VHF Help, Fernandina Beach, FL.

[Vasco]

I have had problems with the range of my Horizon vhf for some time. It was fixed in Charleston a year or two ago(under warranty they did something with the antenna) and worked well until last season. I had all the connections checked in the Bahamas but no joy. The reception range is about a mile!! I'm looking for a technician in the Fernandina Beach area to fix this damn thing once and for all. I'll be down there in a month and would appreciate any recommendations. Thanks.

[Therapy]

It is almost always the antenna . Either a connection or cable connection within connector itself.

[Vasco]

I know it's the antenna. All the connectors were taken apart and re-soldered but still no joy. The antenna at the masthead was replaced. Still not worth a damn. It's all less than 4 years old. I'm thinking of replacing the cable with a heavier one and I want it done right, hence the search for a good technician.

[Therapy]

Ahhh.
I see.
But then I resoldered a new joint three times once ( I have training but am not a pro) before it worked.

[GordMay]

The performance of a marine VHF radio is limited by the quality (and height) of the antenna, and its installation.
A badly designed antenna, fitted with undersized cable and imperfect connections, will make the performance of even the best radio unacceptable.

Use quality coaxial cable and connectors: You can loose considerable signal strength with a poor cable and connections. The longer the cable, the more signal loss there will be. Cable lengths of 10 to 20 feet aren’t of much concern, but a sailboat using small diameter cable running 75 - 100 foot long can loose 80% of its signal strength.
High quality coax is a must, if you want to get the most out of your VHF radio installation.
Don’t use RG58.
Use RG8U* or RG-213*, and keep cable runs as short as possible.
Don't kink the cable, bends should not exceed 2.5 times the cable diameter.

* RG-213 is the same size as RG-8U but with completely waterproof and ultra-violet resistant insulation.

The cable terminal is the PL-259 plug; which should be soldered. Many manufacturers use pressure crimped connections but these are subject to corrosion and need special tools to create the connection.

See also:

Soldering PL-259 Coax Plugs
http://www.seedsolutions.com/gregord...SolderCoax.htm

Soldering PL-259 Connectors to RG-8X
http://ppraa.org/downloads/tech_talk/Pl259%20soldering%20Short%208x.pdf

Making Crimp-On coax connectors for RG-213
http://www.bcdxc.org/pl259_crimp_on_connectors.htm

[scallywag]

Rick,

Also check the connection at the top of thee mast. The way some of the connections are made water/moisture can seep into the connection. Your ground is another possibility. If you have a willing boat owner, take your VHF on hook it up to their antenna. Just some trouble shooting thoghs.

John

[Vasco]

I'm so sick of the damn thing I think I'm going to replace it with RG8U. Right now it's RG58. My main problem will be trying to run it from the mast (deck stepped) to the chart table. God knows where the wire runs. I know it's not the unit itself but before I go to the trouble of a whole new antenna and cable I would like it tested. When it did work the range was excellent. The mast is rigged so I'll have to try and feed the RG8U while aloft. Anyone know if it's easier to feed it up with a messenger or feed it down by taping it to the old cable?

[btrayfors]

Rick,

This isn't brain surgery. Troubleshooting a VHF installation is one of the easier things to do on a boat.

Here is one approach:

1. Make absolutely sure the rig is OK. Unplug the existing antenna cable. Connect another antenna (you should carry an emergency antenna anyway). It doesn't have to be mounted high up. Mounting on the stern pushpit will allow you to tell about reception (of, e.g., WX signals and other boats).

2. Replace the RG-58. It's unsuitable for VHF installations, anyway, because of its high loss at VHF frequencies. RG-8X would be more suitable, but RG-213 is better.

3. Replace all the connections: the PL-259 at the rig end of the coax, and whatever connection is made to the antenna atop the mast.

4. If the antenna appears at all damaged or questionable, replace it. It's a cheap fix, and the VHF is a very important piece of gear. Cheap insurance.

Any ham or electronics techie ought to be able to do this with ease. Also, while they're at it, check the power output of the VHF transmitter into a dummy load.

The hardest thing will likely be running the new coax all the way from the rig to the mast top. It may require some cabin surgery but, again, it's well worth it for peace of mind and for safety.

Good luck,

Bill
WA6CCA
S/V Born FRee

[scallywag]

Rick,
This is no different than a hom set on land. Trouble shoot, trouble shoot! You would be surprised what you learn. Living on/or near the ocean you have the same problems. It does not make a difference if you are on a sv. In the desert, where it is dry does make a difference. Patience, patience. I can not believe what I've learned over the past year from this forum.. The best of luck!

John

[bill good]

Rick, What one has to ask firstly is has the radio worked fine in the past.ie simplex contact over 25nms? if yes then find the fault. Before you pull out the cable consider if the cable is clamped or tied within the mast. I would not want to remove the mast from the boat!!. It is true there are losses in RG58 cable at the frequency involved but the heigth above the water will make up for a lot of this loss. hence the question how has it worked in the past? First step would to check the cable by sending someone up the mast & removing the antenna, shorting out the inner of the plug to the outer & the mutimeter should show low ohms at the set end. with out this short no reading. If all is ok then replace the antenna. inspect the connector & make sure the outside part is not moving free of the outer part of the cable. seal the connector & cable with 3m sealing tape. ok so the antenna may still be ok but it has only cost a few dollars & if it is ok then mount it on the back rail as an emerg VHF antenna!! very usefull additional to any boat. If the system is still not working you can take the radio to some two-way service person they can check it for manufacture specs. If old & faulty I would buy a new one. The idea of replacing the antenna is a fault in the antenna can/may damage the transmitter section of a VHF radio. the overall installation can be checked by using a SWR meter if you want to prove all is OK . note I've seen a lot of connectors not put on in the correct mannor & this can lead to transmitter failures.

Hope this helps Bill

[GordMay]

It’s generally much easier to feed & pull the cable up the mast.

[fairbank56]

If your reception range is only 1 mile, then it's not because you are using rg58. You need to do a continuity check as Bill Good stated. If it's good, then it's either the antenna or radio. RG58 is not the best choice but it will give much better performance than what you are currently experiencing. Ever hear of the V Tronix Heliflex Stub? I see these on racing sailboats often. Nothing but a "rubber duck" antenna and a lot of rg58. Low weight and less wind drag. Sure makes them go faster But they still work much better than your current setup.

Eric

[S/V Antares]

Saw Gordon West (Electronics writuse a 25 watt light bulb as a dummy load once. Cheap and easy test. Gets real bright if the output is good.

[Imnine]

This may help:
http://www.saltyjohn.co.uk/resources...stallation.pdf
And this:
http://www.saltyjohn.co.uk/resources...al%20cable.pdf

Most likely an antenna problem, but you could have damaged the radio by transmitting into a very high VSWR, as measured by a VSWR meter. This is a measure of the performance of the antenna system - cable, connectors and antenna. 1.2:1 is really good, 1.5:1 normal, any higher than 2:1 is bad. Many radios have a feature which prevent transmitting at above about 3:1 VSWR; they cut out transmission and flash 'antenna' on the display.

[rleslie]

When you install new connectors, make certain that the wire is free from corrosion. After installing new connectors with no increase in siganl, we found that corrosion had worked it's way down into the antenna wire. I had to cut off about two feet on wire atop the mast until I got to clean wire. Fortunately there was about five feet of extra wire in the run.