Columbia 817-6

[Doug66]

I picked this up last Sat at an antique mall for $38. The control box door is missing, as well as the channel selector knob and the back.

I decided tom go ahead and give it a shot. I don't have any info on it right now, and I can't find a Sams on ebay for sale (214-2), so I'm starting out blind.

I found several spare tubes laying around the chassis, and the hi voltage cover is also missing. I'm assuming the set has hi voltage troubles and someone gave up after trying some replacement tubes.

I went ahead and replaced the 2 main electrolytics tubular units under the chassis. One was a 4 section and the other a 3 section. I decided to try a power up on the variac. Sure enough, no hi voltage. I can get some noise out of the spkr but never could get a station to come thru.

I going to start on the paper caps tonight.

[WISCOJIM]

You should change that white tubular cap that is blown apart at the top right of your under chassis picture.

[old_coot88]

Are you sure that's a cap? It looks more like a Gravel Gertie (sand coated flat resistor).

[Radiotronman]

I've got a mahogany model a year or two earlier. It's also missing the control door. Good find though!

[Doug66]

It is a sand coated resistor. There is no markings on it, but think it is working for the moment as it does get warm. As soon as I can get a Sams, I will replace it and the other sand resistor.

I have made SOME progress. First, my 75/300transformr was bad. Trying another one gave me sound, but the volume control is not working. It looks like someone has tinkered with that section also.

There is a electrolytic cap in parallel with an 8 ohm power resistor coming off the 6BQ6 and going to ground. No voltage on the pos side. That my be why I have no high voltage. They both look like replacement units. I need to find out exactly what goes there.

[WISCOJIM]

The cap with the end blown open next to the chassis wall.

[Doug66]

Ok, now I see what you a talking about. That is in the audio circuit directly on the 3 prong connection for the audio transformer. Yes, definitely one of the next caps to get replaced.

[Phil Nelson]

Originally Posted by Doug66

I can't find a Sams on ebay for sale (214-2), so I'm starting out blind.

It may be more expensive than eBay, but you can always order the Sams manual from Sams:

https://samswebsite.com/

Regards,

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

[WISCOJIM]

Doug, I've got a spare 214-2. $5 mailed sound okay? PM me.

[WISCOJIM]

The 6BQ6 area of the schematic...

[Doug66]

Jim, thanks a bunch for posting the thumbnail of the horiz output section. I've definitely got the wrong parts going to pin 8 of the 6BQ6. Someone has put in a 5 ohm 10W resistor in parallel with the capacitor, and the schematic says I need a 220ohm.

Would you do me one more favor and look at the parts list and see what size that resistor is. Its R97, a 220 ohm.

PM Sent also

[WISCOJIM]

Sure, 220Ω @ 2-watts.

[old_coot88]

Originally Posted by Doug66

Someone has put in a 5 ohm 10W resistor in parallel with the capacitor, and the schematic says I need a 220ohm.

Sounds like they were trying to get more width out of it. Have they played with the values of the G2 resistors R98 and R99?

[Doug66]

Yikes! All I had was a 1 W, and I put that in there. I'll see about getting a 2W. I don't have any voltage on that pin anyway, and I should have 15V. The rest of the voltages on that tube are messed up as well so have an idea where to start troubleshooting

I do hear the oscillator running, so I'm somewhat confident its not the problem.

Funny thing, EVERY paper cap I have seen in that set is 600V unit. You normally see sets with a variety of voltage rated caps from 200V to 600V. Either they got a good buy on strictly 600V units or the just went for overkill.

[Electronic M]

Check H out tube grid bias to make sure your osc. drive is making it to the output. If you have proper grid drive and no screen grid voltage issues, then check your flyback.