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  1. biff44

    Quick and dirty strain relief for a wire soldered to a PCB

    no not hot melt glue. that will be rigid and just peel off the board. use an RTV type of glue. make sure there is some RTV attached to the wire insulation AND the circuit board, or whatever you are soldering this wire too. then, just as important, make sure the wire has some stress relief in...
  2. biff44

    Hi are there any other techniques a

    yes. you can make a variable frequency motor drive, and pair it with a speed controllable motor. such as: https://www.groschopp.com/whitepaper/how-to-use-vfd-variable-frequency-drive/ in bigger applications, this is fairly common. i have a small milling machine that controls the spindle speed...
  3. biff44

    waveform problems on oscillator circuit

    it looks like the crystal circuit has more than one frequency resonance, and the total circuit is actually oscillating at two frequencies simultaneously. have you looked at the wave form with an AC coupled spectrum analyzer. you might have to add L-C circuits to suppress the unwanted oscillation
  4. biff44

    micro components to drive a shaft

    there are things called MEMs actuators. I wonder if they might be too small for your application though.
  5. biff44

    Flex Circuit Tear Protection

    so can you stiffen the area around the punched hole? maybe have a small picture frame of copper around the hole? Glue on a 5 mil picture frame of G10 board?
  6. biff44

    External signal to trigger a PFET once only???

    An SCR will also act as the thyristor mentioned above. on the SCR gate, it you put a voltage there above the trigger level, DC current will flow thru the SCR, and will continue to do so even if the gate voltage goes back to zero. your big problem is that this trigger voltage is between zero and...
  7. biff44

    LED Landscape Lighting Radiated EMI Registers S9 On HF Amateur Radio

    use an emi filter. Shunt capacitor, series inductor, shunt capacitor right at the power supply hook an oscilloscope to the "DC" output, and record what frequency the noise is at. then design a filter to stop it www.MaguffinMicrowave.com Maguffin Microwave wireless design consulting
  8. biff44

    Isolation valve(Block Valve) installation for Rupture Disk & PSV

    a valve in front of a rupture disk? she go boom! www.MaguffinMicrowave.com Maguffin Microwave wireless design consulting
  9. biff44

    H-Bridge driver

    MP8046DF-LF-P at Mouser.com. a couple of bucks www.MaguffinMicrowave.com Maguffin Microwave wireless design consulting
  10. biff44

    microwave sensor independant of polarization

    well, I would use a circular polarized antenna (probably in round waveguide), then convert it back to single mode waveguide, and then hang a schottky diode detector across the E field direction. Schottky diodes are pretty fast, if loaded with a resistive load on the bias port...
  11. biff44

    Looking for RFTech MM-3000B Documentation

    since it was a MA, USA firm, it is possible it was approved for use in the USA. If so there might be a manual and/or test report on file at the FCC. Look for an FCC ID number on the equipment. If you find it..u are in luck. Enter it here...
  12. biff44

    OL interference

    THEN, there are the board issues. Sounds like you have an open PCB--i.e. no shielding. While many systems can not afford the cost...it sounds like you are working more on a military type system where cost is less important. Try putting your PCB into a channelized metal housing. By...
  13. biff44

    OL interference

    Well, reading this post with some hilarity, there are a number of potential issues you are facing. 1st, you need to do a sub-system level analysis of your block diagram. Sounds like you have some sort of mixer as an upconverter, and possibly amplifiers or filters. 1st u need to look at the...
  14. biff44

    OL interference

    OL signal, OL tone...are these supposed to mean something to us? www.MaguffinMicrowave.com Maguffin Microwave wireless design consulting
  15. biff44

    EMI suppression at 2.4 GHz

    you could slip some of this stuff over the wires. Probably good for another 10-15 dB. http://www.arc-tech.com/cables.php www.MaguffinMicrowave.com Maguffin Microwave wireless design consulting
  16. biff44

    Could be a laser beam used as an antena to detect EM waves?

    There are previous papers where a fiberoptic cable is coated with something (like thin silver layer) and it responds to a microwave signal by causing an optical phase shift. That is using a laser, but not freespace. There would be plenty of non laser methods, like using neon lightbulbs...
  17. biff44

    How do you measure the impedance of speakers connected to a p.a. amplifier?

    BTW, you can measure the actual impedance using an "audio impedance meter", which apparently are available new for a few hundred bux. If you are crafty, you can do the same with an oscilloscope--display the voltage and current sine wave outputs and Zload=V/I (complex math. You can see the...
  18. biff44

    How do you measure the impedance of speakers connected to a p.a. amplifier?

    there are a few ways to respond to this problem: 1) lock up the amplifiers and their speaker connections in a metal cabinet 2) go inside of the amplifier itself and install a series resistor so that the maximum output current is not exceeded. 3) go inside of the amplifier itself and install a...
  19. biff44

    Antenna for EMC testing

    Precompliance testing is done to assure, to a reasonable level, that you will pass the EMI leakage testing if you send the unit to a calibrated test lab (and spend lots of money doing so). So you not only need an antenna that covers your frequency range, you need one that is...
  20. biff44

    Group delay calculation through S-parameters extracted from a touchstone file

    No problem. I had to do that manual calculation for a project because, even though I have used Group Delay's hundreds of times before, when I actually tried to manually calculate it out I was way off until I hunted down the right units. I did just see one small error in the nomenclature...

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