New VHF, but no sound except Ch16

[Rafiki]

I fitted new Lowrance Link 8 VHF today. I had it tuned to Ch 16 while working on the boat and could hear transmissions on that channel ( I didn't try any others). Late in the day I decided to do a test call to the Marina office , they could hear me perfectly but I couldn't hear their reply at all. Other symptoms were very little or almost no 'squelch' no matter how I adjusted the relevant control. When the Marina was trying to reply there was a faint click or change in the slight background noise. The set was on 'International' Any ideas what might be wrong.

It has a setting for internal speaker which I have set for On.

Next week I will carry out a further check by re-installing the one I've taken out.

Regards

 

[William_H]

I don't know much about this radio but it sounds like a trick of DSC system to silence all calls except those directed to you by MSN number. You perhaps need to disable the DSC controls in some manner. Read the book good luck olewill

 

[Neeves]

If you cannot find anything in the operations manual, which I always read as a last resort!, why not ring Navico and ask them? Its new, its in warranty, if its not in the manual - maybe it should be and they would want to know.

Here, in Oz, Navico bend over backwards to help.

Jonathan

 

[KAL]

Sounds very similar to a problem I had, which turned out to be a poor connection between the antenna and cable. It would be very worthwhile getting in a proper marine electronics engineer to test and repair for you, as they will have the equipment tovtrace the exact location of the fault.

 

[jwilson]

It's not set to US channels is it?
Many VHFs offer a choice of international channels, and some like 16 work identically everywhere and some only in places the radio is set to. Your (American) radio may think it's in the USA.

 

[alteredoutlook]

what channel were you using when making the call to the marina office on?
Have you tried calling other stations using different channels?

 

[VicS]

I fitted new Lowrance Link 8 VHF today.. The set was on 'International'

Regards

I think I would double check that the international channel set is selected , but if it says INT on the display it should be!

change it to another set and back again

It only affects a about a dozen or so channels but you dont say which channel your marina uses. It could be one of those. Ch 80 ???

Try listening on one of the single frequency intership channels

 

[Rafiki]

Thanks for everyone's suggestions. I called the Marina on Channel 80 and on M. I think I also tried another one they suggested, but all with the same result; they could hear me, but I couldn't hear the reply.

Next Sunday I will re-install the old one and check with that - which should prove whether it relates to the boat/aerial or the VHF itself. Mind you i did hear the old one working about three weeks ago when the boat was surveyed.

After that the next stage is to call Navico next week when I'm at the boat.

Regards

 

[boatingdave]

Firstly - with every new install you should VSWR the antenna, if you have a fault with the aerial then it is possible that you would still transmit (with a bad VSWR) but the receiver could be as deaf as a post. I think DSC is getting mixed up with CTCSS in some of the cause/effects that are being described. I'm assuming you've programmed the MMSI number? Some units have limited functionality until this is done. Unfortunately the described symptom could have several causes. It will be something very simple though.

 

[Rafiki]

Yes I programmed in the MMSSI number ( I believ this stays with the boat, so I used the same number as the VHF I removed).
What is meant by "Firstly - with every new install you should VSWR the antenna". What is VSWR? and what is "CTCSS" ?
Regards

 

[William_H]

Yes I programmed in the MMSSI number ( I believ this stays with the boat, so I used the same number as the VHF I removed).
What is meant by "Firstly - with every new install you should VSWR the antenna". What is VSWR? and what is "CTCSS" ?
Regards

VSWR is the voltage standing wave ratio. It uses a special meter which measures the power (voltage) of the transmitted signal going up the to the antenna then measures the signal that comes back. (reflected power). Now in a perfect antenna system all the power goes up to the antenna and out into the ether. If the antenna is bad or there is a break or short in the cable then all the power is reflected back to the transmitter. (which is why the transmitter an be damaged by a bad antenna but not so much in modern radios).
The VSWR (or SWR) meter is a little box that connects into the antenna cable. (usually at the transmitter end). A mediocre antenna gives a reading of something like 2:1 a good antenna 1:1 a really bad one is infinity to 1.
Now unfortunately it is not a simple as I describe because the cable soaks up power. So a bad connection at the antenna (the usual place) with say a 15 metre small diameter cable can lose something near 1/4 of the power going up and if this is reflected back another 1/4 is lost coming back so that reflected power is like half of what you sent up making you think the antenna is not so bad. The larger or low loss cable is much better.
Ebay has lots of (V)SWR meters listed. But beware many are not suitable for VHF 160mhz.
It is also possible to have a device which tests the cable by sending a very short pulse of electricity up the cable and observing on an osciloscope the pulse returning. The time taken can indicate how far the fault is along the cable. Good for telephone cables but not so much for a boat antenna cable.
Google has some ideas on how to make one. But this can be a bit tricky. You use a 52 ohm resistor to simulate a perfect antenna to test.
I still think your radio problem is in the soft ware set up however. good luck olewill

 

[ghostlymoron]

When you tested by calling the marina, how do you know they were receiving you if you couldn't hear their response?
Is your voltage alright. We once had our radio switching to ch16 unexpectedly which had us baffled. Turns out that it defaulted to that channel if the voltage is low.
I should try another radio (known to be good), this will eliminate aerial problems. Ensure supply voltage is at least 12.5. If all good, check all settings. Good luck.