VHF Problem

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SimonP85

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I posted a couple of weeks ago about a problem I was having with my Silva S15 VHF - here.

I have been down today and checked the fuse as suggested (which was absolutely fine) and also attached the emergency aerial and tried but again couldn't hear myself on the handheld while speaking on the fixed set (as with the normal aerial). I can however still hear the handheld 'clicking' and the display shows a good receiving signal strength so I wonder if it a faulty microphone as suggested? Any thoughts would be much appreciated.
 
Looks like either a bad connection in the mike plug or in the mike itself.

If it is one of those 4 or five pin mike plugs see if you can slightly squeeze the round metal sockets in the plug with a pointy compass or something to make them give firmer contact on the pins. If you can find a friendly ham he might help in exchange for a beer or something /forums/images/graemlins/smile.gif

There is a micro switch and insert in the mike and either could be faulty.
 
I have seen at least one microphone where the very fine wires of the coil connection in the microphone insert itself were corroded through. If you open up the mic you(may) will find the round lump 3to 4cms across like a tiny loud speaker with 2 wires going to it. A connection to the wires should show about 200 ohms resistance. If it is the largish lump type then if it has a very high resistance that is the problem. If it is just a tiny button less than 1cm in diameter that is the mic then that type will have high resistance.
In any case you problem is probably in the microphone handset itself. So borrow another get it fixed or more likely cheapest is a new radio.

good luck olewill
 
[ QUOTE ]
I posted a couple of weeks ago about a problem I was having with my Silva S15 VHF - here.

[/ QUOTE ]

I would still suggest investing £40 in a VSWR meter and patch lead. AFAIK, this will either rule in, or rule out, connection issues.
 
I had one of these sets a couple of years ago, lasted two seasons during which I had several problems requiring return to manufacturer. Finally, the volume button on the hand set failed. I now have a nice reliable ICOM with a command mike in the cockpit. Miss the NAVTEX though.
Interesting that they are no longer made.
 
When the PTT button on the microphone is pressed does the "TX" indication appear in the bottom RH corner of the display? If not then the unit is not switching into transmit mode. possibly due to a fault in the microphone unit or connecting lead. Either way its not really DIY repair unless you are very happy to delve into bits of complex electronics.

Clearly a lot of suggestions coming from people who dont know this radio and who have not bothered to find an instruction manual on line. I suggest to those people that they take the time to look at the INSTRUCTION MANUAL
 
The S15 is still made but now branded Nexus NX2500. My old S15 still soldiers on and would happily replace it with a 2500 when the time comes.
 
I suppose the handheld is receiving o'k. and the spare aerial is o.k.?
Try a test on both to a neighbouring boat .... a good way to get to know others. Lend the neighbour your spare aerial too?
Try on a boat to boat working channel, 08 would be fine so you are not clogging up 16.
Take the set out and get it tested by someone in the electronics/radio world
... your info doesn't say where you are?
 
Richard is spot on, a VSWR meter is the way to go. Mine is in the AE CCT all the time monitoring not only the TX O/P power but the AE and cable too.

All this for less than £40.00.
 
I am uneasy about trying to talk and listen to yourself at the same time. At such short range you could get bad distortion on the handheld, you have different paths for hearing your voice, the handheld could even shut reception through overload. Much better to test with a radio check, preferably with a firend on another boat.

Assuming your main set still isnt transmitting. You have tried two different aerials so it would be very bad luck but not impossible if both were faulty. The key thing is to try and find out if the set is even trying to transmit when you press the PTT button (its FM so you dont need to say anything) so the first thing to look for is the transmit indicator on your set. Usually something on the lcd screen or a small led.

If it isnt trying to transmit, can you borrow a spare mic to try from somewhere? PTT button contacts can get dirty and stop working. Alternatively take the mic to bits and clean the PTT contacts.

If it is trying to transmit, then either buy an swr meter / borrow a third aerial / remove your set and try on someone else's boat with a known good aerial. Your problem in this case is either duff aerial or failed electronics. If the latter, throw the old radio and buy new.
 
Thanks for the replies.

The display does show "TX" in the display when the ptt button is depressed. The handheld works fine - did a radio check to confirm this. There is no mic plug to have a dodgy connection - its hard wired into the front of the unit.

I'm not really very keen to try a DIY repair on it. It's hardly been used since I got it as we sold the boat soon after and have only recently got back on the water. I'm almost tempted to say that I've never actually heard it working!
 
In any case you problem is probably in the microphone handset itself. So borrow another get it fixed or more likely cheapest is a new radio.
*************************************************

I have usually found an EX CB insert from an old mike works.

I think the problem here is modulation of the carrier as at day one the poster said there was a carrier so regardless of knowledg of the radio having a TX icon or direct wiring we know the set IS TRANSMITTING which is no help having a VSR meter as the meter will not show any difference between a dead carrier and modulated carrier.

The mike is easy to open usually just make sure you do it carefully as the method of securing the ptt lever and micro switch may not be obvious if you pull it apart and let all the bits fall out. You maybe find you can get an insert from an obliging ham. The insert is as described in another post here.

You may find the problem is just a disconnected wire in the mike.

Thanks Vic for remainding me some mikes are direct coupled however I mention facts like these connections so folk other than the OP who may have such and are experiencing problems might look at theirs where applicable. No end of older VHF radios have been binned just because of these connections. I have recycled many over the years and in fact have about 4 non DSC radios here at present presented as non working and in all cases it has been mechanical problems like a broken solder joint in a mike plug and corroded core in a speaker seizing the cone. and stuck PTT switch.

The hardest job sometimes can be working out how the contents of the mike should vit in the mouldings to be 100% secure as some have been designed internally like a chinese puzzle which can make it more difficult to fix with alternate parts which are not identical in shape.

This sounds like a warranty issue so you could pursue this.
 
I had exactly the same problem last year with my S15.

I tried everything and read up all I could on the forum but it came down to what Scotty_Twister said in your first thread - poor connection - in my case fortunately at the deck plug level.

Both sides of the plug looked fine including removing the rubber boot etc but on stripping one part right down I could see the problem . Also a fellow club member helped with his meter.

I spent hours on what was a very simple problem and also fix. As Scotty says check ( or as I did re-do ) every part of your cable from the plug into the back of the set up to the mast.

Best of luck and hopefully you will find it quicker than I did !

John
 
On the Silva that I inherited with my new boat, the mike was not working properly, I undid the screws and carefully took it apart, the transmit micro switch was corroded, I gave it a squirt of wd40, cycled it a few times and then re assembled it. It has worked perfectly since.
Stu
 
[ QUOTE ]
I undid the screws and carefully took it apart, the transmit micro switch was corroded,

[/ QUOTE ] But in the case of the one that is the subject of this thread the TX indicator on the display panel comes on so not likely to be problem with the PTT switch.

Was yours a complex thing with a key pad and other buttons like the S15's mike?

It has been stated that the emergency aerial was tried with no joy. If that was plugged directly into the radio all problems with the fixed aerial and deck socket have been eliminated.
 
Yes complex, it is an S10? all functions available from the mike, the switch was complex with springs etc, the stupid thing would attempt to transmit, but would break down when the power was drawn thru the switch. The switch is vulnerable because the rubber boot to protect it is not v good.
Stu
 
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