[BC] BE AM 2.5 stereo problem

[Andy Linton]

Thanks Tom. I was considering the caps.

However I think I missed something the first time round. When I was fault finding I was disconnecting the audio from one INPUT of the Optimod 9100B2, as the outputs are harder to get to.

But tonight I dis'd the output, and the tx input disappeared on that side. So now I reckon its the Optimod that's got loadsa L-R crosstalk, not the tx.

So I'll be looking though the 9100 now to see whats going on!

Cheers!

------------------------

Andy Linton
Kilkenny, Ireland.
 

From:Tom Taggart <tpt at literock93r.com>

Andy..

Great to hear you have AM stereo, which makes IBOC look like a  
grade-school science experiment.

Last time I worked with AM stereo it was with a Motorola C-Quam  
exciter driving a RCA high-level modulated tube transmitter (A 5U or  
something like that--getting on 25 years). Into a  3 tower dogleg  
array with a 1938 phaser. We had better separation than that...

So I would be suspicious of the transmitter or exciter rather than the  
antenna (although if you had a dummy load..)

Given that you have apparently not used this system for a while may be  
the problem is as simple as a leaky cap.  As I vaguely remember you  
can drive the AM stereo monitor from a sample off the exciter--so if  
separation is poor there a shot-gunning of filter, coupling and bypass  
caps may be in order.

If low-level is OK, than we need to wait for the BE experts to chime  
in. Never worked on their 2.5 kw AM.