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  1. elebish

    Capacitor requirements?

    If the input to the 3.3 regulator is only 5 volts regulated, is that sufficiently higher than the 3.3 volt output to give good regulation? Remember, the input can not change due to the first 5 volt regulated output! As a rule, I never use 2 regulators in series! As for the caps (as you mention...
  2. elebish

    Finding resistor value/winding resistance

    Does "winding" resistance refer to impedance as a result of an ac component being applied to this RL circuit? When the circuit is purely "resistive", there will be no lead or lag. The "L" in RL could mean inductive reactance which is expressed in ohms and is determined by the frequency of the ac...
  3. elebish

    Capacitor requirements?

    As for the caps, use the values called out. Using values too high will cause more current draw when first turned on! Those caps are for the purpose of maintaining a steady output under varying loads and to filter out fluctuations from the ac input after rectification.
  4. elebish

    Capacitor requirements?

    Generally, a regulator must have an unregulated input to be able to have a regulated output when the load changes. I suspect that both regulators should be fed by the same unregulated input as long as the 3.3 regulator can handle VDD with the current being drawn by the 3.3 volt regulator.
  5. elebish

    How do I boost a TV antenna amplifier to bring in weak signals?

    Check the signal right at the antenna. Should be about 300 uv for clean picture. 150 uv may give satisfactory results. If less than that, an amplifier at the antenna will only amplify what you already have. Try a larger antenna! Amplifiers downstream of the signal source is for the purpose of...
  6. elebish

    How do I figure out what is jamming the RF signal in my garage

    Try turning off one item at a time. First your computer, then your wi-fi unit, your electronic dog collar if you are using one, the tv, the stereo, home burglar system, any test equipment you may be using, a tread mill if you have one, remote controlled lights or fans, and smoke detectors. If...
  7. elebish

    Old rca trouble

    To get the newly formatted tv signals to show on an analog tv, you must have a digital to analog converter, (about $50). That converter will convert the digital to an RF carrier modulated with an NTSC video signal no longer being transmitted. An old vhs vcr may be used also.
  8. elebish

    Need help to identify a component!

    If the resistance of the thermistor is approx. 12 ohms @ 68 f, and gets lower when heated up, it is a NTC type (negative temp coefficient). This is not difficult to check. If the coil of the solenoid has a diode across, that is meant to reduce the dc back emf to keep the coil from re-energizing...
  9. elebish

    Hitachi v-1100 oscilloscope repair parts or advice

    This component is called a hybrid because it contains several different components formulated to create a circuit designed as a space saver and maybe for good accuracy since it is laser trimmed. Removing the "good" hybrid component and making measurements will be difficult without a "laboratory"...
  10. elebish

    Fender stage 160 amp blowing fuses

    The use of the zeners depends on what the unregulated voltages are. You are right about the MOV not changing the normal operation of the 16 volt circuits. I would still install the MOV, since transients at the 230 input would introduce transients every where in the amp. Try this substitute from...
  11. elebish

    Fender stage 160 amp blowing fuses

    You may not need those 2 zeners if you place a MOV at ac input.
  12. elebish

    Fender stage 160 amp blowing fuses

    I suspect that being where the diodes are placed, that they are to keep the voltages in the neg and pos legs of bridge output to + and -16 vdc and to suppress transients. I don't see a varistor at the 230 vac input, placed after the on/off switch. Install a varistor (MOV) across output of the...
  13. elebish

    Fender stage 160 amp blowing fuses

    Glad I could help. Zeners are difficult to test with unit turned off. Typically .6--.7 Volts forward bias with diode checker ohm meter. Isolation and substitution are good techniques to use when troubleshooting if possible.
  14. elebish

    Fender stage 160 amp blowing fuses

    http://www.schematicsunlimited.com/f/fender/fender-stage-100-160-guitar-amplifier-schematic Use the diagram on the bottom left that applies to your input voltage. Hope this helps! Ed.
  15. elebish

    Fender stage 160 amp blowing fuses

    The red wires are the higher voltages that feed the output transistors. When disconnected, the hum will disappear but the hum could be coming from the pre-amp section if the big filter caps and bridge diodes are good. Leave red wires disconnected and check lower dc voltages that feed the pre-amp...
  16. elebish

    Fender stage 160 amp blowing fuses

  17. elebish

    Oscilloscope used as a component tester

    You may be referring to a curve tracer. I would use direct probes, a gain of .5 volts for Horizontal, 1 volt for vertical and I would direct couple the probes (DC). Be careful not to over bias bipolar transistors as they will destroy. Also, watch your collector voltage! Ed.
  18. elebish

    Component identification please!!

    Right Steve! Caps below 1 ufd are generally marked in pfds. I do believe it is a tantalum since the positive end is marked instead of the negative end. Tantalums usually have a large ufd value respect to size but voltage ratings are low and the leakage rates are very low, about the same as paper...
  19. elebish

    Component identification please!!

    330 uf is a lot of capacitance for that size cap! Just a thought!
  20. elebish

    Heater repair - mystery switch

    If there is a capacitor in the circuit, check it and replace if needed. Capacitors are sometimes used to keep the arcing at a minimum across contacts! Ed.
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