[RFI] FM modulated RFI on 3.885 and more

KD7JYK DM09 kd7jyk at earthlink.net
Sun Feb 14 20:51:15 EST 2021

"Any ideas on which devices are suspect?"

I'd suspect the wireless voice/data/modem extenders/phone jacks, popular 
from the late 80's, maybe early 90's, onward.  Perhaps not so popular 
now, but the thrift shops are full of them for a few bucks a pair, so 
stands to reason they'd still be in use.  Most operated in, or around 
80m, for some reason.  I used to hear several of my neighbors phones on 
them, usually voice, sometimes fax, data, modems, et cetera, whatever 
they would normally plug into a jack.

Interesting side-note, the old cordless phones with speech inversion 
"security", could be heard flawlessly with an Icom IC-706 MKII on HF in 
RTTY-Reverse mode, whether the 80m phone extenders, or even the 4x MHz jobs.


More information about the RFI mailing list