Learavian 402 C
& Mason-Bowles RDF project  |
Learavian
402 C 7 tube
superheterdyne AC/DC receiver, with broadcast, 2.2 to 6.2 mHz marine,
and beacon. It is advertised as not working... but that helped me get it for a reasonable price. I look forward to recapping, repairing and aligning it, then taking it for a ride to some local hilltop for some aero-beacon direction finding. So far I found two tubes are bad, and replaced them. See below. I'm sort of curious what the "mic" jack is for. This is not a transmitter, so I suppose there is a built in PA, running the mic input through the audio amp stage. But it seems to me you could call out in a loud voice louder than the resulting output... this will be an interesting feature to try. The "Lear" in Leavian is Bill Lear of Learjet fame. He is also the inventor of the eight-track tape player, and many other inventions and innovations in radio, aviation, and elsewhere: http://en.wikipedia.org/wiki/Bill_Lear |
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I was glad to see the extraordinary condition of this radio. The decal logo is intact, the covering only has minor fraying, and the handle is also in good condition. There is a heat mark on the side... perhaps a power supply issue. The rectifier tube is a miniature tube, and away from the mark... so I do not think it caused the discoloration. Perhaps the power cap. You can also see an image of Adrian Reynold's 402 C on his site, "Adrian's British Tube Portables". He has many radios from other parts of the world, too, and the site is a "must see". He also has an earlier, Art Deco, Learavian unit. I've missed those a few times on eBay... probably one to Adrian! |
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The cord is housed in a nifty compartment of it's own. I believe the plug and cord is original. The cord covering looks perfect. |
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The radio still appears to have all original tubes. Seven are octal, and two are miniatures. The battery is not leaking, only slightly swelled. |
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With all good tubes, there was still no sound at all. So I removed the chassis, and found the problem... sort of. I now know why the outer fabric is burned... it appears one of the power supply capacitors fried and burned. Wax all over, burned insulation, disconnected wires. Someone tried to solder one back on, poorly. So I have a Sam's Photofact on it's way, and will replace whatever is missing, along with the other caps. This is a real "snowball" of a project. But I actually look forward to the challenge of getting it all sorted out, and hearing sound out of this 58 year old radio. |
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This 1948 ad got me interested in the radio to begin with. I had wondered if a Mason-Bowles (M/B) radio could ever be found, and recently noticed the brand tag on the picture. It thought this would help identify it, or find an image of it on the 'net. So I blew the ad up and showed it to my daughter. She was sure that the name began with "L" (I thought it was a stylized "S" for "Seamaster"). But this clue sent me back to all my old Yachting Magazines, and I found the Learavian 402 C was the unit M/B used! It seems they simply bought and used stock 402 C's by mounting them on a lazy-susan (turntable) with compass rose and indicator. I'm planning on mocking up a replica M/B turntable. Luckily the company posted the dimensions of the bottom board in their ad. The straps appear to be the canvass army type, with metal ends. The rose I can print out on photo paper, then mount on a card. The most complicated part will be the radio mounting board, which seems to be routed for the straps, and clearance for the rose and indicator. I'm hoping an appropriate lazy-susan can be found at Bed Bath and Beyond, or Home Depot. |
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 Mason-Bowles gave it's address as 1216 Industrial Trust Building. Were they manufacturing these RDF conversions up there on the 12th floor? Quite a bold operation... really selling a simple gizmo, but marketing it as wholly thier own radio unit. To the left is a 1946 ad for the Learavian. |
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