Two Tube "Doerle"

Homebrew Regenerative Shortwave Receiver




This is a project modeled after the Doerle designs that were popular in magazines of the early 1930s.  This radio uses two #30 tubes and operates on batteries.  It has shortwave coverage in two bands, 4.8 to 7.5 MHz and 7.3 to 12.0 MHz using plug in coils.  That covers the most popular shortwave broadcast bands from 60 to 25 meters.

I bulit this set myself back in 2005 and now it needs to find a new home.





The wooden box is made of 1/2" plywood with box corners.  It has a lacquered finish.  The front panel is made from black plexiglas.  The upper binding posts are for Ground and Antenna.  The lower terminals are in parallel with a 1/4" phone jack to allow use of headphones with either a plug or with phone tips.  High-impedance phones are required. There is a wooden bottom cover not shown in the photos.

The controls are Main Tuning with a Fine Tuning control just to its right.  Further to the right is the Regeneration control and then above is an Antenna Trimmer which compensates for different antenna lengths.  The audio transformer is an original Hedghog type.  Tube and coil sockets are from ACE (Crosley).  The main tuning cap is a FADA type modified for shortwave frequencies.

The radio comes complete and in working condition.  The two type 30 tubes are included as are the two plug-in coils.  You will have to supply your own battery arrangement and a set of high-impedance headphones.  The voltages required are 45 volts for the B+ which can be obtained with five regular 9 volt batteries in series plus 3 volts for the A supply which can be obtained with two C or D batteries in series.  The #30 tubes only require 2.0 volts and there is an internal provision to reduce the 3 volts from the batteries.  These tubes were made for battery operation and have a very low current draw.  My replica batteries in the top photo are not for sale.

Schematic documentation is also included.

Shipping will be via USPS Priority Mail at a flat rate of $20 to any USA address.

Thanks for looking.

-Bill (exray)


.