The radio would have been designed for different output tubes and voltages. If you are using 90 volts instead of 135 and 01A tubes two C- tied together will be correct. Use - 4 1/32 volts for C battery.
You could use a 71A for output with 135 volts. In this case - 22 1/2 volts would have been used for bias on this tube.
Don't know your specific radio but this is how most were used in 1920's.
Norm
:Hi -
:I have an early "Tangley" TRF set and a few questions I hope someone can answer. There are jumper wires between the B+135V and B+90V set connector scews as well as a jumper between two C- connector screws. Was the previous owner only have batteries for one or the other voltages and just jumpered them to save money?
:If I leave the jumpers in place should I only operate the set at the lower voltage settings?
:Thanks!
:Paul
The key thing here is the C voltage.
201's and 112's use -4.5V at 90V B+, and -9V at 135V B+.
171's use -16.5V at 90V B+, and -27V at 135V B+.
Also, don't run your detector [hopefully a 200] at more than 45V B+.
I do recommend that if you use an old speaker,that you don't go past 90V unless you are sure of the winding on the speaker's coil. My Radio Magnavox M4 horn speaker opened up both times I tried it at 135V B+, and believe me, those coils are a real pain in the a** to fix [oh, I'd say #44 enamel wire, about as thin as my hair]. But then again, your speaker might be able to handle the load, and if not, well, let's hope your coil opens at the surface like mine did, and not deep inside the coil!
:Hi -
:I have an early "Tangley" TRF set and a few questions I hope someone can answer. There are jumper wires between the B+135V and B+90V set connector scews as well as a jumper between two C- connector screws. Was the previous owner only have batteries for one or the other voltages and just jumpered them to save money?
:If I leave the jumpers in place should I only operate the set at the lower voltage settings?
:Thanks!
:Paul
:Yes, you should be able to use all of the common tubes, 201's, 112's, and 171's.
:
:The key thing here is the C voltage.
:
:201's and 112's use -4.5V at 90V B+, and -9V at 135V B+.
:
:171's use -16.5V at 90V B+, and -27V at 135V B+.
:
:Also, don't run your detector [hopefully a 200] at more than 45V B+.
:
:I do recommend that if you use an old speaker,that you don't go past 90V unless you are sure of the winding on the speaker's coil. My Radio Magnavox M4 horn speaker opened up both times I tried it at 135V B+, and believe me, those coils are a real pain in the a** to fix [oh, I'd say #44 enamel wire, about as thin as my hair]. But then again, your speaker might be able to handle the load, and if not, well, let's hope your coil opens at the surface like mine did, and not deep inside the coil!
:
::Hi -
::I have an early "Tangley" TRF set and a few questions I hope someone can answer. There are jumper wires between the B+135V and B+90V set connector scews as well as a jumper between two C- connector screws. Was the previous owner only have batteries for one or the other voltages and just jumpered them to save money?
::If I leave the jumpers in place should I only operate the set at the lower voltage settings?
::Thanks!
::Paul