Raymarine VHF Scan Problem

[swist]

The SCAN on my 2004 RayMarine VHF is less than helpful because it always stops on channel 28, where there seems to be a carrier present (but other than a hiss, nothing being transmitted). You have to hit SCAN again to keep going but then it stops on the next cycle at the same place.

I think ch 26-28 used to be the old ship-to-shore telephone channels, which became obsolete (I think) with the advent of the cell phone. What am I picking up?

 

[Boatist]

Re: Raymarine VHF Scan Problem

Channel 26 to 28 are normally ship to shore but still in use out here in the west.

Since your hearing nothing on that channel just delete it from the scan list and the scan should work normal. Another option would to turn the squelch up and see if that will cause it not to stop on that channel. Turning up the squelch can cause you to miss some weak signals.

Some Depth finder/Fish Finders will cause a radio to stop on one of the channels so try turning every thing off to make sure interference is not comeing from a source on your boat. Engine, depthfinders, GPS, Radio, blower, anything electrical.

 

[jurgenscraft]

Re: Raymarine VHF Scan Problem

For the scan to constantly stop on the same channel on every scan cycle, there must be some form of a signal, carrier,or tone modulated signal at that frequency, but if there is no sound other than reciever noise or blank carrier, then there must be a carrier just strong enough to stop the scan.the thing is to find out the source of this carrier, this may be the product of harmonics from any appratus using radio frequencies to function, I would be checking the following, depth sounders, fishfinders, on board computers, radar and so on, switch off all other elecrtical and electronic appratus and let the transceiver go through a few scan functions. There might also be a carrier from some local security system or what ever local to you, causing the scan to stop, What happens if you cruise down the river or lake to a new location? do you have the same problem?if so then the problem is local to your boat, I would remove the radio and take it to a technician who has the equipment to carry out the squelch threshold tests as well as set up the receiver, to the required specifications, the other option is to change the scan programme so that the channel in question is eliminated from the scan sequence, if you are sure that you would not be using it again.Have you tried any form of communication on channel 28, if so, were you able to hear the other station above what ever caused the scan to stop. KIND regards William Wright

 

[swist]

Re: Raymarine VHF Scan Problem

It's not something on the boat. It happens with everything else off including the engine.

I did find in the manual how you can program the scan to stop at only certain channels. A little awkward if you want to scan most of the channels, since there is no function to "scan everything but X, Y, or Z" But not a big deal. Thanks for the help.

 

[jurgenscraft]

Re: Raymarine VHF Scan Problem

If it is not something fron onboard the vessel then it must be something like a pager system or other commercial radio services in the area,( 10 to 15 Km radius ) I recently installed 5225 - FLT eliminator antenna on our vessel in order to eliminate a land mobile station causing interference to our radios while in harbour, and what a difference, no interference, all gone, these antennas have a built in filter which really works, for you guys in the states this should be very easy, go over to your Shakespeare dealer and have a look at the Galaxy XP range of antennas, I have my eyes on the 5018-FLT for my 24 foot Cabin cruiser,Best of luck,William Wright.