10-24-2023, 04:24 PM
S-14
8" cone
36-1144
610F, 610T, 620, 625 model used in. Note there is a 610B that uses the same chassis as the other 610's but the spkr is a 6" job so it wouldn't be a good match for your application.
1-42 tube as Pentode
32-7019
1 ohm VC impedance
400 output transformer resistance
1140 FC resistance
65ma FC current
It's looks like the S-7 is a good match for the unit. It was used in the Model 60 and a number of the 5/6 tube 1937 models.
That's the specs for the original spkr.
I suspect that the original spkr wiring only had three wires as the B+ side of the opt and one end of FC are connected together. The four wire cables are relegated to the set w/push/pull output stages.
If you can't find a dynamic spkr and you have to replace w/a pm spkr you'll need a 7k to vc output transformer, an 8" spkr, and a choke, the high inductance the better. You could use a resistor instead of the choke but it make a lousy filter and filter cap will have to be doubled or tripled to kill the 60cy hum.
8" cone
36-1144
610F, 610T, 620, 625 model used in. Note there is a 610B that uses the same chassis as the other 610's but the spkr is a 6" job so it wouldn't be a good match for your application.
1-42 tube as Pentode
32-7019
1 ohm VC impedance
400 output transformer resistance
1140 FC resistance
65ma FC current
It's looks like the S-7 is a good match for the unit. It was used in the Model 60 and a number of the 5/6 tube 1937 models.
That's the specs for the original spkr.
I suspect that the original spkr wiring only had three wires as the B+ side of the opt and one end of FC are connected together. The four wire cables are relegated to the set w/push/pull output stages.
If you can't find a dynamic spkr and you have to replace w/a pm spkr you'll need a 7k to vc output transformer, an 8" spkr, and a choke, the high inductance the better. You could use a resistor instead of the choke but it make a lousy filter and filter cap will have to be doubled or tripled to kill the 60cy hum.
When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!
Terry
