Coax Connector Failure

[rwidman]

Folks, your VHF radio is a safety device. Something to allow you to call for help if you are stranded, injured, or sinking. If it fails because of shoddy workmanship, where are you now?

If there's any doubt as to your ability to install the radio and antenna system properly, it's time to call in a pro. Your life and the lives of your friends and loved ones could depend on it.

[colemj]

I agree, test the radios and antennas before cutting and making new connectors. Go up, pull off the antennas and bring them down and connect them with known, good pigtails for testing. If all is well, then you know the coax system is bad. Friends of ours recently bought a new VHF antenna that was DOA, so it does happen.

As for your life, and those of your loved ones, now being at risk because of your stupid test move, I think you also need to go back and re-rig your mast with 1" stays and shrouds and increase the chain plates by 150% because if they go down you lose your ability to call for help.

Alternately, you could install a HAM 2M modified to work on marine bands in addition to the marine VHF so that you had redundancy. You could, say, mount the Ham antenna on your spreader and the VHF on the masthead. And also have a handheld.

Now why didn't you think of that?

Mark

[Dockhead]

Originally Posted by rwidman

Not in my opinion and I am an experienced electronics technician. Only a hack would pierce insulated wire for testing. If his (or your) standards are lower than mine, fine, but he has now created another potential point of failure.

Well, obviously I am a hack -- the results speak for themselves

But as to the piercing of the jacket -- no one should get overexcited. Even a hack like me knows not to leave it like that. I will cut off that part and start over. The purpose of this destructive testing was to figure out whether I am systematically screwing up the connections or not.

As to calling in pros -- I am an Extra Class ham radio operator -- soldering my own connectors is a matter of principle -- I will keep climbing the mast until I get it right. Thanks to Nick, Bill, Dave, and others for actually helpful input.

[s/v Jedi]

Originally Posted by Dockhead

Well, obviously I am a hack -- the results speak for themselves

But as to the piercing of the jacket -- no one should get overexcited. Even a hack like me knows not to leave it like that. I will cut off that part and start over. The purpose of this destructive testing was to figure out whether I am systematically screwing up the connections or not.

As to calling in pros -- I am an Extra Class ham radio operator -- soldering my own connectors is a matter of principle -- I will keep climbing the mast until I get it right. Thanks to Nick, Bill, Dave, and others for actually helpful input.

That's the spirit Stiff upper lip

[rwidman]

Originally Posted by Dockhead

Well, obviously I am a hack -- the results speak for themselves

But as to the piercing of the jacket -- no one should get overexcited. Even a hack like me knows not to leave it like that. I will cut off that part and start over. The purpose of this destructive testing was to figure out whether I am systematically screwing up the connections or not.

As to calling in pros -- I am an Extra Class ham radio operator -- soldering my own connectors is a matter of principle -- I will keep climbing the mast until I get it right. Thanks to Nick, Bill, Dave, and others for actually helpful input.

Well, I hope you get everything straightened out soon.

[Wotname]

Originally Posted by Dockhead

Well, obviously I am a hack -- the results speak for themselves

But as to the piercing of the jacket -- no one should get overexcited. Even a hack like me knows not to leave it like that. I will cut off that part and start over. The purpose of this destructive testing was to figure out whether I am systematically screwing up the connections or not.

As to calling in pros -- I am an Extra Class ham radio operator -- soldering my own connectors is a matter of principle -- I will keep climbing the mast until I get it right. Thanks to Nick, Bill, Dave, and others for actually helpful input.

Here's hoping it is a really simple problem - the connector up the mast not fully screwed onto the antenna. One would think this would be very unlikely but I have seen it more than once -especially by people sort of new to the PL259 .
Shows up as the centre conductor being open circuit.

Next best thing would be a crook antenna (no, two crook antennas) .
Again unlikely but just possible.

If it was me going up the mast to sort out the problem, I would jury rig a resistor across the connector in the cabin (both of them actually). Any value that is handy and then go up the mast with ohm meter in hand and measure the resistance across the inner and outer of the upstairs connectors.

It should read the value of the jury rigged resistor plus a couple ohms for the cable.

This will tell you right away if you need to pull apart the mast connectors or not.

I reckon you will find them to be OK especially as you apparently didn't stuff up the lower connectors.

[Dockhead]

Originally Posted by rwidman

Well, I hope you get everything straightened out soon.

Thanks. Me too.

[Dockhead]

Originally Posted by Wotname

Here's hoping it is a really simple problem - the connector up the mast not fully screwed onto the antenna. One would think this would be very unlikely but I have seen it more than once -especially by people sort of new to the PL259 .
Shows up as the centre conductor being open circuit.

Next best thing would be a crook antenna (no, two crook antennas) .
Again unlikely but just possible.

If it was me going up the mast to sort out the problem, I would jury rig a resistor across the connector in the cabin (both of them actually). Any value that is handy and then go up the mast with ohm meter in hand and measure the resistance across the inner and outer of the upstairs connectors.

It should read the value of the jury rigged resistor plus a couple ohms for the cable.

This will tell you right away if you need to pull apart the mast connectors or not.

I reckon you will find them to be OK especially as you apparently didn't stuff up the lower connectors.

Thanks, that's a good plan. The spreader antenna is a screw on PL259/SO239. I guess it is conceivable that I didn't get it screwed down well. In any case, your test procedure is better than just whacking it off and doing it over again.

The masthead one will be more complicated. The antenna has a pigtail of RG8X -- no screw on connector. I put on an "N" type plug on that, and an "N" type jack on the RG213. I guess I can check the jack with a resistor, but not sure how to test the pigtail. The antenna is supposed to read shorted (internal dipole). I guess if it reads open at the pigtail, I know I have a problem. If it reads shorted, then EITHER there is a short in the plug, OR everything is OK there. But since I get an open circuit below, it means there must be an open connection in one of the connectors, or between them.

Unlikely to find a shorted plug on the pigtail AND a bad connection in the jack, I guess, but that is the only scenario for a shorted plug, since I get open circuit below.

[s/v Jedi]

Remember, a dummy load is just a 50 Ohm resistor. For the masthead galaxy, put the dummy load on at the navstation, go up and disconnect the antenna. Now measure resistance of the long cable, should be 50-55 ohms range. Next take the antenna off and bring it down.

If the antenna is supposed to read short (check that info again, many dipoles are open and I believe the one with silver contacts is different than the brass contacts?!) but doesn't then cut off the connector and test on the cable. You can also strip coax and jury rig to radio output (use clothes pin) to check if it's working or not (SWR meter)

Good luck.

[Wotname]

Originally Posted by Dockhead

Thanks, that's a good plan. The spreader antenna is a screw on PL259/SO239. I guess it is conceivable that I didn't get it screwed down well. In any case, your test procedure is better than just whacking it off and doing it over again.

Originally Posted by Dockhead

The masthead one will be more complicated. The antenna has a pigtail of RG8X -- no screw on connector. I put on an "N" type plug on that, and an "N" type jack on the RG213. ........

For the record, convention has the jack on the pigtail and the plug on the feeder (coax). Of course, the convention does not have to be followed and sometimes there is good reason not to.

Jedi is right, the easiest resistor to attach to the coax will be the 50 ohm "dummy" load. I figured you probably didn't have one but perhaps this is the time to get one. This and a SWR meter will be become your two best RF friends (plus a few inter-series connectors/adaptors - N type; UHF; BNC).

[rwidman]

If the cable reads "open" now, connecting the pin and shield together with a clip lead can be the dummy (zero ohms) resistor.

Two clip leads and any low value (100 ohms is a good start) resistor from Radio Shack would work.

A pair of clip leads is part of my tool box. Not the little bitty ones from Radio Shack, but 18 0r 16 gauge flexible wire (one red, one black) about 2' long with heavy insulated alligator clips. These are good for testing electrical and electronic connections.

[Quirocat]

Just installed my new vhf radio, went up the 16m mast, fot the first time-yikes, removed the old antenna, installed the new one with coax connector(please work,), spliced the new cable to the huuuge old one at the masthead and had wifey puuuullll. Nada. Back down the mast with my burly arms and puuulled, nada. Back up the mast with a string spliced to the old cable at the base, and pulll. Nada de nada. Any suggestions as to how to get the old cable out so i can finish the install?

[nigel1]

Originally Posted by Quirocat

Just installed my new vhf radio, went up the 16m mast, fot the first time-yikes, removed the old antenna, installed the new one with coax connector(please work,), spliced the new cable to the huuuge old one at the masthead and had wifey puuuullll. Nada. Back down the mast with my burly arms and puuulled, nada. Back up the mast with a string spliced to the old cable at the base, and pulll. Nada de nada. Any suggestions as to how to get the old cable out so i can finish the install?

Just been through the same process, and discovered that the helpful boat builders had cable tied the antenna cable to all the other cables going up the mast. Left me two options, drop all the cables, or leave the old cable in place and drop in the new antenna cable. Went for the latter.If the mast had been off I might have gone differently.
I capped off the old antenna, so at least it is there as a back up.
Use a means to stop the new cable slapping about inside the mast.

[Dockhead]

Originally Posted by rwidman

If the cable reads "open" now, connecting the pin and shield together with a clip lead can be the dummy (zero ohms) resistor.

Two clip leads and any low value (100 ohms is a good start) resistor from Radio Shack would work.

A pair of clip leads is part of my tool box. Not the little bitty ones from Radio Shack, but 18 0r 16 gauge flexible wire (one red, one black) about 2' long with heavy insulated alligator clips. These are good for testing electrical and electronic connections.

Thanks a lot. I bought resistors yesterday (a bag of them of various values; the only way they sell them at Maplin's, the UK's answer to Radio Shack). I have clip leads. I'm going up the mast tomorrow.

[Dockhead]

Originally Posted by s/v Jedi

Remember, a dummy load is just a 50 Ohm resistor. For the masthead galaxy, put the dummy load on at the navstation, go up and disconnect the antenna. Now measure resistance of the long cable, should be 50-55 ohms range. Next take the antenna off and bring it down.

If the antenna is supposed to read short (check that info again, many dipoles are open and I believe the one with silver contacts is different than the brass contacts?!) but doesn't then cut off the connector and test on the cable. You can also strip coax and jury rig to radio output (use clothes pin) to check if it's working or not (SWR meter)

Good luck.

There was a yellow tag on the Galaxy which said something like "Warning: Antenna Will Test Shorted", or something like that.

I wish I had bought an SWR meter. Now I won't have time to get one before going up tomorrow (today is a bank holiday in the UK).

I do have a 100 ohm resistor. I guess I'll solder on a couple of leads with alligator clips and do as you suggest. Sounds like a good plan.

Thanks, everyone, for the excellent advice. I feel pretty well equipped with information and am ready to tackle it again.