Fixed VHF Poor transmission / reception

[Dave_Rolfe]

I have just installed a new ICOM M505 radio in my boat, replacing the old VHF set that was fitted.

On receive the sound quality is OK but every few seconds the sound breaks up so you only hear parts of the message. I have tried transmitting and again, it works intermittently. I tried calling the coastguard to report arrival in port after giving a passage plan earlier in the day and ended up using a handheld as the CG could not hear my transmission on the ICOM /forums/images/graemlins/confused.gifalthough the aerial was only about a mile away and in sight.

Can anyone make a suggestion as to the likely cause of the problem. Aerial is mast head with a join in the cable after passing through the deck by way of male / female sockets.

 

[TheBoatman]

It sounds like you have a bad/dry joint somewhere in the aerial?

Peter.

 

[cliff]

Or old coax, or a duff antenna.
Connect up your emergency antenna (you do have one, don't you?) and try again.
--------------------

"Artificial intelligence is no match for natural stupidity"
sailroom <span style="color:red">The place to auction your previously loved boatie bits</span>

 

[Dave_Rolfe]

Where the cable goes into the plug that goes into the back of the radio the thin central cable is soldered to the central pin of it but the woven part of the coaxial cable is not soldered anywhere. Is this right and if not where should it be soldered to ?

 

[bedouin]

The screen is not normally soldered but relies on good physical contact to maintain the electrical connection. However I would be surprised if a poor contact on the screen caused a problem with reception (at least of strong signals).

 

[Salty John]

It should look something like this:
http://www.saltyjohn.co.uk/resources/How%20to%20fit%20a%20PL259%20plug%20to%20coaxial%20cable.pdf

Sounds like you have a bad connection somewhere in the antenna system.

 

[Benbow]

[ QUOTE ]
However I would be surprised if a poor contact on the screen caused a problem with reception (at least of strong signals).

[/ QUOTE ]

I wouldn't.

The best advice above is to try your emergency antenna and take it from there.

 

[ColinHuggins]

Installing a new VHF recently I involved my friendly Sparks to connect the gps. I heard him mumble something about a poor aerial connection, and the difference now is amazing - yesterday I called up my local Emsworth club to find I was speaking to a member in Cowes, 15 miles away and hardly line-of-sight, while my aerial isn't very high (low MoBo see.)

So it's well worth getting it right.