HR-10 worthwhile mods

[Alan W. Fremmer]

Here's my  two cents on the subject.  Can't remember where I found these.  
Also,  have not attempted any of the mods. 


Heath  HR-10/B receiver: 
Correcting low BFO injection  level: 
Solder a 3/4" piece of solid  insulated hookup wire to pins 9&2 of V4. 
Connect a VTVM from pin 1 of V5 to  ground and turn on the BFO. Adjust the spacing 
between the  wires 
for a +10vdc indication on the  VTVM. 
Regulated  B+: 
Measure the voltage at the  junction of R44, R43, and C56. Subtract 5-10 
volts from this measured value and  connect a 5 watt zener of this voltage from 
terminal strip L pin 3 (cathode) to  ground. 
Regulated BFO  voltage: 
Connect a 30 volt 5 watt zener  from pin 1 of V4 (cathode) to ground and 
change R39 to 33K 1  watt. 
Smoother audio response and less  distortion: 
Remove C36   
After the above is completed,  realign the Osc. and BFO 
73, Alan -  KB2HEI

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