|
|
Post by homerbb on Apr 15, 2011 10:13:30 GMT -5
I have been given this old radio, and am considering it as a project radio. It powers up, and seems to key according to the freq counter, but needs some crystals as not all the channels are on the mark. Some are in the 22 Mhz range. Additionally, After sitting warming up a few minutes something inside toward the right front popped, and billowed smoke; a capacitor, I am assuming. I know the radio isn't worth much monetarily, but what about the likelihood of making the old thing right again? Doable with today's resources? I even have an old Turner +2 I can mate to it.  |
|
Sandbagger
Administrator/The Boss 
Posts: 6,249 
|
Post by Sandbagger on Apr 15, 2011 10:54:14 GMT -5
I have been given this old radio, and am considering it as a project radio. It powers up, and seems to key according to the freq counter, but needs some crystals as not all the channels are on the mark. Some are in the 22 Mhz range. Additionally, After sitting warming up a few minutes something inside toward the right front popped, and billowed smoke; a capacitor, I am assuming. I know the radio isn't worth much monetarily, but what about the likelihood of making the old thing right again? Doable with today's resources? I even have an old Turner +2 I can mate to it. It's a decent radio to get your feet wet with learning to restore tube rigs. It's a typical Panasonic chassis. Chances are the "pop" that you saw was a .1uF 600V capacitor which is used to tap the transformer for the -82V supply. They pop quite frequently when they've got 40 years under them. Crystals should not be hard to find as they use a fairly common crystal frequency mixing scheme. |
|
|
|
Post by homerbb on Apr 15, 2011 11:15:37 GMT -5
|
|
Sandbagger
Administrator/The Boss
Posts: 6,249
|
Post by Sandbagger on Apr 15, 2011 22:11:04 GMT -5
There are a few trouble signs in that Robyn mobile. It sure looks like a case of reverse polarity. The protection diode is supposed to protect against that by providing a short which is supposed to blow the fuse. But a lot of knuckleheads don't realize why the fuse is blowing and they replace the fuse with a 30 amp (or some tin foil). Then the diode either shorts completely, or blows open. The fact that that electrolytic cap is also blown tells me that the protection diode eventually opened up allowing the reverse voltage to be applied to the cap causing it to blow. The real scary part is that the rest of the radio was likely exposed to the reversed polarity and it might have blown several other parts. It's also possible that it might work ok. But I wouldn't be surprised if the audio amp was out or some other part of the radio was inop. |
|
|
|
Post by homerbb on Apr 17, 2011 1:22:24 GMT -5
Just what I figure, too. I'll put the parts right that I see, and then if it's an ongoing problem, I'll decide whether to press on.
|
|
|
|
Post by rifleman on Apr 17, 2011 10:06:13 GMT -5
I agree that both of the radios are ones that are great to get your learn on.
Easy to find electronic components, and fairly easy to work on (NO SMT's).
Also, there are SAMS manuals for each: GTX-2300 SAMS #91; and SX-101 SAMS #71.
Good luck, and have fun with them !!!
|
|
|
|
Post by homerbb on Apr 17, 2011 10:31:48 GMT -5
It's a new venture for me. Thanks for the encouragement.
|
|
