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TUCoPS :: Radio :: ic28a_4.txt

Icom IC-28A and 28H mods




IC28A.4
 
The long, noisy squelch-tail of the Icom IC-28 (A or H model) 2-meter 
transceiver can be shortened by replacing C110 (4.7 uf) with a smaller 
value (0.1 to 0.47 uf).  (I can't remember the source of this 
information.) 
 
I put a 0.33 uf in my IC-28H; it's a very worthwhile modification. 
 
The capacitor is on the bottom board (the one with the lithium 
battery), just southeast of IC4 as you face the front of the upside- 
down radio.  The only difficult part is finding the right p-c pads to 
desolder on the back of the board. 
 
To remove the board:  Remove bottom plate, unplug speaker.  Unplug 
coaxial antenna connector (gray wire).  Other connectors may remain in 
place.  Remove 5 mounting screws, one in each corner and one near 
center.  Tilt the board out of the radio.  The button in the upper 
left corner is CPU reset; you may have to reprogram the memories if it 
is pressed.  Remember that, although the radio is off, parts of the 
circuit are live so be sure not to short any part of the board during the
modification. 

 


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