Cherry G81 KeyboardI bought two Cherry G81 keyboards years ago, way back in 2003 if my memory serves me right. The main reason I bought them was because they had a USB hub built into them (4 ports) and they keyboard, whilst of the membrane type, was of a very high quality. The keyboards have served me well, but I thought it would be a good idea to get a more compatc, less clicky, keyboard for use with my Amateur Radio computer.

A number of more modern alternatives have been tried, but none gave me the correct key spacing (I kept hitting the wrong keys), the reassuring feel, or the built-in hub (being able to plug pen drives in without having to scrabble beneath the table is such a luxury). Furthermore, I couldn’t find one keyboard for less than £30 that didn’t reject RF interference. Whilst transmitting PSK-31 data the transmission would stop at random positions in a message, presumably because the RF was causing the ESC signal to be sent to Ham Radio Deluxe, cancelling the transmission.

I considered purchasing a new Cherry keyboard, and I still might, but wondered why I was being so stupid. Put the G81 back in-situ and problem sorted. I’m now back enjoying normal service. This keyboard’s a true star – years old and still working hard.

Recommendations

Any keyboard to be used on a computer near and HF transmitter should have a ferrite choke at both ends of the USB cable. One to stop RF entering the PC via the cable, and one to stop RF entering the keyboard and interfering with the processor inside that. Some of the keyboards I tested contained ferrites in the cable, but were ineffective.

Fitting ferrites yourself can be difficult as USB cables are often too thick to be able to wrap it a couple of times around a clip-on ferrite. So if you’re thinking of purchasing a good quality keyboard with effective ferrites included in the cable, think about a Cherry keyboard.

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