on 7 January 2013
Great little kit. I made it in one afternoon and it worked well first time. Cased in a nice quality cardboard box finished to look like an old valve radio. Designed like a home-constructor Short Wave kit of fifty years ago, it's a TRF with detector, audio amplifier and output stage. First two stages made from transistors, output stage is a simple chip. It performs about as well as a good example of an old three-valve TRF would do. Stations can be got without too much trouble once you get the hang of the reaction control. Basically, keep the second knob from the left turned up to the point where the set is just short of whistling and hooting, and you will get plenty of audible stations. To find stations, scan slowly with the reaction control up just a smidge further and the stations show up as whistles. Back off the reaction a bit and re-tweak the tuning and there you are. Practice makes perfect. It only has one tuned circuit but on today's Short Wave bands you can get the stations picked out from one another without too much trouble even though there is no slow motion drive on the tuning knob. As supplied it covers roughly 3.5MHz to 9MHz, though the tuning scale is not accurate. I fancied covering the 31m band so I carefully unscrewed the iron dust core of the tuning coil and was rewarded with good 31m band with the dust slug sticking out of the coil about five millimetres. Yes, I did get Radio Australia on it! I used a big aerial, plugged into socket A3. A smaller aerial will work OK in aerial socket A2, and a very small aerial with low capacitance to earth will work OK in socket A1. The instructions look to be very thorough but they are in German only, so only take on this kit if you can successfully make a three-stage SW TRF from a good circuit diagram and some good photographs. It is a nice circuit and it works well, though like its old valve cousins, it needs not only a decent aerial, but a proper earth too. Without an earth it's all squeals and no stations. The circuit board is very small and you need to be capable of tidy soldering for the thing to stand a chance. Good quality stuff and with a bit of skill it goes together well. Runs from a 9V PP3 battery so safe and economical.