I need an old fashion electronic/radio technician

[tillergirl]

One component on this PCB is defective. I have the wiring diagrams, I have the notes, I have the decoder waveforms: I have no knowledge on how to use all that. The closest expert I have found so far is in Italy. Anyone know how to make sense of this sort of thing or knows someone who might know please?

P1050097 by Roger Gaspar, on Flickr

 

[Tradewinds]

Is this off a Neco autopilot (692)?

 

[tillergirl]

Yes

 

[Tradewinds]

OK. That will be Daniele Fua in Italy. Great bloke.

Looking at my circuit diagrams it's the Control Unit PCB assembly.

I converted my Neco 692 to a Simrad Nac3 control unit (just kept the motor part). I have a control unit in my shed somewhere. Is this of any use to you? Maybe swop the board out (or even the whole unit). The whole shebang was serviced by Derek Coventry back in 2010.

If you want it you can have it.

Cheers
Nigel

 

[tillergirl]

Yes, yes, yes!

Yes Daniele has been giving me guidance. Originally when I bought Sea Dog, the three components were imcompletely connected (for those who don't know the Neco but are interested - the Neco is a 1970-1980s automatic pilot that comprises a Compass, Drive Unit and Control Unit). Following Daniele's guidance I tracked down a fault on one of the Relays in the Drive Unit and he gave a me link to track down a new relay - there were 22 in stock in Texas; I ordered a pair on the Wednesday and on the Friday morning they arrived! The Drive Unit is therefore correctly performing. I then tracked down some dodgy wiring by the previous owner and resolved that. The next stage is to set up the 'Lining-up' process and that is where I have the problem.

The Potentiometer in the Drive Unit is performing 100%. I line that up at 'neutral position'. When I set up the 'Lining-up' process the Drive Unit and the Control Unit is connected but the Compass is deliberately disconnected. By turning on the Control Unit, the Drive Unit should stay in the 'neutral positon' but it turns to port and set-up the 'neutral positon' off centre. To restore the Drive Unit in mid position, the Trim knob needs max Trim to starboard. I hope that makes sense. The Trim potentiometer is performing ok but there are some 'components' on the PCB between the two potentiometers and that is where there is the problem.

Nigel - Daniele has said it is easy for an 'old fashioned electronics/radio engineer' to find the problem and the components are readily available. He has said that to send the Control Unit would be too expensive - its 4.8 kgs! and he recommended me to find an engineer OR find someone who had a Control Unit! Even if someone can do the engineering (I have been exchanging emails with Paul Rainbow right at this moment) it would be really handy to get hold of another Control Unit. I would love to hold of it please.

 

[Tradewinds]

I'll send you a PM with contact details tomorrow when I've dug out the unit from underneath the rubbish in my shed. We can meet somewhere mutually convenient during the next week if that fits in with you.

 

[tillergirl]

That would be lovely. Thank you. Let me know in your PM what you want for it.

 

[Tradewinds]

Nothing Roger. You provide a great service for all us East Coast sailors - nice to do something for you.

Oh, perhaps the name of where you got the relays from in the States - just in case.

Be in touch tomorrow.

 

[tillergirl]

PRD-5DY0-12 TE Connectivity / P&B | Mouser

I fear the Interweb isn't very good on the climate. It took 3 lorries and 4 planes!

Thanks.

 

[Tradewinds]

Roger.
Sent you a PM

 

[penberth3]

One component on this PCB is defective. I have the wiring diagrams, I have the notes, I have the decoder waveforms: I have no knowledge on how to use all that. The closest expert I have found so far is in Italy. Anyone know how to make sense of this sort of thing or knows someone who might know please?

P1050097 by Roger Gaspar, on Flickr

Do you know which component has failed? Whatever is wrong, that looks like an easy job for any half-decent radio/TV repairer or amateur radio/electronics enthusiast. Surely there's someone closer than Italy!

 

[ex-Gladys]

Unfortunately we don't... (I'm Roger's other pair of hands). There is some documentation about looking at various waveform outputs from the controller which are then interpreted to switch the drive unit to turn to either port or starboard, but that needs an oscilloscope and a lot more expertise than we possess between us...

 

[maby]

Do you know which component has failed? Whatever is wrong, that looks like an easy job for any half-decent radio/TV repairer or amateur radio/electronics enthusiast. Surely there's someone closer than Italy!

That is a very good point - check the Club Finder page on the RSGB web site (Club Finder - Radio Society of Great Britain - Main Site : Radio Society of Great Britain – Main Site) and make contact with a nearby radio club - the board you posted is old school electronics and a trivial repair for any qualified radio amateur.

 

[tillergirl]

Thanks Maby. Larry and I have a last attempt at some tests tomorrow. (Nigel - I got exactly the same problem with your replacement Control Unit! With my Control Unit I was failing to complete the first stage of the Lining-up procedure - the first stage would skew the setting off centre. When I plugged in your Control Unit, I suffered exactly the same issue. Daniele is finding the potential coincidence of the same error too much to accept at this stage. Your Control Unit had been serviced as well! Can be the two Control Unit have exactly the same fault. So we must examine further into the Rudder Feedback potentiometer in the Drive Unit. What is mystifying is that there is nothing (other than wiring) in the Drive Unit to 'interfere' with the potentiometer and it was performing its test 100%. I am hoping there is a wiring issue but I fear the logic of the readings in all the previous tests suggests there is no problem in the wiring.

But two pairs of hands tomorrow and an objective full forensic is the next step. Then that reference will be very handy thanks.

 

[Tradewinds]

I'm sorry to hear that Roger. As I said to you - I'm no electrician when it comes to this sort of thing. Funnily enough, back in the day, I knew at least two people who would find this stuff easy and fixable. Seems they are a dying breed.

Do you want your book back?

Let's hope Daniele can shed some light on it.

 

[dolabriform]

Hi Roger
I have a basic oscilloscope which I could lend you if you get stuck.
Regards
David

 

[tillergirl]

Thanks David. Certainly my technical knowledge has arrived at a cliff marked 'ignorant'. Daniele in Italy has been very kindly giving me a series of tests to run using a multimeter and that has been ok. Larry has helped me understand some of the wiring diagrams but the chapter 'Description of the Circuit Function' has a collection of English words assembled in sentences which completely mystify me. I don't know if Larry can work and use an oscilloscope. The last thing I want to do is to blow everything apart.

Actually I am hoping that tomorrow I have found that I had missed something that is obvious - even if it is embarrassing!

 

[dolabriform]

Thanks David. Certainly my technical knowledge has arrived at a cliff marked 'ignorant'. Daniele in Italy has been very kindly giving me a series of tests to run using a multimeter and that has been ok. Larry has helped me understand some of the wiring diagrams but the chapter 'Description of the Circuit Function' has a collection of English words assembled in sentences which completely mystify me. I don't know if Larry can work and use an oscilloscope. The last thing I want to do is to blow everything apart.

Actually I am hoping that tomorrow I have found that I had missed something that is obvious - even if it is embarrassing!

Hi Roger

Let me know how you get on. The oscilloscope is actually quite easy to use, almost as easy as a multimeter. If the tests won't take long I can probably spare an hour or 2.

Regards

David

 

[dolabriform]

'Description of the Circuit Function' has a collection of English words assembled in sentences which completely mystify me.

 

[tillergirl]

That is very kind of you. I can forward a copy of the two pages about how the Control Unit components interact.

Larry and I will be down shortly and I'll report back.