#25 Icom IC-745 repair part 1. tear down and review of problems

[The Radio Shop]

#25 Icom IC-745 repair part 1. tear down and  review of problems

In this video we have a look at Icom IC-745vHF transceiver.
Although this is listed as an all mode rig it does not have AM transmit.
On 24 MHz and up we have an intermitted problem on receive and transmit, this is due to crappy plastic trimmer capacitors in the VCO unit. We will also look at ways to replace the internal battery that holds the information in sram. If this battery dies the unit becomes a brick since it looses all of its factory programming for the cpu.




https://www.youtube.com/watch?v=wxvNi-BB0Xc

Trimmers (current part numbers as of 3/8/2016)
4610000100 (CV05A0601 CTZ51A 6pf)  $2.92 ea...  4 pieces

4610000110 TRMR CV05C1201* VCT51C CTZ51C 12pf  $2.92 ea  6 pieces



IC-745 PLL VCO Trimmer Replacement & 2nd LO Upgrade by Frank A. Ellis W3UHF
http://www.qsl.net/icom/ic745/main.html

Ram battery replacement instructions
http://www.icomcanada.com/techbulletin/tb1/ram_card.htm

ram programming
http://jvgavila.com/soft_ham/icom/ic_ram.htm


ICOMPROM ICOM Non-Volatile RAM Module
https://www.piexx.com/?main_page=product_info&products_id=26


Service manual
http://www.radiomanual.info/schemi/IC745_serv.pdf

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Programming for the ram board files and interface schematics.

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Program interface

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745 speaker terminal location