SH GX2150 RAM3 problem

[Ken13559]

Very glad I can see sog, cog, hdg and course of ships around me. However, I've this intermittent problem with the RAM3 extension mic at cockpit. Everything works except that when I transmit, receiving party only hear static. Thinking mic to be problem, I Intercom to cabin and have no problem. I test transmitting using mic on vhf unit and no problem. I connect the RAM3 mic directly to vhf base unit via its included extension cable and I still cannot send my voice msg. As mentioned Intercom between cockpit and cabin works. So anyone has this problem before? I'll be writing to Standard Horizon but would like to hear from anyone here if they experienced this and know of a fix. Thanks.

 

[Skipper]

Check the mode selection setup in the mic manual. I think there is a selection for radio type.

Also, did you attach the ferrite core?

 

[Ken13559]

Skipper, didn't know there's mic setup!! Ok will check. Only 1 ferrite core, fitted at near mic end of extension cable. End at vhf no ferrite core. Is that correct?

 

[Ken13559]

Found the Mode selection in manual. It doesn't seems to have anything to do with mic/voice. Anyway also saw instructions that says put mouth 1/2" - 1" from mic. That is very very close. When using Icom vhf, the mic is usually 2"-3" away. Hmmm, got to try again with mouth closer to mic for the GX2150.

 

[Skipper]

Found the Mode selection in manual. It doesn't seems to have anything to do with mic/voice. Anyway also saw instructions that says put mouth 1/2" - 1" from mic. That is very very close. When using Icom vhf, the mic is usually 2"-3" away. Hmmm, got to try again with mouth closer to mic for the GX2150.

That was the only compatibility issue I could think of from memory. So, it must be a connection or device issue. Make sure the external speaker wires on the mic cable are protected from shorting. Check all the mic connections IE: check for bent prongs, loose fittings, etc. I don't think the mouth distance would be the culprit, especially since it works in intercom mode.

You don't want to disconnect the mic when the radio is on. That could foul things.

Yes, only 1 ferrite.

 

[Ken13559]

Got a reply from SH. I'm asked to try wire the power directly to battery. Perhaps one suspect is voltage drop? I'll give that a try as well. No harm trying all that I can, short of opening up the sets.

 

[Skipper]

Got a reply from SH. I'm asked to try wire the power directly to battery. Perhaps one suspect is voltage drop? I'll give that a try as well. No harm trying all that I can, short of opening up the sets.

I thought about voltage drop, but discarded it since you said it worked from the main unit. Unless the small additional current needed to power the mic drops the voltage enough when x-mitting.

If it is a power issue, you want to check the ground too.

 

[Ken13559]

I thought about voltage drop, but discarded it since you said it worked from the main unit. Unless the small additional current needed to power the mic drops the voltage enough when x-mitting.

If it is a power issue, you want to check the ground too.

It seems unlikely to be voltage drop but I'll it anyway.

 

[Fred Villiard]

Try holding everything still with no stress on the cord, and see if the static is gone. If it is then you probally have a bad connection in the shield fo the mike cable.

Many years ago when I was in the two way service business, bad or broken shield in the mike cable was about 25% of the service repairs.

 

[alexco38]

Can you transmit clearly from the base unit?

You can hear intercom doesnt mean the antenna, coax, plugs are ok.

 

[Ken13559]

All my test points to mic sensitivity when on transmit. Even intercom sounds good at normal distance to mic. Mic at vhf base unit sound good at normal distance to mic. So i assume when Tx from extensions mic sensitivity is dial down to prevent wind noise. I tried talking into the mice with mouth very close to the mic hole, almost kissing it, and the other party receive me "loud and clear". So do I suppose that's the right way to use the extension mic?