RCA Victor7T174K TV
 

This is my latest acquisition. It is in a limed oak finish. The lacquer is shot and I plan to strip the remaining lacquer off and recoat. The veneer is in good shape with the excepton of a small chip in the top. i can live with that. I like this set for its compactness and very profound early TV style. Is is complete with all the knobs, none of which are broken (unbelievable). I found out from some research that this model is called the Kendall. It has a 17 inch screen and features four IF stages. I bet it will be quite a performer.

The set had previously been working but now there was no picture. Upon removing the back I discovered a brightener hanging off the 17QP4 glass picture tube, never a good sign. I put my crt tester on it and it started out on the red but slowly came up to green. I ran it at 7 volts for a few minutes and it went well into the green area. It seems to be a good tube after a little wake up with no shorts or anything. I'm not sure what the brightener was doing on there to begin with. I found one electrolytic in the voltage doubler that was getting warm so I disconnected it and temporarily clipped in a new cap. This time I got white noise from the speaker and nothing else. The neon bulb tester told me the horizontal stages and flyback are working. The high voltage measures only 8KV when the Sams says it should be 13.2KV. I know the power supply will have to be rebuilt since the selenium rectifiers and electrolytic cans are original. I have not looked under the chassis yet. The set is reported to have been recapped. There is only a small pile of wax at the bottom of the high voltage cage. Overall the chassis looks to be in good shape. There is no sign of 1950s yoke cover disease. I did notice that in addition to having a lighted tuning dial that there is a pilot light mounted at the center bottom where the legs are. I assume this is so you can tell the set is on if the doors are closed, very interesting feature. My question is this. is there supposed to be some kind of lens in front of the cabinet pilot light? I just have a small hole visible from the front of the cabinet. it almost looks like there might have been nothing there, especially seeing the way the lamp fits into the hole from the back. I am really looking forward to restoring and using this set.

It does lack one feature that most of my sets also lack and that I need to install fairly quickly. It is the WAF or Wife Acceptance Factor. It rarely comes pre-installed on any vintage set. :D Here are some photos of the set as I received it.

I would think that cabinet (with doors closed) would have some measurable WAF. It is rather attractive. :-)

Oh, yeah, I think the WAF oughta be FINE once you get the cabinet spiffed up...That's a pretty set !

There was a push-in jewel that went on the front of the set for an indicator. I've seen them before, but dont have a clue as to where to get one today.

I thought there might have been something like that. I will find something to put in there. I don't expect it will be that difficult.

Right now I am testing some material to remove what is left of the existing varnish. I hope this is not going to be too troublesome. The only two sets I ever had refinished were done by professionals. i would like to try this one myself.

Great looking set! :yes: Good luck with the restoration.. Cheers

I think it should have a pretty high WAF considering it is a nice looking set.

Not only that, it features the KCS66 chassis which is a greater performer. Besides having a an excellent S/N cascode tuner and keyed AGC, it features a full 4MHz video bandwidth, has intercarrier sound and a DC coupled video amplifier. (Does this sound like RCA salestalk?)

RCA went to the DC coupled video amplifier I believe with the 8T241 KCS28 chassis. It dropped DC coupling with the KCS47 and went back to it with the KCS66. DC coupling generally means improved low frequency phase response which means the picture quality on this set should be excellent.

It is a great find!:banana:

Does this set really have full 4 MHz video? I thought only the 630 chassis had that. I too think this is a beautiful set. I find myself staring at it even though it does not yet work. It seems to be well built as well. The chassis is in good shape. I don't recall seeing any rust anywhere. I am going to take my time with this one and make sure it comes out right. I think I am going to love this set once I get it going. According to the Sams this set also has DC restoration.

Yes indeed, all of the RCAs apart from I believe the 621TS and 721TS had 4MHz video at least until until 1953.

Actually the set does not have DC Restoration. (DC restoration implies the DC component has been restored with a diode clamp). Your chassis is better: it instead has DC video amplifier coupling. This is better because capacitor coupling affects the high and low frequency and phase response. DC coupling eliminates the problem hence the video response will be better and no clamp is required.

This is a very well designed set.

Cheers Terry

I think I have the metal table model version of this set.

Tom C.

So, basically this set has "DC preservation" and doesn't need restoration because it never took away the DC component?

The metal table model is the one shown on the cover of the Sams. It is quite stylish too.

Factory Installed Video Input Jack
 

I was looking over the Sams for this set and discovered that it has a video jack connected directly to the cathode of the video output tube. I did notice on the back that there is an extra RCA jack on the chassis. It is not labeled unlike the one for the phonograph input. I just assumed it was a second audio input until I looked at the Sams. Was this for test or setup purposes? I don't imagine there was anything for the customer to connect to this in 1952. I will probably use this input to do the setup after I get the set going again.

You are right. This set does not have DC restoration. I was getting confused with another RCA schematic. The video detector diode is connected to the video output cathode through a coil and a resistor.

I just checked and mine is a model 17-T-200, and it also has two RCA jacks on the back.
http://i1095.photobucket.com/albums/...y/DSCN0859.jpg
http://i1095.photobucket.com/albums/...y/DSCN0861.jpg
http://i1095.photobucket.com/albums/...y/DSCN0862.jpg

My set has been low on my restoration list, but now that I know that it has a video input I'm rethinking my prioritys. I don't have the schematic (if your sam's covers my model you could make me very happy by sending a copy to me) so I don't know if one could connect a DVD player, VCR, etc. to it directly, but even if will not work directly I bet a OP amp circuit could be built and installed under chassis to make it work (I sort of hope for the latter as I'd like to try my hand at creating said OP amp circuit).

Good luck on your restoraton.

Tom C.

PS: I think you have got a cooler cabinet on your set, but I'm still glad to have the table model due to my space limitations.

The Sams I have does not cover your model number but it does mention chassis numbers KCS66C and KCS66D. If this is your chassis let me know. I have the Sams as a pdf file and will be happy to send you a copy.

As far as using the video jack for a DVD player, you would also need another audio input. The supplied phono jack only works when the selector is in the phono position thus turning off the TV picture circuits including the CRT filament and sweep stages.

Your set looks great. Is the front of your set metal as well? I know some metal cased sets have plastic front panels and CRT bezels. I notice the back on yours has a moulded step to it. The console set just has a flat back. I found an advertisement for these sets.

I just checked and the chassis is a KCS72-M2. I guess I'm going to have to look for a sam's elsewhere.

I'm not concearned by the switch for phono jack, and heck I could probably rewire it to let the sweep circuits, and the audio and video outputs run, while killing the voltage to filaments of RF and IF only.

The entire cabinet is metal.

Gotta run.

Tom C.

I looked through my RCA notes and all the KCS72 chassis (A thru D) are for 21 inch sets. I did find service data for a 17T150 which has the identical cabinet to yours and features the KCS66C Chassis.

Can you provide a tube line up of your set? Have you found the service notes just yet?

Cheers, Terry

I'm not sure if I have the sam's or not as I have two boxes of somewhat random and incomplete folders that I should search before I shell out cash for the folder or ask some one to go to the effort of sending me a copy.Edit: I've confirmed that I don't have a copy of the sam's.

According to the sam's site it is folder number 184-12 (KCS72A) that contains the data for my model (17t200), but I hate to buy it from them as it usually costs a fortune.

My set IS a 17" screen model. If you have the folder and the tube on the schematic is a 21" you might want to check the parts list as I have found on other sets I have that among the types listed in the parts list are sometimes tubes with completely different screen sizes than in the schematic (I speculate they did this to give the CRT number for model varyants with different screen sizes).

I tried to get a picture of the tube layout in my set, but I could not get a ledgible picture. If you still want the tube layout I supose that I could copy it by hand or try again to get a picture.

Tom C.

I checked the KCS72A data for the 21T207. The chassis layout looks similar to the KCS66A. However the ttubecompliment is somewhat different. Also the KCS72A has three video IF tubes and the KCS66A has four. The other noticeable difference is the KCS72A has two tube rectifiers (5U4 and 5Y3) in place of the selenium rectifiers.

Tube compliment of KCS72A 21":
6CB6 RF amp
6J6 Osc Mixer
6CB6 three stages of VIF
12AU7 2nd detector Vert Sync amp
6AG7 video amp
6AU6 two stages SIF
6AL5 ratio detect
6AV6 first audio
6K6 audi out
6AU6 AGC
6SN7 horiz sync
6J5 vert osc
6K6 vert out
6SN7 horiz osc
6BQ6 horiz out
6W4 damper
1B3 HV rect
21AP4 pict tube
5U4 and 5Y3 rectifiers

Does this match?

If the jack is connected to the cathode, wouldn't that be an output, rather than a video in? Considering I'm not looking at the schematic it's hard to say for sure. :scratch2:

After a long time of sitting about this TV is finally getting its turn at restoration. I pulled the chassis and found that it had been partially recapped and some of the repairs looked quite old. Much of the earlier repairs are sloppy and it looks as though the shop used whatever parts were on hand There are still a lot of paper caps and old electrolytics that need to be changed. Many of the paper caps have been replaced with ceramic discs. Most of the tubes are replacements. I suspect the CRT has been replaced at some point but it checked good on my tester when I tried it again this morning. The chassis needs a really good cleaning but first I wanted to get the power supply working so I could test the set and find out if the major components were good.

The selenium rectifiers each had a silicon diode bridged across them, definitely not good workmanship. I replaced the rectifiers, two electrolytics, the caps across the AC line and the cord. I also installed a fuse holder so I can have some protection for the transformer from shorted caps.

I put the chassis in the cabinet and tried the set out. With the plate cap off of the horizontal output tube I got sound and tuned in my in-house analog station on channel five. I reconnected the HO tube and got a bright full raster and a decent picture. The tuner is seriously dirty but it looks quite good.

The first program I tuned in was I Love Lucy, seems appropriate for a 1952 TV. I wish the tube had a little more brightness but it is non aluminized so I suppose I shouldn't expect modern set brightness levels. Yes, the ion trap is adjusted correctly. Linearity and synch are good, tone is really warm from the large speaker. I think I have a really good one here. I just have to correct a lot of sloppy repairs and finish the recap.

Hi All;
Is the WAF better now that you have it somewhat working ??
THANK YOU Marty

Not quite yet. She was tired of it sitting around with the finish half stripped and threatened to haul it to the curb. She was please yesterday when I said I was going to begin the restoration. Frankly, I am tired of it sitting around unrestored when I know what potential it has after it is done. My son asked if he could play Wii on it and have it in his room since the SPC set in his room has a failing picture tube. I don't think I will permit that since little kids are rough oboth furniture and electronics.

I had that exact set as my very first. I was around 9, and my uncle, who did TV service, gave it to me with the blessing of my parents, who knew I wouldn't kill myself messing with it. It came with a photofact, and my uncle was sure that I wouldn't get it running again.

I did get it running, and kept it for several years, until we moved to a new home in 1967.

Sure did bring back some GREAT memories looking at yours. I hadn't thought about that set in 30 years or more. Thank you for posting it!

I'd sure love to see more pictures of it.

I worked on this set some more today. I replaced some paper caps and corrected some of the previous replacements. I am surprised this set works as good as it does with the hack repairs that were done on it. In several places, paper caps were replaced with ceramics that were doubled up. One cap in the horizontal section was not even the correct value. You can see the pile of nasty parts I pulled out of this set and there is still many more to go. After this work I figured I had better run the set again to make sure I had not messed something up in the process. Much to my delight it still works and the brightness control has better range and the contrast control functions better. The tuner is extremely dirty but I will save that for towards the end. I watched part of a movie on it and it really is a great performer. I made good progress but have a long way to go before I am satisfied with it.

Great news! That picture looks good. Glad that it works so well now. The rest should be down hill. Please continue to let us know how it is going.

It has been a while since I worked on this set. MySaturdays have been taken up with other things and it has just been sitting. Today I decided to tackle the tuner. I am going to have to paint the chassis as my attempts to clean it are removing the plating and now it looks worse than just dirty. The tuner is a separate assembly bolted to the chassis and connected by a few wires. I thought unhooking the tuner and working just on that would be a good project for today. I took note of what wires go where and marked them since three of them are the same color. I ended up painting many of the metal housing parts because they would not clean up well. The silver paint I bought said metalic on the can which I assumed to be metal colored. It turns out to be metal flake. I'm not going to use this on the chassis. I will get some flat paint for that. It turned out alright nonetheless.

I have never seen a tuner assembly like this. The part with the detent is a separate removeable piece. The whole thing has incredible redundant shielding. You really have to disassemble it to clean the contacts. The tubes have individual shields plus the top of the tuner has a cover. There is no way you can just squirt some Deoxit through a hole in the shield and be sure of reaching all the wafer switches. I took the whole thing down, cleaned all the moving parts, regreased with some white lithium grease and put it back together. I am replacing the few parts on the back of the tuner terminal strip. I really want this set to be a good reliable performer.

My wife does not like the light colored finish on the cabinet. She says if I refinish it in a dark color I can put it in the living room. That suit me fine as It needs refinishing anyway, I prefer dark woods and I can park my 1937 Philco 37-610 radio on it. I have a DTV converter hooked to an agile modulator so this set will get over the air content the old fashioned way. I am also going to hook a Roku box to it for Netflix and Hulu. I am setting a goal to have this set fully restored andin daily service by Labor Day.

I will post some pics from my laptop. The iPad won't let me do it for some reason.

Here are some before and after pics of the tuner assembly.

i recently got a metal table model simular to this and i think its 21" , after reading this post something that was just thought of as what am i going to do with it has now been bumped up to where am i going to put it .

let him play the wii on it as long as he promises not to hit the set or bump it , might be fun for him and maybe friends .

mike

well i looked mine is later it is the KCS88K chassis , anyone know anything about that chassis ?

mike

Worked on the set a little more this evening. Since it will be a while before I find out if my cleaning of the tuner was successful and the fact that the tuner is hard wired and inaccessible for cleaning without disassembly i decided to make it modular. I added Molex plug for the wiring and an RCA plug for the signal cable. This way, if I need to service the tuner, I can remove a few bolts, disconnect the plugs and remove it. While this is certainly not original, it does make the set easier to service.

If I get enough of my projects done this summer to get to it I'll start a restoration thread with pictures. It is near the bottom of my cue due to the very weak CRT.