Thanks, Alan, those are pretty good stories :) On Mon, Dec 4, 2017 at 6:51 PM, wrote: > > These two stories remind me of a story that appeared in Electronics > Australia "Serviceman who tells" feature. This was a column written by > someone whose identity was concealed by the editor, but ran a typical one > man radio/TV service business in a suburb of Sydney, Australia. This > particular story was related to him by another serviceman who ran a simil= ar > business in an area that had a number of residential tower blocks in his > 'catchment area'. This particular story concerned a customer whose TV wou= ld > periodically not receive a certain TV channel, even though they were line > of site to the transmitter. Said customer was some way up one of the towe= r > blocks, and despite some visits to the abode the problem was not diagnose= d. > Eventually customer was told to call him immediately the problem recurred > and he would come around promptly. In due time said phone call happened, = so > serviceman goes to the home and sure enough the channel concerned was jus= t > visible in the snow that was typ! > ical of a very weak signal in the days of analogue TV. No matter what he > did to the set to attempt to repair the problem produced any improvement, > so after some time he ends up standing in customers lounge pondering what > the cause of this strange loss of channel was - it was one specific > channel, all the other channels were as strong a signal as they had ever > had. His eyes are wandering around the apartment as he was thinking, and = he > realised that son was playing with his train set on the floor - and the > loop of track was about right size for a dipole at the VHF frequency of t= he > channel concerned. A moments stoppage of the train and breaking a track > joint soon restored the picture on the channel of interest. > > Another story from the same source concerned a colour TV that would give > only B&W pictures on a certain channel. This was eventually tracked down = to > the 300 ohm ribbon from the terminals on the back of the cabinet to the > tuner being secured with a piece of wire looped around a suitable point a= nd > then had the ends twisted to secure the ribbon cable conveniently out of > the way. The loop combined with the twisted ends combined to make a tuned > circuit at the colour burst carrier frequency on this particular channel > which acted as a trap preventing the colour burst from reaching the tuner= .. > A quick trim of the amount of twisted portion (which were fairly long) > produced colour pictures. > > -- > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .