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  1. tubbytwo

    LM317 high voltage

    I know the max for the ML317 is 37VDC, but is there a way to boost that  to 90VDC at about 30mA? I'm looking for an alternative to four 22V Zeners. The arguement was that IF a Zener shorted, the rest could also go.
  2. tubbytwo

    TDA7052 VS LM386 Question

    Is there any advantage in using the older, LM 386 over the TDA7052? The Phillips TDA seems to be a great amp chip with low draw and higher output, not to mention just about completely self contained. Of course it costs three times as much. Anyone have any experience with it?
  3. tubbytwo

    LM386 Amp with 4 Ohm Speaker

    All schematics show an 8 Ohm speaker. Any change in parts to use a 4 Ohm speaker?
  4. tubbytwo

    9V battery & cap

    I'm using an LM386N in a simple amplifier and am using a 200uF cap parallel to the battery, before the switch, for noise supression. Should the cap (with no leakage) run the battery down in a week?
  5. tubbytwo

    Neon flashes with the music

    Is there a simple way to have a neon bulb (ne-2) flash with the music of say a portable CD player or AC radio?
  6. tubbytwo

    Antenna transmit pattern

    Can someone tell me if my 30 foot east/west antenna has the best transmitting range north/south or as I heard somewhere that it was around 20 degrees off vertical. I know this is the wrong forum for a question like this but with all the traffic here I figured it was worth a shot. Thanks in...
  7. tubbytwo

    Sound activated NE-2

    I have a one tube AM transmitter that I plug a portable CD player in to so I can broadcast old music to my antique radios. I would like to have a neon bulb on the front of the transmitter to monitor, or flash bright/dim with the music. Right now the only way I can tell if it's working is to turn...
  8. tubbytwo

    Simple voltage doubler

    Hi all. I need to supply my one tube transmitter's plate with 250VDC and I was going to use a voltage doubler out of the 120V transformer with two diodes and capacitors, then a bleeder resistor to lower the voltage. My question is, can I substitute the second diode with a zener to regulate...
  9. tubbytwo

    117L7 tube test

    First off, sorry if this is the wrong forum. I built a small one tube transmitter (Lil'7) and everything was perfect, except it didn't work. After double checking everything three times I tested the new 117L7 tube (from AES) and found one plate (pin 3 output) measured about 650 (good) and the...
  10. tubbytwo

    isolation transformer question

    I have an old home built isolation transformer that is nothing more than two (110/24v) stepdown transformers back to back. It works and is only good for about 140 watts. I just noticed that the center tap on each 24v sides are NOT connected. Any benifit it connecting them. Just found this forum...
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