jeffr@sri-spam (Jeff Rininger) (08/15/85)
I am having problems with signals from my (and my neighbors) televisions getting into my HF radio gear. What I am experiencing is "howling" signals spaced about 15 khz. across the HF spectrum; 20 meters seems to be the worst. I am using a Butternut vertical, and Atlas, Ten Tec and Heath radios. I would appreciate hearing from anyone who has an idea how I can eliminate this "reverse TVI" problem. Tnx es 73 Jeff Rininger (jeffr@sri-spam) KA6ZBU
george@genat.UUCP (George Gorsline) (08/23/85)
> I am having problems with signals from my (and my neighbors) televisions > getting into my HF radio gear. What I am experiencing is "howling" > signals spaced about 15 khz. across the HF spectrum; 20 meters seems to > be the worst. I am using a Butternut vertical, and Atlas, Ten Tec and > Heath radios. > > I would appreciate hearing from anyone who has an idea how I can eliminate > this "reverse TVI" problem. > > Tnx es 73 > > Jeff Rininger (jeffr@sri-spam) > KA6ZBU I tried to mail a response, but the path didn't make it... What you have is ITV - the 15.75 kHz horizontal oscillator is radiating and giving you the problem. It isn't too easy to live with. Some ideas: 1. If you disconnect the antenna, does it go away? If so, its coming via radiation. Add a high-pass filter to the TV, and a ferrite rod or toriod on the power cord. If the set has a metal chassis [dream on], then ground it but carefully as AC cord reversal could be a shock hazard. 2. If its coming via the power line, the above is useful as well as a line filter on the rig [computer surge suppressors often work well]. A good ground especially on a vertical is always helpful. Mounting the vertical on the roof so its above the "view" of the TVs should help. Finally, you may have to live with it. In a dense urban area you will have all sorts of crud you can't eliminate and all sorts of nasty things you do to your neighbours as the result of being *VERY* close. An expense ricebox with good blanking and using hardline or 100% coverage coax to a balun on on a dipole or a reasonable radial system on a vertical are helpful, but ultimately you gotta live with it. I know from ten years of living in a row house with the antenna (beam) on the roof, 75 m from a 110 KV power line in downtown Toronto - oh I forgot the hill too! But, DXCC and good hamming is a matter of making do and forgetting about those W5s with the 200' towers in the quiet country! It also means you sometimes have to call twice to crack the pile HI HI! GL es 73, -- George Gorsline, Jr. VE3FIU / K8HI One of the VE3YDX gang... Y DX? Because it's there(~Y)! Genamation, 351 Steelcase Rd. West, Markham Ontario L3R 3W1 {allegra|linus|ihnp4|...}!utzoo!mnetor!genat!george (416) 475-9434