05-10-2013, 01:38 PM
Since I had my 610B on the bench for some routine maintenance and since I now have some better test equipment (not to say a clearer idea of what I'm doing) , I decided to go back over the alignment procedure.
I managed to improve the output from the IF transformers by a fair bit but I ran into some minor issues when aligning the broadcast band.
Firstly the adjustment for the antenna compensator (adjustment number 5) has very little effect - only very very slight. Is that normal ? The oscillator trimmer and the 'padder' work as expected.
Secondly, although I'm now getting stations more accurately in the right places, I notice a tuning 'whistle' just as I tune into a station. When it's tuned in, all is well - so it's not really a big deal - but it was not there before. I'm not convinced that reception e.g. picking up weaker stations, is as good as it could be.
What did I do ?
Any thoughts or ideas greatly appreciated
Performance on SW is excellent so I have not touched that
The schematic is here :
http://www.nostalgiaair.org/Resources/798/M0013798.htm
Thanks !
Chris
I managed to improve the output from the IF transformers by a fair bit but I ran into some minor issues when aligning the broadcast band.
Firstly the adjustment for the antenna compensator (adjustment number 5) has very little effect - only very very slight. Is that normal ? The oscillator trimmer and the 'padder' work as expected.
Secondly, although I'm now getting stations more accurately in the right places, I notice a tuning 'whistle' just as I tune into a station. When it's tuned in, all is well - so it's not really a big deal - but it was not there before. I'm not convinced that reception e.g. picking up weaker stations, is as good as it could be.
What did I do ?
Any thoughts or ideas greatly appreciated
Performance on SW is excellent so I have not touched that
The schematic is here :
http://www.nostalgiaair.org/Resources/798/M0013798.htm
Thanks !
Chris
