My new predicta
 

I just got home and as soon as I got out of the car I gave it a much more detailed look and I saw modern capacitors underneath the set so I pulled out the chassis and someone replaced all if the caps underneath but not on the board!!
On the pc board everything was original and there were two black beauties that were cracked. After all if this I decided since most if the components had been replaced it would be reasonably safe to power it up I got good sound but it was a little weak and no raster I suspect a cold joint in a tube socket since I saw a raster when it was in the mall but I didn'ta leave it on long enough to warm uphttp://img.tapatalk.com/d/13/03/18/ja8y7e9e.jpg.
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Congrats on the new Predicta!

Check out Bob's series of videos on the Predicta Holiday. A LOT of good tips in there and how to deal with the early PCB's and the cuplates.
http://www.youtube.com/playlist?list...2y62xYCp5PgZx_

Good for you my friend :)

Wow, not only a great price but so much work already done for you!!

Makes me wonder where the set came from... it might be interesting if you get a chance to talk to the dealer and ask them the backstory.

I would like to know its story and why the person stopped working on it. Hopefully they dident discover that some unobtainun part wasn't fried like the flyback or CRT

Looks like it has the original thermistor and filament dropping power resistor. Often one or both of those are bad.

The thermisistor is good but I don't know what the dropping resistor shops measure at on my ohm meter?

Also what should the voltage readings be on the pins of the CRT?

You can download the Sams service info for free here: http://www.earlytelevision.org/tv_sc...s_postwar.html

Thanks! That will be a lot of help when I get into the set more.
So do you guys think when I pull the PCB I should rebuld all of the networks that seem to go bad frequently and all of the resistors as a precaution?

I wouldn't rebuild the networks unless you really want the practice. If you'd like to tackle one, which in my opinion is the worst offender and also the simplest to build, tackle the vertical integrator, which is the short 4 pin network next to the vertical output.

Hi All;
Joseph, Bob Andersen, has in His Predicta Video's, about How He rebuilt His Integraters.. Check it out And then decide..
THANK YOU Marty

I will. I was just thinking that since the boards are so hard to remove in these that I would just do them all while it was out since they seem very failure prone. Has anyone actually opened up one of these networks to see what exactly is inside?

Yes, I did at some point in the videos. Some are just encapsulated discrete components (carbon comp resistors, ceramic caps, etc). Other networks (vertical integrator) are made from carbon and metal deposited on a ceramic substrate.

Here's my restoration thread in case you haven't read it yet:
http://www.videokarma.org/showthread.php?t=255328

If the video output tube (6aw8a) is gassy or dead would that cause the screen to be completely dark I just looked at this tube with the set on and it is very purple inside when on so is the horizontal output tube.
I have determined there is HV but I don't have a probe to measure the exact voltage but I can get a 1/2 centimeter spark to the housing of the flyback transformer.

Sounds like your HV is ok... disconnected video line will definitely cause a dark raster. That line runs separately from the harness coming from the back of the CRT as a single wire that plugs into a post on the board next to the video output.

Hi All;
Joseph, HV may be Ok..
But, purple tubes are not, that needs to be addressed.. It could be a bad tube or too much of a load on the tube..
Check with Old Coot, He would direct you correctly on what to look for and what's wrong.. The cause of the Purple tubes..
THANK YOU Marty

Thanks, the video line is connected. I will wait on replacing tubes untill I get the rest of the paper caps and out of tolorence resistors out of the set. Also I will message old coot tonight and see what he has to say.

Ordering parts tonight

Parts ordered with just radios since Mouser seems to always short me on some parts.
I actually ended up having to order more resistors than I needed to reach the minimum amount of 20.00

Ok do out of curiosity I turned the brightness up all of the way and turned out some of the lights in my room and I was able to see a faint raster that is off center. Could this be a 6 volt CRT being run off of 2 volts I didn't see very much filament glow when I looked at the neck of the picture tube. I am hoping that it is just a combination of a weak tubes/aged caps on the PCB

If that was a 6V heater, it would light up like crazy (since your heater string is constant-current* at .6A, and a 6V heater is rated at much lower amperage, it'd get around 12-15V across it). Hopefully the dim raster is not caused by flat emission in the CRT. If it is, has anybody ever had any success rejuvving those 2.5V jugs?:saywhat:

*Series strings are constant current, while parallel circuits are constant voltage. That's why series strings have tubes with such odd heater voltages all running the same current.

I wonder if anyone has tried to duplicate these evidently troublesome PC boards yet. A little film (for lack of remembering the correct name), some copper and a chemical or two, and you can make anything you want.

Both the 2.35 and 6.3 volt CRTs use 600mA of current. When replacing a 2.35v CRT with a 6v one, it was commended to short out a section of the big filament dropping resistor to compensate for the four volt difference. However, since AC line voltages are typically four or more volts higher now, I wouldn't do it.

I've tried rejuvinating a couple original 2.35v 21EAP4s with no luck.

...

Whether to replace the Predicta couplates (networks) pre-emptively is a tossup, in my view. If you build all of the replacements correctly, it won't do any harm. But you might be wasting your time and somewhat decreasing access to the PC board.

PRO:

Occasionally, a couplate does need replacement. Building a substitute is not rocket science; you can see how to do it in my Predicta articles or Bob's Holiday restoration thread.

Replacing them might increase the TV's long-term reliability, or at least your confidence in it. Replacing them might eliminate the need to pull the PC board in the future, a process that involves risk (risk of damaging the board or miswiring something).

CON:

Not all couplates go bad. If that were true, there wouldn't be a working Predicta left on Planet Earth. I suspect the majority of working Predictas still use their original couplates, or nearly all of them.

Tubular ceramic caps are extremely reliable. The resistors inside couplates may drift off value, but the question is, how much is too much?

Your replacement couplates will be bigger than the originals. Each new one decreases access to other components around it. This can complicate getting to test points on the board or even make it harder to replace a tube.

Each couplate has multiple terminals, and if you're too rough unsoldering and removing an old one, you may pull loose the foil on the board or otherwise damage it.

Replacing the couplates degrades the TV's originality.

SUM:

The decision requires you to judge the tradeoffs among several factors: originality, reliability, risk, and efficient use of the restorer's time.

Although I have replaced couplates myself, I don't want people to get the idea that automatically "shotgunning" all of them is a necessary part of every Predicta restoration. A more conservative approach would be to replace the high-risk caps and badly out-of-tolerance resistors on the board and then see how well the TV works.

Regards,

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

Ok i guess I will wait rebuld all of the couplets and see how it works with the orgional ones. Would it be a bad idea to replace all of the resistors on the PCB since I ended up ordering them to meet the 20.00 minimum order at just radios?

Uh oh, my mistake. Sorry for giving bad info. I erroneously assumed 6V heaters ran lower current. Last thing i'd want to do is give bad info to a newbie.

But the constant current/ constant voltage distinction between series and parallel circuits is maybe worth noting.

Yes, it's definitely worth noting. This is also an issue with the 17" parallel filament sets where the low voltage CRT ran off a separate tap on the power transformer. If it's replaced with a 6 volt CRT, the filament lead should be switched to the 6 volt tap.

Whatever was the reason for Philco's having the 2V jugs in the first place? I had just assumed, without researching it, that it was for matching current in the heater string.

I think it was a consequence of making a tiny electron gun for the very short neck.

Looks like you're right. Here's this from Tom Albrecht, himself a maven and guru of all things television..
http://www.radiomuseum.org/forum/phi...a_holiday.html
Seems like Predicta was like the 'Edsel' of TV sets, beset with funkiness of design but highly collectable.

So does anyone know exactly why this set was called the 'Holiday?

It's known as The Holiday since it was introduced by Philco during the Christmas holiday of 1958.

I forgot to add-"during the shopping season"

Ok that makes sense I thought that they were called that because they made some for the holiday inn

As I am looking at the new caps put in I see some which are not in the right place exactly :scratch2:
atleast he bought the correct values! I will put everything as it should be tonight and test the set again!

Got the parts fixed and it still does the same thing. I guses I should wait untill my parts get here and they are installed to start trying to figure out what's wrong since about 40% of the paper caps are still in the set

Predicta Holiday
 

I thought it was because the model was made for the Holiday Inn chain. There's at least one picture I've seen on line with one mounted on a wall shelf in a Holiday Inn room.

From what I have read and gathered, the 17" sets where the ones pushed out to the motel chains, not the more expensive wood cabinet 21" Holidays, due to their cheaper cost and their failure in the consumer marketplace. These sets are the commonly seen beige colored cabinet Debutantes, where as the consumer versions were all in charcoal. They also lack antennas. These sets seem to have been made into 1961 while all consumer Predictas were dropped by then.
Philco also had a division called Tele-Sound that leased TV sets to the hospitality industry too that used these Predictas at that time.