Icom ic-m45 VHF radio not transmitting

[trobinson017]

I have an Icom ic-m45 VHF radio that is not transmitting. I can receive just fine but no transmit. When I key the mic the radio goes silent but no sound gets transmitted. Normal radio sound returns when I release the mic button. I have a marine antenna attached to the radio. I haven't been able to find any troubleshooting info on the internet. I sent an email to Icom support but haven't heard back yet.

Anybody have any advice on what I can test or check to figure out what's wrong and fix it?

Thanks!

Tim

 

[Boatist]

Re: Icom ic-m45 VHF radio not transmitting

It would help to know it this is a new installation or a unit that was working.
So much depends on what test equipment you have. If you has a standing wave bridge and a 50 ohm load I would put it in 1 watt with a load resistor on the output of the SWR meter. Get off the normal busy channel and key the mike and see what kind of power out you have. While there also check the standing wave ratio. It should be 1 to 1. If you have a hand held vhf also see if you can here it when you talk.

If you have power out but no modulation and can only here the carrier on the handheld then I would start checking the mike.

If it works in this mode and you can here it on a handheld then I would remove the load resistor and connect the antenna. Again with 1 watt on a non busy and non emergency channel check the standing wave ratio. Should be less than 1.5 to 1. Some radios will go into transmiter protect mode as soon as a 2 to 1 standing wave ratio but most closer to 3 to 1.

If you have a high standing wave ratio then check the antenna connection. Make sure the coax is not shorted or the dilelectric melted allowing it to short. Remove the Pl259 and reconnect after cutting off an inch.

good luck