Ben wrote: Roger that. The tubes are the easy part as there is a mountain of NOS (new unused old stock) floating around at acceptable prices. The coils needed as well is capacitors with adequate high voltage ratings are harder to find. You will also need resistors with .5 and 1W rating also scarcer and more expensive.. In many parts of the circuit the current generation metal film resistors exhibit too much inductance compared to the older carbon composition types. The power transformer you can plan on paying dearly, salvage from old gear or winding your own (on a dead one salvaged). FYI: doing a vacuum tube tuner at 88-108 mhz is as much a mechanical project as electronic. The preferred tubes for that are the old RCA Nuvistors (6ds4 and 6cw4 also available as NOS) but the sockets may be a challenge. there are other tubes that do nearly s well in the miniature basing. If this is stereo, a stereo decoder using tubes is a ponderous afair and none I've worked with are as good as the mid 80s or later solid state PLL based designs. Coils for this will be hand made if you really want to and design data will be scarce. Do try to find a mid 1960s RCA receiving tube handbook (circuits you will need are in the back). The easy way, find a Dynaco or Heathkit Tuners and refurbish it. Typically $50 in capacitors, a few tubes and they will live again. I completed a 5 tube 3.5 to 4mhz am/ssb/cw receiver from my junk box a few years ago. Based on current prices for the common parts it was greater than $200 for the parts new. Heavy cost items, aluminum chassis, power transformer (6.3V at 3A and 150V secondary), audio output transformer, IF coils, tuning capacitors, dial assembly, tube sockets, 1/2watt resistors, forms for hand wound coils. I know this as a friend wanted to duplicate it so I made a parts list (with acceptable substitutions) and he priced it deciding to pass on it. He had no old parts to draw on. Having built and maintaining ham gear using tubes the mechanical issues and finding suitable parts makes it difficult. While interesting and hobby fun I can build from scratch with conventional solid state devices faster and better radios. My junk box is not only bigger than most it also yields a lot more 35+ year old parts! Allison

On 2 Jan 2010 at 23:38, Geoffrey Reed wrote: Were those the ones that used a plastic body rather than a metal casting? --Chuck

On 3 Jan 2010 at 13:03, David Griffith wrote: Why not start with some simply 1 and 2 tube designs. e.g. TRF, regen/autodyne, superregen? Two-tube superhets are also possible. Dig up some old radio experimenter's books from the 1940's and 50's for suggestions. --Chuck

Tony Duell wrote: One place to look for simple superhet and other recievers without the high voltages needs: http://www.junkbox.com/electronics/lowvoltagetubes.shtml Having used space charge tubes I can say they are available and fun to work with. Also it's a nice thing to work at 12V and not worry about getting a shock. Allison