IC-R100 how to add SSB reception modification

[mitaux8030]

I've put together this modification how-to for adding SSB reception to the venerable Icom IC-R100 receiver. It will eventually appear on another famous mods site, once Erik gets to his email. But for the time being, to give early access to the information, I've uploaded the pdf to my Google Drive to freely download.

IC-R100 SSB modification.pdf

drive.google.com

And here's a quick video of the mod in action, comparing audio quality with the famed IC-7300. Sure, it's not as smooth as resolving SSB as it's full sized, fully loaded, HF dedicated brother, but for a relatively simple mod going into a radio not designed for SSB, and not really meant for serious HF, it does pretty well:

Hope this brings a bit of new life to some old R100s out there.

 

[VK3RX]

Great job - well done

 

[tunnelmot]

Outstanding. I have a Kenwood RZ 1 and wish it had SSB capabilities.

 

[mitaux8030]

Outstanding. I have a Kenwood RZ 1 and wish it had SSB capabilities.

You could adapt this circuit to work with the RZ-1. It also has a 455kHz final IF, and injecting the BFO output from this circuit into the RZ-1 around pin 9 of IC4 on the IF board should do the trick. You'll have to experiment with the value of the 130k ohm resistor to achieve the optimum BFO injection level. You'd also likely have to switch the BFO on/off using an external switch fitted to the back panel.

The RZ-1 even has a similar 2nd IF tune offset that the R100 has too, that you can take manual control over to provide fine tune 'clarifier' on SSB. It would involve injecting +5v via a 1k ohm resistor when the BFO is turned on to the output of Q7 on the PLL board, and then relocating VR1 on the PLL board to somewhere on the back panel so you can manually tune it.

It might be possible to achieve a 'no holes' installation on the RZ-1 using the BEEP button (for example) to toggle the BFO on/off and have the squelch do double-duty as the SSB fine tune when the BFO is turned on... I didn't research that aspect.

 

[cistercian]

That is really cool! I love my R100 and have used it a lot. It is really hot on 800mhz.
They are great radios and mine still works well. It is an early unblocked example.

 

[fires999]

Morning,
First scanner / receiver I was given was by someone whose barn we had been called to next to the local airport on fire...occupant and I got chatting as I was into CB dxing, few mins later he gave me his mint but unused r100 he said never used anymore !!!!!
This was back in 1994 and it had the SSB mod added at that time !!!
Sadly radio was lost in a house move with a box of other radio equipment including a kenwood rz 1 that in 1995 cost a fortune to replace and find...insurance paid for that !!!)
Fires 999