![]() ![]() Some of these Satellits I did more than 10 years ago and they still play OK today. I have also experienced this with AC operated sets (RF-260) with the audio stages that draw excessive current and bog down the reg'd supply line. This doesn't explain the osc Xistor problem but most of the rest of it. Buy It Now 71 results for grundig vintage transistor radio Save this search Update your shipping location Shop on eBay Brand New 20.00 or Best Offer Sponsored Vintage 1960 Grundig Party-Boy Transistor E-200 Radio Pre-Owned C 118. My suspicion is that Grundig engineers biased these Xistors at the extreme lower limits to conserve battery power and with aging they just ned more bias. So I applied my bias change technique, added a 1.8K across the 1K cathode (ooops, emitter)resistor and VOILA!! works like a champ. Knowing the problems with trimmer caps I checked/swapped with known good modules in the drum, still no low end on 41&49. I tried 3 different types and the same problem existed. would go dead at the low end of the scale. (I had already "fixed" the 2nd mixer a year or two ago) In doing an alignment on SW2-9 I found that on 41& 49 meters, the L.O. Last week I was working on one that had a dead RF amp transistor. In other words, the transistors were OK but due to aging(?) needed more bias. A number of years ago, I learned that if the SW2-9 goes dead after a few minutes of operation, lowering the bias resistance on one or both of these transistors would solve the problem. ![]() This circuit mixes down the 1.85 mHz signal from the 1st mixer board to 455 kHz. It has 2 transistors of the same type (BF-184), one is the oscillator, the other is the mixer. This radio has a second mixer on the SW 2-9 bands. Maybe some of you smart guys can shed some light? I was working on a Grundig Satellit 6001 last week and found some interesting although not unfamiliar problems. Hello all, I don't usually hang around here(no tube thingys)but I have an interesting observation. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |