Czechoslovakia was never part of the USSR. After WWII Czechoslovakia was an independent country that was part of the Warsaw Pact, like Poland or East Germany.
Hello Jim, at 36:44 I think these are the orientations of the jumpers on the voltage selection plug, showing how the jumpers are connected across the points a - f just above them. (Continuity testing with the plug could confirm this.) With one of the two resistors open, I can see that this could result in a very high resistance through this part of the circuit and very low current flow. Why not try replacing the two connected resistors at 17:04 by cutting the other non-broken coil and soldering or jumping some high wattage wire wound resistors across the tabs? If it doesn't work, you are no further behind! This is a nice radio.
I seem to remember that these radios don't work unless the dual lights are intact . They are part of the chain . I repaired one years ago and I'm sure that was the fault . I also remember the case gets very hot when used on 250 v here in the UK . Hope you get to fix it
Yes, you are right. Dial lamps must be OK, they are used as fuse for the radio. 250V is too much. Radio was designed for 220V +5% -10% and it was hot even at this voltage.
The tubes are in series they are the loops in the line after the light bulbs. Probably not working because the voltage change switch is in wrong position.
Tesla was known for making good products before Czechoslovakia was swallowed up by the communist European block after WWII, they continued producing under communism, somewhat limited by their economic system, and today they still produce some high quality products under INTER-SAT LTD. But at the time this radio was manufactured I doubt that there would have been much demand for their electronic products in countries where 110/120V-60Hz is used which includes not only North America but most of Latin America. With the exception of Argentina, Peru, Bolivia, Chile and Paraguay, and some of the smaller Caribbean islands that use 220/230-50Hz, all other South American and Caribbean countries were heavy consumers of U.S. made electrical equipment and also German brands that could be switched to 110/120. As in the U.S. some countries can use both 110/220V-60Hz like Cuba and Belize, for certain specific electronics.
Tesla was established after WW II when all electronic companies were put together. Before WW II there were Telegrafia in Pardubice, Philips branch in Prague, Tungsram in Bratislava and many others. 110-127V/50Hz were also used in Europe before central power grid was built. So many european sets built till 60s had voltage switch.
@@xsc1000 You are right, let me clarify, I was referring in my comment to Elektra which became part of the Tesla conglomerate in 1946. Thanks for your correction.
Should be no different than an All-American 4/5 with the difference in the line voltage. Measure all filaments and dial light for continuity. Use regular testing processes for everything else. Check for shorted caps, open resisters and coils.
There is small difference. Because there is voltage switch between 120 and 220V, filaments are connected 2 different ways. If 120V is used, there are 2 filament strings, with 220V voltage all filaments are in serie.
When you look at the second schematic diagram, you can see circle down left with letters a-f. And near are two positions of the power selector described. When you select 120V contacts a-b, c-d and e-f are connected. When you select 220V contacts a-e and b-c are connected. It looks like the 700ohm resistor (upper part of the power resistor) is broken. When this happen, the UY1 filament is disconnected when 120V is used and all filaments are disconnected if 220V is used. So you have to fix this resistor first and also check the dial lights - they are used as fuse. They are 6,3V/0,3A. Filament voltage is 20V for UCH 21, 50V for UY1 and 55V for UBL21. The letter U means tubes designed for serial filament string with 100mA current Dials with european city names were common all over Europe till 80s.
The heaters are shown in the schematic near the lightbulbs. These radio's quite often have the same problem: broken dropping resistor and the one on yours doesn't look that well. These aren't that difficult to restore the tubes are probably still good. The capacitors are probably all shot. Restored two of these and they are actually good radio's with decent reception. They were build in former Philips Factories confiscated by the communists. They actually have a lot in common with a couple of Philips radio's
Greetings Jim: Assuming that the main component inside is a 240 to 120 ac transformer, you merely need access to the windings of the transformer. First verify that your blue-boxed unit claims that it goes between 240 & 120 vac approximately, and how many watts it can handle with negligible transfer losses. If it only lists amps, then know that the amps go down when you step up the volts. Power in = power out. When disassembled you have access to the windings. Safely test using your 120vac Variac to see what output voltage you get when feeding a 10vac low voltage into one side and verify that the opposite winding gives you higher or lower AC out. If lower, you are feeding the 240v side, if higher you are using it in step up mode. Now that you know which is which, you can use it to either step up or step down as you need to. To power the radio in North America you need to step up to 220-240.
There is hole in the back cover near the powercord. When you put cover back, you should see the voltage radio is set on. In fact its the upper one value.
Czechoslovakia was never part of the USSR. After WWII Czechoslovakia was an independent country that was part of the Warsaw Pact, like Poland or East Germany.
Hello Jim, at 36:44 I think these are the orientations of the jumpers on the voltage selection plug, showing how the jumpers are connected across the points a - f just above them. (Continuity testing with the plug could confirm this.) With one of the two resistors open, I can see that this could result in a very high resistance through this part of the circuit and very low current flow. Why not try replacing the two connected resistors at 17:04 by cutting the other non-broken coil and soldering or jumping some high wattage wire wound resistors across the tabs? If it doesn't work, you are no further behind! This is a nice radio.
I seem to remember that these radios don't work unless the dual lights are intact . They are part of the chain . I repaired one years ago and I'm sure that was the fault . I also remember the case gets very hot when used on 250 v here in the UK . Hope you get to fix it
Yes, you are right. Dial lamps must be OK, they are used as fuse for the radio. 250V is too much. Radio was designed for 220V +5% -10% and it was hot even at this voltage.
The tubes are in series they are the loops in the line after the light bulbs.
Probably not working because the voltage change switch is in wrong position.
7:10...for the HELL of it-(?)
8:40...Bosnia/Yugoslavia...
Tesla was known for making good products before Czechoslovakia was swallowed up by the communist European block after WWII, they continued producing under communism, somewhat limited by their economic system, and today they still produce some high quality products under INTER-SAT LTD. But at the time this radio was manufactured I doubt that there would have been much demand for their electronic products in countries where 110/120V-60Hz is used which includes not only North America but most of Latin America. With the exception of Argentina, Peru, Bolivia, Chile and Paraguay, and some of the smaller Caribbean islands that use 220/230-50Hz, all other South American and Caribbean countries were heavy consumers of U.S. made electrical equipment and also German brands that could be switched to 110/120.
As in the U.S. some countries can use both 110/220V-60Hz like Cuba and Belize, for certain specific electronics.
Tesla was established after WW II when all electronic companies were put together. Before WW II there were Telegrafia in Pardubice, Philips branch in Prague, Tungsram in Bratislava and many others.
110-127V/50Hz were also used in Europe before central power grid was built. So many european sets built till 60s had voltage switch.
@@xsc1000 You are right, let me clarify, I was referring in my comment to Elektra which became part of the Tesla conglomerate in 1946. Thanks for your correction.
Should be no different than an All-American 4/5 with the difference in the line voltage. Measure all filaments and dial light for continuity. Use regular testing processes for everything else. Check for shorted caps, open resisters and coils.
There is small difference. Because there is voltage switch between 120 and 220V, filaments are connected 2 different ways. If 120V is used, there are 2 filament strings, with 220V voltage all filaments are in serie.
When you look at the second schematic diagram, you can see circle down left with letters a-f. And near are two positions of the power selector described.
When you select 120V contacts a-b, c-d and e-f are connected. When you select 220V contacts a-e and b-c are connected.
It looks like the 700ohm resistor (upper part of the power resistor) is broken. When this happen, the UY1 filament is disconnected when 120V is used and all filaments are disconnected if 220V is used. So you have to fix this resistor first and also check the dial lights - they are used as fuse. They are 6,3V/0,3A.
Filament voltage is 20V for UCH 21, 50V for UY1 and 55V for UBL21. The letter U means tubes designed for serial filament string with 100mA current
Dials with european city names were common all over Europe till 80s.
To to radio nie je z Ruska. To je výrobok ČSSR !
The heaters are shown in the schematic near the lightbulbs. These radio's quite often have the same problem: broken dropping resistor and the one on yours doesn't look that well. These aren't that difficult to restore the tubes are probably still good. The capacitors are probably all shot. Restored two of these and they are actually good radio's with decent reception. They were build in former Philips Factories confiscated by the communists. They actually have a lot in common with a couple of Philips radio's
Greetings Jim:
Assuming that the main component inside is a 240 to 120 ac transformer, you merely need access to the windings of the transformer.
First verify that your blue-boxed unit claims that it goes between 240 & 120 vac approximately, and how many watts it can handle with negligible transfer losses. If it only lists amps, then know that the amps go down when you step up the volts. Power in = power out.
When disassembled you have access to the windings. Safely test using your 120vac Variac to see what output voltage you get when feeding a 10vac low voltage into one side and verify that the opposite winding gives you higher or lower AC out. If lower, you are feeding the 240v side, if higher you are using it in step up mode.
Now that you know which is which, you can use it to either step up or step down as you need to. To power the radio in North America you need to step up to 220-240.
Why make a video of a radio your not going to fix
Maybe since you had the radio upside down when you plugged in the 120v ,220v, Plug Maybe it's on the 220v Setting is why the radio wont-work.
There is hole in the back cover near the powercord. When you put cover back, you should see the voltage radio is set on. In fact its the upper one value.
Lots of uch21 tubes on ebay
It always seems that some things are a major calamity for you. You talk too much and don’t seem to get much done. No wonder you’re losing fans.