VicTrawler
Senior Member
- Joined
- Mar 19, 2015
- Messages
- 234
- Location
- Canada
- Vessel Name
- Halcyon I
- Vessel Make
- 1984 36' Universal Europa Sedan
This is a problem I've been dealing with for over two years now. I have a stop-gap solution but I'd really like to get to the bottom of it.
The boat came with an iCOM VHF radio with a command mic for the flybridge. When I first got the boat, everything worked fine. Both the main unit at the lower helm and the command mic worked perfectly.
After installing a solar panel and a SSB radio, we left port and that's where this problem started: I could no longer talk on the command mic without getting a ton of feedback (high-pitched tones), and the incoming transmissions were also hard to copy due to interference. Again, this was at the command mic only. The main VHF unit continued to work fine. The first stop-gap solution was to use a portable VHF on the fly bridge.
Once at a different port, I borrowed a compatible command mic from a second-hand marine store (for a small fee) and tried it out. Same problem, so the issue was obviously not the command mic.
Many months later, back at home, and after doing a bit of research online (with very few results), I determined that the main unit was actually at fault, as it wasn't allowing the command mic to work properly. I went out and bought a brand new iCOM VHF radio with a brand new command mic. THAT DIDN'T FIX THE PROBLEM! Once again, interference on the command mic, but no problem with the main unit.
So obviously a wiring issue, right? No problem, I'll re-wire the radio, and run a direct line to the battery, both supply and ground, with an in-line fuse. Keep the power supply as clean as possible. I've heard people say it's a good idea to still have power to the VHF with the battery switch off (in case of a fire) so you can still call for help. Makes sense. Win-win.
Except not. The re-wire didn't fix the problem.
Okay, back to the drawing board. What causes feedback on a mic? Usually it's when the mic is too close to the speaker. That doesn't really explain why I'd get interference when receiving transmissions, but it's worth a shot. So I connected an external speaker to the command mic instead of using the command mic's internal speaker. Lo-and-behold, problem solved! No more interference on transmission and no more interference when receiving.
So, that's the setup I'm currently running with (command mic with external speaker connected). I'd prefer to not require the external speaker, though.
Now, the question is, why would ALL THREE command mics that I've tried have that exact same issue? And if it's just a defect with iCOM command mics, why had no one on the internet reported the same issue?
I'm also trying to figure out if there could be any possible correlation between the solar panel and SSB installations and feedback on the command mic. For the record, I've tried disconnecting the solar panel and SSB completely, but that didn't solve the problem.
Any ideas?
The boat came with an iCOM VHF radio with a command mic for the flybridge. When I first got the boat, everything worked fine. Both the main unit at the lower helm and the command mic worked perfectly.
After installing a solar panel and a SSB radio, we left port and that's where this problem started: I could no longer talk on the command mic without getting a ton of feedback (high-pitched tones), and the incoming transmissions were also hard to copy due to interference. Again, this was at the command mic only. The main VHF unit continued to work fine. The first stop-gap solution was to use a portable VHF on the fly bridge.
Once at a different port, I borrowed a compatible command mic from a second-hand marine store (for a small fee) and tried it out. Same problem, so the issue was obviously not the command mic.
Many months later, back at home, and after doing a bit of research online (with very few results), I determined that the main unit was actually at fault, as it wasn't allowing the command mic to work properly. I went out and bought a brand new iCOM VHF radio with a brand new command mic. THAT DIDN'T FIX THE PROBLEM! Once again, interference on the command mic, but no problem with the main unit.
So obviously a wiring issue, right? No problem, I'll re-wire the radio, and run a direct line to the battery, both supply and ground, with an in-line fuse. Keep the power supply as clean as possible. I've heard people say it's a good idea to still have power to the VHF with the battery switch off (in case of a fire) so you can still call for help. Makes sense. Win-win.
Except not. The re-wire didn't fix the problem.
Okay, back to the drawing board. What causes feedback on a mic? Usually it's when the mic is too close to the speaker. That doesn't really explain why I'd get interference when receiving transmissions, but it's worth a shot. So I connected an external speaker to the command mic instead of using the command mic's internal speaker. Lo-and-behold, problem solved! No more interference on transmission and no more interference when receiving.
So, that's the setup I'm currently running with (command mic with external speaker connected). I'd prefer to not require the external speaker, though.
Now, the question is, why would ALL THREE command mics that I've tried have that exact same issue? And if it's just a defect with iCOM command mics, why had no one on the internet reported the same issue?
I'm also trying to figure out if there could be any possible correlation between the solar panel and SSB installations and feedback on the command mic. For the record, I've tried disconnecting the solar panel and SSB completely, but that didn't solve the problem.
Any ideas?
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