"Sony Air 7" squelch replacement
 

Hello,

I have a little sony air 7 radio that is working nicely.
The volume pot was defective so I have replaced it with a new one.
Unfortunately the squelch is now dead. This potentiometer is a little special as it has an auto and manual feature (pot can be both turned and pressed up and down) I am simply unable to locate the same pot or anything like it. The best I have come up with is a pot with the same resistance but it only has three pins. The original pot has 8 pins (if I remember correctly) When I solder the new pot on, the sound is dead entirely.

So for now the only way I have been able to keep the radio alive was to solder a 100k resistor to two points which seems to bypass the dead squelch and enable the volume to work independently.

Does anybody have a clue how I could use the three pin pot?

Re: "Sony Air 7" squelch replacement
 

You can't do any switching without a switch, if an ordinary pot is your only replacement option you will have to decide which mode you prefer, Manual or Auto, for Manual short out the switch connection nearest the pot to the switches middle connection, for Auto connect the switch connection that's furthest from the pot to the switches middle connection.

The only other alternative I can think of at the moment is a separate single pole change over switch mounted somewhere if there's room, and hard wired to the volume control panel.

Lawrence.

Re: "Sony Air 7" squelch replacement
 

Hi ms660,

Thank you for replying to me.
This could be great! I guess I would take the manual function for more control.

Could you please take a look at this picture, I just want to be sure this is the right one i need to short. (I have put a RED box at the point where I think you refer too)
********************8DPtsD0/IMG-20190117-174347.jpg

Thank you so much for taking the time to help me.

Regards,

Re: "Sony Air 7" squelch replacement
 

Yellow (link) for Manual.

Light Blue (link) for Auto.

And remove your added resistor.

Hopefully....

Lawrence.

Re: "Sony Air 7" squelch replacement
 

Re: PM.....Yes, I looked at the schematic and the volume control board layout, I found the full manufactures service manual online.

Lawrence.

Re: "Sony Air 7" squelch replacement
 

Hi
You can repair these pots
What happens is the wiper becomes detached from the plastic holder
To take the pot apart you have to file the ends off the two rods holding it all together
Carefully taking notes as you take it apart ( take pictures ! ) you will see the wiper has come loose
Clean the surfaces and scrape for the glue to work
Use a drop of super glue to hold the wiper in place and then cover with epoxy
Reassemble and use large paper clips to replace the rods
Bend over the ends or solder
Fiddly job but do able
Cheers
Pete

Re: "Sony Air 7" squelch replacement
 

Unfortunately, the trace was broken during the unsoldering process.
Right bollocks I made of it. I did what MS660 said but the squelch still does not work.
I tested the potentiometer and it works fine and has the correct resistance.
After tracing the PCB back with wires, the volume would not work ^^
So I had to try a bunch of weird stuff and finally with a few more trials the volume is back.
I'd probly need a resistor or something as the volume pot turns the volume up way too fast, so it does not take a lot of turning before the volume is up full. Maybe less than 1/3 turning the volume pot and the volume is blasting away.

Anyway it's working again the squelch is just on all the time now where as before it was not working at all. I guess it's a fix in a way but far from great.

Here's a picture of the mess, maybe someone will have a laugh, maybe someone will not.

********************zsnsD12/IMG-20190118-162631.jpg

Re: "Sony Air 7" squelch replacement
 

That is a symptom of you using the wrong "law" for the pot. Volume-controls generally need a Logarithmic resistance-curve because this matches the human ear's perception-of-loudness.
I suspect you may have fitted a Linear pot.

Re: "Sony Air 7" squelch replacement
 

So far as I can make out (at least) from your last photo, you've connected the volume control and the squelch control as rheostats and you've connected the wiper along with one end of the squelch control to ground via the "Manual position" switch contacts and connector CN4/1.

Lawrence.

Re: "Sony Air 7" squelch replacement
 

I too am trying to restore an Air 7 to normal service again. With zero volume and weird operation of the squelch pot I decided to pull the radio apart and get to the pots to repair them.
So far I have just taken the volume pot apart. It sort of exploded on me, I have reconstructed it apart from the wiper as I have no idea how it should be orientated within the pot. I've never seen the internals of one of these before.

Any help such a photos of how the wiper locates would be most welcome. They sure are fiddly. It would help if I could get the circlip off the end of the rod but I haven't found a way of doing that as it's so small and very tight.

I'm dreading doing the squelch pot as that is most probably much more complicated.

If anyone could assist I would be most grateful.

Cheers, Andy.

Re: "Sony Air 7" squelch replacement
 

Just an update on the repair of the volume pot.

I managed to put it back together again after super gluing the wiper on to its plastic base. The pot now works to a fashion, there are a few dead spots which means the knob had to be twiddled with to find the sweet spot. The squelch pot also needs fixing but I am able to operate the radio with it switched to auto.

I have found a website that has direct replacements for the 2 pots, they are not cheap at 30 euros each but it would mean I end up with a mint example of the air 7. I will decide what I am going to do in the next couple of days.

Cheers
Andy

Re: "Sony Air 7" squelch replacement
 

I take my hat off to anyone trying to repair the volume pot, it looks far too fiddly for me. Is it possible to source a replacement, the first post indicated they had replaced it with a new one?

Thanks