Fixed VHF Issue

[LONG_KEELER]

Standard Horizon fixed VHF.

For some reason ,this sailing season , I cannot transmit and I get "low battery" message on the set and lots of noise when pressing the PTT. Incoming is fine.

I'm getting 12.7V showing on the multimeter for the ship's supply and the connections seem ok.

Any ideas ?
TIA

 

[iamtjc]

Measure the supply voltage when you are pressing transmit. That will give you a truer picture of the resistance in your power supply cabling.

 

[iantomlinson]

I have exactly the same going on with my standard horizon set. Low battery. 12.7v also. Inline fuse had bad connection but didn't cure it. Pulled mic apart and seems to work for a short time. I think the tx button on the mic could be packing in(lack of use). Watching with interest to see if there a common fault.

 

[LONG_KEELER]

I have exactly the same going on with my standard horizon set. Low battery. 12.7v also. Inline fuse had bad connection but didn't cure it. Pulled mic apart and seems to work for a short time. I think the tx button on the mic could be packing in(lack of use). Watching with interest to see if there a common fault.

T he "Troubleshooting Chart" says ...

"Hi Battery or Lo Battery" message is appeared when the power is turned on .

Confirm the power supply is between 10 volts and 17 volts DC. Nothing else unfortunately.

 

[st599]

Does the voltage drop when transmitting? Could there be a short in the antenna cable?

 

[mikegunn]

I had a similar problem with an Icom set. Returned the set to the OEM and they found everything in fine working order. I was directed to check every electrical connection to the set with particular emphasis on the fuse holder. That was the culprit! The fuse seemed firmly held but upon closer examination exhibited a significant amount of pitting corrosion. Synonymous with electrical arcing. Replaced the complete fuse holder eradicated the defect! icom explained that when the PTT button is pressed there is a current surge which can momentarily exceed 20A. If there is a dodgy connection anywhere that will be sufficient to induce arcing and thus pass a current. The surfaces damaged by arcing can suffer an increase in electrical resistance which may be enough to prevent further transmission of a signal. This is not always obvious because every time the PTT button is pressed the current surge may be enough to transmit a “clicking” noise but nothing else.

Mike

 

[LONG_KEELER]

Epilogue
I changed the fuse and holder which was a good thing to do do anyway, but this did not solve the problem of only being able to transmit on low power .

I ran a cable direct direct from the battery to the VHF set and I was able to transmit on both low and high power without any problems. I think either the cable run was too long or there may be some other issue that I have been unable to identify.

I have decided to stay with the direct wiring from the battery as I believe this is sometimes recommended as a safeguard .

Thanks for your assistance.

 

[mogmog2]

OP has solved his problem but I'll post this in case it helps anyone else. We had Rx ok but no Tx as well. This'll be why... Shield braid dissolved for ca 4" at the masthead. I'm surprised we got anything!

 

[iantomlinson]

Another easier fix. I've just found our wiring wasn't tinned so 2 core 2.5mm flex. Bit crap but the copper was black corroded. Replaced with proper stuff and all can hear my boring tones. Works on high power and all good now. bit basic for a sparky(sorry roy).

 

[jaminb]

Fixed mine yesterday and it feels such a relief as I have known it hasn't been working properly since we owned the boat.

Initially the aerial and hawk snapped off in lump conditions, this was replaced but a subsequent radio check revealed only a Weak but Readable. After some further experimenting I concluded receiving was acceptable but transmission was terrible. The inline fuse was cleaned of corrosion and this improved matters but still sub standard. So yesterday replaced the aerial wire and what a difference. I got a Loud and Clear from NCI Calshot and on low power from Hythe Marina from my berth in Shamrock (both several miles away and neither are in line of sight).

The cable was probably the original (17 years old). I did notice a green nick where it passed below deck and there was a thick layer of Nyogel on the aerial connection. I left the old cable in the mast so no chance of a thorough mogmog2 style autopsy.