[Heath] AJ-53 or AJ-21 schematic?

[DTerry8123 at aol.com]

Morris:
I have a Heath AJ-30. It has a 10 KHz. whistle filter in the audio  output 
that is tuned to a null at 10 KHz. Yours may be the same.
Dan Terry
 
 
In a message dated 2/22/2012 7:10:37 A.M. Eastern Standard Time,  
mdilli at nnwifi.com writes:

I just acquired one of each of  these high fidelity AM tuners and could use 
some documentation.    Since they both appear to be quite similar, docs for 
either would probably be  sufficient.   
 
I have forged ahead, repairing a locked slug in an IF  transformer in the 
non-functional one  and then with comparison to the working one for 
alignment.   The IF  frequency seemed to be non-standard around 460 KHz (yes, I tried 
455 KHz but  it had problems) so I used that and the old tuner came up FB.  
 The only question remaining is about what appears to be an  adjustable 
filter coil on the output stage.   I am  assuming that it is for blocking any 
residual IF frequency that might slip  through detection and beat with a 
recorder erase  oscillator.

 
Thanks for the  bandwidth,
 

Morris  



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