New TRX- IC-7100, a look inside

New TRX- IC-7100, a look inside

I have just purchased a new IC-7100 to replace the FT-857 and FT-897 all-band, all-mode TRX I had. The Yaesu TRX were good radios, but dated designs.

The IC-7100 on the other hand is a very modern design and radical form with a separate touch screen controller. The IC7100 is a similar but different design to other modern Icom TRX such as the IC-7410 and IC-9100. All are software-defined radios, with all modulation and demodulation done in software/firmware in the DSP and codec chips. All other signal processing is also done in software.

Analogue devices are used for amplifiers and mixers. Band, low-pass and roofing filtering is done with discrete components, but all signal filtering is done by the DSP.

I will say more of the design, but for the moment I have some photos of the main unit's PCBs. The mechanical design is simple.

The top board is the frontend for both Rx and Tx with most components of one side of the board mainly because of the size of the filter components.

The TX transistors do all bands, 1.8 - 470 MHz. The transistors are bolted to a serious fan-cooled heat sink, seen from underneath, with the small signal board folded to the side..

The small signal board is connected by one coax cable for both RX and TX RF, plus two flat cables for all other connections.

On the small signal board there are components on both sides of the PCB. The top side has all the DSP chips. There are three computers running the TRX.

The single coax cable carries both RX and TX between the two boards. This connector is of special interest for tapping point for an SDR, after the all the TRX frontend and filters. An opto-coupler will be necessary to turn off the tap during TX. This is the case for some Yaesu TRX first IF taps and hopefully will be straightforward.

So, a compact, modern designed TRX, easy to access for servicing and the like.


  1. Thank you Andrew for the interesting review. I am also looking for how to tap into the IF for the SDR panoramic display for my IC-7100.

    73, Ted VE7VIB

  2. Great review thanks just bought my 7100 waiting for it to appear 73 de Gary K8JCR


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