07-12-2024, 11:52 AM
Well, the filaments of all tubes plus pilot, without the 80, draw 24W.
I am not counting the centertap resistors.
I do not know what the efficiency of the power transformer is. Or what the initial losses that occur just from plugging it in without load.
You have 16W going somewhere. Does the transformer get too warm over time without load, if you just plug it and run without tubes?
You said your filament voltages are good, which is a good sign; how about the Hi-V rectifier - it is supposed to be around over 600V end-to-end.
The tubes (with 80 in) dissipation should be around 17W.
The rectifier is another 10W in filament power, plus the dissipation (plate resistance times the full rectifier current, which I do not know).
L7 will drop some significant power.
L6 will also drop some.
The radio, which is comparable to Philco 20, should be about 75W total.
Remove all tubes, so transformer has no load, and see what it draws and whether or not it gets hot.
PS. Check the biases (when tubes are in) against the tables. See if any tube runs too hot. The 80 is always very hot when loaded.
Measure voltages across the tube; especially across 80 (P to K).
PPS. Cannot see the field coil consumption, but in Philco 20 it is about 5W (125V at 3,100 ohms)
I am not counting the centertap resistors.
I do not know what the efficiency of the power transformer is. Or what the initial losses that occur just from plugging it in without load.
You have 16W going somewhere. Does the transformer get too warm over time without load, if you just plug it and run without tubes?
You said your filament voltages are good, which is a good sign; how about the Hi-V rectifier - it is supposed to be around over 600V end-to-end.
The tubes (with 80 in) dissipation should be around 17W.
The rectifier is another 10W in filament power, plus the dissipation (plate resistance times the full rectifier current, which I do not know).
L7 will drop some significant power.
L6 will also drop some.
The radio, which is comparable to Philco 20, should be about 75W total.
Remove all tubes, so transformer has no load, and see what it draws and whether or not it gets hot.
PS. Check the biases (when tubes are in) against the tables. See if any tube runs too hot. The 80 is always very hot when loaded.
Measure voltages across the tube; especially across 80 (P to K).
PPS. Cannot see the field coil consumption, but in Philco 20 it is about 5W (125V at 3,100 ohms)
People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
