06-11-2015, 01:07 AM
Fred;
I'm not sure how the tuning light or lights are supposed to behave in this D-F Lyra model, on my Rogers 10-60 the tubing light stays bright when it's off a station, but dims when it's on a station. Some of these Rogers built sets had a tube dedicated to the operation of the tuning light or lights, I can't tell whether this set has one or not, but the light is connected in parallel with a 8600 Ohm resistor, and in series with two 10K ohm resistors, and then those are paralled with a 20K Om resistor, in the B+ circuitry. If the diagram on Nostalgia Air is correct then this set should also have variable IF bandwidth, which is what the arrows through the IF transformers are supposed to represent, it's a form of fidelity control, try playing with the tone control and see if the tuning light changes it's behavior.
Regards
Arran
I'm not sure how the tuning light or lights are supposed to behave in this D-F Lyra model, on my Rogers 10-60 the tubing light stays bright when it's off a station, but dims when it's on a station. Some of these Rogers built sets had a tube dedicated to the operation of the tuning light or lights, I can't tell whether this set has one or not, but the light is connected in parallel with a 8600 Ohm resistor, and in series with two 10K ohm resistors, and then those are paralled with a 20K Om resistor, in the B+ circuitry. If the diagram on Nostalgia Air is correct then this set should also have variable IF bandwidth, which is what the arrows through the IF transformers are supposed to represent, it's a form of fidelity control, try playing with the tone control and see if the tuning light changes it's behavior.
Regards
Arran
