I have a 8-T-241 on the bench. The wood cabinet was totally gone (termites) and its been sitting around for a while, so I decided I would have some fun with it. It looks pretty good, not a lot of work done, but it does seem to have had at least a few of the can caps replaced. I am in the process of doing a reform on them now, so far they seem to be coming around quite well. After that I will replace the bumble bees and the wax caps and see where it is. I plan to do a clip one lead and test procedure of the bumble bees JIC they are still ok. The idea is to do the MINIMUM work for a baseline run, then trouble shoot and replace as required.

If anyone has a scan of the schematic and is willing to share it with me pls let me know. I can prob get by with out it at least for this initial cap phase.

I'm surprised that schematic isn't already on the ETF site, perhaps if you ask Tom Albrecht he can scan it and add it there.

I think you'll find all of the caps are too leaky to use even for a quick test. This set is also well known for having bad mica caps in several circuits, when you get that far you will want to test them also.

if they are leaky the will get replaced, but I want to test them before removing just to see how little it can take to get one up to running for a baseline. My technique is to just clip one lead hook up the cap tester, check leak, check value, if needed get new cap, check leak, check value, pig tail (unless easy to remove, don't like to break things) replace.

indeed the mica caps in the sweep circuits will be tested as well, been down that road with the T-120, which looks a lot like this one.

I don't think there is a lot of difference between this one and the T-120, you might find that schematic helpful until you get the correct one for the 8-T-241.

well that went well all 3 sections of the under the chassis can reformed well. I used the eye tube tester started at 25v left alone for an hour or so, the eye fully opened (was about 1/2 open at 25v on each section 150/450/150) let it set there for a while then bumped up to 150 again about 1 hour and the 150 sections test fine now. The 450 I bumped to 250, 350 and then 450 about 1 hour each time. Opens fully and within 10 seconds now on all sections. Will test again tomorrow to see how well it holds up over nite. Then move on to the next can.

2 of the 4 cans down, so far so good they have both reformed very well. the next one is for sure a replacement, so should be interesting to see if it checks out/reforms as well as the other two, one of which is for sure orig to the set.

There are several brown plastic caps with markings like the bumble bees, they will be check the same as the BB's cut one leg test replace if needed.

Dave - I think I have an RCA manual and schematic for that. Do you have the chassis number? Something like KCS28...

cap number 3 starting now, looking ok so far, at this rate I should be ready to baseline run in about a month

I thought I had a full RCA service manual for this chassis, but I don't. I do have the Telaide though...

http://www.oldtubes.net/library/free_manuals/RCA_KCS28.pdf

Mark

Hello dave ,
to bad you were not closer to me I have a Spare cabinet

I was actually thinking of just making it into a display piece, no mods to it just a simple jig to hold the CRT in place and some rubber feet. I sorta like the idea of having it out in the open for guest to see, Its amazing how many peeps don't even know what a tube is, the under 40 crowd never delt with tubes back in the day, so unless there is some reason to know about them they have no clue (I get a lot of light bulb answers when I show a young person a tube).

I recall the u test'em tube testers at the pharmacy's and of course radio shack, IIRC even stores like 7/11.

How ever if you are willing to part with you cabinet, maybe we can work out a deal. being empty it may survive shipping.

I got a bit side tracked on this project with a local find of a GE color roundie, but I should be able to get back on it again.

the GE has a VERY weak CRT so I am not super motivated to get back on it. I did replace the filter caps, interesting that they did not reform well at all compared to the much older caps I am finding in this RCA.

I tried making some video, not sure how it came out, I may post on you tube if I don't come across as too much of a dork and the info seems useful. I also fear the focus may be bad.

Lots of progress, (will start on the ARK after this been raining cats and dogs), so far 3 of the 4 cans have reformed and perform like new, working on the last one a 40/40/10 all 450, it looks like a replacement. ALL but on of the paper caps (wax,bumble bee and brown bee) tested pretty badly for leakage and values so I went ahead and replaced them. The only one I left was a single black beauty that tested fine. I am waiting on the outcome of the reform on that last can, and still have a few papers in the intergrater but that's about it.

the ball bearing in the tuner detent is MIA, I dont hear it rolling around inside the tuner so I guess its either stuck inside or fell out and has been lost. I pulled out the tuner shaft and fear I may have gotten one of the sections out 180 degrees (it thats possible, I think the tuner shaft is flat inside, if its D shape and can fit the waffers in only one way then I should be ok. I am pretty sure I can find a donor ball bearing, if not skyjunk will have one.


so the plan is to finish up the recap, check the tubes for shorts, check the B+ rail for shorts, check the voltage divider for opens and shorts the the chassis. If all that looks good I should be good to go for a power up. I am holding on replacing the micas in the horz and sync sep until after the baseline run. I did check the one mica that is grid coupling cap to the HOT, it was fine for value and leakage, but I know they can act up with heat.

the 40/40/10 seems like its going to be ok as well. that leaves me with just the integrater caps, and then will be done with the cap project. So I prob could have tried it with some of the old papers in place but I chickened out and went a head and replaced them (all but the single black beauty that is). the single electros that were part of the AGC filters were bad one was open the other shorted AND way out 50uf not 5uf which I have seen before. Anyway hope to have a power up soon, will get some pics when I find the stupid camera.

some pics of the action so far

almost missed a couple caps on the VC. All done now but getting tired so will resume tomorrow, start with tube testing for shorts, then hookup voltmeter to B+ get out the metered variac, do a power up with no HOT, then will put in a crt test tube and the HOT.

one 6SN7 tested very weak (vert out) the 1B3 tested bad (just below diode ok) and a 6AG5 in the tuner tested very weak, went thru my pulls and found good tubes for all. Every thing else checked out so should be good to go later today for a test run.

power up, audio works (rec OTA signal, just need to fix the detents), no HV. checked the plate lead (un hooked) from the HOT, B+ is there. I get out the BK 1076 analyst feed a plate drive, HV comes up so that clears the damper/flyback.

I will next feed the HOT a grid signal to see if that does it.

grid drive to hot from 1076 restored the HV as well that clears the HOT, so it has to be in the osc, going to start with some resistance checks including the horz osc coil.