Gregb
12-26-2022, 11:11 AM
Check out my Christmas present from the wife! Anyone have any information on this thing? Looks to be some kind of teaching aid and uses the same tuner and IF strip as a Predicta.
Greg B
Greg B
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View Full Version : Philco TA505 TV Gregb 12-26-2022, 11:11 AM Check out my Christmas present from the wife! Anyone have any information on this thing? Looks to be some kind of teaching aid and uses the same tuner and IF strip as a Predicta. Greg B timmy 12-26-2022, 11:32 AM That’s interesting does it work? Gregb 12-26-2022, 11:46 AM That’s interesting does it work? Not ready to power up yet, it is missing one tube and the power supply needs to be gone through first and there are a bunch of electrolytics scattered though out that should be looked at. Greg B timmy 12-26-2022, 12:11 PM Yeah the power supply caps should be first. Do you have some kind of schematic to figure out what tubes it takes and of the whole circuit. Is this black & white or color judging by the size of the flyback it looks like a color flyback. Gregb 12-26-2022, 12:34 PM I have no schematic or any documentation of any kind, I was hoping someone here would have something. It is black and white for sure. timmy 12-26-2022, 12:37 PM Could be a teaching aid right out of Philco for there own techs. Very interesting project would like to see that working. No schematic hmm that’s a bummer but take your time and you will get there. AlanInSitges 12-26-2022, 02:41 PM Man that is extremely cool! What a find! I'm looking forward to see what we find out. Definitely reach out to the ETF and see if they have any information on it (I'll bet it's something they'd like to have). zeno 12-26-2022, 03:06 PM Thats pretty pissah. Its a trainer, I have seen others I think RCA. For a manual date code some of the big parts, make a tube list. Then post it here & I bet it almost matches a Philco TV. Someone will recognize it then you can get a Sams. Maybe find the real paperwork in time......... Who ever picked this for you really hit the nail on the head ! It would be hard to beat IMHO. 73 Zeno:smoke: LFOD ! Dave A 12-26-2022, 06:53 PM It looks very clever for instruction. The major sections of a set are on the front in blocks (B+, IF, audio, sweep, et al.) just jumpered between. The local components are on the back where the instructor could easily insert a bad component/board to track down. Start on the front tubes to isolate and then move behind to the components. The schematic for this had to be an adventure in parts locations. A one-of-a-kind score. bandersen 12-26-2022, 11:25 PM Very cool. Philco used that same IF strip in many sets for several years. The rest of the construction looks custom for this trainer. Chris K 12-27-2022, 05:44 AM Very cool. Philco used that same IF strip in many sets for several years. The rest of the construction looks custom for this trainer. Looks like Predicta/Seventeener IF strip. What a cool piece! What does it say on the Philco badge on the bottom? Gregb 12-27-2022, 10:08 AM The little tag just shows the model number, TA505, and power info. Made in Canada Todays project is make a tube list and see if I can get some info on some of the parts and post here as suggested by Zeno above. Maybe someone will recognize the layout. Gregb 12-27-2022, 02:14 PM Here is a tube list, if you recognize please let me know. Thanks I will have to pull some modules to get any part numbers and that will be next. Tuner 6GK5, 6HG8 IF 6DE6, 6DE6, 6AM8 6BY8 2 X 6AW8 6CS7 Hoz Out Module 12AU7, 12BR7, 6DQ6 6DA4 6AB4 2 X 6AQ5 audio out module 1 emty 7 pin socket init4fun 12-27-2022, 03:26 PM I wonder if the empty 7 pin on the audio module might be a 6AV6 (or 6AT6) ? Also, I might as well join everyone else in saying GREAT SCORE !!!!!! :thmbsp: Gregb 12-27-2022, 03:42 PM It could be, at some point I will start tracing the circuit back and see if I can figure out what tube should be there. This is a great score and I am hoping it will help me improve my TV repair skills. DavGoodlin 12-27-2022, 04:45 PM Based on the tubes listed, it resembles a typical 1956 or 1957 Philco BW using a transformer. Chassis is TV-330 or 7L41. That is such a neat piece, but you may need to restuff all those caps to keep it looking original. bandersen 12-27-2022, 04:49 PM Ah, Dave beat me to it. Interesting to see how their design evolved over time. old_coot88 12-27-2022, 07:59 PM I wonder if the empty 7 pin on the audio module might be a 6AV6 (or 6AT6) ? Maybe I'm dreamin', but didn't Philco use a 6BN6 gated-beam tube at some point? Try a I might, I couldn't spot the empty 7 pin socket (or the buzz control pot that would accompany it). Dave A 12-27-2022, 08:14 PM Did Philco have a Canada division of some sort? Curious as this is built in Canada and found in Canada. Enquiring minds want to know. And I would like to hear the discovery story. Gregb 12-27-2022, 08:19 PM Did Philco have a Canada division of some sort? Curious as this is built in Canada and found in Canada. Enquiring minds want to know. And I would like to hear the discovery story. Yes there was a Canadian Philco, located in Toronto Ontario. It was listed for sale on Kijji in Calgary, my daughter lives there and between my wife and her they got it for me, paid $80 for it. Gregb 12-27-2022, 08:20 PM Maybe I'm dreamin', but didn't Philco use a 6BN6 gated-beam tube at some point? Try a I might, I couldn't spot the empty 7 pin socket (or the buzz control pot that would accompany it). When looking at the front picture, third module down on the left side, brown 7 pin socket with a control directly below the socket. Gregb 12-27-2022, 08:21 PM Based on the tubes listed, it resembles a typical 1956 or 1957 Philco BW using a transformer. Chassis is TV-330 or 7L41. That is such a neat piece, but you may need to restuff all those caps to keep it looking original. Thanks, I will have a look old_coot88 12-27-2022, 11:18 PM When looking at the front picture, third module down on the left side, brown 7 pin socket with a control directly below the socket. Oho! Got it. Goin' blind in one eye and can't see outa the other. :o Gregb 12-28-2022, 11:35 AM Oho! Got it. Goin' blind in one eye and can't see outa the other. :o I had a close look at how the socket is wired and it looks like a 6AB4 should go there as well as the socket above it. First one being an amp and second a phase inverter for the pp 6AQ5 output stage. I think later today I am going bring it up very slowly on my PR57 and see what happens. All of the tubes are Philco branded and tested good as new other than the missing one and the horizontal output, it had been changed. I am still planning to recap the power supply and I just noticed the fusistor is missing. Gregb 12-28-2022, 06:07 PM I chickened out and did not power it up, pulled the power supply and checked the caps two of them are shorted. Good thing I decided to check first. I will re-stuff the old cans and report back when completed. timmy 12-28-2022, 06:22 PM Can’t let those power supply caps go it’s safer to change them rather then chance burning up the power transformer. Gregb 12-29-2022, 12:47 PM I have re-capped the power supply, re-stuffed the cans that were there. Two were Philco brand one was Aerovox so maybe a past replacement. Thought I should check the fuse and the holder was broken so replaced that. Had a five amp fuse in it, thought that was a little high so installed a three amp. Brought it up slowly on PR57 and I have sound and a full raster but no picture, sorry my picture does not show it but it is full. The tuner is really flaky so will pull that next and go through it. timmy 12-29-2022, 04:51 PM If any wax caps say goodbye to them Gregb 12-30-2022, 09:27 PM Went through the tuner and the vertical/horizontal control modules and I now have a picture. At first there was no sync but I found an open jumper that looked on purpose, maybe the last teaching fault before the unit was retired. I have attached a couple pictures, sorry they are not the best. I can't seem to get a good picture of a crt image. timmy 12-31-2022, 04:55 AM That’s a huge start it’s getting there. AlanInSitges 01-03-2023, 04:05 AM Man this is a great start to the new year, seeing that thing already powered up and working. Also: holy shit that thing is huge! From the earlier pics I thought it was a tabletop thing. Gregb 01-03-2023, 08:27 PM Its not very big really, just over 3 feet tall and about 2 feet wide. It would be just about the right height on a lab bench while the operator was standing in front of it. I have it working fairly good but still have two problems to sort out. The contrast control is effective over a small area in the center of it's range and outside of that area it causes major buzz in the audio and makes the picture very unstable. The other issue is an intermittent that comes and goes and can be initiated by tapped on the frame of the unit. It effects only the vertical and suspect maybe tin whiskers in a control. pdr-fml 01-04-2023, 09:05 PM That's got to be the easiest to work on television ever! Definitely function over style. old_tv_nut 01-05-2023, 10:12 AM ... The contrast control is effective over a small area in the center of it's range and outside of that area it causes major buzz in the audio and makes the picture very unstable... Is it an actual contrast control in the video out stage, or an IF gain control like some early sets? Gregb 01-05-2023, 02:59 PM Is it an actual contrast control in the video out stage, or an IF gain control like some early sets? I am a little backed up with customer repairs so had to put the toy aside. Once caught up again I will have a look and report back. |