very viscous, adhesive-type substance

Any thoughts on the specific type of cable???

Can I even be confident that this cable is 50 ohm impedance???

Thanks in advance for any information.

JOHN - AC4JK
 
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RFI-EMI-GUY

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I am guessing direct burial CATV cable by the description. You can calculate impedence by first measuring the ID of the shield and the OD of the center conductor. The formula and calculators are on line.
 

JamesO

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Agree, it sounds like an RG-11 75 Ohm "Flooded" or Direct Burial type of cable.

Many of the 75 Ohm larger size cables have a 14 AWG size center conductor while many of the 50 Ohm RG-8 or larger size cables have a 10 AWG size center conductor.

Not many of the 50 Ohm larger diameter cables are "flooded" or used for direct burial. Chances are someone picked this spool up on the side of the road where a CATV install was going on.

RG11 Direct Burial Cable - 1000 FT | ShowMeCables.com
 

chief21

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Thanks RFI and JamesO for your comments. Based on your input and what I've read elsewhere, it looks like I've got a bunch of TV cable here. It's also good to know the general rule of thumb for determining cable impedance. Thanks.

John
 

JamesO

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Many scanner users will actually install RG6 75 Ohm cable, the biggest problem is finding and installing the proper connectors if you plan to use it.

As mentioned it is probably a fairly low loss cable that should be fine for RX purposes.
 

trp2525

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Many scanner users will actually install RG6 75 Ohm cable, the biggest problem is finding and installing the proper connectors if you plan to use it...
I've been using RG6 Quad-Shield coax for my home scanner antenna installations for many years with good results. I use high-quality compression F-connectors on each end of the coax (same compression connectors used by the cable and satellite TV companies). I then use a high-quality F adapter on each end of the coax. Typically an F-to-PL-259 adapter or an F-to-N adapter is used on the antenna end and an F-to-BNC adapter is used on the radio/scanner end. BNC compression connectors for RG6/RG6 QS are also readily available and can be used on the radio/scanner end to avoid having to use an F-to-BNC adapter.

Bob Grove of Grove Enterprises used to advocate and advertise in his catalogs the use of economical RG6 coax with F connectors for scanner receiver use. Grove also used to stock a full array of high-quality F adapters for use with 75-ohm coax and those adapters would cover just about any connector combination needed.
 
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