View Full Version : Our current projects
Eric H 10-27-2002, 03:41 PM Hi all,
I thought I'd start a thread where we can post pictures of what we're working on right now.
I'll start it off with some pictures of the cabinet for the Hoffman model 613 TV I'm working on.
The first one shows some veneer damage that goes clear through to the base wood.
http://www.vintagetvsets.com/tempimg/hoffcab.jpg
I didn't want to reveneer the whole thing so I just sanded it and filled the gouges, it's pretty noticeable but hopefully will be less so after I apply the Lacquer top coat.
http://www.vintagetvsets.com/tempimg/hoffcab2.jpg
and here's the "Good" side.
http://www.vintagetvsets.com/tempimg/hoffcab1.jpg
Okay, your turn :D
Eric
Hey Eric,
That scratching on the side looks like a cave drawing of an alien skull!
Rob
Steve K 10-27-2002, 06:06 PM Two weeks ago today I bought this Motorola 8 inch electrostatic deflection set at the Rose Bowl fleamarket. The cabinet was in very poor condition and the vertical and horizontal sections were a mess (rewired, parts missing, etc.). I have it almost done. I am sending for the correct channel knob tomorrow. The picture on the screen looks better than the photo of it. I have yet to master taking a good picture of the screen of operating sets. This is only the second time I'm uploading pictures so I hope this works!
Steve K 10-27-2002, 06:08 PM Here's the screen picture. I don't know how to get two pictures in one post.
Eric H 10-27-2002, 10:23 PM Hi Steve, that's a nice looking Motorola.
Coincidentally I won the bid on eBay for one just like it this afternoon.
Eric
Charlie 10-28-2002, 01:03 AM I took apart the Sylvania set and gave it a bath in the driveway. Was pretty nasty looking. I then found it to have a toasted power transformer. I found an another chassis like it in the attic and brought it home for a donor. About the time I checked out and swapped the transformer, I caught a cold and spent most of last week and this weekend hocking stuff up! :puke: Haven't got much further than that. I still need to change some caps out. I feel much better this evening, and hope to be out in the garage soon. Here's a shot of the cleaned chassis and the donor.
Charlie 10-30-2002, 03:52 PM Got the Sylvania Halolite up and running late last night. After changing the power transformer, filters, and paper capacitors, I found it wasn't getting any high voltage to the crt. Found a .0022 cap in the horz width circuit that was shorted out. After replacing, the HV came back and made a pretty decent picture considering i haven't made any more adjustments since turning it on. Of course, the cap was in a really tight spot to get to. Seems the culprit is always in the worst possible place! Actually, I had skipped changing this one when replacing the rest because it was in such a tight spot. Live and learn! For now on, start with capacitors that are the hardest to get to!
In a few days, i'll run it for a several hours watching it to see if anything else goes out. Then I'll start on the cabinet.
Here's a scene from today's episode of General Hospital.:smsex:
Eric H 10-31-2002, 12:00 AM Congrats on the Sylvania Charlie! That's a great looking picture!
I have been working on my 49 Hoffman tonight, it's starting to come to life. Here's a picture of it running a test CRT.
The tuner drum is not installed here nor most of the I.F. tubes and it's also missing a 50 watt power resistor but it has High Voltage and some sweep.
Eric H 11-02-2002, 01:24 AM Further update on the Hoffman. I'm nearly done recapping it.
It only had about an inch of vertical sweep which turned out to be an open oscillator transformer, I swapped it out with a used one from a junked RCA KCS47 chassis and now it works.
Here's a picture of it with the 12LP4 installed.
Even though I haven't recapped that section the radio is working too! at least on FM.
Charlie 11-23-2002, 08:53 PM This is my current project, although I haven't touched it in two days due to yardwork and other errands needing attention. It is a Zenith model 5758, with the 24MC32 chassis. It was a set I pulled from the TV shop several weeks ago. This set looks extremely identical to the 5040/29JC20 I am in search of. As far as the looks go, the only differences are the legs are placed inward under the cabinet instead right on the corners, and this one has the UHF tuner. The 5040 was only VHF.
So far, I've only pulled the chassis and gave it a bath in the driveway. It was hurtin' for one! Looking the chassis over, I couldn't visually find anything that failed. Maybe that means the picture tube is no good. :( Perhaps not, but that thought crossed my mind. I don't have a crt tester, so I will have to find out the hard way... get the chassis up and going and then plug it in!
The cabinet is in semi-decent shape. The top is hurting pretty bad, and I will probably have to cover it with a new piece of veneer. The rest of it is ok, but once the top is fixed, I'll refinish the whole thing.
I'm not sure how far I will get with this... I return to the ship in a week and I will have other things to do that will take up my time. Hopefully, I'll get far enough to completely power it with the CRT plugged in and have some sort of picture. The rest of it will have to wait till I return from the ship again.
Charlie 11-23-2002, 08:57 PM The chassis after a bath...:eek:
Eric H 11-23-2002, 11:49 PM Those Zenith chassis sure are nice looking, not at all like the crappy PC board RCA & most everyone else used.
Are those Compactron sockets I see?
Eric
Charlie 11-24-2002, 04:36 PM Eric,
Yes, this has a few Compactrons in it. I like this type of chassis for the terminal strips used. The components underneath have plenty of room, and because of the style of strips, the components seem to be layed out nicely, and easier to remove/replace. Since the terminals all stick thru the top of the chassis, it is usually easier taking readings from various places.
My big Curtis Mathes chassis was the same way, and it was extremely easy to replace parts under the chassis and do a nice neat looking job. :D
Steve K 11-25-2002, 05:14 PM I'm in Wisconsin this week for Thanksgiving and thought that I'd recap my projection set. RCA must have received a great deal on war surplus capacitors as this set must have a thousand of them. Anyway I got it working. I'll post a picture of a screen shot but it will look a lot worse than it really is. The picture is watchable but it needs to be in a dark room. The set does have a NOS projection tube in it.
Steve K
Steve K 11-25-2002, 05:15 PM Here's a picture of the picture:
ChuckA 11-25-2002, 05:46 PM Steve,
Looks like your mirrors have gone south. I have 4 of these sets and the flat mirrors are usually dull from many years exposed to the air, and not much can be done to bring them back. If you haven't already done it, cleaning the curved mirror in the housing can help a great deal, most of the ones I have have been in good shape just lots of dirt. Just don't rub very hard.
I think it was Rob who posted a good description and adjustment procedure for these Schimdt optic systems.
Chuck
Charlie 11-25-2002, 06:08 PM Steve,
The chassis in that set looks easy to work on... dealing with one chassis per section. Do the different pieces plug into each other, or are the wires from one chassis to the next soldered into one another?
Charlie 11-25-2002, 08:26 PM I put partial juice and later full juice to the Zenith 24MC32 chassis. The tubes all light up, but I found it has no B+ voltages. It uses silicon rectifiers, and they seem to have taken a dump. Now I'll have to make a trip to the parts house. Sure wish it used 5U4's... I have plenty of those laying around!
Eric H 11-25-2002, 11:59 PM Charlie, my 56 Zenith portable uses the same construction on it's chassis.
So easy to recap, just heat the terminal from the top and pull the cap out, shove a new one in the hole and add a little solder!
I have a bunch of Compactrons that were going to hit eBay, let me know if you need any and I'll see if I have it.
Eric
Steve K 11-26-2002, 09:14 PM Chuck:
The mirrors have been cleaned but the curved one is ok but not perfect. The mirror in the lid looks perfect but to me it looks like a standard mirror. Should that one be mirrored on the surface like modern projection sets? If so where do I get one?
Charlie:
The seperate chassis plug into one another. There are about as many cables and plugs as capacitors! The chassis are not hard to work on but two of them have three to four can electrolytics each. I'm too lazy to take them out, cut them open and restuff them so I must somehow cram the new caps under the chassis. Sarnoff would roll over in his grave if he saw how it looks now but it works. I would probably do it more neatly if I were rebuilding it for someone else.
Steve K
ChuckA 11-26-2002, 10:15 PM Steve,
Both mirrors are front silvered. The spherical can be re-silvered by H.L. Clausing in Skokie, IL. (http://www.clausing.com/main.html)
The flat mirror I've been told is not a candidate for re-silvering due to size and age, best bet here is a thin rear surface mirror you can get at a local mirror shop.
I'm restoring a Berkshire Regency and have had the spherical mirror re-silvered and I have a new mirror from a modern HD set to replace the flat mirror.
Chuck
ChuckA 11-28-2002, 07:27 AM Here'a a shot of what happens when the project is bigger than a boxcar. I had to bring the test bench to the TV to troubleshoot & align the receiver from the RCA Berkshire TV.
Hope to start on the TV section next.
Chuck
jshorva65 01-16-2003, 09:43 AM Hello all!
I've been extremely busy lately. Had a hectic Holiday season, working on several customer-requested restorations, still developing and producing reproduction parts, attempting to find time for some refresher business management classes, seeking some help from local Community Development agencies in getting loans for financing some big projects (my guitar and hi-fi amp lines, and the vintage tv replicas I've been asked to develop by a few friends in the furniture business). To get a jump on the project and get my design skills back into practice, I've been attempting to create drawings similar to the ones John Vassos must have created when he designed the 621TS. Eventually, I want to build replicas of several pre-war and a few post-war sets. The project is in its infancy at the moment, but I've managed to reconstruct some of the basic geometry of the 6211TS cabinet based on its relationship to the space that its chassis and picture tube occupied. Here's a preliminary sketch generated from the complex 3D vector model I'm creating. It's nowhere near finished, but gives some indication of what I'm attempting to do.
jshorva65 03-14-2003, 11:05 AM I decided to take a few days off from customers' restorations to look into one from my own collection. This is an RCA 8T241 from eBay that was in pretty good electrical shape, so I decided to tackle it as a mini-vacation. I just had a "tough dog" case involving a Bendix with a badly damaged I.F. transformer and no available replacement that I had to pack up and ship home unfinished. Here's a shot of the 8T241 after the initial testing. The set has picture and sound after re-forming the electrolytics, checking for bad paper caps and replacing two I.F. tubes. I'll turn it on and post a pic of it running that 5" test CRT later today.
John,
Are you planning to replicate the vintage chassis on the prewar sets too or put modern guts in the repro vintage cabinet?
I had a 8T241 that had a trashed cabinet and used it as a source for a 10BP4 that I needed for another set, my first, the 1948, 10" floorstanding bakelite Admiral consolette. This RCA chassis also sourced a vertical blocking transformer for the Admiral which had one with an open winding.
Rob
rcaman 03-14-2003, 04:18 PM hi everyone. i have a lot of parts i also have some i.f. transformers
flybacks. if is something i think i wont need i will gladly sell or trade to one of the members of this forum. i have a lot of picture tubes also. steve
jshorva65 03-14-2003, 05:11 PM Here's the 8T241 chassis running a 5" test CRT. I also replaced C76 and C77 in the grid circuit of the Vertical Output tube because they showed marginal test results on the Sprague TO-4. Replacing those caps made it easier to get good linearity and sufficient height at the same time, which was a little tricky with the old caps.
About the pre-war replica sets, they'll probably have a modern TV chassis inside simply because I doubt that some of the more exotic parts would be available. If I could afford to make my own parts, I'd definitely love to put a line of replicas into production with all-tube chassis' and RF-type HV supplies disguised in shells that resemble the old "killer" HVT's.
Charlie 03-14-2003, 05:22 PM John,
What's with the interesting safety glass in front of the crt and chassis?
jshorva65 03-15-2003, 09:36 AM What's with the interesting safety glass in front of the crt and chassis? Charlie,
That's a subtle reminder from the author of the graphics software that I've been trying out that it's time to fork over some cash or pick another program. Actually, it's a pretty neat little program so I might just invest the 30 bucks or so and buy it.
John
jshorva65 03-15-2003, 11:14 PM Well, I had a little setback with the 8T241 today. I put it back in the cabinet last night and watched it for about 2 hours with no problems, but today the picture was intermittently blacking out. with accompanying "screeching" noises coming from inside the HV cage. I shut it down and discharged the HV lead to the chassis, but didn't get the usual spark from the stored HV in the doorknob cap. OK, I thought that maybe the doorknob cap that was good yesterday might have suddenly failed, but it threw a healthy spark when I discharged it directly at its terminal. That left only one possible culprit, so I decided to have a look under the HV rectifier socket at the 1-Meg, 1-Watt resistor between the the HV rectifier / doorknob cap and the corona ring / CRT anode. Bingo, that resistor was open. I need to go get some 1-Meg/1-Watt resistors on Monday.
jshorva65 03-18-2003, 10:15 PM Here's that 8T241 again. I picked up the resistor yesterday, but didn't get around to installing it until this morning. I didn't like the looks of the HV Rectifier filament winding, so I re-wound that while I had the cage apart. Here's the picture of the set working with the cabinet fully put back together. Unfortunately, my cheap camera and shop lights don't do it much justice. At least the picture looks nice and sharp. This set has one of the brightest and sharpest 10BP4's I've ever seen.
Eric H 03-29-2003, 04:02 PM OK, I admit this set is boring compared to some of the 40's sets posted here but...
Here's the guts of the GE I posted earlier over in the B&W Portables thread.
I have only replaced a half dozen caps and already the picture is looking pretty good :D
The CRT shown in the pic is the original or the first replacement more likely since it has a 1961 date code, It is shot and is only being used for test purposes.
I have obtained a brand spanking "new" GE tube, still in it's original box dated the 30'th week of 1957!
It's been waiting 46 years for it's chance to show a picture :eek:
Eric H 03-29-2003, 04:04 PM Here's a pic of the itty bitty lil' Ion trap.
The tube is a small neck 110 deg job but still has a trap, didn't think they went that late!
Eric,
Does the CRT you put in have an aluminized screen AND a bent gun? Aluminized screen CRT's do not need an ion trap. If the gun is straight it doesn't need an ion trap either....but you know all this. :)
I too am surprised. I thought ion trap/bent guns went out with the switch to small neck tubes and higher deflection angles.
Rob
jshorva65 03-30-2003, 03:50 PM The advent of the aluminized screen was the last step toward eliminating the ion trap and bent gun construction and you're right that the small-neck tubes were the first to eliminate the ion trap. There were, however, some large-neck test CRT's that didn't use ion traps, but I have yet to see one of those without a burn in the center of the screen. The burn could be from ions, but it could have also resulted from operation of the tube without deflection. I always take my test CRT out of its case and install it through the yoke of the chassis that I'm testing, but some previous owner of the tube might not have done that. It only takes one time to burn the phosphor.
jshorva65 04-29-2003, 05:09 PM Here's my latest non-customer project. It's the Fada TV30 that I bought from Tim last year. I started recapping it shortly after I bought it, but found myself too busy to finish it right then. Before I started recapping, I ran my usual preliminary tests on the circuitry and reviewed some notes that Chuck had written about his experience with the set before Tim owned it. This set has been passed around like a groupie ... lol. I'm about 90% finished with recapping it and have been firing it up at several convenient points to check my progress. So far, it appears that I've corrected all the issues from Chuck's notes and I have a recognizable picture and some sound that keeps getting better as I recap more stages. By the time I'm done with the recapping, my second B&K 415 should be arriving and I'll re-calibrate that unit for 21.25 MHz IF work, leaving my first 415 set up for 39.75 MHz. Here's an under-chassis picture of the TV30. Note the Amprobe inductive ammeter and the divider coil fitted to a "cheater cord" that I use with my Variac when I'm powering these old sets up.
jshorva65 04-29-2003, 05:13 PM Here's how the picture looks at this point. It's not great, but at least it confirms that I'm making meaningful progress with each step.
Originally posted by jshorva65
Here's my latest non-customer project. It's the Fada TV30 that I bought from Tim last year...I ran my usual preliminary tests on the circuitry and reviewed some notes that Chuck had written about his experience with the set before Tim owned it
John,
I was the previous owner of Tim's Fada TV-30. This is the one that had some minor grey paint splatter on the front. I had a raster on it briefly until one of the wax caps under the chassis in the Horizontal section started to crackle and bubble. At lkeast that is what I guessed it must have been. The raster went out as the cap shorted I'm guessing. I never pulled the chassis to investigate. Nice to see someone finally doing this set!
Rob
John,
In my experience screen burns from deflection failure are small, sharply defined burns. Phosphor burn from ion bombardment are larger sized darkened smudges. I have a Dumont 15AP4 that has no aluminizing and a straight gun (no ion trap). It is like new for emission and has no ion burn. When I tested it for emission when I got the set home it had obviously not been run for decades. It immediately shot up to perfect emission without delay, clearly a low mileage CRT. Many of these old CRT's read good, but only after taking a while for the emissive coating on the cathode to reawaken. It is in a very rare Sightmaster 15-S-1 set.
This tube is kinda crude, has some shape distortions, probably from almost colapsing in the baking process. If I own a vintage CRT that I'm afraid might blow up in my face from merely handling, this would be the one.
Rob
jshorva65 04-29-2003, 08:29 PM This is the one that had some minor grey paint splatter on the front. Yes, and the paint came off nicely with a small amount of denatured ethanol and soft cloth. The finish and lettering survived intact. I'm going to have the set's few cosmetic flaws fixed at some point during the repair. Actually, the blanking out of the raster was from a cold-solder connection. It looked as if it had been serviced a few times through the years, and one of the techs didn't quite get the solder flowing when he put a new cap in the video output stage. The voltages on the CRT drifted way off, cutting off the beam. The CRT in that set is absolutely incredible, definitely in the top two of all the 10BP4's I've seen so far. I have 6 sets in my collection that use 10BP4's, five good tubes and one rebuildable dud. My 630TS lost its CRT thanks to the Postal Service -- bonk, snap. hiss. Luckily, I had bought a good tube on eBay for a spare, but my Fada 899 has a dud tube. I guess the dud goes in the 630TS until I can get the other massive damage repaired. By then I hope to find another good spare or the extra cash to have the dud rebuilt.
Here's the Fada 799 that will be the next set from my personal collection to be recapped when I find time. I finished the initial evaluation last week. Aside from a snapped detent spring in the tuner and the need for recapping, the set is otherwise in mint condition. I got sound and something resembling a picture when I put in the 5AXP4 test CRT and put the Variac to it, but then I set it aside to finish the work I'd started on the TV30.
Eric H 04-29-2003, 10:43 PM My latest project is this Hallicrafters 505.
Like my T-54 it was a basket case, I had to have some knobs made and I bought a back and CRT off eBay a while back.
I have started recapping it but ran out of .1's and .22's so I wil have to wait till I restock to finish.
jshorva65 04-30-2003, 09:00 PM Here's the recapped TV30 working much better. Rob, you were on the right track with the HV after all. The 1M/1W filter resistor had changed value, causing very poor regulation. HV was present and would produce a raster, but increasing beam current would start to drag the HV down as the Brighness control was turned up past 90%. With that cold solder joint that I had fixed earlier throwing the CRT's bias out of whack, it turned out that the increase in beam current from the grid going positive would cause an increasing drop across the filter resistor with a resulting sag in HV output that would ultimately blank the raster.
I'm waiting for a B&K 415 that I'll be re-calibrating for efficient alignment of 21.25 MHz IF systems and will be aligning this set with this "plug-and-play" system. For now, I'm setting it aside until the 415 gets here.
Kamakiri 04-30-2003, 09:51 PM Originally posted by Eric H
My latest project is this Hallicrafters 505.
Like my T-54 it was a basket case, I had to have some knobs made and I bought a back and CRT off eBay a while back.
I have started recapping it but ran out of .1's and .22's so I wil have to wait till I restock to finish.
I may have a couple of brown original Halli knobs around if you need em.
Eric H 05-01-2003, 01:43 AM Originally posted by Kamakiri
I may have a couple of brown original Halli knobs around if you need em.
Thanks Tim but I have a complete set of repros. :D
jshorva65 05-01-2003, 09:40 PM Pulled the tuner assembly from my Fada 799 chassis to have the tuner detent spring made and riveted by Quality Tuner Repair in TX. I've also started removing the tuner and speaker from my 630TS. The 630's control shafts and speaker were severely damaged in shipping along with its 10BP4. I've managed to fix the vert/horiz hold controls and plan to repeat the same repair on the on/vol/cont control. The bright control will need to be replaced. Here's the area that was hit hardest.
That's one serious case of cone rot on that electrodynamic speaker there John! :( Is that a case of Brown rot?
Rob
jshorva65 05-02-2003, 08:33 AM No, Rob, that speaker is a fine example of our own Postal Service at work. More accurately, it's an example of what happens when an eBay seller does a crummy job of packing a device he / she has never attempted to ship before despite having detailed instructions provided by the buyer. This is proof that cutting corners and not following directions is an invitation for Murphy's Law.
On the bright side, the voice and humbucking coils appear to have survived intact, and I understand that this is going to reduce the reconing cost somewhat. Since only the brightness and tuner shafts actually broke, that also makes for a slightly better prognosis than if they'd all snapped. Again, a better job of packing would have prevented this.
I've set the Fada and RCA "twins" aside on an out-of-the-way shelf in the shop ... out of reach of postal workers. All the shipping I've done recently has been handled by private carriers. Jan's son-in-law operates a small shipping company called Tamco Delivery and has access to a Liquid Form packing machine. He can do deliveries for me in the Great Lakes region and can subcontract longer trips. Costs are somewhat higher than UPS or FedEx, but the quality of the service justifies the difference. I still use UPS and FedEx on most long trips, but Tamco will be doing all packaging. For anyone who is interested in Tamco's services, the mobile number is 440-336-3006.
ChuckA 05-02-2003, 03:58 PM Here's my next PROJECT for 2003 and probably 2004. I've removed all the electronics the cabinet is heading for my cabinet restorer next week, from past experience it should be done around Thanksgiving.
Chuck
ChuckA,
That set looks rather old. You sure it's worth the cost and effort restoring? ;)
Rob
ChuckA 05-02-2003, 05:11 PM Rob,
You sound just like my wife ;)
Chuck
Eric H 05-17-2003, 07:09 PM This Hallicrafters 505 is looking better.
A paper tag on the chassis identifies it as a T-54 and is dated Sept 15 1948.
Am I correct in assuming the 505 and the T-54 used the same T-54 chassis or maybe someone has done a switcheroo sometime in the past?
wiseguy 05-26-2003, 06:15 PM here is one of my favorite RCA sets,I have had it awhile,the first pic is the cabinet before,second after,the camera really picks up very minor shades of color,it turned out excellent,this will be my last project for awhile..a long while,( i even have a porthole on e-bay that i lost insterest in..).so i figured i should get the cabinet done before i get carried away on other things.
interesting how the wood on both sides of the front mask is a tad different than the masking,it looks fantastic in real life!!
any suggestions ? notice how someone had installed a tiny speaker in place of the original..? hehe..(NO I didnt do it)
terry
wiseguy 05-26-2003, 06:30 PM here is after..looks better than the pic shows,i have to put the lettering back on and install the chassis..
ok guys.. one question... i can stuff the original 10bp4 crt back in,
or install a 10fp4 crt,the 10fp4 looks fantastic in this set.. the 10fb4 is n.o.s,even with warranty tag...the 10bp4 test perfect..
what would you do? install the 10fb or 10bp..???
thanks
terry
Eric H 05-26-2003, 07:00 PM Hi Terry, I haven't seen you around much, I almost wrote you the other night just to see if you were OK
That 8TS30 looks great!
Personally, I would put the FP4 in it, it's a perfectly legit replacement tube for that set.
Eric
wiseguy 05-26-2003, 07:03 PM SIDE...love this set..) interesting how the front mask changes from left to right angles..i kept thinking something is wrong,must be how it was back then..)
and hello eric H,nothing new and excitng,just building up a old broadcast camera selection,i finally got a air type pedistal to mount these VERY heavy cameras on to work on..):;
terry
jshorva65 06-26-2003, 03:08 PM Yet another customer's set (Sparton 5085) ready to be picked up. The backlighting from the window and a cheap camera don't do it justice, but the picture is nice and stable. There were some bad resistors and cold-solder joints along with a broken connection on the flyback. This was a DIY project that went beyond the restorer's level of experience, although he did do some neat work with adequate use of insulating tubing to prevent shorts. Most of the soldering issues were in hard-to-reach areas under the chassis.
jshorva65 06-26-2003, 03:12 PM Here's my latest score for my personal vintage b/w collection ... another RCA 721TS. This one had received a very nice recapping some time before I bought it along with a NOS 10BP4. Minor adjustments of the Horiz Osc. got this chassis working great. It's all set for my display room where its cabinet is waiting. Picture is courtesy of my 5AXP4 bench test CRT.
ChuckA 06-26-2003, 03:59 PM Here's a link to one of my current projects,
http://www.myvintagetv.com/decca_1000.htm
It's a Decca 1000 projection set. I've recapped it, and have good B+ from power supply, but no audio or any light on the CRT. The CRT does light up just after I power the set off, so I can assume the CRT is good and I have some HV. This set uses a pair of 6SN7's as CRT protection, if sweep is lost they shut down the CRT so not to burn the screen, could explain the no light problem , but not the no audio. As soon as I get the backlog of customers sets done I'll get back on it.
Chuck
classicradios 07-05-2003, 07:17 PM Hello All,
I've begun restoration on the 16" Porthole TV Combo. I've replaced about 85% of the caps so far. Also 2 open power resistors. The CRT tests slightly weak but still gives a good bright picture. The image is a bit distorted right now as you can see in the photo. Seem to squash up at the top and stretch down below. Any thoughts on what causes this to happen? This is a problem I haven't seen before and am wondering if there is an adjustment for it. I haven't touched the lytics yet. Thanks for any suggestions.
Jim
Eric H 07-05-2003, 08:00 PM It's almost certain that will be a bad Lytic(s) in the Vertical circuit.
There are usually several attached to the vert osc/output tube and that is a classic symptom.
The vertical height and linerity controls will fix small problems but that is severe!
Strange, many old sets will fire up and work to some degree but the Vertical is the one thing that is always messed up :dunno:
Charlie 07-05-2003, 08:55 PM Wow... is that Lucy??? She's a little down in the mouth! :p:
classicradios 07-05-2003, 11:38 PM Yep,
Bad electrolytics in the Vertical section. 3 resistors also needed replacing. Looks great now! The audio is very clear. It's nice Zenith put the buzz control on the back of the chassis instead of under the CRT like in the 1950 model. Still have some work to do on the Radio/Phono. Stay tuned.
Jim
jshorva65 07-06-2003, 06:20 AM You'll want to look in the Vertical Output circuit for the cause of the nonlinearity in most cases. The Vertical Linearity control will correct minor nonlinearity but it's a sign of circuit trouble if the control has to be turned too close to either extreme to get a good, linear sweep or if the control reaches the end of its rotation without fully correcting it. Electroytics are most often to blame and there are a few around the oscillator and output stages for decoupling and bypass. You've got full height, so I would say the waveforms' amplitudes should be close to correct unless the Vertical Size control has to be cranked way up. Good vertical locking indicates that the oscillator is able to synchronize correctly. Also check any waveshaping networks for an out-of-tolerance resistor or cap. If you haven't replaced all the paper caps in the vertical section, one of those could be part of the problem, but electrolytics are the most likely culprits. Vertical output amplifiers are basaically single-ended Class A audio amps designed to have very low distortion and optimum low-frequency response.
classicradios 07-06-2003, 12:38 PM I finished replacing all the electrolytics today. Very good vertical locking, Never flips or rolls. Just watched Rita Hayworth in "Gilda" and everything looked great even the TV.:) The only oddity left is getting the picture to lock in when the set is turned on. I always have to give the horizontal hold a slight turn to lock the picture then everything is fine. I waited a full 3 minutes when First started to see if it just needed to warm up but no luck. My 1950 Zenith Porthole locks in about 30 seconds after it's turned on. Any ideas?
Jim
Jim,
Once you have the picture locked apply a small piece of scotch tape down at the bottom of the screen where you won't see it. It will hold the picture stable.
Let us know if this works K? ;)
Rob
classicradios 07-06-2003, 05:25 PM Ha Ha,
Everyone knows you have to slap the sides of the cabinet and pound on the top or is that a lost art form?
Jim
Eric H 07-11-2003, 01:44 AM Not at all Jim, I use that technique on my Computer Monitor all the time.
Originally posted by classicradios
Ha Ha,
Everyone knows you have to slap the sides of the cabinet and pound on the top or is that a lost art form?
Jim :lmao:
Eric H 07-11-2003, 01:58 AM So I'm working on this RCA 2T51 re:http://audiokarma.org/forums/showthread.php?s=&threadid=7085
After replacing several caps inside the HV cage the #*&$ thing didn't work anymore :dammit:
I futzed with it for an hour or so before I remembered this set uses an electromagnetic speaker and it WON"T WORK if it's not plugged in :dammit: :dammit: :uzi: :nerd:
Heh heh.. anyway it works again now, the picture is nice and bright after getting rid of the bad resistor and getting some HV to the CRT Anode. :beerchug: Nice and clear too, even with the 8" test CRT I was using.
Only thing now is the Vertical is badly messed up, there is a three section Lytic I haven't done yet and I am pretty sure that will take care of that.
I don't think I'm going to recap the I.F section, it is working great right now so why tinker and screw up the alignment?
Eric H 07-20-2003, 03:57 PM Well I've got this set working pretty well :D
I added a page to my Site for it and made a small video.
Let me know what you think
http://www.vintagetvsets.com/2t51.htm
jshorva65 10-21-2003, 01:01 PM This was a massive project! Lots of circuitry in this set (35 tubes) and it's now fully recapped with a nice and bright used 19AP4. The original dud was going to be rebuilt, but got "aired" during shipping to Hawk-Eye. Obtained a replacement with help from Hawk-Eye. The tuning dial cord on these things is a real fun project to re-string, especially since Sams "forgot" the diagram for the TV/FM dial cord. They have the AM tuner's stringing diagram, but this set didn't have the AM tuner or phono options.
Big Dave 10-22-2003, 12:00 AM I brought up my Andrea 16" roundie on Saturday. Most of the lytics reformed nicely. The radio sounded great with no hum:D
Now it's time to get caps. One of the lytics in the vertical, I think, is dead shorted (low voltage).
I enabled the HV after reinstalling the 16GP4 and was rewarded with an image. It was nice and bright with washed out video. I know this set will look great after I recap.
Alright, I should have recapped before I brought it up, but the local parts distributer's hours conflict with my work hours.:mad:
If you don't mind vidcaps (I don't have a digital camera or scanner), I'll start filling the gallery.
I think I've got a winner here.:D
Originally posted by Big Dave
If you don't mind vidcaps (I don't have a digital camera or scanner), I'll start filling the gallery.
I think I've got a winner here.:D
Go for it!
classicradios 10-24-2003, 06:16 PM Here's my latest project, A GE 24" Television.
I had to replace 6 "Lytics" and 9 caps to get it back to great performance again. Nice set with a clear picture and the Mahogany cabinet is near mint. Got this one from captainmoody, Thanks!
Jim
Eric H 10-26-2003, 02:21 AM Nice set Jim!
:thmbsp:
ChuckA 10-27-2003, 06:28 PM Just picked up another project for those cold winter days. This one is a 24" RC-200 Radio-Craftsman with a Radio-Craftsman cabinet.
Chuck
ChuckA 10-27-2003, 06:30 PM Here's a tighter shot of the tube and chassis.
Big Dave 10-27-2003, 08:32 PM I got the Andrea recapped this weekend. Here is a screenshot of the set on. The image is washed out by the light on my camera, but it was CBS football, with the Clowns, uh, Browns getting beat again.
:dammit:
I'll try to post a better shot to the gallery.
Big Dave 10-27-2003, 08:34 PM Let me try this again.
Eric H 10-29-2003, 12:08 AM I finally felt like digging in to a new project so I started on this 48 or 49 Emerson.
Actually I had a quick look at this set some time ago, installing the 5 rectifier tubes and patching up the ballast got it running enough to show a raster.
Eric H 10-29-2003, 12:10 AM Here's the 5 25Z6 rectifier tubes.
Eric H 10-29-2003, 12:11 AM and look at all the cans I get to restuff! Fortunantly most of them have paper covers and one section so those will be a breeze!
Eric H 10-29-2003, 12:13 AM The original Emerson jug still checks good
Eric H 10-29-2003, 12:16 AM The chassis was filthy! Worse, it has a lot of that greenish film that I have been told is Cadmium Oxide, highly toxic and carcinogenic!!
I found it comes off easily using Tub & Tile cleaner (basically Muratic Acid) this also takes the chassis down to the bare steel but since the Cadmium plating is shot already that doesn't really matter.
ChuckA 02-13-2004, 07:07 PM Back in May of 2003 I posted a picture in this thread of my "project" TRK-12. Well 10 months at the restorers and more money than I care to think about I have it back home again. I think it was well worth the wait.
Over the past 10 months I have been able to acquire all the missing parts, the only thing left is to have the radio push buttons made.
Chuck
Eric H 02-13-2004, 10:12 PM Wow Chuck, that looks beautiful!
Eric H 02-13-2004, 10:17 PM Famous last words.
This set has been a nightmare to recap!
It's finally working halfway decent though the horizontal is a little twitchy and on the edge.
It wouldn't tune anything at first, found out the fiber shaft that runs through the tuner had broken off right behind the front shaft. Got it on channel 3 and now it's working.
Originally posted by Eric H
and look at all the cans I get to restuff! Fortunantly most of them have paper covers and one section so those will be a breeze!
Morden2004 02-14-2004, 06:40 AM Well, TV & tube guys, I have a question.
In several posts you guys mention 'washing down the chassis'.
Exactly how do you do this and what liquids do you use?
How long do you dry it out?
Precautions?
Etc.?
I hope this hasn't been answered before at length - if so just point me in the right direction and I'll go away (and read) :D
Thanks in advance,
Paul
Charlie 02-15-2004, 08:08 PM Paul,
This link should give you a good idea of how to go about cleaning the chassis, and many other pointers as well. Good luck.
http://www.earlytelevision.org/restorationadvice.html
ChuckA 02-18-2004, 04:26 PM Just thought I'd show off the TRK-12 in operation.
Chuck
domfjbrown 02-19-2004, 07:17 AM Chuck - that's amazing :) I've wanted a MIL set since I saw one in Exeter's museam in 1982 (I don't think this one works since BBC don't have 400 lines transmissions any more :))
It amazes me how something made 60-odd years ago can look that good and work that well, when things like my sister's old 1984 PYE b&w are long dead....
Jeffhs 02-19-2004, 12:16 PM Was browsing this thread and saw a couple more of the Zenith TVs I like so much. Glad to see you guys are getting your sets working as they did when they were new. I had a basement full of sets like that (of all makes) back in the late '60s-early '70s, a good many of which were Zeniths. My pride and joy was a 23" Zenith console which was missing every tube but the HV rectifier and CRT when I got it (rescued the set from a trash pile). Took me the better part of a year to retube it, but it was well worth it as it worked, and well (very well for a set made just six years before I got it), as soon as I turned it on after putting the last tube in. I think it's true what has been said about older sets being put out just because the owners replaced them with newer models. There was absolutely nothing wrong with that Zenith 23" set of mine, except that the tubes were missing.
I've seen Zenith TVs with Compactrons as well in the 30-odd years I've been experimenting with electronics. In the late '70s I had a Zenith 19" Space Command 300 portable which worked well as far as the TV itself was concerned, but I never did get the remote working as the hand unit was missing. That set, however, had several Compactron tubes--the horizontal output tube and, IIRC, the AGC keyer (the latter being combined with a couple other tubes). The vertical oscillator/output tube may have been a dual-function Compactron as well.
BTW: The Zenith console color set shown in one of the posts here may well be an all-channel version of the 29JC20 table model. The latter (and a related set, the 27KC20) were made in the early '60s, before UHF was a requirement in new sets, although in some TV markets with only UHF channels such as Youngstown, Ohio and areas with intermixed VHF and UHF network stations, the all-channel versions were available even before April 30, 1964 (the date the all-channel rules went into effect).
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