[Elecraft] Keyboard RF Interference

[Ron D'Eau Claire]

How about a wireless (not Bluetooth) keyboard, especially since they apparently only "come alive" when a key is pressed and there's no cables, etc. 

I have an Anker A7723 2.4G that, IIRC, cost me about $20 that I use with my P3. 

Out of curiosity, I turned it on, wrapped wire around it and connected it to the antenna terminal on my KX3. It was just enough antenna to bring WWV in weakly on 10 MHz and the noise background was just perceptibly higher than with no wire attached to the antenna term. It still didn't register on the S-meter. 

Pressing keys did not produce a rise in background noise on any band from 160-6 meters.

73, Ron AC7AC



-----Original Message-----
From: Elecraft [mailto:elecraft-bounces at mailman.qth.net] On Behalf Of GRANT YOUNGMAN
Sent: Sunday, February 21, 2016 9:12 PM
To: elecraft
Subject: [Elecraft] Keyboard RF Interference

Can anyone suggest a COMPACT keyboard used with a KX3/PX3 in a “near antenna” portable environment that you have found to be clean of RF hash?

I purchased a small USB keyboard (Gearhead, from Fry’s), and its matrix scanner is generating tons of RF garbage — spreading noise spikes at around 8 kHz intervals all over 40/20M.  It’s coming from the keyboard itself.  Ferrites on the USB cord have no discernible impact on the garbage.  Touching the metal bottom plate significantly increases the level of the noise.  When portable I’m generally only 5-15’ from the antenna (a Buddipole).  

At least the keyboard was cheap enough to be a non-painful throwaway.

Thanks … 

Grant NQ5T
K3 #2091, KX3 #8342




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