09-18-2016, 03:38 PM
Finally getting back to this after getting a usable transformer. If you're out there, Terry, here's where I'm at:
The audio output is strong and clear when I touch the center tap of the volume control. Using the soldering iron trick, when I touch the grid caps of all of the tubes that have them, I get a strong buzz through the speaker on each. I cannot receive any stations with a long wire connected direct to the antenna clip, however. But if I clip the antenna wire direct on to the grid cap wire of the #77 1st det. tube, I get several stations across the dial, albeit at a reduced volume and somewhat garbled sound. When I clip the antenna on the next tube instead (the #78 RF Amp), I get one station clear (not garbled), AM 620, a strong Milwaukee station but at very low volume. The rest of the dial is silent.
In checking voltages, P to K on the 42 driver tube is 129 and should be 190. On the #77 1st Det tube however, P to K reads 364! If should only be 185.
The antenna coil (#7) and the wave trap coil (#1) measure very close to where they should be, however. I get around 5.5 ohms on the #7 and about 2.2 ohms on the #1.
I'm stuck. Any help on what to check or what could be the cause would be most appreciated. Resistors all check good. I only changed the electrolytic caps and the few paper caps the set had. I didn't start restuffing blocks yet. I'm just trying to get the thing to play. I don't like going flat out replacing everything right off the bat.
The audio output is strong and clear when I touch the center tap of the volume control. Using the soldering iron trick, when I touch the grid caps of all of the tubes that have them, I get a strong buzz through the speaker on each. I cannot receive any stations with a long wire connected direct to the antenna clip, however. But if I clip the antenna wire direct on to the grid cap wire of the #77 1st det. tube, I get several stations across the dial, albeit at a reduced volume and somewhat garbled sound. When I clip the antenna on the next tube instead (the #78 RF Amp), I get one station clear (not garbled), AM 620, a strong Milwaukee station but at very low volume. The rest of the dial is silent.
In checking voltages, P to K on the 42 driver tube is 129 and should be 190. On the #77 1st Det tube however, P to K reads 364! If should only be 185.
The antenna coil (#7) and the wave trap coil (#1) measure very close to where they should be, however. I get around 5.5 ohms on the #7 and about 2.2 ohms on the #1.
I'm stuck. Any help on what to check or what could be the cause would be most appreciated. Resistors all check good. I only changed the electrolytic caps and the few paper caps the set had. I didn't start restuffing blocks yet. I'm just trying to get the thing to play. I don't like going flat out replacing everything right off the bat.
Greg V.
West Bend, WI
Member WARCI.org