Charlie
12-18-2003, 11:55 PM
Well, here is proof that sometimes a break is needed when you just can't find the problem in a set.
Several years ago, my ex-wifes's grandmother gave me this 1960 Motorola 21C10CW set. Hadn't been used since 1970. It needed new tubes in the tuner, and also had a problem with a severely faded picture that wouldn't lock into sync. I had spent countless hours on it back then... thinking the problem was in the AGC. All of the old caps were in surprisingly good shape, but I went ahead and changed the lytics anyway. All of the tubular ceramic caps checked like new. But, i never found the problem and finally gave up thinking that maybe I just needed a rest from it.
Today, several years later, I decided to try injecting signals thru the different stages, and found that I got a good picture after the detector. Turns out, there was a 8.5 uh choke just after the detector diode that was open. Slapped another in there and ended up with a great picture.
So, when you have one of those sets that just wont cooperate with you, stick it in the corner for about 5 years before trying again.
This set has a really nice ?copper?, all hand-wired chassis. It was built pretty sturdy. Other than some dust, this chassis is really clean. I am assuming that the CRT has been changed because I would think Motorola would have used their own CRTs. Heck... all of the tubular caps in it have the Motorola name and emblem on them. This set has a Dumont CRT in it.
Several years ago, my ex-wifes's grandmother gave me this 1960 Motorola 21C10CW set. Hadn't been used since 1970. It needed new tubes in the tuner, and also had a problem with a severely faded picture that wouldn't lock into sync. I had spent countless hours on it back then... thinking the problem was in the AGC. All of the old caps were in surprisingly good shape, but I went ahead and changed the lytics anyway. All of the tubular ceramic caps checked like new. But, i never found the problem and finally gave up thinking that maybe I just needed a rest from it.
Today, several years later, I decided to try injecting signals thru the different stages, and found that I got a good picture after the detector. Turns out, there was a 8.5 uh choke just after the detector diode that was open. Slapped another in there and ended up with a great picture.
So, when you have one of those sets that just wont cooperate with you, stick it in the corner for about 5 years before trying again.
This set has a really nice ?copper?, all hand-wired chassis. It was built pretty sturdy. Other than some dust, this chassis is really clean. I am assuming that the CRT has been changed because I would think Motorola would have used their own CRTs. Heck... all of the tubular caps in it have the Motorola name and emblem on them. This set has a Dumont CRT in it.