03-20-2018, 09:29 PM
Thanks once again, Terry. Here's the progress report:
I did the OSC test with a second radio. I had this 37-84 set to 620 AM on the dial, and the second radio set to around 1100 and could hear the OSC coming through the test radio. The station didn't come through but I knew I found the OSC, as when I turned the 38-84 off, I got normal static on the second radio. Repeated the test with another restored tube radio and got the same results. Now the rewound primary on the OSC coil still has gaps between the windings, but the right number of turns and wound in the right direction. I'm getting a lot of stations (with the test ANT coil...see below), just not the strong local one at 1470 but I suspect I may need to do an alignment to find it. So I'm kinda on the fence if I should try rewinding the coil to get the windings closer or leave it as is?
I unhooked the existing ANT coil wires (which measured 2.6 ohms on the primary and 5.7 ohms on the secondary) and gator wired in the antenna coil I have from a parted out model 89. That primary measures 16.5 ohms and the secondary 9 ohms.
With the model 89 ANT coil, the radio has good volume and control of volume. And received lots of stations. Then I disconnected the model 89 ANT coil and gator wired the ANT coil from the radio back in, not touching the tuner or volume control. With the ANT coil from this radio I have very low volume. Yet neither winding reads open. Possibly it's green spots cutting down on the volume? Or could the higher resistance on the model 89 coil be boosting the volume? I suspect rewinding the primary of the ANT coil is next. I'm still using the volume control that was in the radio, and measures around 500K. I'm trying to find one that measures 20K as the schematic calls for. Not sure how much it will affect the performance, though.
Oh, and Dad says hi
I did the OSC test with a second radio. I had this 37-84 set to 620 AM on the dial, and the second radio set to around 1100 and could hear the OSC coming through the test radio. The station didn't come through but I knew I found the OSC, as when I turned the 38-84 off, I got normal static on the second radio. Repeated the test with another restored tube radio and got the same results. Now the rewound primary on the OSC coil still has gaps between the windings, but the right number of turns and wound in the right direction. I'm getting a lot of stations (with the test ANT coil...see below), just not the strong local one at 1470 but I suspect I may need to do an alignment to find it. So I'm kinda on the fence if I should try rewinding the coil to get the windings closer or leave it as is?
I unhooked the existing ANT coil wires (which measured 2.6 ohms on the primary and 5.7 ohms on the secondary) and gator wired in the antenna coil I have from a parted out model 89. That primary measures 16.5 ohms and the secondary 9 ohms.
With the model 89 ANT coil, the radio has good volume and control of volume. And received lots of stations. Then I disconnected the model 89 ANT coil and gator wired the ANT coil from the radio back in, not touching the tuner or volume control. With the ANT coil from this radio I have very low volume. Yet neither winding reads open. Possibly it's green spots cutting down on the volume? Or could the higher resistance on the model 89 coil be boosting the volume? I suspect rewinding the primary of the ANT coil is next. I'm still using the volume control that was in the radio, and measures around 500K. I'm trying to find one that measures 20K as the schematic calls for. Not sure how much it will affect the performance, though.
Oh, and Dad says hi
Greg V.
West Bend, WI
Member WARCI.org
