Icom IC-756 (IC 756 IC756) transceiver mods reviews software and diagrams

   
 
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20 November 2024, 2:37 UTC 


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Icom IC-756 (IC 756 IC756)
IC-756
Programming interface schematics for Icom:
Programming software for Icom IC-756 (IC 756 IC756) :
PDF User Manual for Icom IC-756 (IC 756 IC756) :Icom IC-756 Instruction Manual
PDF Adjusments Procedures Manual with schematics for Icom IC-756 (IC 756 IC756) :
Schematics for Icom IC-756 (IC 756 IC756) :

Mods for Icom IC-756 (IC 756 IC756) :
    Icom IC-756 (IC 756 IC756) filter modification
    Icom IC-756 (IC 756 IC756) wide band modulation
    Icom IC-756 (IC 756 IC756) Spectrum Scope Adjustments
    Icom IC-756 (IC 756 IC756) ACC1 Audio Output Increase
    Icom IC-756 (IC 756 IC756) General Coverage H.F. TX Mod (1.6 - 30.0MHz)
    Icom IC-756 (IC 756 IC756) Expand TX Frequency

Icom IC-756 (IC 756 IC756) technical specifications :  Icom IC-756 (IC 756 IC756) technical specifications



Icom IC-756 (IC 756 IC756) Spectrum Scope Adjustments

Access to the RF Unit is required.

Remove bottom cover and then remove cover to RF Unit - see below.

To increase overall Scope gain:

Lower the value of R963 (100k as fitted).

I put a 56k 1/4w through-hole resistor across R963 - see above - making the combined resistance approx 36k.
(One resistor leg was soldered to pin 2 of IC-961 and the other leg to the junction of R966 and R964)

To be neater you could remove the small 0603 SMT resistor and replace it with a 39k 0603 part.

To adjust Scope base-line:

Trimpot R966 will adjust the base-line of the Spectrum Scope.