VHF Troubeshooting

[Mike S]

I have a Uniden VHF with DSC. It is hooked to my GPS and indicates the GPS signal is being received. I have a Shakepeare metal antenna.

I cannot send receive for some reason, but don't know where to start - radio, cable, or antenna. Any help?

Thanks,

M

 

[windknotnc]

Can you pick up weather? Does the "TX" light up when the key is depressed? Are you sure your antenna is good? Is it a new antenna with a good plug? Give us more details on these items and maybe we can diagnose.

 

[Mike S]

Radio lights up, appears to be working, so I suspect either antenna cable or antenna. I cannot send or receive. I am looking for some orderly troubleshooting steps to ID the exact problem so I can FIX IT. Frustrating.

Thanks for any help.

 

[DaleH]

I am looking for some orderly troubleshooting steps to ID the exact problem so I can FIX IT.

1) You cannot without a SWR meter made for VHF sets.

2) DO NOT turn it on anymore, as if it is the antenna you could be ruining the set.

3) I have one of the special meters referred too, but it is already out on loan with someone else right now.

You could borrow it, but I'd need you to cover postage/shipping both ways, follow the enclosed instructions VERBATIM, and enclose a $100 check that will be returned or ripped up once I receive the meter back and confirm a post-use check out as fully functional. It diagnoses the set itself, the antenna itself, and then the integration of the two.

That said, I'd bet $$ it is your antenna. See if you can borrow one ...

 

[evetsmd]

Just a couple of thoughts......most VHF antennas are a sleeve dipole type......put an ohm meter across the center pin and ground of the antenna.....it should be open, not showing a short.
If u read a short it still may not be the antenna......could be just the coax or connectors that's shorted......do you have a connector on both ends of the coax?

Antenna connectors are PL259 type, some are solder, some are crimped....if the connector was removed when installing the antenna to route the coax, the solder on types are more difficult to install and replace....gently hold the coax and try and twist the connector body, if it rotates freely, good chance the connector installation has failed.

See if the radio receives.......remove the existing antenna, using just about any kind of wire......carefully insert(don't force anything) into the center female portion of the radios antenna connector. Give a listen on several channels......if the receive part of the radio is OK, you should here communications....DO NOT TRANSMIT WITH THIS TYPE OF HOMEMADE ANTENNA.......

Most newer vhf radio transmitters will shut down if they see a bad load (antenna)......safety feature to protect the xmtr.

My guess would be it's the connectors or coax........the only way to test the transmitter is with a 50 ohm dummy load and swr meter......kind of what Dale is suggesting.....or as Dale has also suggested, borrow an antenna and give it a try.

Do you have any Ham Radio or CB Radio friends, they would more than likely have these tools.....

Hope this helps a little!

Steve

 

[Brent]

Here is a video

http://www.shakespeare-antennas.com/med ... lt.asp?p=8

Manual
http://www.shakespeare-marine.com/pdf/art-3.pdf

 

[Mike S]

You guys are great. Now I have a place to start. I could not find anything written to help me begin looking for a cause.

Thanks again.