Icom IC-821H (IC 821 H IC821H) transceiver mods reviews software and diagrams

   
 
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22 November 2019, 14:55 UTC 


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Icom IC-821H (IC 821 H IC821H)
IC-821H
Programming interface schematics for Icom:
Programming software for Icom IC-821H (IC 821 H IC821H) :
PDF User Manual for Icom IC-821H (IC 821 H IC821H) :
PDF Adjusments Procedures Manual with schematics for Icom IC-821H (IC 821 H IC821H) :
Schematics for Icom IC-821H (IC 821 H IC821H) :

Mods for Icom IC-821H (IC 821 H IC821H) :
    Icom IC-821H (IC 821 H IC821H) mods
    Icom IC-821H (IC 821 H IC821H) X-Band mod
    Icom IC-821H (IC 821 H IC821H) mods for extended TX/RX coverage
    Icom IC-821H (IC 821 H IC821H) Frequenzerweiterung

Icom IC-821H (IC 821 H IC821H) technical specifications :  Icom IC-821H (IC 821 H IC821H) technical specifications



Icom IC-821H (IC 821 H IC821H) mods for extended TX/RX coverage

I have tested this on my IC-821H and it worked, needless to say I assume no responsibility for damage to your rig.

D101 thru D108 are the relevant parts (diodes) and are located on the display board. You will have to remove both up and down covers and flip-down the front panel to gain access to the display board. 'Installing options' section of the user manual describes this procedure.

D101 thru D108 are all SMD parts mounted near the center of the display board forming a single row, D101 being the one closest to the S-meter. Note that some diodes may be missing on the row, in my USA-version of IC-821 D101, D102, D106 and D108 were missing.

Removing D101 extends VHF RX (to 136-174MHz) (default for USA ver.)
Removing D103 extends UHF RX (to 420-460MHz)
Removing D105 extends VHF TX (to 136-174MHz)
Removing D107 extends UHF TX (to 420-460MHz)

There is no need for resetting to make this mods effective.

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