11-27-2017, 12:01 PM
jcassity;
OK, thanks for that item. I will check mine to see what is happening with the dial string and levers.
This morning I did do a check of all the tubes. All checked OK except for the 6J5, which in this set was a metal tube. The 6J5 had no emission whatsoever! The tube did get warm, but just no emission. I had another 6J5 that checked good from an E H Scott 800B tuner parts chassis. I installed that tube so that the audio section would have some chance to work.
Now for the checks on the power transformer, 5Y3, 300 ohm resistor in the B+ and the AC measurements:
AC input voltage this morning was 123VAC.
Measuring at pin 4 and 6 of the 5Y3 socket, tube removed, 705VAC
Measuring ground to pin 4 of 5Y3 socket, tube removed, 352VAC
Measuring ground to pin 6 of 5Y3 socket, tube removed, 352VAC
Measuring pin 4 to 6 of the 5Y3 socket, tube installed, 690VAC
Measuring Gnd to pin 4 of the 5Y3 socket, tube installed, 345VAC
Measuring Gnd to pin 6 of the 5Y3 socket, tube installed, 345VAC
Measuring at 5Y3 cathode, tube installed, 31VAC and +337VDC
Measuring at the first Electrolytic filter section, +311VDC
The 300 ohm resistor is hot but not smoking and although I would not want to keep my finger on it, it is well within the capability of the 5W resistor I installed.
My next step will be to try the chassis with a speaker and an antenna to see if I can pick up any stations.
Here are a couple of pictures of the chassis;
Joe
OK, thanks for that item. I will check mine to see what is happening with the dial string and levers.
This morning I did do a check of all the tubes. All checked OK except for the 6J5, which in this set was a metal tube. The 6J5 had no emission whatsoever! The tube did get warm, but just no emission. I had another 6J5 that checked good from an E H Scott 800B tuner parts chassis. I installed that tube so that the audio section would have some chance to work.
Now for the checks on the power transformer, 5Y3, 300 ohm resistor in the B+ and the AC measurements:
AC input voltage this morning was 123VAC.
Measuring at pin 4 and 6 of the 5Y3 socket, tube removed, 705VAC
Measuring ground to pin 4 of 5Y3 socket, tube removed, 352VAC
Measuring ground to pin 6 of 5Y3 socket, tube removed, 352VAC
Measuring pin 4 to 6 of the 5Y3 socket, tube installed, 690VAC
Measuring Gnd to pin 4 of the 5Y3 socket, tube installed, 345VAC
Measuring Gnd to pin 6 of the 5Y3 socket, tube installed, 345VAC
Measuring at 5Y3 cathode, tube installed, 31VAC and +337VDC
Measuring at the first Electrolytic filter section, +311VDC
The 300 ohm resistor is hot but not smoking and although I would not want to keep my finger on it, it is well within the capability of the 5W resistor I installed.
My next step will be to try the chassis with a speaker and an antenna to see if I can pick up any stations.
Here are a couple of pictures of the chassis;
Joe