vef: MD/37 (MD37); Vefsuper Lux (Geographic 3
The MD37 that I have has different valves from the all A-series shown in the listing page. The audio output valve is an EL3 and the IF amplifier is an EF6. I believe these to be as built at the factory, since the heater winding of the power transformer is tapped for both 4V and 6V3, and separate wiring is provided for 4V and 6V3 valves. I presume either valve shortages or a cost advantage for the E- series valves must be the cause, since the extra heater wiring would cost something to do.
Also, the switch on the bandwidth control is different. The schematic shows a single switch, but this radio has two, operated by two different cams at different points in the rotation. The result is either nothing connected to the anode of the first audio amp, or 1.4 nF, or 5 nF to ground, with more capacitance being added added as the bandwidth increases.
I am the owner of VEF SUPER LUX MD/37 and trying to collect more information about it.
Can you please let me know the serial number of your radio? Normally all known versions of VEF SUPER LUX MD/37 are well documented, but the version with double heater wiring is not known.
Thank you in advance for any information.
My VEF is serial number 000976. HOw mnay of these radios are known to exist now?
One of these days I will have to find the time to patiently glue the glass rods back into the map display. Since all the frequencies have changed anayway, if I get a few in the wrong holes it won't much matter...and since many national broadcasters have abandoned SW transmissions, it'll matter even less.
Near San Francisco, California USA where I live, I can only get the BBC in the early morning only on 9740 KHz. I think the transmitter I'm listening to is in Thailand, so it takes a very good radio and my good outdoor antenna to do this.
Thank you very much for reply!
San Francisco is nice, I've been there a couple of times.
I am surprised you can receive so fiew stations there. And indeed, all the cities at radio's scale changed the frequencies.
I am aware about five different modifications of MD/37. The last documented serial number is 1011 - this radio was manufactured for Norway. Not many, right? You have one of the last made.
If you need schematics - please let me know - the one available here is for very early version - for s/n from 1 to 65.
Do you have pictures of your radio? Especially bottom part of it, with all components installed.
If it is possible, please send them to me. My e-mail is: firstname.lastname@example.org
Information about your radio is very interesting, since even experts in Riga, were it was made - are not aware about version with double heater wiring.
Thank you very much in advance,