wiring of tweeters on Philharmonic.

[jonathan dollimore]

I finally managed to acquire a set of tweeters for my Philharmonic. However they were missing the plug  that connects them to the main speaker via a two pin socket on the base of the latter. Now, tested on the bench the tweeters both work (relief....). However connected up to the main speaker they don't seem to - although its difficult to tell vis a vis the over-riding volume of the main speaker. But here's my specific query: the aforementioned plug and socket have one pin (plug) and hole (socket) larger than the other, suggesting that the wiring into the speaker is one way round rather than the other. Given that I don't have the plug I don't know which way this should be. And before tackling the main problem of the tweeters (probably) not working, I'd like to get this clear. It's probably obvious, but not to a dunce like me and your advice would, as always, be much appreciated.

[Norman S Braithwaite]

It sounds like your Philharmonic may be the AM-FM version with the optional four unit speaker system (flush mount woofer, crossover chassis, and two tweeters). If this is the case, the tweeters are only active when the receiver is switched to FM. If not, we will need to know more about which version of the Philharmonic that you have.

Norman

[jonathan dollimore]

Sorry Norman, I should have said: mine is a 30 valve  AM only model.

Norman S Braithwaite said:

It sounds like your Philharmonic may be the AM-FM version with the optional four unit speaker system (flush mount woofer, crossover chassis, and two tweeters). If this is the case, the tweeters are only active when the receiver is switched to FM. If not, we will need to know more about which version of the Philharmonic that you have.

Norman

[Norman S Braithwaite]

OK, the only reason for large and small pins on the plugs for that version is to phase the tweeters correctly to the woofer.  The tweeters should work even if out of phase.  If they do not work, the culprit may be the 2-mfd crossover capacitor in series with both voice coils.  If open, the tweeters will not operate.  If shorted, the tweeters will operate but you risk damaging the voice coils with bass notes.  Other than that, check to make sure you have continuity through all plug connections.  Lack of continuity at any connection will prevent the tweeters from operating.

Norman