Nolan Woodbury
06-25-2005, 05:01 PM
Hi everyone,
Now that I've discovered how to resize photos, I can post a couple now.
The first is a radio I got this week. It's a C730R; the square version of my favored G730 that uses the C705 chassis with a large oval speaker and the square tweeter. This radio didn't work very well, but thanks to some of the posts here it plays like a new set. The main problem was weak reception and channel fading. The second problem was the heat damage located on the top right of the cabinet and finally, the tuning slide was off. After pulling the chassis out, I noticed the heat shield was missing (right on top of where three of the C730's tubes; the 12AU6, 19T8 and 35C5 output tube live) so I fashioned a new one from heavy duty aluminum foil, folded about 3 times. Using one of my other radios, I pulled a corner of its shield down a measured it: about .040 thick. My new piece is close to that. After gluing that in, I loosened the tuning indicator and moved it to approximately the correct position, cleaned the dial lens with Mirror Glaze and put it away. Using the 'one tube' theory, I replaced the RF-amp tube with my last 12AT7 / ECC81 Mullard, then ordered two more from the Tube Depot. It's all together now and working wonderfully! $16.50 from an eBay member who told me it was dead.
The second is a radio I was after for quite a while. It's a burgundy bakelite K725 with very little oxidation on the gold tuning arm and trim, but terrible reception. Using Chad's advice of "hum = capacitor trouble while reception is likely from weak tubes," I replaced all of the tubes (including the RF-amp tube) and set about replacing/repairing the broken tuner cord. I've shown the finished chassis in this photo. The bakelite was very dull (smoke? oxidation? dirt? Most likely a combination of all three) and nothing I tried would bring back the luster. Finally, I reached in my motorcycle cleaning supplies and pulled out a can of Mothers Aluminum polish that I slightly diluted with water. Magic! Lots of elbow grease, but the shine is spectacular! This radio doesn't have the presence and tone of my favorite Zenith's (K731, G/C730's) but it is a beautiful example of late 40s-early-50s Zenith technoligy. I am very proud of the "Armstrong System" sticker on the back and the fact it works great now.
Thanks everyone (especially Chad) for the informative posts. They've helped turn my piles of junk into treasure. What's next? :-)
Now that I've discovered how to resize photos, I can post a couple now.
The first is a radio I got this week. It's a C730R; the square version of my favored G730 that uses the C705 chassis with a large oval speaker and the square tweeter. This radio didn't work very well, but thanks to some of the posts here it plays like a new set. The main problem was weak reception and channel fading. The second problem was the heat damage located on the top right of the cabinet and finally, the tuning slide was off. After pulling the chassis out, I noticed the heat shield was missing (right on top of where three of the C730's tubes; the 12AU6, 19T8 and 35C5 output tube live) so I fashioned a new one from heavy duty aluminum foil, folded about 3 times. Using one of my other radios, I pulled a corner of its shield down a measured it: about .040 thick. My new piece is close to that. After gluing that in, I loosened the tuning indicator and moved it to approximately the correct position, cleaned the dial lens with Mirror Glaze and put it away. Using the 'one tube' theory, I replaced the RF-amp tube with my last 12AT7 / ECC81 Mullard, then ordered two more from the Tube Depot. It's all together now and working wonderfully! $16.50 from an eBay member who told me it was dead.
The second is a radio I was after for quite a while. It's a burgundy bakelite K725 with very little oxidation on the gold tuning arm and trim, but terrible reception. Using Chad's advice of "hum = capacitor trouble while reception is likely from weak tubes," I replaced all of the tubes (including the RF-amp tube) and set about replacing/repairing the broken tuner cord. I've shown the finished chassis in this photo. The bakelite was very dull (smoke? oxidation? dirt? Most likely a combination of all three) and nothing I tried would bring back the luster. Finally, I reached in my motorcycle cleaning supplies and pulled out a can of Mothers Aluminum polish that I slightly diluted with water. Magic! Lots of elbow grease, but the shine is spectacular! This radio doesn't have the presence and tone of my favorite Zenith's (K731, G/C730's) but it is a beautiful example of late 40s-early-50s Zenith technoligy. I am very proud of the "Armstrong System" sticker on the back and the fact it works great now.
Thanks everyone (especially Chad) for the informative posts. They've helped turn my piles of junk into treasure. What's next? :-)