06-22-2021, 05:56 PM
Have been working on a Model 65. Have lurked out here on the site for some time, and you folks have been helpful in the past, so here goes:
I have rebuilt a number of Philcos in my time but this is my first TRF unit. Doing all the usual repairs, caps, (yes, including the power supply) and all out of spec resistors. Making progress but have run into a couple of issues.
First, the Philco 3518 choke is a shielded 150H, 10ma unit with a DC ohms measurement of 4,000 ohms. Mine reads a shade under 83 ohms, so I would suspect it has a short. My question is regarding a replacement as chokes with a 150H rating are apparently rare birds. Checked Hammond, etc, but have not been successful. Any ideas or does anyone have a 3518 they might part with?
Secondly, although I have yet to fire this old beauty up, I did check continuity across the speaker connector and got continuity but some rather large resistance measurements; on the small pins a rather unstable 40K ohms and the large pins read a steady 240K ohms which seems somewhat high to me.
Of course the schematic is unhelpful, so not sure what to expect, but I do suspect the coil and what I presume to be the output transformer which sets atop this glorious piece of cast iron. Anyone out there with Model G that might check theirs?
I do appreciate it...
I have rebuilt a number of Philcos in my time but this is my first TRF unit. Doing all the usual repairs, caps, (yes, including the power supply) and all out of spec resistors. Making progress but have run into a couple of issues.
First, the Philco 3518 choke is a shielded 150H, 10ma unit with a DC ohms measurement of 4,000 ohms. Mine reads a shade under 83 ohms, so I would suspect it has a short. My question is regarding a replacement as chokes with a 150H rating are apparently rare birds. Checked Hammond, etc, but have not been successful. Any ideas or does anyone have a 3518 they might part with?
Secondly, although I have yet to fire this old beauty up, I did check continuity across the speaker connector and got continuity but some rather large resistance measurements; on the small pins a rather unstable 40K ohms and the large pins read a steady 240K ohms which seems somewhat high to me.
Of course the schematic is unhelpful, so not sure what to expect, but I do suspect the coil and what I presume to be the output transformer which sets atop this glorious piece of cast iron. Anyone out there with Model G that might check theirs?
I do appreciate it...
Richard
