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  1. dorke

    Help selecting my 1st DSO please.

    No hurry, they are well known and sell for a few years already. You can watch reviews on YouTube as well.
  2. dorke

    Help selecting my 1st DSO please.

    Here is a learner's scope for just 15$US. Should be fine up to 200KHz,small and very portable. A hobbyist dream .:cool:
  3. dorke

    Where To Start ..?

    ThermO, Please take care those caps are very dangerous !!!:eek: Properly discharge them before handling and check with a DVM that they are discharged , don't ever short them !
  4. dorke

    Farberware Food Processor FP3000FBS

    Yes,they would do fine but are a bit pricey. Here is another option,make take a bit longer to arrive: https://www.ebay.com/itm/10-x-1N4742A-1N4742-ZENER-DIODE-1W-12V-FREE-SHIPPING/260830733418?epid=0&hash=item3cbab9246a:g:ZBgAAOxyFiRRzKhZ Note: 1.Do not connect the board to power with DZ1 out...
  5. dorke

    Farberware Food Processor FP3000FBS

    Since DZ1 shows 001 on both directions outside of the board we have found the problem, a shorted zener diode. Get a new one, ohm it before you solder it in. Please check diodes D1-D4 the same way( in circuit)
  6. dorke

    Recommend UK calibration service please?

    Well, If you are into test equipment repair you definitely do need to have a calibrated and very accurate DMM. You didn't specify which kind of equipment... There are so many types, which may require calibrators for R,L,C,ACV,RF power,distortion etc... you may end up having a full Calibration...
  7. dorke

    Farberware Food Processor FP3000FBS

    "this is what it is reading on DZ-1: With Red Probe on black (+'ve) line = 001 With black probe on black (+'ve) line = 001 " This looks like a short on DZ1.(can be the Zener,or other parts which are paralleled to it) What is written on DZ1? How are your soldering skills? De-solder and Lift...
  8. dorke

    ON Semiconductor diode

    Welcome to EP. It looks like it is a TVS of 53/62V(makes sense?) part number 1.5SMC62AT3 here is it's datasheet. Possible replacements here.
  9. dorke

    Recommend UK calibration service please?

    The HP34401A has no "mechanical calibration" inside it . The manual does recommend calibration at least once every 2 years. This is mandatory if your meter has been repaired! If not,in practice you can do it yourself through the extensive "self test". Read about it in chapter 4 of the 34401A...
  10. dorke

    Farberware Food Processor FP3000FBS

    Yes, Checking for correct drooping of ACV. The Red reading is too low. That makes the biggest brownish capacitor a suspect(next to the yellow cubed one). But there can be other issues. Please recheck the Red voltage (ACV), and add the pink(ACV) , Please make these DCV measurments: 1...
  11. dorke

    Turntable Repair - Stopped Spinning

    Remove the belt and try spinning the table,it should move effortlessly. Is the belt you have put in the exact correct size,is it too small, too tight? With the belt out, try spinning the motor pulley/shaft,again it should move freely. Don't oil the motor if it turns freely. Then, Start with...
  12. dorke

    Farberware Food Processor FP3000FBS

    Please check the following pairs of color(both probes on each point of color) in ACV(200), careful, 125VAC expected(blender connected to mains)! In this order: Blue ,yellow,red. What do you get?
  13. dorke

    Oscillator

    Here is an even simpler one. Simpler to explain and understand. Any number of odd gates can be used, you can use 1,3,5 from an hex schmidt-trigger and notice the effect on the oscillation period. Obviously, You should use an oscilloscope to test it.
  14. dorke

    Choosing the right NTC

    Look at the description of the module. It has two set points acceleration temp and full speed temp. Have you tested them both?
  15. dorke

    Farberware Food Processor FP3000FBS

    "I've also tested voltages around the board, and they vary from 125v to 60v near to the main black wire input, then seem to be around 0.4v around the main IC and the rest of the circuit board. I've also tested the satellite switch board, and when the correct pin on the IC is monitored for a...
  16. dorke

    ips521 mosfet

    Well, They are not obsolete yet,but declared EOL . They will be available from Infineon till mid 2018. You should contact Infineon here for replacement or were to buy them. Note, the other big question for you to find out is: why did they fail?
  17. dorke

    Analog TV Tuner struck by lightning

    A lightning strike could be a real problem. The high voltage it introduces on the power lines and input cable may destroy a lot of devices in the TV. Does the operation of the TV work? Does the remote control work? Do your Tv other inputs work( RCA,15pin etc.)? If the above don't work,the TV...
  18. dorke

    Calculating reflection coefficient

    What you are doing wrong is you don't take into account the length of the transmission line. You have found the coefficient at the load and source points, they need to be recalculated at distance l, taking into account the transmission line length,l, and the alfa and beta. And yes a smith...
  19. dorke

    help i.f transformer how to make one

    As a beginner you need not and should not build a transformer ! All you could ever need may be bought cheaply. In fact professionals rarely build a transformer,they buy them as well.
  20. dorke

    Relay differences

    I wonder where did you get the 30A info from? The data sheet states 2.7A,so you can use a "smaller" relay ,a 10A one will do fine, It will cost you less than 2$(Omron,Panasonic). see here. https://www.mouser.com/Electromechanical/Relays/Automotive-Relays/_/N-b19z1?P=1z0x3ubZ1z0x3x8&Ns=Pricing|0
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