what is the best easy way

[stoots]

i have a bunch of antennas up and the coax is run threw the wall up nad over the roof . it would be a big pain to check the coax with one volt meter by pulling the coax ends close enough to test.

so leaving the coax where it is what is the cheaper way of running a test for breakage.. Coax is only used for recieving. thanks andrew stoots

 

[N_Jay]

i have a bunch of antennas up and the coax is run threw the wall up nad over the roof . it would be a big pain to check the coax with one volt meter by pulling the coax ends close enough to test.

so leaving the coax where it is what is the cheaper way of running a test for breakage.. Coax is only used for receiving. thanks andrew stoots

If the antenna is a DC short you can check for continuity between the center and ground, but a shorted cable will show the same.

You could put a known resistance on one end and measure the other.

They would tell you if it is open or shorted.

As long as you can get ti both ends you can easily check for open and shorted, but a cable can stiull be bad, and not be open or shorted.

 

[flyingwolf]

Disconnect Coax from ant and reciever. Apply voltage to one end of coax. Use a 9 volt and tape shuld be no prolem. Then goto the other end and measure for voltage at that end. If no breakage you should get voltage. No voltage there is a break. Have to dig further then.

 

[Thayne]

1. If you have a good ohmeter disconnect everything from both ends, then put the meter on the megohm scale and put it across one end of the coax and make sure the resistance is infinite, or almost so.

2. Then, put your ohmeter on the lowest scale and short the shield and center together on one end. (Make an adapter or use alligator clips) then
Read the resistance on the other end; it should be very low, 0-2 ohms depending on the length.

That will give you some pretty good info, but the coax still may not be good for high frequencies--but that is much harder to check.

best I can think of without a few more beers

 

[stoots]

more info on ( how to)

the coax is about 100 feet long and is used between 30mhz and 900 mhz. hope this will help in getting some good ideas. thanks andrew stoots

 

[N_Jay]

Re: more info on ( how to)

the coax is about 100 feet long and is used between 30mhz and 900 mhz. hope this will help in getting some good ideas. thanks andrew stoots

What type of coax, as many are "bad" by definition for 900 MHz at 100 feet!

 

[stoots]

more info

iam using 4 gray rg-8x. and 2 rg-6u coax. i dont think any are bad but want to make sure while weather is pretty and nice . andrew stoots

 

[John_M]

1. If you have a good ohmeter disconnect everything from both ends, then put the meter on the megohm scale and put it across one end of the coax and make sure the resistance is infinite, or almost so.

2. Then, put your ohmeter on the lowest scale and short the shield and center together on one end. (Make an adapter or use alligator clips) then
Read the resistance on the other end; it should be very low, 0-2 ohms depending on the length.

That will give you some pretty good info, but the coax still may not be good for high frequencies--but that is much harder to check.

best I can think of without a few more beers

I think that this is the easiest way to check for a bad (Open core) in the cable. (This is called a continuity check)

John.

 

[N_Jay]

Re: more info

iam using 4 gray rg-8x. and 2 rg-6u coax. i dont think any are bad but want to make sure while weather is pretty and nice . andrew stoots

Standard RG-8 is not very good at 800 MHz.
About 6 to 7 dB per 100 feet.