I'm constantly amazed at the lengths we'll go as hams to overcome the poor engineering and manufacture of consumer products.
-----Original Message----- From: [email protected] <[email protected]> On Behalf Of Jim Brown Sent: Wednesday, November 23, 2022 5:01 AM To: [email protected] Subject: Re: [Elecraft] Running high power On 11/22/2022 2:36 PM, Al Lorona wrote: > 1/ interfered with FM broadcast radio. > > 2/ caused the internet to drop out every time I keyed up on the lower bands. > > Am I the only one? Those of you who run high power all the time... how do you > deal with these annoyances? Both are caused by lousy design of the equipment. Band-aids are SERIOUS common mode chokes on every wire connected to the victim. Follow guidelines for HF transmitting chokes for the bands involved, winding each individual cable through a #31 2.4-in i.d. toroid. Those wires are receiving antennas coupling RF into that badly designed stuff, and chokes kill RF current on them. http://k9yc.com/2018Cookbook.pdf 3/4-in and 1-in i.d. #31 clamp-ons can work with 4-5 turns, but they MUST be wound in sequence around the core. See the photo on page 10 in http://k9yc.com/KillingReceiveNoise.pdf As Vic has noted, use a serious choke at the feedpoint of every antenna, use only coax-fed antennas, matched to the feedline resonant on the bands where they are used, using that same Cookbook as a guide. Try to locate antennas as far as practical from victim equipment. An end-fed antenna, vertical or otherwise, ending in the shack is a recipe for RFI to equipment. ALWAYS provide a serious counterpoise for any end-fed antenna. If you don't, that antenna will use everything in your home as a counterpoise, causing RFI. In summary, take antennas seriously, -- their design, their location, chokes at the feedpoint, bonding in the shack. Avoiding the problems you describe is nothing more or less good engineering practice. Also, some cable/DSL modems are notorious for RFI susceptibility. W8JI solved a problem by complaining to the vendor, who gave him a replacement. This usually requires taking the complaint up one or more levels. 73, Jim K9YC ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
