BRETING 12 RADIO RESTORATION
March-April, 2013

The Breting 12 receiver was purchased at the annual auction held during the 2013 Charlotte, NC, meeting of the CC-AWA (Carolina's Chapter of the Antique Wireless Association).. During the auction preview time, this "diamond in the rough" caught my eye. Some time ago, I had read about Breting receivers in the ARRL publication, 50 Years of Amateur Radio Innovation. I had the winning bid; and the next day, it was time to get the 60+ pound monster in the house, I determined the radio was basically complete but unfortunately, was missing one 6D6 tube, and the 432KC crystal used in the bandpass filter. The tuning did not work and the bandswitch mechanism was frozen.

Two Views of the Uncleaned Chassis
The pictures only partially capture how dirty the chassis top was before restoration.

The first order of business was to do an Internet search to find out as much information as possible about the Breting 12 radio. Perhaps someone had restored one of these radios and could be of assistance. I was able to locate Tom, NE7X who has restored one of these beauties and has excellent restoration information on his Website.

An interesting thing about the Breting 12 is that none of the controls on the front panel were factory labeled. I had just assumed someone had repainted the front panel and done away with the writing. Tom has nice drawing of the controls which I have modified to reflect the actual controls on my radio.

 

I used a damp cloth, Brasso, and Q-tips to clean the chrome chassis. A product called Nevr-Dull polished the aluminum tube shields to a chrome luster. Here is picture of the cleaned chassis. Not bad for 78 years old!!! More chrome than a 1958 Oldsmobile!!

 

One of the valuable services Tom, NE7X did during his restoration was to generate an accurate schematic diagram. After printing several copies of the schematic, I started to run down all the modifications, and to remove the modifications done to the radio over the past 78 years. After several hours of confusion, I just decided to remove the many "wires that led to nowhere, and the dangling parts" and use the good schematic to put things back to original. I decided to leave 3 useful modifications. First, on the original chassis, the BFO is adjusted by a knob that exits from the chassis to bottom of the cabinet—not practical at all !!  A previous owner had removed the original front panel audio switch that permitted the audio section to serve as transmitter audio modulator and had installed a BFO trimmer in its place. Also, a previous owner had installed a operate/standby switch. This one I left also since removing it would have left a hole in the front panel. The radio originally operated with an electromagnet voice coil speaker. A filter choke was added as a substitute so a permanent magnet speaker could be used.
Here is close up of the useful BFO trimmer modification
Close up photo of the operate-standby switch addition.

 

My friend Gerald, K4NHN, who has many years of experience in radio restoration, was able to provide the correct cloth-covered replacement line cord as well as a good assortment of original NOS cloth-covered wire that was used in the chassis rewiring. The replacement capacitors were readily available from an antique radio restoration vendor.
Here are 2 pictures showing the before and after chassis wiring.

 

Once all the paper and electrolytic capacitors had been replaced along with the considerable rewiring, it was time to double check everything. I used another copy of correct schmatic and a highlighter pen to verify the wiring.. After review, it was time to plug the radio into the electrical outlet! It sprang to life!!
I am amazed at the sensitivity and the rich "tube sound" audio quality of this 78 year-old radio. The push-pull audio amplifier is rated at 16 watts.
The backlit dial is a real beauty.
The Completed Restoration
Breting with Speaker

100 Plus Hours of Time Required for Restoration
(After taking this photo, I was able to find all the correct knobs from a Ebay seller.)