01-08-2011, 08:57 PM
Sorry for not posting this earlier!
The 112 is now completely restored and works quiet well.
After recapping I powered the radio up through a dim-bulb tester through 25, 40, 60, and 100 watt lightbulbs. Small amounts of audio came out with the 100W bulb and generally everything seemed like it was fine. Power up straight into the wall produced loud audio and tuning seemed to work fine.
Generally it worked pretty well. But there was clear audio distortion coming from somewhere. Lots of random poking around led me to look at the speaker drive signal on my scope. This showed pretty clearly that part of the waveform was very truncated. Somehow (I don't remember how...) I figured that one of the 45 audio tubes was bad. 45 tubes are annoyingly expensive because some audiophile people love them. So I ended up replacing both 45s with 1619s from here (http://www.dialcover.com/tubes.html). That completely solved the distortion problem. This problem also led to the only instance of electrocution in the project: when I foolishly decided to adjust the scope with one hand and the radio volume control with the other....ouch.
This is him all powered up (with the original 45s, one of which is blue):
[Image: http://farm3.static.flickr.com/2172/2399...a7_z_d.jpg]
And all put back together:
[Image: http://farm4.static.flickr.com/3049/2402...9a_z_d.jpg]
It currently has knobs from my (also now in restoration) 36-650. I need to find a source for the right knobs.
I use the radio about weekly. At power up there is a slight hum at about 3 seconds, and then audio comes through at about 15 seconds. It takes about 5-7 minutes before everything is entirely warmed up and stops drifting. I think there is slightly more hum than is supposed to be there. Also the volume control is annoyingly scratchy at the lower part of the range. It is a weird (to me) metal wheel in a carbon(?) sleeve affair. I've tried to clean it, but am afraid of harming it further. So I scrub it up and down every once in a while and live with it.
here is a picture of the volume control:
[Image: http://farm3.static.flickr.com/2220/2367...fe_z_d.jpg]
The 112 is now completely restored and works quiet well.
After recapping I powered the radio up through a dim-bulb tester through 25, 40, 60, and 100 watt lightbulbs. Small amounts of audio came out with the 100W bulb and generally everything seemed like it was fine. Power up straight into the wall produced loud audio and tuning seemed to work fine.
Generally it worked pretty well. But there was clear audio distortion coming from somewhere. Lots of random poking around led me to look at the speaker drive signal on my scope. This showed pretty clearly that part of the waveform was very truncated. Somehow (I don't remember how...) I figured that one of the 45 audio tubes was bad. 45 tubes are annoyingly expensive because some audiophile people love them. So I ended up replacing both 45s with 1619s from here (http://www.dialcover.com/tubes.html). That completely solved the distortion problem. This problem also led to the only instance of electrocution in the project: when I foolishly decided to adjust the scope with one hand and the radio volume control with the other....ouch.
This is him all powered up (with the original 45s, one of which is blue):
[Image: http://farm3.static.flickr.com/2172/2399...a7_z_d.jpg]
And all put back together:
[Image: http://farm4.static.flickr.com/3049/2402...9a_z_d.jpg]
It currently has knobs from my (also now in restoration) 36-650. I need to find a source for the right knobs.
I use the radio about weekly. At power up there is a slight hum at about 3 seconds, and then audio comes through at about 15 seconds. It takes about 5-7 minutes before everything is entirely warmed up and stops drifting. I think there is slightly more hum than is supposed to be there. Also the volume control is annoyingly scratchy at the lower part of the range. It is a weird (to me) metal wheel in a carbon(?) sleeve affair. I've tried to clean it, but am afraid of harming it further. So I scrub it up and down every once in a while and live with it.
here is a picture of the volume control:
[Image: http://farm3.static.flickr.com/2220/2367...fe_z_d.jpg]
