Kenwood/Trio KT-5550 Tuner problem

[MrRadish]

Hi all, I've just bought a Trio KT-5550 off ebay and of course it doesn't work properly... It switches on fine, and sound comes out when set to FM mono, but set to FM Stereo / Auto Muting (same button) there's no sound as though it's constantly muting. The Tuning balance display (whatever it's officially called) is perpetually stuck to the left of centre. It twitches back and forth as the dial is moved along, but it never moves close enough to the centre to become stereo and stop muting.

It's a very simple tuner and in great cosmetic condition so I'd like to keep it if possible. Is this something a no-brain, no-DIY skill person can resolve? It looks like there are tiny sockets I can twiddle inside, but I don't know what they do. If not then it'll have to go back, but that would be a shame. I don't need it to be perfect, so long as I can get sound out of it in FM stereo I can then play with it until I'm happy.

Any help appreciated!

[Firebottle]

It looks like there are tiny sockets I can twiddle inside, but I don't know what they do.

So don't twiddle them Andy :doh:

Seriously though it's not a good idea without proper test equipment. Are you trying out this tuner with a decent antenna connected?

With these older tuners there is one adjustment that can go off tune over a long time (years) that prevents the signal being 'centred'.
Take a close up picture of the pcb and post it up.

:cool: Alan

[MrRadish]

I haven't twiddled anything, yet. ;)

http://i963.photobucket.com/albums/ae113/stormfriend/IMG_1939_zpsgxfwgkci.jpg (http://s963.photobucket.com/user/stormfriend/media/IMG_1939_zpsgxfwgkci.jpg.html)

[Firebottle]

OK Andy, good picture.

Where the string crosses at the very front of the picture there are 2 metal cans directly behind. The left has a white adjustable core and the right has a grey adjustable core.
One of these is the 'quadrature coil' and is often found to need a little adjustment in older tuners.

Warning Please heed this - the adjustable core material is a very brittle ferrite material and must not be adjusted with any metal tool. It will crack and then your stuffed (been there on a few occasions).
Use a plastic or nylon tool, shape a plastic tooth pick or something similar.

Adjust one at a time and see if that improves things, you should only need about a quarter of a turn probably. If one makes no difference then put back to the original position.

Don't twiddle anything else or you'll end in the sh1te.

Cheers,
Alan

[struth]

Those plastic or nylon cable ties can sometimes be used too

[MrRadish]

That worked, thanks! It was the grey one that needed turning although I doubt the white one ended up quite where it started. :-) I lost track of how much twiddling was involved but I'm pretty sure I dialled in over a full turn in the end. The tuning meter now flicks either side of the centre position as I move the dial and the FM Stereo indicator lights up correctly. It's playing Radio 3 in the background as I type this and it sounds pretty good.

The hardest part was finding something plastic to turn it with. My cable ties weren't quite strong enough and everything else I tried was too large, so I ended up cutting a sliver off an old loyalty card and using that. That's the most value I ever got out of that card.

[Firebottle]

Excellent, I am very pleased it worked for you.

:)

[MrRadish]

Aaargh! So I was listening to the tuner earlier and it sounded very good. A little hard or glary in the treble on occasion, but really engaging and musical most of the time. I then switch over to Netflix to watch a film, which I do, and to see the evening out I switch back to the tuner again afterwards. All I get is distorted and broken noise, with partial hints of an anthem playing, random panning between speakers and occasional spurts of what sounds like another station breaking through. I sit there hoping it will sort itself out, but it doesn't. I tune it off and on again, but no joy. I then switch to Radio 4, which works fine...

I go back to radio 3 and it's still completely messed up. But now I hear what sounds like a tape deck mangling the tape and start thinking the BBC got hacked again. So I check the schedule and what do I find? They're playing Stockhausen's Hymnen in four channel surround sound. Either it's the most experimental thing I've ever heard or my old tuner can't handle it. Either way, I don't mind now I know what's going on but I nearly binned my new tuner! The gits. :mental: