I recently sent the email below to:- G0MGX AROS & IW COordinator On 04/05/2017 15:50, Ray Coles wrote: Good afternoon, I have finally got around to reporting a bizarre issue I always encounter when I work JT65 mode on 10.138 MHz (30m band). I listen to the band and copy a few (usually European) stations. I might then decide to call CQ or reply to a station. At the exact end of my transmission (or possibly before when I wouldn’t hear it) a strong modulated carrier kicks in, apparently automatically. This carrier and its 1 KHz or so tone makes listening very uncomfortable, but it doesn’t necessarily prevent JT65 replies being received. If I am alone on the band the carrier will stop (apparently automatically after a delay), but if there are other fairly strong stations it may continue, presumably continuously triggered by them. So, if there is a lot of band activity it just looks like a permanent interfering tone, but if I am alone or seeing only weaker stations on the band it quite obviously is triggered by my transmission. This only occurs on 30m, but I do see it on both my Elecraft K3 and my iCom 7300. My antenna is currently a full size G5RV but was also evident when I was using a BuckMaster OCFD. I usually transmit around 25W but turning the power down to 10W makes no difference. I believe it must be an automatic jammer because it is always “On duty”. I have tried to remember when it started but I have no proper recollection. At least 6 months I’d say. 30M is a very useful band as we approach Solar Minimum, and this jammer takes a lot of the pleasure away. I don’t know if it is triggered by other modes like PSK or CW. Is it me? 73deRayM0XDL G0MGX replied that he thought it was something known to the EMC forum and suggested I join and post. So here I am!