RAN Technology

The Clegg Interceptor receiver and Allbander converter

Vintage Ham Radio 0 Comments 05/29/2021 

It's not just for VHF!

Posted By: Robert Nickels (ranickels)


I'm always thinking about interesting combinations of equipment to try out on the air.   One day while rearranging the shack I was getting ready to connect my Globe Scout Deluxe back up with a Collins 51S-1 receiver when the LED (the energy-efficient version of the old light bulb) came on.

When I first started playing with DVB-T dongles back in 2012 I wanted an upconverter so I could listen to HF, as their tuning range only came down to about 25 MHz.    I thought of the Cless Allbander which was an upconverter for the Clegg Interceptor receiver that moved most of the HF range up to the 4 MHz coverage of the Interceptor, but decided it would be easier to just design a modern equivalent using an NE-602 and an off-the-shelf clock oscillator module.    As that concept was refined it became the RANVerter and was featured my first QST article on SDRs in January 2013.    My friends at Hayseed Hamfest sold hundreds of kits and I hope that inexpensive introduction to SDRs helped many hams and SWLs join the modern world of software-defined radio.  

The Clegg Interceptor and Interceptor B receivers are excellent VHF receivers tuning the 6 and 2 meter bands in four 1 MHz segments.   While sold as the companion to the Zeus AM/CW transmitter, the Interceptor is basically an 18 tube 6 meter receiver with a built-in 2 meter converter and has selectable USB/LSB and AM detectors, a crystal IF filter, noise limiter, and the famous Eddystone dial.   The "B" model has separate filters for AM and SSB while the original model like I have adds a switchable audio filter.  Both do a fine job on both SSB and AM, and with the Allbander speaker-upconverter, coverage is extended to include 3 to 22 MHz and 27-31 MHz, which includes all the (then) amateur bands.

So I though, why not put the Interceptor-Allbander to use as an HF receiver with one of my classic transmitters?    i designed the VERSA-TR RF-actuated T/R and muting board for just this reason - to make it easy to mix-and-match vintage equipment.    The board is stuck to the side of the Globe with magnets and automatically mutes the speaker when the Globe Scout is in transmit.   When I want to use the Clegg on VHF, the Zeus will mute the receiver via it's muting connection so I can switch between the two with one switch.   I do have to spin the Eddystone dial all the way to the other end but that's half the fun of using the Interceptor!

Since it's a bit hard to find the manual for the tube-type Allbander, I've included a link below for the pdf file.    It uses a crystal LO to move the HF spectrum to the 4 MHz bandwidth of the Interceptor (50-54 MHz) but a modern-day equivalent could be made using the same approach I used in the RANVerter, with Epson programmable oscillators providing the LO injection for each desired range  (see schematic below).  The Allbander used 3rd overtone crystals, so for the first range that covers 3-7 MHz the crystal frequency is 15.667 MHz which tripled to generate the converter LO at 47.0 MHz.    Then the first range of the Interceptor that tunes from 50 to 51 MHz provided coverage from 3 to 4 MHz.   The top range (53-54MHz) tunes 7-8 MHz, so the 80, 60, and 40 meter ham bands could be tuned on the Interceptor with one $4 oscillator module and this simple converter that can be built for about $10.   A tuned circuit could be added to provide front-end selectivity but the simple filter shown has proven sufficient to keep strong AM and FM signals from overloading the converter when used with SDR dongles.

I hope this encourages others to get a little more use out of the wonderful Clegg Interceptor receiver!


    A while back I acquired a six channel HF transceiver made by the Radio Industries division of Hallicrafters, probably in the 1960s, called an SBT-20.    It is capable of 20 watts SSB or 5 watts AM (or CW with an optional board) in the range of 2-12 MHz and thus was probably aimed at commercial and light-duty military applications.   The radio could by ordered with fu...  READ MORE
- Robert Nickels (ranickels),  06/07/2021 

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- Robert Nickels (ranickels),  04/29/2021 

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Boatanchor parts from the home improvement store
Category: Technical
 It's not often that you can buy a replacement part for a vintage transmitter or amplifier off the shelf at the home improvement store, but this is one example.   And since it's not a perfect drop-in replacement, here's now I adapted a new Broan-Nutone BP-27 bathroom-kitchen exhaust replacement fan to fit into a Johnson Desk Kilowatt.These small shaded-pole "C frame...  READ MORE
- Robert Nickels (ranickels),  04/23/2021 

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Category: Vintage Ham Radio
 When I got my Novice license in the fall of 1965, my dad had also decided that as long as he was taking me to the classes at Blue Valley Amateur Radio Club in Seward, Nebraska, he might as well try for his license too.    I was fortunate that not only were my parents supportive of my ham radio interest, but my dad could build anything.   So the first thing was a 40 f...  READ MORE
- Robert Nickels (ranickels),  04/13/2021 

The WRL Duo-Bander 84

An "only 50 cents per watt" transceiver
Category: Vintage Ham Radio
  Go Mobile!  That was an attractive marketing message to 1960s era hams who were enjoying the fun of operating SSB mobile, and WRL knew a low-cost rig that didn't have to be hauled back and forth to the car would be a winner.   Heathkit and Swan had already proven that with their single (mono) bander transceivers, but what if you're heading out in the middle of th...  READ MORE
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    After the conclusion of World War II, there were only about 300 radio amateurs in Japan.   In the  year 1952, the JARL reported that only 30 provisional licenses were granted.    Realizing the value of ham radio in developing a technological workforce, Japan introduced its entry level Class 4 licence in 1959 -  it would prove to be the world's most succ...  READ MORE
- Robert Nickels (ranickels),  03/24/2021 

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