12-02-2007, 01:12 AM
Thanks for the response, Ron.
What got me so exasperated is that I could put an IF signal though it--very clear and strong. I found the "Special section" in the front of Rider's Volume 8 that did a lot of simplification and explaining. Finally, a bit of advice from my old standby copy of "Elements of Radio Servicing" broke down the systems even further into simple tests of the oscillator components. It boiled down to testing each part which only showed a couple of resistors 10% over value(replaced, probably needlessly) and a check to see if the tuning condenser was somehow shorted to ground. I did not see anything but some dust and a couple of plates that were ever-so-slightly misaligned.
After some tweaking of plates and brushing and blowing the dust out, it fired right up!! There was a lot of dirt on this chassis when I got it, maybe that was it.
A couple questions/comments:
First, the schematic says the IF is 470; yet the chassis stamped 465. Which is right?
Second, I found resistor number 43 listed on the print as 40,000 ohms; yet the resistor installed in the chassis was 4,000 ohms. This resistor looked like a factory installation. What gives? Has anybody else noticed this?
Third, I suppose that there are always going to be changes during the production run; this radio had several differences to the published schematic. there were two bakelite condenser blocks near the output transformer instead of the individual components I expected to find.
Lastly, does anyone make a set of the station call letter windows for the dial? Or do others just cut up an old dial for the pieces?
Thanks to everyone on the Phorum, it's a GREAT resource. I have a 116, two 37-116's and a 38-690 waiting for attention; I suppose I'll be bugging you again soon
What got me so exasperated is that I could put an IF signal though it--very clear and strong. I found the "Special section" in the front of Rider's Volume 8 that did a lot of simplification and explaining. Finally, a bit of advice from my old standby copy of "Elements of Radio Servicing" broke down the systems even further into simple tests of the oscillator components. It boiled down to testing each part which only showed a couple of resistors 10% over value(replaced, probably needlessly) and a check to see if the tuning condenser was somehow shorted to ground. I did not see anything but some dust and a couple of plates that were ever-so-slightly misaligned.
After some tweaking of plates and brushing and blowing the dust out, it fired right up!! There was a lot of dirt on this chassis when I got it, maybe that was it.
A couple questions/comments:
First, the schematic says the IF is 470; yet the chassis stamped 465. Which is right?
Second, I found resistor number 43 listed on the print as 40,000 ohms; yet the resistor installed in the chassis was 4,000 ohms. This resistor looked like a factory installation. What gives? Has anybody else noticed this?
Third, I suppose that there are always going to be changes during the production run; this radio had several differences to the published schematic. there were two bakelite condenser blocks near the output transformer instead of the individual components I expected to find.
Lastly, does anyone make a set of the station call letter windows for the dial? Or do others just cut up an old dial for the pieces?
Thanks to everyone on the Phorum, it's a GREAT resource. I have a 116, two 37-116's and a 38-690 waiting for attention; I suppose I'll be bugging you again soon
