Restored Heathkit AR-3

Discussion in 'Amateur Radio' started by W5RKL, May 2, 2017.

  1. W5RKL

    W5RKL Member

    I recently fully restored a Heathkit AR-3 four band short wave receiver. I picked up the AR3 on eBay and knew it had problems.

    I completely disassembled the receiver down to a bare chassis. The attached pictures that show various stages of the restoration.

    The receive was fully disassembled down to the bare chassis. Components such as the RF gain and volume control pots, Mode switch, BFO coil, IF transformers, main and band spread variable capacitors, individual RF, Mixer, and Oscillator coils, band switch assemblies, and power transformer were cleaned and reused. The chassis was discolored by age, corrosion and accumulation of years of grease and dirt. The original copper clad chassis would not clean up so I sanded the chassis then painted it Rustolium Special Metallic Copper paint from the local True Value Hardware store. The tube sockets were replaced with new 7 and 8 pin socket obtained from eBay. The rear panel octal socket was not replaced as it was in very good condition. All the wiring, including the metal spring type shielded cables were replaced with new wiring and new shielded cables. The triple capacitor can had physically leaked on the bottom so it was replaced with a new DX-100 triple capacitor can with the same capacitor values and a new metal mounting plate obtained from Hayseedhamfest. Since the new DX-100 triple capacitor can mounting plate was slightly larger, the mounting holes would not line up so new holes were drilled. The IF cans were removed and disassembled. The IF cans' internal fixed mica capacitors were removed and the IF can were reassembled, installed on the chassis, and new external fixed 100pdf mica caps were connected across each IF cans' primary and secondary winding's. New fixed capacitors and resistors replaced all the old original capacitors and resistors throughout the receiver. New multi-tab terminals strips replaced the old worn out terminal strips. All new mounting hardware screws, washer, and nuts replaced the old mounting hardware. New rubber grommets replaced the original dried out grommets. The original 2 blade non-polarized power cord was replaced with a new 2 blade polarized power cord. A fuse holder with a 3/4 amp fast blow fuse was added as the receiver did not originally have a fuse holder. The front panel was cleaned with 409. The cabinet, made of plywood covered with what appears to be a "Peel & Stick" covering, was cleaned with both 409 and water. A few coats of Armor Al was applied to the cabinet and a new clear dial cover was installed behind the front panel.

    The total time from start to finish took about a week and a half. Restoring the AR-3 was a lot of fun.

    Mike W5RKL

    AR3 Front View.jpg
    Right Front View.JPG
    Bare Chassis.JPG
    Restored Bare Chassis.JPG
    Restored AR3 Rear View.JPG
    Front panel view.JPG
  2. WD5JKO

    WD5JKO Member

    Mike, Thank You for such a nice post. That receiver is really as good as new now. That said, how well does it work?

  3. W5RKL

    W5RKL Member

    Hi Jim,

    Thank you for the nice comments.

    The alignment on bands C and D needs more work but Bands A and B are fine.
    The IF amplifier oscillated at first. I had to back off the slug peak so it would
    not oscillate. Once I did that I could go through the IF alignment without any
    further problems. The BFO coil is not very stable in the mount so it warbles
    a bit. I have it adjusted to 456Khz.

    The Band spread knob had a vernier dial that broke so he Band Spread knob
    does not have an indicator. I leave the variable capacitor fully meshed until
    I find a replacement. Not in a big hurry for one.

    The original clear front panel dial cover was warped from heat and badly discolored.
    I initially used a piece of clear plastic from a thin and clear "Grocery store Grape/Strawberry
    container" but that will be replaced with a piece of 1.5mm thick clear plastic I have.

    I have another similar project in the works, a complete restoration of a Heathkit
    GR-91 four band short wave receiver. I had one when I was in high school before
    I got into ham radio. The GR-91 I have is missing the top cover, rear cover, and the bottom
    metal plate. The bottom plate is not hard to replace but finding a top cover that's not bent out of
    shape and/or has additional holes drilled into it by a previous owner is going, to be a
    bit difficult. I plan on taking the receiver down to a bare chassis, replace all the
    resistors on the PC board, inspect and fix any PC board foil runs that are bad,
    and get it working again.

    Today the Heathkit IM-32 VTVM I picked up on eBay arrived so I spent the afternoon
    fixing it and it working properly again. A previous owner put solid state tube replacements
    in for the 12AU7 and 6AL5. One or both of them were bad causing the meter to peg fully
    to the left and right when the AC, +/- DC and Ohms switch positions. Replaced them with
    actual 12AU7 and 6AL5 vacuum tubes and the IM-32 started working again. Once the switches
    and pots were cleaned the alignment went flawlessly. Another vintage Heathkit analog VTVM
    added to my collection.

    Always something to do when you're having fun.

    Mike W5RKL
  4. W6MQI

    W6MQI Member

    I had a GR-91 when I was a young whipper snapper I thought it was the coolest thing around at the time. I remember listening to those Russian jammers thinking they were aliens signals from space, hey I was 7 yrs old give me a break:icon_shh: Anyway back then there was lots to listen to on the SWL bands not like today. Please post pictures of the resto progress I'd love to see them.
  5. W5RKL

    W5RKL Member

    Hi Dave,

    I'll post some pictures of the before, during, and after restoration. I still need to find
    the top cover for the GR-91. I'm going to cut a piece of aluminum as a bottom cover then
    add some feet. That's not difficult to do but finding a top cover is going to be rather tough.

    Yes today's SWLing is not what it use to be. Another SW receiver I wanted back in my
    high school days but couldn't afford it was a Hallicrafters S-108. My Scout Master let
    me borrow his S-108 for a couple of weeks and I feel in love with that receiver. I recently
    picked up a nice S-108 on eBay. I spent a couple of days going through the receiver
    replacing all the old paper capacitors and the capacitor can from
    S-108 capacitor kit. Cleaned all the switches and pot and checked the alignment and added
    a fuse holder with a 1 amp fast blow fuse. I did the same things to my SX-110 receiver I
    picked up on eBay. I had to replace the dial Band Spread dial cord in the SX-110. Both
    receivers work great. I use a 1954 Hallicrafters SX-71 (Run 4) with my Heathkit
    Apache TX1 on 75 meter AM.

    Mike W5RKL
  6. W5HRO

    W5HRO Administrator

    What you need is one of these. I sold mine back in the late 1990's because I had too much big stuff, but for SWL the SX-42 is about the best one ever made and mainly because it produces the best audio quality into a big speaker. It also has FM.

  7. WQ5Q

    WQ5Q Member

    Mike, you did a beautiful job on that old radio. Really nice.

  8. W5RKL

    W5RKL Member

    Thank you Kelly. I had a lot of fun rebuilding the AR3. I replaced the triple capacitor can
    with a larger diameter hayseedhamfest DX-100 can that has the same capacitance values
    the original can did. The mounting plate is a bit larger so I had to drill new holes so the
    new mounting plate lined up.

    I'm doing the same thing to a Heathkit GR-91 four band SW receiver. The GR91 does not
    have a top cover so I'm looking for one.

    Brian, that's a nice SX-42. I have a few Hallicrafter receivers. The receiver I use a lot
    is an SX-71. I also use a Hallicrafters S40B.

    Mike W5RKL

    Hallicrafters SX-71.JPG Hallicrafter S40B and Heathkit QF-1.JPG