A remote Power Supply for the SB-220

Discussion in 'Amateur Radio Amplifiers' started by WA6MHZ, Apr 26, 2017.

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  1. AF6LJ

    AF6LJ Ham Member QRZ Page

    Yes it does, it has the EMI filtering already in it.
    The only thing you need to do is one side of the output needs to be connected to the chassis, along with the ground terminal. You May have to put a choke on the output lead that feeds your circuits and it needs to be At the power supply. Do not choke the lead that you connect to chassis.
     
  2. AF6LJ

    AF6LJ Ham Member QRZ Page

    Oh and one more thing...
    The W7RY QSK board is complex and if you are not going to do real QSK I wouldn't see the need for it.
    You DO need a relay to cut off the tubes on RX...
     
  3. WA6MHZ

    WA6MHZ Subscriber QRZ Page

    There is a AG6K bias Keyer I have a schematic for, but it involves a FIxed current source from a 120VDC supply and the relays are driven in series. So maybe the W7RY is still the way to go
     
  4. WA7PRC

    WA7PRC Ham Member QRZ Page

    IMO, it's not complex. Being able to run QSK isn't the ONLY reason for it. It also:
    • prevents hot-switching
    • electronically regulates and switches operating & cutoff bias
    • uses dead-quiet relays
    • uses hermetically-sealed relay contacts
    Rich AG6K's idea works. W7RY's PCB does it all, plus electronic bias regulation/switching.
     
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  5. KD2ACO

    KD2ACO Platinum Subscriber Platinum Subscriber Life Member QRZ Page

    I do remember my very first post to Pat several years ago... :) You really want separate returns for those meter lines because the signals will get swamped (meters pinned one way or the other) in the noise if you share the returns with the grounds.

    If there's something I've managed to learn from Steve WB2WIK, it's that you probably only need to meter the grid current. Everything else falls where it will anyway and there's not much to do about it! So, one twisted pair for grid current... :p

    edit: actually I've learned lots from Steve and both of you too!
     
    Last edited: Apr 26, 2017
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  6. AF6LJ

    AF6LJ Ham Member QRZ Page

    I agree with you however.
    Remember Pat is moving the power supply out of the cabinet and the W7RY board is designed to run off 210V from the bias winding of the transformer.
    I'll send pat a copy of the circuit but I don't think that is what he wants.
    The electronic bias switch is dog simple, and we should be able to build something that will fit into his current design.
     
  7. AF6LJ

    AF6LJ Ham Member QRZ Page

    I have always been of the belief that you can't meter too much.
    Everything can be mearured in the negative end of the power supply, it is simple and Heath has already done it for him.
     
  8. WA7PRC

    WA7PRC Ham Member QRZ Page

    85VAC (rectified, +120VDC). It's easily modified to operate from a different voltage.
     
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  9. AF6LJ

    AF6LJ Ham Member QRZ Page

    Agreed.
     
  10. KD2ACO

    KD2ACO Platinum Subscriber Platinum Subscriber Life Member QRZ Page

    I like meters too. But remoting them or even putting them in the same chassis has better results with two wires to the shunts because the signal is millivolts at the shunt and gets lost in the gook. I had this problem (erroneous grid I readings) at the same time Pat had this problem in 2013 IIRC, which is why I posted this issue back then once I found out what was going on with help from W8JI's website.
     
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