1938 Marconi Canada Model 136 Automatic Shortwave Radio
Marconi, Canada's Prestigious Radio Company, built this "overlapping layer" wood beauty, after model 79 my second Marconi restoration
In a Nutshell
A Beautiful and Big Table Radio with Police-Amateur and Shortwave Bands, made by the Canadian Marconi Company in 1938, in almost Perfect Condition, serviced and working fine on all bands
Introduction: Guglielmo Marconi himself, after successfully sending a message across the Atlantic in 1901, founded the "Marconi's Wireless Telegraph Company of Canada" in 1903. In 1925 the company was renamed Canadian Marconi Company (CMC). A brief history of CMC can be found in ref.1 below.
The milestones are summarized on the website of still existing CMC (see ref.2), including the reception of S.S. Titanic’s distress signal sent by Marconi employed Phillips and Bride on April 15, 1912 shortly after midnight over Marconi Wireless. Other milestones were the start of radio production in 1921, and
establishment of the Canadian Broadcasting Company (CBC) in
1931. I had restored before a 1936 model 79 (now in radiomuseum.org, ref.3), and pict.45 shows other examples of these "toppled tombstone" designs. The striking feature of this radio is its rare "overlapping layer style" cabinet. Yedidovich and son expertly describe this style for Silvertone radios (Colonial Radio Corp.) of the same vintage (ref.4, see also ref.5 for my Silvertone 4666). Model 136 has 6-station automatic tuning and a magic eye (6U5) tuning helper. The console model 137 has the same 7-tube chassis, table models 141 and 144 have one 6F6 tube more (in parallel, not push-pull!). The radio is covered with at least 7 different beautiful burl veneers. The dial and push-button escutcheons (pict.17) are made from a ceramic composite with a burl wood grain photo-finish. The adjustment screws for the 12 automatic caps are made from (insulating) wood (pict.38), not needing a screwdriver for setting them.
About my radio:
The radio is in excellent condition, the cabinet has its original finish, the few unoffending irregularities not warranting a refinishing. The photo-finish of the two escutcheons is perfect. All other parts, including knobs, speaker and speaker cloth, the Marconi and HEPC decals, are original too. A new old stock (NOS) new in box (NIB) 6U5 magic eye tube has been installed and the chassis recapped. The two bias cells could be rejuvenated (see techies below), but were finally replaced by batteries. The left side green "Automatic" indicator including lettering has been remade. All moveable parts have been treated with contact spray. The radio plays fine on all bands, which is hard to demonstrate since AM reception at my place in South Chilliwack is very poor. An AM transmitter and the newly installed closed circuit 3.5mm phone plug (to replay CD and mp3 players, iPods and cell phones) have been used in a youtube video showing the radio working (ref.6 or click on thumbnail 48). Please e-mail me (Kris) for any questions, ich spreche Deutsch, je parle Français.
For the techies only:
Bias cells are used to provide Q-point (~1Volt negative) bias to tube grids, without using a C-battery or an extra transformer secondary winding. An alternative measure is introducing or increasing the cathode resistor of the corresponding tube. Bias cells deteriorate with time by drying-out electrolytes, and lose their voltage. Often a rejuvenation is possible by momentarily boiling the cell in water, then slowly letting it warm up again to room temperature and re-sealing it with glue. I sucessfully rejuvenated both cells (pict.30), but found the voltage decreasing again after a few days, probably caused by leaks in the seal between both ends. I therefore finally used two 1.5 Volt mini-batteries (picts.31,32). Note that the smaller electrode of a bias cell is plus, whereas it is minus for a mini-battery.
Here are the specifications:
Technical Description of Item
Manufacturer
Canadian Marconi Co. Ltd. CMC
Model
136
Type
6-tube AM/BC and SW Superheterodyne Receiver
Production Year
1938
Serial Number
136-660480
Cabinet
Overlapping layer style toppled tombstone cabinet with assorted veneers
Dial
Slide rule dial, edge-lit reverse painted glass and 3 illuminated band indicators
