Icom IC-Z1A (IC Z1 A ICZ1A) transceiver mods reviews software and diagrams

800MHz receive.

Install two transistors.
Part #UN9110 can be ordered from ICOM Service Department.

This mod is not for the non-technical person. The radio pretty much has to be completely disassembled to get to the pads.

1. Remove the control head and battery.
   
   
2. Remove the 4 back screws and 4 battery compartment screws.
   
   
3. Separate the case.
   
   
4. Locate the circuit board with the two channel select/squelch knobs. This is the board we're looking for. Unfortunately, it's an the back.
   
   
5. CAREFULLY remove the wide ribbon cable that connects the upper and lower circuit boards.
   
   
6. LOOSEN the three screws an the LOWER circuit board.
   
   
7. Remove the two screws an the back of the radio, an the top of the battery compartment.
   
   
8. Remove the three screws an the battery contacts.
   
   
9. Slide the RF assembly up and it should separate from the rest of the radio.
   
   
10. Remove the knobs and carefully remove the ring nuts from the case.
    
    
11. Remove the metal bracket that is between the case and the pots.
    
    
12. CAREFULLY Desolder the grounding tob an the left side of the circuit board.
    
    
13. Remove the two screws holding the board down.
    
    
14. The board should now be free. Carefully wiggle and pull and pry until the board is released. You may have to partially or fully remove the battery spring mechanism.
    
    
15. Flip the board over. There is a large multi-pin jack an the back, slightly high and centered. Look for two empty, 3 pin pads right next to it.
    
    
16. Carefully solder the two transistors onto the pads.
    
    
17. Check your connections. You do NOT want to have to disassemble this twice.
    
    
18. Check them again.
    
    
19. Reassemble the radio in reverse order. Remember to resolder the grounding tab.
    
    
20. Turn it on. Select UHF, key in an 800MHz frequency and listen. There is no need to reset the VFO or memories.

Diagram:

This is a close up view of the area to looking for.
(sorry, no picture yet.)

# = 3 pin part, diode/transistor 

|| = 2 pin SMD diode/resistor

(*) = 3 pin surface mounted transistor.

      (*) (*) ||  ||                      #   # 
#                      || || || || 
           +-------------------------------+ 
           |      MULTI-PIN JACK           | 
           +-------------------------------+

            ==              ==       ||   ||

(kinda hard to draw in ascii. This diagram needs a non-proportional font to look right...)