DuMont Blonde Revere Restoration

[IsthmusTV]

Hi all,

I was able to make good progress over the rainy weekend on my blonde DuMont Revere RA-113. This is the set that I picked up at the beginning of August and wrote about in this thread: http://www.videokarma.org/showthread.php?t=258995

I had the advantage of Phil Nelson's excellent write-up on the restoration of his RA-113 which was a great guide (thanks Phil)! Here's the chassis on the workbench before I started:



I decided to replace the electrolytics under the chassis instead of restuffing, since there was plenty of room. The modern replacements are so much smaller!


The flyback looks great. The new HV caps are from Just Radios in Canada:



After restringing the dial cord (which fortunately was easier than I thought it would be) I decided to try a power up with a metered variac. No smoke or strange noises, and current draw was just under two amps.


I got nice clear audio and a very dim raster:


I recalled that both HV rectifiers tested very weak, so replaced them both. Then things progressed quickly.


Here's after adjusting the ion trap:


And after adjusting the horizontal frequency and the other usual stuff:



I'm very pleased with the nice, bright picture! The video response is great enough that I see the color interference dots. There are still 4-5 paper caps yet to replace. The picture is somewhat canted, so I need to adjust the yoke and/or focus coil. And as some of you know, I have what I hope is a new old stock (or rebuilt) 17BP4 that I bought on eBay due to arrive on Thursday. There seems to be plenty of life left in the original 17AP4, but it will be nice to have a spare. The tuning eye tube is very dim, so I'll need to find a replacement.

This was a lot of fun and it's almost a let down at how easy it was

I'm looking forward to watching bandersen restore the one he's got!

-Clark

[tvtimeisfun]

Nice looking set hope you get plenty of tvtime on this set a great find just as well happy veiwing...Timothy

[Phil Nelson]

Wow, looking good. All that in one weekend? You work faster than I do (well, I did have a couple of issues like a busted tuner gear). An original 17AP4 suggests this was a low-hours set. Maybe it led a pampered life and retired early.

That blonde cabinet should be really striking. The RA-113 is very enjoyable to watch -- big screen, great audio.

Regards,

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

[IsthmusTV]

Wow, looking good. All that in one weekend? You work faster than I do (well, I did have a couple of issues like a busted tuner gear). An original 17AP4 suggests this was a low-hours set. Maybe it led a pampered life and retired early.

Hi Phil,

Actually, I had also done some work on it last weekend, too. And before that, I studied the SAMS and Riders so I knew what I was getting into. (Thanks again for scanning the SAMS folder!)

I do think it's probably a low hours set. The 1/4 amp pigtail fuse was blown and jumpered with a 2 amp fuse At least one of the filter caps was a dead short so it may have been pushed aside quite a while ago. I'm very glad that the seller hadn't tried to power it up.

The audio on TV is still lower than it should be, although the peak for good audio corresponds well with the best picture. The volume receiving FM stations is much louder. I haven't attempted any alignment yet.

It turns out that the original focus control is OK, but I'm still glad to have a back up. Now I'm just waiting to see if this CRT I bought on eBay for $50 make it in once piece:

[Phil Nelson]

Originally Posted by IsthmusTV

The audio on TV is still lower than it should be, although the peak for good audio corresponds well with the best picture. The volume receiving FM stations is much louder. I haven't attempted any alignment yet.

Yes, the TV volume was low until I did some tweaking, as noted in my article. The FM radio volume is still significantly louder, and I suspect that is just the nature of the beast.

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

[wa2ise]

Originally Posted by Phil Nelson

... The FM radio volume is still significantly louder, and I suspect that is just the nature of the beast.

That's true. The deviation of broadcast FM radio is much higher than that used for TV sound. 75KHz vs 25KHz IIRC. This deviation difference results in the FM radio stations being louder than TV station sound.

[brianweber4]

Originally Posted by IsthmusTV

Hi all,

I was able to make good progress over the rainy weekend on my blonde DuMont Revere RA-113. This is the set that I picked up at the beginning of August and wrote about in this thread: http://www.videokarma.org/showthread.php?t=258995

I had the advantage of Phil Nelson's excellent write-up on the restoration of his RA-113 which was a great guide (thanks Phil)! Here's the chassis on the workbench before I started:



I decided to replace the electrolytics under the chassis instead of restuffing, since there was plenty of room. The modern replacements are so much smaller!


The flyback looks great. The new HV caps are from Just Radios in Canada:



After restringing the dial cord (which fortunately was easier than I thought it would be) I decided to try a power up with a metered variac. No smoke or strange noises, and current draw was just under two amps.


I got nice clear audio and a very dim raster:


I recalled that both HV rectifiers tested very weak, so replaced them both. Then things progressed quickly.


Here's after adjusting the ion trap:


And after adjusting the horizontal frequency and the other usual stuff:



I'm very pleased with the nice, bright picture! The video response is great enough that I see the color interference dots. There are still 4-5 paper caps yet to replace. The picture is somewhat canted, so I need to adjust the yoke and/or focus coil. And as some of you know, I have what I hope is a new old stock (or rebuilt) 17BP4 that I bought on eBay due to arrive on Thursday. There seems to be plenty of life left in the original 17AP4, but it will be nice to have a spare. The tuning eye tube is very dim, so I'll need to find a replacement.

This was a lot of fun and it's almost a let down at how easy it was

I'm looking forward to watching bandersen restore the one he's got!

-Clark

That's a good picture!

[bandersen]

Hey, that's was quick Nice job! I hope mine goes as smoothly and good luck with that VDC CRT


P.S. brianweber4 could you please edit your post so it doesn't duplicate every single photo ?

[holmesuser01]

Impressive.

My RA-113 has 3 15K capacitors, where I see 2 on yours.

Your entire set looks lovely.

[Phil Nelson]

Yah, mine has three 15KV caps: two above the platform and one below.

Phil Nelson

[Kevin Kuehn]

Nice work, Clark. That sure looks like a super clean chassis. I suppose it helps that these are mounted vertical in the cabinet. Great looking picture you have too.

[IsthmusTV]

Thanks for all the nice comments! I'm really enjoying the high quality of this set. It's the one and only DuMont that I have experienced and it has not disappointed. And mine also has three .00047 uF HV caps, I just snapped the photo before I had installed the one on top of the two 1X2s.

My next steps will be to replace the few remaining paper caps (they're in the little shielded compartment in the sync section) and find a replacement 6AL7. I have also yet to do any work on the cabinet, which fortunately won't need much.

The VDC CRT is scheduled to arrive Thursday by USPS. It's being shipped in its original box which has some water damage. I'm hoping that they double boxed it.

-Clark

[holmesuser01]

So glad to see another DuMont being brought back to life!

[Sandy G]

VERY impressive !

[bandersen]

That extra pin might not be connected to anything electrically. Some CRTS have that to help the CRT socket hold on. Got my fingers crossed