Rx no Tx on VHF

[Leighb]

Another problem with new boat.
VHF Radio appears to receive OK, but no transmission.
What is likely cause?
Aerial, or internal to set?
The Tx light comes on when the PTT switch is depressed on the handset.
How to make diagnosis?

 

[Billjratt]

Try your emergency aerial first (or borrow one). If that's not an option, check the ammeter (measure the current drawn) when you press PTT - it should be 5 amps if Xmitting at 25 watts. Set radio to 1 watt and see if your neighbour can hear anything. The radio will shut down to save its'self from destruction if transmitting high power into a bad aerial, but will try to xmit low power. Check connector at base of mast for ANY corrosion and blackness of copper wire. Replace (not clean) any bad bits - VHF could be your best friend in the future.

 

[dickh]

I had exactly the same problem a few weeks ago and found that the aerial wire in the deck socket was corroded. Cut about 2" and refitted, cleaning up all the connections and now receive and transmit very well! Before I was only receiving Thames Coastguard occasionally.

 

[machurley22]

I see you have another thread about your charge light not going out. There may be some connection. /forums/images/graemlins/smile.gif

If your battery is not being charged properly there will came a point, as the voltage drops, where your VHF is unable to transmit although reception is still fine.

 

[Leighb]

Thanks all,
Will check the aerial connections tomorrow.
I don't think it is low voltage, as both batteries are brand new and fully charged before putting in boat. Have only started engine once and run VHF and echosounder for about an hour!
I do have an emergency aerial, so will try that out as well.

 

[CPD]

Minor point, but having a handheld to check main VHF operation is useful.