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Discussion in 'General Technical Questions and Answers' started by 2I0TMR, Aug 12, 2018.

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  1. 2I0TMR

    2I0TMR Ham Member QRZ Page

    Hi everyone

    I am looking for some parts for my Mohawk RX1 or where I could get them please. I am restoring it to its original closest parts as I can. The on-off/vol switch, RFG , IFG and 5 bulbs.

    Potentiometer: 1 meg on/off vol switch (0.556 of an inch/14mm threaded part of the shaft)

    10k linear (0.556 of an inch/14mm theaded part of the shaft)

    100k linear (0.556 of an inch/14mm threaded part of the shaft)

    Bulbs: 6/8V0.15A

    I would very much appreciate if someone could help me in this matter.

    Many Thanks


    2i0tmr Michael
  2. KB4QAA

    KB4QAA XML Subscriber QRZ Page

  3. 2I0TMR

    2I0TMR Ham Member QRZ Page

    Cheers i will give them a try .
  4. W9GB

    W9GB Ham Member QRZ Page


    Heathkit (Benton Harbor, MI) sourced parts for their kits from WW2 surplus and automotive/electronic surplus parts, as well as the OEM component manufacturers (many in Chicago/Great Lakes region). I have listed the Major OEM suppliers below.

    In your region, Farnell — part of element14, which Newark in Chicago is member —
    is your “Go To” Electronics component distributor (save $$ trans-Atlantic shipping).

    CTS (old Chicago Telephone Supply) : Potentiometers, 24 mm (~1 inch) common
    as well as 16 mm sizes (model 270, 280, 282, 284)
    Musicians and Guitar Amplifier restorers (major buyers) use the 24mm size (450G).
    Other 24 mm models: 450, 295 and 026 (5 watt)

    CTS : Elkhart, IN (HQ), Global locations

    Keystone Electronics (New Hyde Park, NY) : Assembly Hardware, Lamp/Bulb holders.

    Chicago Miniature Lamp (CML) now a Visual Communication Company (VCC)
    in Carlsbad, CA : Incandescent Bulbs

    Abbatron / H.H. Smith (Meadville, PA) : Assembly Hardware

    Heyco (New Jersey) : Strain Reliefs and Grommets

    Switchcraft / Connex (Chicago & Villa Park, IL) : Jacks/Connectors

    Grand Power Systems (Grand Haven, MI) : Transformers/Chokes

    Belden (St. Louis, MO) : Hookup Wire and Coax
    Outlets (Used; New Old Stock)

    Surplus Sales
    Last edited: Aug 13, 2018
    2I0TMR likes this.
  5. W9GB

    W9GB Ham Member QRZ Page

    2I0TMR likes this.
  6. 2I0TMR

    2I0TMR Ham Member QRZ Page

  7. 2I0TMR

    2I0TMR Ham Member QRZ Page

    Thank you for your help
  8. K9STH

    K9STH Platinum Subscriber Volunteer Moderator Platinum Subscriber QRZ Page

    The length of the threaded mount for the potentiometers is something to watch out for. Those used by Heath for the RX-1 Mohawk are longer than on many controls even back in the late 1950s and early 1960s when the receiver was new.

    There are a fair number of new controls available with the exact resistance of the originals but the threaded part is not long enough to go through the chassis and then the front panel. Most are "almost" long enough but do not pass through enough to get the nut on to secure the control.

    I have run into this when working on the TX-1 Apache, RX-1 Mohawk, and HA-10 Warrior.

    Glen, K9STH
    2I0TMR likes this.
  9. W9GB

    W9GB Ham Member QRZ Page

    Bourns used a different Switch Assembly than CTS for ON-OFF function on potentiometers.

    Alpha Products potentiometers : without and with switch. Resemble CTS in design.
    Alpha has 16mm and 24mm models with switch function.

    In my parts box, I have 2 rotary switch assemblies for the
    Alpha Products potentiometers (Oxnard, CA).

    Thanks to the Music Industry (Guitar Amp restorers and musicians like Eric Clapton/Neil Young: How many $$ do you need?) ... solutions are available.
    Longer threaded mounts. (CTS, 450G series)

    The beauty of many legacy CTS (and Bourns) potentiometer designs ... is that you can CAREFULLY disassemble for Customizations (Changing front threaded mount, Adding rotary switch function).
    ** CTS offered a “Build Your Own Potentiometer” kit of parts in 1960s ... would be useful for the restorer today. **
    This capability VARIES by manufacturer and model of the potentiometer.
    NOTICE the 4 metal tabs (on front of pot) that are bent 90° to attach the threaded mount — these can be exchanged from a matching “older”, failed potentiometer.
    Bourns potentiometers use a coarse spline shaft.
    CTS potentiometers use a fine spline shaft.

    In addition to length of threaded bushing height, you have to watch overall shaft length.

    CTS or Bourns 500k pots are typically used with Gibson Les Paul's(R), PRS, or other Humbucker equipped guitars. Long shaft (3/4" bushing height) for guitars using a control plate, short shaft (3/8" bushing length) for guitars where pots mount through the body.
    As a general rule, Les Paul guitars, built after 1977 - but excluding historic reissues, used potentiometers with long shafts.
    Last edited: Aug 14, 2018

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