Hubert transceiver

homebrew undocumented burly electronic radio transmitter

Inside View

About H.U.B.E.R.T.

When I came across this one on eBay, I was just window shopping, looking for something that I had not seen before. I was immediately intrigued by its face and I knew that it was not like anything already in my collection. Listed at 24 pounds, I was not sure about paying shipping so I hesitated and the auction closed. But I couldn't stop thinking about it. It was burned on my brain.

I kept checking back and it was finally relisted. I decided to reach out to the seller to find out what "it" was. The seller could only tell me that it was home built and was found in a barn in New England. This was enough for me. I was ready to bring my one-of-a-kind radio-something home!

When it arrived I could tell by the two thick wired coils that it was a radio transmitter and a radio receiver (what is commonly referred to as a "transceiver"). The maker of this homebrew had done precision work with design and layout. Unfortunately, no labels were added to let me know what all of the dials and switches do. I will need to trace out a schematic in order to know more.



Dimensions: Weight (approx.): 24 lbs.

Vacuum Tubes

  • 5 7c5
  • 1 cat eye
  • 1 6l6
  • 1 926
  • 1 unmarked
  • 1 unmarked RCA microtube with cover
  • Radio Type




    Equipment needed

    8-slot Power Adapter




    What's in the box?


    Turn it to eleven!

    There are always 2 ways to go with this...change the components to make the physics work out where what registers on the dial is correct...or change the dial.

    2 tubes & coil

    2 coils & tubes

    Receiver is on the left and the transmitter is on the right. Note how the transmitter coil has wider windings . This is due to the high voltage needed for transmission.


    Laminated switch

    From its appearance, this is a reused, 1930's toggle switch that is not connected to anything. Purely for show.

    What else?


    A lovely relay

    Relays are switches controlled by an electromagnet. It's like a transistor but with moving parts.


    Crystal holder and adapter

    This is Hubert's crystal oscillator which resonates at the frequency of 6275 kilocycles (kc) or 6 MHz. It provides the frequency needed for the transmitter and the receiver but is not a currently approved ham band. It's from the 1950s with an adapter allows it to fit into the slot designed for the 1939 machine.

    old capacitor

    Anyone remember the Sprague jingle?

    "Don't be vague ... ask for Sprague"


    Transmitter Overview

    The top tube is a "cat eye" or cathode ray indicator tube. It is the tube in the brass eyelet on the front of the radio in the main picture. To see what it looks like when in use, please see This video from video blogger W1UJR.


    Capacitors to replace

    Wax and paper capacitors of this era will need to be replaced with new ones before powering up.


    Feel free to contact me if you have any information or experience with this equipment. I look forward to hearing from you!