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VHF and antenna troubleshooting

Old 03-04-2012, 03:13 PM
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Default VHF and antenna troubleshooting

Someone here has got to be smarter than me

I'm trying to solve an ongoing issue with my VHF. I was suspect of it all last season but stupidly kept convincing myself it was working ok with some close distance radio checks. I have a new ICOM 504 VHF and Shakespeare Galaxy 5225 antenna within the past year.

In an effort to figure out where my problem is, I bought the Shakespeare VRT-3 tester. My radio test output pegs at 30 watts which I assume is a good thing and means the radio is ok. My Antenna VSWR test is about 25% into the red, so over 3 on the scale which indicates an issue. The radio RX test works, I get the tone but a lot of static which is maybe the root of my problem.

When I first installed the antenna, I wanted to save myself the trouble of snaking the wire through the radar arch so I cut the wire about a foot from the end of the antenna and used one of the Shakespeare solderless connectors that you crimp and screw the connnector on. That left me with one splice (new antenna/old antenna run to radio). If I could have easily snaked the wire with the connector, I would have.

I installed the new ICOM and just by chance noticed a lot of static when I start threading the ground connector onto the radio when listening to one of two weather channels. When I pulled it off so it didn't make contact, they were clear as day. That leads me to trying another connector at my splice (same kind) and replacing connector at radio with same results. Fast forward to this year...

Now that I have a test device to confirm my suspicions, I bite bullet and snake new (the piece I cut originally) wire from the antenna to the radio. I re-splice the connection (again) using the Shakespeare solderless union AND similar PL-259 at the radio. That gives me the results above using the test device. And dammit if the weather channels aren't clear as day with the threaded ground not attached to the radio, just the center pin pushed in.

I know these solderless connections get mixed reviews but could I being doing it wrong every time? Unfortunately, I'm running out of room... meaning not much wire left on the antenna end as it's gotten shorter with every attempt to repair. If I could make a connection inside the antenna, I could eliminate the splice but now way to elminate putting a new connector on the radio end.

What would you guys go next?

Old 03-04-2012, 03:22 PM
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Replace the antenna, don't cut the cable.
Old 03-04-2012, 06:05 PM
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I think you are going to have to replace the antenna. You have a male and female of them is probably no good.

Buy a Digital 529...tape the old coax to the new coax and use it as a fish to pull the new coax through. Screw on the connector and you are done.
Old 03-04-2012, 06:50 PM
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Originally Posted by BobCT View Post
... could I being doing it wrong every time?
That's a loaded question. Do what Crabpot Man said and solder the connector.
Old 03-04-2012, 07:09 PM
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And if your ART-3 "pegs at 30 watts", I am wondering if perhaps it was not calibrated properly before each part of the tests. Very few full-power 25 watt VHF radios will even actually ouput the stated 25 watts. Many are closer to 22 or so. never heard of an unmodifed marine VHF putting out close to 30 watts. So that might make the VSWR reading a bit suspect as well, though it does sound like there may be a connector problem .

I (non-pro) like the so-easyShakespeare gold-plated Centerpin PL-259's and have found them very reliable at maintaining good VSWR under 1:1.5 on my setup . But I take great care to wipe on a little dielectric grease to the cut end and sheath of the cable under the connector, then after inserting the centerpin, I carefully use wide slip joint pliers to sequentially crimp down opposing pairs of teeth of the inner centerpin connector a little bit at a time , so that all the teeth emebed with equal just-enough pressure and do not get deformed or squish the cable or short the grounded shield to the center conductor. It's easy to squeeze too hard the 1st time , then you need to re-cut & use new Centerpin.

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