I just stumbled across this on ebay and couldn't pass it up: not for $15. I'll make it my birthday present to myself. It's a Dumont RA 392. It looks is pretty good shape. Unfortunately, the seller has already plugged it in: static & no pic. Maybe no damage was done. The only concern I have is part of the CRT looks dark in the center. I hope that's either a stain or the light reflected on it and not a bad CRT. I'll find out in a week or so.

Doug

I hope he knows how to pack it.

The dark CRT is most likely just dirt on the surface of the CRT or the safety glass.

Tom, it had not occurred to be about there being a safety glass. Maybe it's just dirt then. I was watching this DIRTY Motorola on Ebay with an opening bif of $30 which ends Fri. No one has bid on it yet, and I was planning on bidding myself. However when this Dumont popped up with a set price of $15, I decided to go for it instead. It looks like a husband and wife team selling, so like Johnnyscan said: I hope they pack it right.

Doug

Looks suspiciously like a film of tobacco smoke on the face of the CRT or the inside of the safety glass. It will wash right off with ammonia and water. Used to be a good moneymaker for repair shops to clean the screen so the customer could see the picture again. Sometimes like the difference between night and day.

When I do restore a TV, now, I always make it a point to clean the safety glass inside and out. My one exception is m,y GE M-5 which I bought some yrs ago just to use in my workshop. It's since found its way into the house, but I never attempted to clean the glass on the inside when I first restored it. I don't know if the CRT has to be removed or not on it as my Sams doesn't say. However, for at least 10 years there has been a dead daddy long legs type of sipder between the glass and CRT in the 9 o'oclock positioin as well as other dirt that has fell down over the years. I just had the back off of that set this past weekend replacing the line fuse holder, but I hate the thought of having to pull the chasis then the CRT. I guess I should check to see if there is a way to remove the safety glass without having to remove the CRT. I just turned that set on (it's in my office) and after writing this, that spider stands out like a sore thumb!

Sometimes you have to take the whole set apart, in order to remove the CRT from the cabinet. Some manufacturers made it easier by making the safety glass able to be removed from the front of the cabinet. On a set like the DuMont pictured, look for a few retaining screws in either the top brass colored glass retainer or the lower one (probably under the edge of the cabinet). If none are visible, then you probably have to disassemble the whole thing.

I just reread my Sams on my GE M-5. The front trim strip does come off by screws allowing safety glass removal, so that spider will soon be gone. As far as the Dumont, I'll have to see when it arrived, but it WILL be cleaned no matter what. I haven't found a Sams on the Dumont yet (373).

Doug

Despite the dirt, this one looks nice.

I do like the covering on that Dumont cabinet though. It should be pretty easy to clean up. Remonds me of the old 1950s Ampro reel tape recorder my dad had when I was a kid. It had a similar style covering. I think it will be a beter buy than that blue Motorola. Some of the blue paint was chipping off the back of it.

It arrived this morning. It seems to be in excellent shape. I'll start disassembly in awhile. You guys were right about the safety glass. That stain appears to be just dirt on the inside. Does anyone have a schematic for this: Dumont RA 392 in Sams 373?. There's not one for sale on Ebay.

Doug

PM your email address and I will scan the schematic for you. Do you need any other part of the Sams?

*Make sure you use an isolation transformer when servicing that set.

Johnnysan, I just sent you my email address. Thanks a bunch. If the parts list is not to long, could you scan it also.

My isolation transformer is all ready to go .

Doug

I'm starting to get acquainted with my Dumont. The CRT tested excellent, better than most CRTs I have checked. Since the seller had tried it, I decided to plug it into the Variac and see what would happen: tubes lit, no raster or sound.
At that post I removed the chasis from the cabinet and took 3 photos. It looks like it will be pretty straightforward to work on. I can't see where any caps have ever been replaced. However, someone worked on it one time because the Sams set# is wrote in pencil on the metal chasis.
What I find strange is I see 4 wires coming thru holes in the chasis and going nowhere. See photo 2. Could this be wires used for text points?

Doug

Follow the wires and see where they connect, and then look at your schematic. A test point would usually be labeled with a letter or number, and called out somewhere in the manual.

Phil Nelson

I'll check into that. Johnnysan is scanning me a schematic for it, so when I get it, I'll trace them out. I've pulled out the chasis and replaced 4 paper caps. I dec ided to try another power up. I soon found out this was going to be hard. The CRT is seperate and stays in the cabinet. The yoke is attacked by a plug in socket. I then got the bright idea of turning the chasis around backward and hooking up the CRT socket and yoke. I powered it up and started fiddling with the tuner to try to get some audio. I then heard a surge and felt a shock going thru my lower shirt into my stomach. I pulled the plug and looked. There lay the HV anode that I forgot to connect, and I got zapped!

I guess I'm in the club now!

I decided to just pull the CRTand set it on the table. Another look at the chasis showed one of the old sel rectifiers was broken off. Upon checking, neither one would read. I've just replaced them with new diodes. The next power up gave me a snowy raster with static. With the cable hooked up and wiggling the tubes I can get weak audio thru the snow. I think this set is more dirty than anything with dirty contacts. I've already shot the controls with Deoxit. It took three cleaning with Windex to get that dirt off the inside of the safety glass, and I had to use 409 on the front of the CRT itself since it was so dirty. The CRT has a label on it from National Television Tube Inc in Saddlebrook NJ.
Well back to make cap replacemtn and cleaning.

That's what happens when you have heavy smokers or the set is next to the kitchen.

Might want to consider taking the chassis outdoors and spraying all the tube sockets with a solvent good at cutting tar and dirt, like CRC Brake Cleaner. Then let it dry really good, and use a pointed tool to tighten all the tube socket contacts. That will help with the intermittents.

This should be one of the last sets which DuMont built just before the merger with Emerson, but you can easily see it has none of the quality of the early DuMont sets. Just an entry level series string chassis with nothing in it that doesn't need to be there. They did work fairly well though, but were never reliable. By that time, many of the independents were building equally simple series string chassis because that's what they needed to do to sell at those price levels.

I finally got some intermittent results. I can set a snowy pic and some sound. Tomorrow, I'm going to do some maj cleaning like Mr Detrola suggested and start replacing the filters.

Sorry for the delay in sending the schematic, I had to work tonight.

I think those wires are test points, as Phil said.

Clean the tuner thoroughly, and adjust the yoke position. Get new filter caps in and go from there; looks like the tube is OK.

Johnnysan, thanks again for the schematic.

I did some cleaning today, and I found I have an intermittent tuner tube. The schematic calls for a 5BK7, but there is a 5BQ7 in there. One substitution guide I looked at does not show that as a replacement, but another guide does. However, the tube in there checks bad anyway, so I've got a new one ordered. Maybe that's why it's not playing with great reception now. I'm getting ready to replace my 1st electrolytic, and I'll have to order ereplacements for the rest.

Doug