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Henry 2K classic X HV transformer question

Discussion in 'Amateur Radio Amplifiers' started by N0FAQ, May 1, 2012.

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  1. N0FAQ

    N0FAQ Ham Member QRZ Page

    Hi all, hoping to find some one with info as Ted @ Henry and radiodan didn't have answers.

    Just picked up a Henry 2K classic X from a silent key estate sale.

    The home was very dirty all equipment I purchased was VERY dirty inside and out. This 2K however was spotless on the inside, like hospital clean.
    This led me to think it was unused, when I removed the RF deck, their was no dust on the fan.

    Anyways, going thru this amp, I was getting ready to fire it up. checking the voltage taps on the transformer I see its ready for 240VAC operation which is what I have. the manual states tap 1 and 4 for 240 V.

    upon further inspection I see what looks like a factory jumper between tap 2 and 3, this didn't make sense to me ?

    So using my ohm meter I removed all connections from the input side of the Xfmr and the jumper and ohm'ed them out,
    so leaving one lead on tap 1 i got the following results
    tap 2 0.3
    tap 3 open
    tap 4 open

    when I re install the jumper between tap 2 and 3 the tap 4 reads .8

    from what I can guess is possibly the Xfmr went open for some reason, and the ham jumped tap 2 and 3 to bypass the open circuit ?

    does this make sense? or am I thinking to hard ?

    any ideas would be appreciated.


  2. WB2WIK

    WB2WIK Premium Subscriber QRZ Page

    You're overthinking this.

    I have the 2K Classic X manual and schematic and there should have been FIVE terminals, not four. 1 and 5 are the 240V phase lines, 2 is neutral, and 3&4 should be jumpered together for 240V operation, and the Classic X was wired for "only" 220/240V operation; it didn't have any provision to operate from 110/120V.

    If for some reason they reduced the 5-terminal strip to only 4 terminals (Henry made LOTS of undocumented changes!), then they did something different over time, and the question is whether the neutral should go to 2&3 or to chassis ground (or both).

    If your manual shows different jumpering than mine, it would be interesting to see your manual. Mine is the same as this one on line:
  3. N0FAQ

    N0FAQ Ham Member QRZ Page

    I believe you are referring to page 6 of the manual, where it shows the power hook up to amplifer plug, I think

    I am referring to the taps on the HV transformer its self. please see page 20 and 21 of the manual

    may be im looking at this wrong, but on my HV transformer I have 6 taps on the input side labeled, 1 2 3 4 8 10

    any possibility of removing your cover from the back and looking to see if 2 and 3 are jumped on the transformer

    Thanks rick
    Last edited: May 1, 2012
  4. WB2WIK

    WB2WIK Premium Subscriber QRZ Page

    I don't have the 2K CL X any longer; I had one in 1984-1988 or so, but kept a copy of the manual. After that I had a 3K Premier, which is quite different.

    I see your confusion now; you're right, I was referring to the AC power cord wiring terminal strip.

    The schematic I have (and also on line) does not show ANY "taps" on the transformer primary at all, so the schematic does not agree with what they describe and what you evidently have! Not a huge surprise, Henry was big on making changes and never getting the documentation quite caught up.
  5. N0FAQ

    N0FAQ Ham Member QRZ Page

    Hey thanks for the help anyway, hopefully some one with the same amp will look inside theirs and let me know

  6. W9GB

    W9GB Ham Member QRZ Page

    Rick -

    That is the Export model (200-220-240 VAC only) -- has the old 200 VAC tap for Japan.

    Page 20 says factory shipped (default) was 220 VAC. For USA you should set for 240 VAC,
    and wire to your electrical service on a dedicated 240VAC, 20 Amp circuit.

    Are you familiar with Global (this was Export model) Multi-tap transformer primaries?

    Call Tom, NE7X in Pheonix -- he has a few Henry amps. :)
    Last edited: May 2, 2012
  7. N0FAQ

    N0FAQ Ham Member QRZ Page

  8. W9GB

    W9GB Ham Member QRZ Page

    Rick -

    VERY COMMON, Dual Primaries -- Wired in SERIES when jumper connects lugs 2 and 3.
    Two 120 VAC primaries wired in SERIES becomes a 240 VAC winding
    Return all hookups and jumpers to where you started.

    Figure 10 on Page 27 for this 2K Classic X model (middle photo)
    has a Pictorial of Power Supply and terminal strip --

    FOLLOW the instructions. LOOK at lugs 1-5 for AC line hookup (Pictorial),
    Lugs 1 and 4 for AC input with jumper 2-3 should be right for 240 VAC.
    This is your where your AC connects -- BLACK and RED wire in USA.
    The AC Safety Ground GREEN is connected to Metal Chassis or designated Ground Lug.
    IF this is confusing, ask more questions, or consult an Electrician

    LEAVE ALONE 6-10 (factory).
    Last edited: May 2, 2012
  9. AH6RR

    AH6RR Ham Member QRZ Page

    If the amp is as clean as you say it is find a 240V Variac and power it up and if memory serves me right Henry sold the X model here in the US also, so it must be set up right from the factory for US power. The reason yours does not matach the manual might be because they changed vendors to make the HV transformer.
  10. N0FAQ

    N0FAQ Ham Member QRZ Page

    Thanks for your help

    just spoke with a retired henry guy, and got the correct answer.

    the transformer in this particular amp 1092, is not the standard 1171 that normally comes in this amplifier. he told me that their should be a jumper between taps 2 and 3 on the transformer terminal and to use 1 and 4 for the 240VAC input. anyways going to fire it up tomorrow and see what happens.

    Thanks everyone for your help

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