I was curious if any of the community up here was good with troubleshooting a VHF. I have 2 on the boat with 2 antennas. We went fishing the other day and I am receiving but not transmitting. Or not transmitting much of a distance anyway. I can talk to another boat if he’s within 100 yards or so. I can not get the automated Sea Tow response from the harbor, or a radio check on 16. I can not solder, and would be glad to pay someone for their time.
Thanks, Jason.
I’m no expert on VHF radios, but I would guess an issue with your battery and/or battery connection, since both are acting the same. It takes ALOT more power to transmit than receive.
I would check out the connections first. Then, put a voltmeter on the battery. It will probably read about 12v, but that doesn’t mean much when there is no load. Leave it connected while holding down the transmit button on the radio with it set to Hi Power (25W). If the voltage at the battery drops drastically and stays there, you probably have a bad/weak battery.
Always check the connections first as that’s the easiest thing to check. I pulled this off another forum; its great information:
A VHF Marine Band radio that can receive transmissions from NOAA weather radio stations that are a long distance away should be able to receive regular VHF Marine Band transmissions from nearby boats. There is no reasonable explanation why an antenna could permit reception of NOAA broadcasts but not permit reception of local ship transmissions. The antenna, whatever its condition, would affect both in the same way. The antenna is not likely to perform differently at the NOAA radio frequency than it does at the VHF Marine Band, as the two are close together in frequency.
On transmit, an antenna problem can have a severe reduction in range of transmission. If an antenna has become damaged, the transmitter often contains a sense circuit which reduces power to prevent the transmitter from being damaged. The transmitter then transmits at much lower power into a broken antenna. This combination results in a reduction of transmitter range to a very short distance, perhaps less than a mile.
One element of the installation which is still in common–besides the antenna–is the power circuit. If the power circuit is faulty it cannot maintain proper voltage on transmit, and this will drastically reduce the power.
There are three elements in this system:
–power circuit
–radio
–antenna
You have only changed one element. Check the power. Try a different antenna.
In order to make useful radio checks with another station, you need the other station to have a reliable radio and a reliable radio operator. Your test transmission may have been fine and the other station had a problem with his receiver. To prevent this sort of confusion, use three stations in any radio check. A third station can help reduce ambiguity regarding which station has a problem.
Antenna Testing
You can make a very rudimentary test of the antenna by measuring its DC resistance. You need to know wha