I found the set in an old barn.
The valves were disappeared, exept a 506 as rectifier, but that is not the original.
I tried to find the circuit diagram of the set but I didn't find it.
So I tried to repair it without schematic. But the powersupply-transformer was burned.
I replaced it and tried to repair the set with octal tubes ( f.e.6V6)
Finally by comparing several circuit diagrams I was able to draw the diagram and now the set is working but (no already perfect) with 6 volt tubes.
But I want to restore it with the original or equivalent tubes but I don't know the original numbers of the tubes.
I only know the 16 volts replacemnts types (by comparing the diagrams).
My question now is, can I find the original 4 volt types of valves or perhaps do exits also 6 volts equivalents, that should be also convenient but not necesairly.
Anyway I don't want to replaced the sokets (B5 types) of the tubes, they are still original.
I hope you understand now my question
Maurits
ON7EY
: I found the set in an old barn.
: The valves were disappeared, exept a 506 as rectifier, but that is not the original.
: I tried to find the circuit diagram of the set but I didn't find it.
: So I tried to repair it without schematic. But the powersupply-transformer was burned.
: I replaced it and tried to repair the set with octal tubes ( f.e.6V6)
: Finally by comparing several circuit diagrams I was able to draw the diagram and now the set is working but (no already perfect) with 6 volt tubes.
: But I want to restore it with the original or equivalent tubes but I don't know the original numbers of the tubes.
: I only know the 16 volts replacemnts types (by comparing the diagrams).
: My question now is, can I find the original 4 volt types of valves or perhaps do exits also 6 volts equivalents, that should be also convenient but not necesairly.
: Anyway I don't want to replaced the sokets (B5 types) of the tubes, they are still original.
: I hope you understand now my question
: Maurits
: ON7EY
Hello Maurits,
Thanks for the information. The 506 is a Philips full wave rectifier with a 4 volt filament. It could be the original or a replacement. Do you know the make and model of the set? If so I'll try and find a schematic of the original set and that should tell us what the correct tubes should be. If you have replaced the transformer with one with a 5 volt rectifier winding you should put a 1 ohm 2 watt resistor in series with the heater to reduce the voltage to 4 volts if you want to keep the 506 (it draws 1 amp and is probably about the right vintage for your set). I guess that you have a transformer with a 6.3 volt winding for the heater supply. From your email address I think your in Belgium. The set must be either English or European, I don't think you'll have any great difficulty finding suitable tubes. I agree it will be better to retain the original sockets and vintage tubes. Sorry if I sound a bit vague but if you can find the information it will help. I hope to have more data available on the tubes you listed in the next few days, I'll do what I can. Don.
As I already told you. I found the radio without tubes.
The set is a His Masters Voice 238 AC and it seems to be very difficult to find the circuit diagram. I found the radio in Belgium but it is defenitly a British product. Everything in the set is so Britisch even the mentionning toward the Royal Crown of The British empire.
There is also a label in it with the remark only to use Marconi tubes (so I know that the 506 was not original it is not original, but I can use it of course and it is still in the set, working) and a remark on the obligation to pay tax to the British Government.
I foud a very similar circuit of a DC set made by HMV, Columbia and Marconi (I think 440 Dc, but I am not sure, if you want I can send you the diagram); the values of the condensors and resistors are the same. But this circuit uses 16 volts tubes. I am now looking for the original tubes on 4 volts or equivalents on 6 volts, because the set is now working on 6.3 V octal tubes without changing the sockets (i had to chnage the transformer because it was burned). Of course I will put a resistors in the circuit to adapt the filament tension to 4 v. Or if I find 6V types (but I don't know if they realy exist)I can use the without modification.
Do you see know my question?
Maurits ON7EY
: : Well Don Black,
: : First of all thanks for the answer.
: : I found the set in an old barn.
: : The valves were disappeared, exept a 506 as rectifier, but that is not the original.
: : I tried to find the circuit diagram of the set but I didn't find it.
: : So I tried to repair it without schematic. But the powersupply-transformer was burned.
: : I replaced it and tried to repair the set with octal tubes ( f.e.6V6)
: : Finally by comparing several circuit diagrams I was able to draw the diagram and now the set is working but (no already perfect) with 6 volt tubes.
: : But I want to restore it with the original or equivalent tubes but I don't know the original numbers of the tubes.
: : I only know the 16 volts replacemnts types (by comparing the diagrams).
: : My question now is, can I find the original 4 volt types of valves or perhaps do exits also 6 volts equivalents, that should be also convenient but not necesairly.
: : Anyway I don't want to replaced the sokets (B5 types) of the tubes, they are still original.
: : I hope you understand now my question
: : Maurits
: : ON7EY
: Hello Maurits,
: Thanks for the information. The 506 is a Philips full wave rectifier with a 4 volt filament. It could be the original or a replacement. Do you know the make and model of the set? If so I'll try and find a schematic of the original set and that should tell us what the correct tubes should be. If you have replaced the transformer with one with a 5 volt rectifier winding you should put a 1 ohm 2 watt resistor in series with the heater to reduce the voltage to 4 volts if you want to keep the 506 (it draws 1 amp and is probably about the right vintage for your set). I guess that you have a transformer with a 6.3 volt winding for the heater supply. From your email address I think your in Belgium. The set must be either English or European, I don't think you'll have any great difficulty finding suitable tubes. I agree it will be better to retain the original sockets and vintage tubes. Sorry if I sound a bit vague but if you can find the information it will help. I hope to have more data available on the tubes you listed in the next few days, I'll do what I can. Don.
: As I already told you. I found the radio without tubes.
: The set is a His Masters Voice 238 AC and it seems to be very difficult to find the circuit diagram. I found the radio in Belgium but it is defenitly a British product. Everything in the set is so Britisch even the mentionning toward the Royal Crown of The British empire.
: There is also a label in it with the remark only to use Marconi tubes (so I know that the 506 was not original it is not original, but I can use it of course and it is still in the set, working) and a remark on the obligation to pay tax to the British Government.
: I foud a very similar circuit of a DC set made by HMV, Columbia and Marconi (I think 440 Dc, but I am not sure, if you want I can send you the diagram); the values of the condensors and resistors are the same. But this circuit uses 16 volts tubes. I am now looking for the original tubes on 4 volts or equivalents on 6 volts, because the set is now working on 6.3 V octal tubes without changing the sockets (i had to chnage the transformer because it was burned). Of course I will put a resistors in the circuit to adapt the filament tension to 4 v. Or if I find 6V types (but I don't know if they realy exist)I can use the without modification.
: Do you see know my question?
: Maurits ON7EY
Hi Maurits,
Thanks for the further information. If you can send me a copy of the circuit that you have it would help. I've got some HMV & Marconiphone circuits around your model number but not the 238 AC yet. I'll keep looking. Don.
: : : Well Don Black,
: : : First of all thanks for the answer.
: : : I found the set in an old barn.
: : : The valves were disappeared, exept a 506 as rectifier, but that is not the original.
: : : I tried to find the circuit diagram of the set but I didn't find it.
: : : So I tried to repair it without schematic. But the powersupply-transformer was burned.
: : : I replaced it and tried to repair the set with octal tubes ( f.e.6V6)
: : : Finally by comparing several circuit diagrams I was able to draw the diagram and now the set is working but (no already perfect) with 6 volt tubes.
: : : But I want to restore it with the original or equivalent tubes but I don't know the original numbers of the tubes.
: : : I only know the 16 volts replacemnts types (by comparing the diagrams).
: : : My question now is, can I find the original 4 volt types of valves or perhaps do exits also 6 volts equivalents, that should be also convenient but not necesairly.
: : : Anyway I don't want to replaced the sokets (B5 types) of the tubes, they are still original.
: : : I hope you understand now my question
: : : Maurits
: : : ON7EY
: : Hello Maurits,
: : Thanks for the information. The 506 is a Philips full wave rectifier with a 4 volt filament. It could be the original or a replacement. Do you know the make and model of the set? If so I'll try and find a schematic of the original set and that should tell us what the correct tubes should be. If you have replaced the transformer with one with a 5 volt rectifier winding you should put a 1 ohm 2 watt resistor in series with the heater to reduce the voltage to 4 volts if you want to keep the 506 (it draws 1 amp and is probably about the right vintage for your set). I guess that you have a transformer with a 6.3 volt winding for the heater supply. From your email address I think your in Belgium. The set must be either English or European, I don't think you'll have any great difficulty finding suitable tubes. I agree it will be better to retain the original sockets and vintage tubes. Sorry if I sound a bit vague but if you can find the information it will help. I hope to have more data available on the tubes you listed in the next few days, I'll do what I can. Don.
have a nice day
Maurits ON7EY
: : THANKS FOR COMMENT
: : As I already told you. I found the radio without tubes.
: : The set is a His Masters Voice 238 AC and it seems to be very difficult to find the circuit diagram. I found the radio in Belgium but it is defenitly a British product. Everything in the set is so Britisch even the mentionning toward the Royal Crown of The British empire.
: : There is also a label in it with the remark only to use Marconi tubes (so I know that the 506 was not original it is not original, but I can use it of course and it is still in the set, working) and a remark on the obligation to pay tax to the British Government.
: : I foud a very similar circuit of a DC set made by HMV, Columbia and Marconi (I think 440 Dc, but I am not sure, if you want I can send you the diagram); the values of the condensors and resistors are the same. But this circuit uses 16 volts tubes. I am now looking for the original tubes on 4 volts or equivalents on 6 volts, because the set is now working on 6.3 V octal tubes without changing the sockets (i had to chnage the transformer because it was burned). Of course I will put a resistors in the circuit to adapt the filament tension to 4 v. Or if I find 6V types (but I don't know if they realy exist)I can use the without modification.
: : Do you see know my question?
: : Maurits ON7EY
: Hi Maurits,
: Thanks for the further information. If you can send me a copy of the circuit that you have it would help. I've got some HMV & Marconiphone circuits around your model number but not the 238 AC yet. I'll keep looking. Don.
: : : : Well Don Black,
: : : : First of all thanks for the answer.
: : : : I found the set in an old barn.
: : : : The valves were disappeared, exept a 506 as rectifier, but that is not the original.
: : : : I tried to find the circuit diagram of the set but I didn't find it.
: : : : So I tried to repair it without schematic. But the powersupply-transformer was burned.
: : : : I replaced it and tried to repair the set with octal tubes ( f.e.6V6)
: : : : Finally by comparing several circuit diagrams I was able to draw the diagram and now the set is working but (no already perfect) with 6 volt tubes.
: : : : But I want to restore it with the original or equivalent tubes but I don't know the original numbers of the tubes.
: : : : I only know the 16 volts replacemnts types (by comparing the diagrams).
: : : : My question now is, can I find the original 4 volt types of valves or perhaps do exits also 6 volts equivalents, that should be also convenient but not necesairly.
: : : : Anyway I don't want to replaced the sokets (B5 types) of the tubes, they are still original.
: : : : I hope you understand now my question
: : : : Maurits
: : : : ON7EY
: : : Hello Maurits,
: : : Thanks for the information. The 506 is a Philips full wave rectifier with a 4 volt filament. It could be the original or a replacement. Do you know the make and model of the set? If so I'll try and find a schematic of the original set and that should tell us what the correct tubes should be. If you have replaced the transformer with one with a 5 volt rectifier winding you should put a 1 ohm 2 watt resistor in series with the heater to reduce the voltage to 4 volts if you want to keep the 506 (it draws 1 amp and is probably about the right vintage for your set). I guess that you have a transformer with a 6.3 volt winding for the heater supply. From your email address I think your in Belgium. The set must be either English or European, I don't think you'll have any great difficulty finding suitable tubes. I agree it will be better to retain the original sockets and vintage tubes. Sorry if I sound a bit vague but if you can find the information it will help. I hope to have more data available on the tubes you listed in the next few days, I'll do what I can. Don.