New Henry 2k-4.

Discussion in 'Amateur Radio Amplifiers' started by KC3HUM, Jun 20, 2020.

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  1. KC3HUM

    KC3HUM Ham Member QRZ Page

    Just drove a new Henry 2k-4 home today. Barely could get it up on my tailgate. The manual lists the thing at 135 lbs! Holy crap! And yea I can see why looking under the hood. Things seem overbuilt (or built just right lol). Brass gears everywhere, nice aluminum frame, the peter dahl transformer is twice the size of the transformers in the two lk-500 amps I bought a few days ago. Its a bit dirty and mostly in good shape but there are a few things I need to replace/fix on it. Any help greatly apprecciated.

    Right now it doesn't operate. I have low recieve with the amp compaired to moving both the input and output coax connections with my other amp. I could hear a couple signals with it hooked up to the henry, but moving the input/output to the lk-500 amp, the panadapter lit up like crazy on that amp, and was almost all black with the henry.

    Tubes work within the lk-500 as I switched the tubes from the henry to the lk-500 and I'm getting 600 ish watts out (assuming tired tubes, as the tubes in both lk-500 amps produce about 700-900 watts).

    Voltage is good. 3600 volts on the meter. A bit high from spec in manual, but assuming still normal.

    Plate current is non existent. The amp has a aftermarket plate current meter I believe could have recently been installed as the positive terminal nut was barely screwed on and I needed to tighten that up. I try to put some rf in it and I can hear the relay activating, but no rf out, no grid current, and no plate current. The voltage does drop about 500 volts I believe it was when I was keying the exciter...

    I plan to spend some time with the schematic, but I'm sorta green to electronics diagnosis. Anyone have any ideas to help me out?

    Also looking for some parts to this thing if anyone has a lead on any (prob gonna be hard to find these).

    I need a :

    - band selector knob.
    -a plate current meter ( I don't want this aftermarket one, I want a original Henry one, or at least one that.
    looks more like the factory one).
    -factory tube chimneys?

    Check out the new Henry:

    Attached Files:

  2. KC3HUM

    KC3HUM Ham Member QRZ Page

    A few more photos of the power supply area

    Attached Files:

  3. W9GB

    W9GB Ham Member QRZ Page

    Tyler -

    So, you acquired Bob Benna, N3LWP (SK, Feb. 2020) Henry amplifier.

    Bob often coordinated the local hamfest in Butler, PA at the county’s fairgrounds (Breeze Shooters ARC). Bob worked for Bell of Pennsylvania (as I remember) and volunteer for local fire company.
    FIRST STEP, While De-Energized,
    CLEAN your new acquisition (I even clean the silver plating).

    Create your list of needed parts. THEN Patiently RESEARCH.

    Henry Radio still exists ... and Ted S. Henry often answers the phone.
    They often still have the Hard to Find Parts

    RF Parts in San Marcos, CA is one source for Eimac glass chimneys.

    HOYT Meter in Concord, NH
    is the largest American manufacturer of Analog Meter movements.
    Jewell Instruments is their wholly-owned subsidiary, still mfg. analog meters.

    The Henry 2K-4 meter looks like the Modutec S-series.
    You will need specifications for proper meter match, and a meter scale.

    There are analog meter repair, restoration, and customization shops.

    RAM Meter in Royal Oak, Michigan. Radio amateurs were on staff.

    Weschler Instruments in Cleveland, OH
    Last edited: Jun 20, 2020
    K0UO, W1PEP and W1TRY like this.
  4. KC3HUM

    KC3HUM Ham Member QRZ Page

    W9GB, yes I did aquire this radio from Bobs estate. Good eye, didn't realize I photo'ed his call sign sticker on there. Unfortunately didn't get the oportunity to meet Bob, but sounds like he will be very missed, and also a good member of the Breezeshooters.

    I actually did just this am get this running. At least partially. I cleaned the band selector and the RY1 relay (exciter relay that passes rf through from the rf input bnc and on to the compartment that holds the tubes). Cleaned both with deoxit and the relay with a new 20 dollar bill.

    I also, swithched out the two 3-500z tubes for two in my other amp that I know work well. I read in the manual here that these tubes in the henry are connected in series or somthing like that and I guess when one is bad you need to replace it. Meaning you cant just operate the amp with one working tube like many other amps can do.

    But ya, the amp seems to operate normally. I'm getting 1000w out on 20 meters with 100w drive. Grid current is low at 150ma. Only problem is the plate meter doesn't work, so I will find a replacement like I had intended and see if there are any other bad components causing the meter to not work. I'm tuning for max output, I figure I'm taking a bit of a risk operating with a bad plate meter but idk, should I not have some fun with it making contacts yet???

    W9gb thanks for those links on the parts supply and the manufacturer of the meters!!!! Going to make a call to Henry first and see what happens :)
  5. AC0OB

    AC0OB Platinum Subscriber Platinum Subscriber QRZ Page

    I still have my Henry 2K-4 and use it regularly.

    The first item I would check is the T/R relay contacts may be dirty as I have had this problem in the past. Use Deoxit and a business card or thick paper stock. Spray the contacts and then run the business card or thick paper stock through the contacts.

    Another item, if this Henry is stock, is the resonating capacitor on the PS choke as this cap can fail after many years of use.

    I converted mine from a choke supply to a pure RC filter supply with a different transformer, has been trouble free since then, and it has less cabinet heat.

  6. W9GB

    W9GB Ham Member QRZ Page

    I worked at Slippery Rock (NW corner of Butler county) for a couple of years in early 1980s, before returning to graduate college. So, I was able to attend some radio club events.
    IF Ted does not have the meter, he should be able to tell you the manufacturer/part number.
    Last year, I needed a 24 Volt Relay, model 1365, Guardian Electric (Woodstock, IL) for another project. Although Guardian is in my area (less than 50 miles) and Allied is a local distributor —
    All I heard we’re excuses for inability to Sell one (within 90 day delivery).

    I called Ted Henry, since the same relay was used in many Henry HF amplifiers.
    He had it in stock, so I bought two (2) and the plug-in sockets for that 1365 series.
    Jewell Instruments / Modutec S-series (taut band) Analog Meter
    Data Sheet (circa 2014)
    Catalog Page for various S-series models mfg.
    Last edited: Jun 20, 2020
  7. K3XR

    K3XR Ham Member QRZ Page

    Be very careful of the high voltage in that amp.
  8. AC0OB

    AC0OB Platinum Subscriber Platinum Subscriber QRZ Page

    Some filament lighting problems can be traced to crystalized solder connections in both the socket and the Filament choke.

    Two ferrules clamp the right side of the RF filament choke wires that go to the filament connection block. I de-soldered the wires from the ferrules and the filament supply block and reshaped the ferrules for a better clamping force around the RF choke wires. I then re-soldered those connections with silver solder.

    While under the RF deck, it is also a good proactive measure to re-solder the other side of RF filament choke wires to the tube pins with silver solder. Also check the resistor and capacitor connections.

  9. AC0OB

    AC0OB Platinum Subscriber Platinum Subscriber QRZ Page

    Here is the picture of the underside of the RF deck.


    Attached Files:

  10. K6BSU

    K6BSU Ham Member QRZ Page

    Meters are expensive. I would never replace a meter until I have examined it carefully and tested it away from its radio.

    Sometimes, the problem could be a sticky movement. Many have an adjustment for the bearing

    Make sure the screws (interior electrical attachments) are tight

    You can test using a low voltage source and the proper resistors to get full scale. No need for high voltage test.
    AC0OB likes this.

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