VHF Set up - bit of a personal nightmare

[rwakeham]

I have been battling with the VHF radio ever since I have had the Boat. It is an Icom IC-M601. At first I wondered if the set was faulty, so borrowed one and got no convincing response to or from a handheld on shore. I have tried with and without the command mike attached.

So I then wondered if the aerial was faulty... so replaced the aerial and still no positive radio check. I've checked the aerial connections and can see no breaks in connectivity or loose wires connecting the shield and inner/outer cores.

The aerial goes into a Raymarine AIS box - and I get contacts from boats quite a long way. The situation is not improved when I take out the AIS from the equation.

Also have two handhelds so within the Solent we have been ok - but now venturing further afield and need something more substantial. They work better than the fixed set at the moment.

So what other tests can I run ? Could the AIS box need something other than just plugging in the right cables (nothing in instructions) ? Could there be something wrong with the power supply (the ageing fridge causes a buzzing on the radio) ? Or do I now just borrow another set and test again ?

Thanks in advance for anyones help.

Richard.

 

[alahol2]

Make, borrow or buy an emergency aerial and check if the set is working. At least it would tell you which half of the system has a problem. Because I know nothing about them, and they must work on Ju-Ju, I would suspect the AIS box.

 

[oldsaltoz]

Borrow or hire an SWR meter, this will tell you the antennas output strength.

Or take to a tech and ask him to test it, at least you will know what area the problem is in.

 

[Salty John]

Not quite sure I understand what the problem is because there seems to be an AIS and a VHF radio involved.
If the AIS works OK with the aerial attached, that seems to suggest the aerial is OK.
What happens when you connect the aerial directly to the radio? Does the radio receive?

 

[pteron]

The AIS is receive only though. Does the radio fail to transmit or receive or both?

You can still get a reasonable signal from a mismatched attenna to receive but trying to transmit could be a real problem.

 

[rwakeham]

Mismatched aerial ?

Not sure I have come across this ? What is a mismatched aeriel. the Aerial I bought is a Glomax from the adjacent chandlery shop....

 

[WALLY]

Try connecting the antenna directly to the 603 and see if that works. If it does its a problem with the AIS250.

 

[Rowana]

First of all let me state that I'm no expert in the world of radio.

You say you have replaced the aerial, but have you replaced the cable between the aerial and the radio? If not, I would suggest that you beg, borrow or steal an emergency aerial as has already been suggested. Plug this directly into the radio and see what hapens.

The connections at the end of the cable may be ok, but water could have got in and corroded the cable half way along.


A couple of years ago, my VHF was working when I called the harbour for permission to leave. Mind you, I could just about shout at him directly. However, when I was out, I had difficulty hearing the weather forecast from HMC. Decided to change the aerial AND THE CABLE BOTH UP THE MAST AND INTERNALLY. The difference is nothing short of amazing. Bought the said aerial and cable from Salty John, poster of this parish. Thanks, John

 

[Bosun Higgs]

You are sure the handheld is working OK and that you are both using the same channel? Best do a radio check with the coastguard. SAnyway, a hopefully logical sequence to find the cause:-

1/ Are you hearing anything? Are you receiving the CG on 16 or 67? If you are not hearing anything then either there is no aerial connection at all or the set is faulty.

2/ If you are hearing other stations can you hear the handheld? If not then use another set to have a radio check with. Maybe the CG as above.

3/ Assuming you have reception but not transmission, much the most likely cause is the aerial but nevertheless, firts check that when you press the PTT button, the set indicates on its screen that it is transmitting. ICOM mikes arent the worlds most reliable.

4/If the set is trying to transmit but no one can hear, buy yourself an emergency VHF aerial. You should have onbe on board anyway. It will come complete, plug it in and try again. No transmission indicates a duff radio.

 

[rwakeham]

Now have emergency Aerial + borrowed fixed set

I did replace the cable between the aerial and set - so will try tomorrow evening before setting off for the weekend....

Thanks for all the advice, as always gratefully received.