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  1. alfa88

    In need of RF part ID part 1

    Well I'm stumped. I pulled this off a Glenayre board. It was in a shielded area. I did a Google search and looked on the Toko site. Nada. Any clues? I want to make some RF experiments with these.
  2. alfa88

    Odd Sony WEGA Problem

    I've got an odd problem with my Wega projection TV. Everything works well except that it keeps adding digital channels once it is tuned off. It's almost as if there is a bios battery that is going bad. Any expert opinions?
  3. alfa88

    dvb remote not working how to know ir led

    Remote control testing One trick I've used in the past is to take a snapshot with a digital camera of the business end of the remote while pressing a button. The ir diode will show up as a green spot.
  4. alfa88

    run a low voltage led(3volt) at higher voltage(12-18 volt)

    Poof! If you were to apply 12 v directly to the LED it would flash and go poof! The LED is rated at 3.4V so the math goes 12-3.4=8.5, 8.5Volts/500mA=17ohms, 8.5V*500mA=4.2 Watts. If you don't want your LED to go poof put a 17 Ohm/ 5 Watt resistor on one leg. That is a heck of a LED they usually...
  5. alfa88

    stepper motor control with a parralax basic stamp

    BINGO! Sure enough, you were right Luke. I started browsing on 'H bridges' and happened on this link: http://forums.parallax.com/showthread.php?72568-h-bridge-circuit-question-%28newbie%29. :D
  6. alfa88

    stepper motor control with a parralax basic stamp

    I realize that this is mostly PIC and Atmel territory but I got a Parralax Basic Stamp kit as a gift awhile back. I ran through the book and then it all gathered dust. But now I may have a job lined up and knowledge of stepper motor control would be a plus. I have some steppers from various...
  7. alfa88

    Function Generator Chip

    Function Generator Chips Yea I have a couple XR2206s in my bag of tricks, the ICL8038 was a nice one and I'm aware of the Max038 but even that one is out of production. It seems like the function generator IC market is dead.
  8. alfa88

    Function Generator Chip

    I'm curious if there is company still manufacturing function generator chips.
  9. alfa88

    SWTPC Schematics

    I'm looking for a schematic and possibly the board pattern for Southwest Technical Products' Universal digital instrument plug ins. I already have the mainframe documentation.
  10. alfa88

    Pic Programming Board

    Excellent. Thanks!
  11. alfa88

    Pic Programming Board

    I was scavenging an old pager transmitter and on of the boards was a PIC16C71. Is there a schematic where I could kludge together a programming board?
  12. alfa88

    Need Help Identifing Transistors

    I tore into a 20 year old pager radio and these transistors were in the power amp section. The boards they are on were mounted on massive heat sinks. I tried a Google search and a NTE cross ref and came up dry. A Motorola 587-3737-000-B and a RFP100-100RH (manufacturer unknown).
  13. alfa88

    Sherwood RX 4103 Schematic

    Sherwood Update Still no schematic but I decided to tackle it anyway. The board was riddled with bad solder joints. Most likely due to the fact that Sherwood made all the holes oversize to facilitate manufacture. The stereo works now but I have a hunch the control chip is flaky. Pushing various...
  14. alfa88

    My JVC Tape Deck Circuit board search

    If there's not a bunch of surface mount parts an alternative would be to strip the board, scan it, touch the scan up with a graphics program and make a new board via the laser masking method.
  15. alfa88

    Sherwood RX 4103 Schematic

    I just came across a Sherwood RX 4103 stereo and it turns on and I hear a relay clicking but no audio. If anyone has a schematic I would appreciate a copy.
  16. alfa88

    Does this blown fuse come out?

    Fast Blow A fast blow, 1/3 amp fuse will work. As stated before the end caps pry off. Since the fuse is already bad you could crush the fuse to ease extraction but take care not to break off those end caps or to get broken glass in your eyes. Pliers and needle nose pliers are your friends here.
  17. alfa88

    Colvern potentiometer

    This seemed too easy. Do a search at Newark.com for: CLR110611S10KK . Take a look at the picture. Is that the part?
  18. alfa88

    convert 4.7 volt to 1.5 volt DC

    The voltage drop across a silicon diode is in theory .7volts. 2 of them in series would be 1.4 volts. I don't think a nokia charger puts out too much current so maybe try a couple rectifier diodes. 1N4001, 2, 3, etc. measure before you hook up your load.
  19. alfa88

    Fisher CA-283 Amplifier Left Channel Dead

    CA-283 A schematic would be a world of help. Barring that I would inspect the board for damage after the smoke incident and while you're at it look for cold solder joints. You mentioned 1 channel showing it was getting input. Does that mean the other channel didn't appear to be getting input...
  20. alfa88

    Help with educational material (boost circuits)

    I believe you're talking about a DC to DC converter. Here's a starting point : http://www.maxim-ic.com/app-notes/index.mvp/id/2031
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