Icom IC-7100 Poor Power on Transmit

 If you have an Icom IC-7100 you will know what a disappointment you have felt as you hooked up your transmitter to a power meter and watched the peak output on SSB. Despite your transmitter being set to 100W you will most likely see around 20-30W max on your meter.

After checking all your connections and radio settings, you are probably wondering why your expensive radio is not anywhere near the spec. that it stipulates on the specification sheet. Well, welcome to the real world!

I have no idea what the Icom engineers were thinking when they designed the transmitter feed back loop, designed to avoid overdriving the finals. However, it would seem that they are shutting down the Tx way to early and a simple fix is well shared within the internet community:

The modifications can be done quite quickly if you have a steady hand and a good solder station:

The main board is placed in the solder station with a microscope to enlarge the area to be modified by the addition of a capacitor and a bridge as recommended by DC5WW

The modifications are show in the picture below:

The old man also wanted the radio opened up to transmit and receive to all bands. To achieve this the diode D316 was removed.

After some capstan tape and a blast from the hot air gun, the diode was removed from the PCB. The diode is tiny, take a look for yourself:

An Rx and Tx test showed the transmitter on frequency and with no spurious signals.

Job done!