Receiving problem with ICOM VHF

[eliselar]

Any suggestions for correcting our muffled, poor receiving with VHF IC-M412 Marine Transceiver? We transmit 5/5 but poor reception even close to Marine coastal rescue volunteer station, less that a kilometre away and in clear sight with antenna able to transmit and receive clearly to boats in this area, not ours!

[colemj]

Buy a Standard Horizon unit.

That is not meant to be snarky. We have two friends with that radio and they have the same problem - OK transmit, but never hear anything. Both have bought new radios -guess which brand?

If it is under warranty, send it in. If you bought it at West Marine, take it back and get credit on a Standard Horizon.

Mark

[Reefmagnet]

I had the opposite problem. Could rx ok but no one could hear me clearly on tx. Turned out to be interference from a small inverter onboard. Assuming you've ruled out a faulty speaker, maybe try turning off some other electronics and see if that makes a difference?

[pbiJim]

You might want to borrow a working radio off of another boat & temporarily install it in your boat where your current radio is now installed. Try it & see if the problem is still there or not. It may be a radio problem. It may be an antenna problem. It may be a connection problem. Alternately, try your radio in another boat.

[Phil A]

Turning off other electronics on board is a good suggestion, as is trying another radio in your boat. My background is as a Two way radio technician. You could take it to a radio shop to check receiver sensitivity and audio recovery but those simple checks are a good place to start. Icom units are actually very good and usually test better than most of the Standard Horizon radios. Check out Practical Sailor's reviews and you will see that for yourself. Radio receivers that are dual conversion, i.e. having a high IF and low IF are more susceptible to being interfered with. That could be something simple such as a clock, GPS or anything that has an onboard oscillator. Don't throw out your Icom until you first try to eliminate some things. I hope that helps.

[Phil A]

I re-read your post and it occurred to me that the bad speaker is also a possibility, but only in that it would cause muffled audio. If that is the case, the audio would be muffled but the reception distance would not be affected.

[eliselar]

Originally Posted by Phil A

I re-read your post and it occurred to me that the bad speaker is also a possibility, but only in that it would cause muffled audio. If that is the case, the audio would be muffled but the reception distance would not be affected.

Very helpful. We'll follow your suggestions. Thanks.

[eliselar]

New to this site. Your response very helpful. Thanks.

[DeepFrz]

pbiJim's recommendations also have merit if that is possible for you. A bad cable might pass the higher transmit power more easily than the received signal. At the least try a short piece of coax connected to an antenna mounted on the rail to see if you have a cabling/antenna problem.

[Redcoat]

Check all your connections. If you have a splitter or joint in the cable. Check them. Both ends and the tips of the cables. I'm sure you already looked up the mast to be sure the antenna is there.

[noelex 77]

It is very likely the speaker or the audio amplifier stages. Most of these radios will take an external speaker and they are not very expensive especially for a non marine version.

[Andrew Thompson]

I am having this problem too on a 411. It is definitely not the speaker- easily tested by turning the squelch off. People hear me but I don't hear them, nor do I hear any of the usual banter on ch 16 or fishermen on the working channels. It started as an occasional problem about 4 months ago but now I hear nothing at all unless I turn the squelch almost off, in which case I get a lot of noise but can just hear traffic in the background sometimes. I have bought a new stubby aerial (always handy as a spare) and that makes no difference, so I'm assuming the fault is in the radio. Most disappointing as it has been good up to now, and is only 4 years old.

[Rubikoop]

I could transmit with my M422 but couldn't receive. I sent it off to to repair facility and got it fixed for the cost of one way shipping. For more info, read here. http://www.sailnet.com/forums/electr...air-cheap.html

[colemj]

Interesting - that is 5 people listed here with these lower-end Icoms with the same receive sensitivity issue.

Mark

[Rubikoop]

If you read the link I provided you noticed that ICOM received a bad batch of filters. Assuming that is true wouldn't you anticipate seeing problems during a production period when those filters were installed?