Hello good people. I'd be grateful if anyone has any advice. I have a beomaster 6000 quad, and the amp works well, but the radio section is not so good. It does tune in, at roughly the right place on the dial, but what happens is that as a station is tuning in it gets louder as one would expect, and then when fully tuned in, goes very quiet indeed. I've noticed also that the stereo light and field strength meter don't operate. I guess the stereo bulb could be blown. I had a look inside, and unfortunately someone has got the soldering iron in there before me. I have another 6000 that is totally butchered that I use for spares and I think the radio parts are ok, so before I try to replace all the RF and IF section boards, I'd be really grateful if someone might know more specifically what the problem might be. (something to do with the stereo decoder perhaps) Many thanks, Jerome.

Sounds to me like an IF fault rather than an RF. I don't remember the exact circuit by heart but it could be a mere question of aligning the last IF stage, it's two coils are probably running "on the edge" of eachother so to speak. That will probably be the last IF stage before the stereo decoder.

The signal meter and stereo indicator sits in a separate board, check for broken wires. The signal meter should work but don't expect the stereo indicator to come on before the alignment is correct as it depends greatly on that and signal condition. It could also be seen lighting up just slightly off the signal strength peak, that's very common.

Martin

Hi Dillen

Many thanks, and  yes the radio gets a lot louder just off the signal strength peak although the stereo light doesn't  come on. I have to admit, I know nothing about radios, but I have the circuit diagram and can locate these coils, they are in a section encased by a metal box. Can I align them just by trial and error???

 

I will try this later tonight, and if it doesn't work I'll just replace the boards. I have a beautiful working 6000 and was thinking of keeping this broken one for spares, but it is actually very nice condition so I might sell it if I fix it. Whatever it is definitely worth saving, there can't be so many around these days!!!!
 

Thanks again for the advice, what you suggest almost always works!!!!! 

 

Jerome 

plasticpigeon:

Many thanks, and  yes the radio gets a lot louder just off the signal strength peak although the stereo light doesn't  come on. I have to admit, I know nothing about radios, but I have the circuit diagram and can locate these coils, they are in a section encased by a metal box. Can I align them just by trial and error???

Don't do that! Tweaking here and there usually is not successfull, and once you have everything out of alignment, you need the service manual and lots of measuring equipment to get it right again.

However, if you make good notes of the settings how they are now and carefully try only one coil at a time, you might find where the problem is. The coil cores are usually sealed in position by nail polish like lacquer, you might see if some of them have cracked (moved) already since factory or if somebody has been there before you.

Don't use a metal tool for tweaking - it will affect the tuning by its presence, and will very easily crack the brittle ferrite cores. Make a tool from plastic or hard wood, or try to get one made for this purpose from a good electronics shop.

This was just general experience, Dillen can continue with Beomaster 6000 specifics - I have never even seen one

I agree, trial and error won't get it right. You will never find the correct spot without the right instruments.

A board swap would be the better solution of the two, and fully reversible.

Martin

Oh ok, that is a shame, does anyone know a place in the UK that can align the coils??? I guess a scope and a signal generator are needed. I may be able to borrow these things, but I am not an electrical engineer, in fact I am a mechanical engineer, so I still wouldn't really know what to do unless there is a webpage or reference with good instructions!!!!