Although totally different, it definitely shares some design and a few parts from similar 1950 Philco sets. I saw a few shared components with my 50T-1401. It's great that you got the unmolested set for reference too, that will be a big help. That wooden cabinet looks just like the 50T-1401, except for being smaller with the smaller CRT. These will definitely be a challenge. The bakelite cabinet is really NICE!
Interesting set Bob, this is my first glimpse of the Philco 50T-701/-702. I find the electrostatic deflected sets a bit more interesting. This set was somewhat "old tech" in 1950 but, probably targeting the entry level, low cost customer. With a 6V6 for a power oscillator for the high voltage power supply, I suspect 2 to 3 watts was the output rating. I heard one comment about high voltage drifting quite low as the set warms up. Looking at the design, I think the voltage rating of R58, R59, and R60 is being exceeded. These resistors are 4.7 meg, 1 watt carbon comp. I think they may have a maximum voltage rating of 500 volts, yet they (from my calculation) appear to have 870 volts across each one. Excess voltage, heat, humidity, and time does some weird things to carbon comp resistors. Interesting power supply; a half wave rectifier to achieve 120 volts, then a half wave voltage doubler to achieve 310 volts. I think that is the speaker field coil as the filter choke in the 120 volt supply. I was surprised to see .0047uF caps used to couple the sweep signal to the deflection plates for both the horizontal and vertical. I assumed the vertical coupling cap would be at least 10X the value to minimize distortion of the sawtooth wave. For L1 and L2, 3 henry coils are hard to come by in a solid state world. I was going to suggest using the primary of a 6 to 9 watt, 120 Vac, 60 Hz power transformer, which should have about 3 henries. I suspect it wouldn't work very well due to the excessive winding capacitance. Loctal tubes; the first high frequency tube base. Philco must have had a hand in that design, as they were a common site in Philco radios since 1937. Loctals were the tube of choice in the British WWII radar sets for the receiver IF amp.
I can't wait until you start on these Philcos ! These have a notorious High voltage fade and after they warm up, the high voltage dips down to about 2kv instead of the 5 kv needed. According to the forum, they even had some coils wound to the original specs and they too fade. It is a mystery to them. Several A.R.F. members stated they used the coils off old junker Motorola sets. I have not started on mine, but I have a Miller 4525 5 kv coil hoping that will work. Fun vid as always Bob !
Yeah, I've heard about the HV problem. I'm inclined to leave it original. I wonder if it was an issue back then? I can't imagine someone spend all that money on a lemon
@@bandersentv One of the old timer techs posted they were fine back in the 50's, that's why its such a mystery. Secondly, the new coils they wound fade as well.
I love them! Throw caution to the wind and do a Shango on it! Yes, I'm joking but those are some cool finds. It's good thing I'm not closer to visit the swap meet or my truck would go home full. Living the mountain west, we didn't have TV till about 1954 so I rarely find anything as fun as you did. Enjoy them!
Bob, If you don't have any luck finding replacement knobs you could have some 3D printed. I have printed knobs for stereos in the past with great success. Cheers, Kelly
Hallo Bob, her is Radio Rainer, neues von Gestern youtube. From Germany, ei have a great Museum of Radio and TV Colaction, 1938,HMV.and a many Tv's vrom1952German made Russian TV Great Britain. Color TV from 1968 it is a lot off Tv's 150,and Radio400. Nice to meet you. 😊
If it was not for the ascetics of the Philcos I would not give them the time of day. There engineers spent more time skirting patents than making a functionally superior performing set. I did like their early solid state color TVs. Very easy to service. Good picture too...
Hello again, been watching alot of these b&w restorations now but i seem to have a bit of a snag on the 8-301w sets currently So i replaced a majority of the caps and a few resistors but theres a weird flickering now happening to the screen when it plays a video of something flashing and im wondering if you had any experience with something similar So what it looks like is the horizontal bending towards the center before the vertical rolls like a flutter but right after that its locked back in with no defects (besides some warpage due to the set having bad linearity from its construction) I believe its either some sort of short or a problem in the coil tuning but id like a good opinion before messing with the coils If i had a good way of contacting i could send a small video clip of what i mean but thats really all i have so far holding them back for their restoration
@bandersentv well i meant it as sort of a general question as i have had a few other sets do it in the past as well but i could never find out the cause of it
when I went to get schematics.... on the etf...........it automatically sent me to the sams website , was this just a glitch and the service info is still available on the e.t.f.?
Ya that was great Alway like a good look At the set itself. Big fan of Our Miss Brooks 52-56 I think. The big crossover years From radio to tela plays So you still get the jokes Without looking... listen to old time radio since the 70's And they did a bunch of Tv related shows on both Formats Rammbling now But love what you do Just like to see more glamor shots of these old beauties. Thanks for saving history! That some used to think of As old garbage. A fan.
In the 1970's my local TV Repair Shop used a mirror on the wall behind the bench to view the screen.
Although totally different, it definitely shares some design and a few parts from similar 1950 Philco sets. I saw a few shared components with my 50T-1401. It's great that you got the unmolested set for reference too, that will be a big help. That wooden cabinet looks just like the 50T-1401, except for being smaller with the smaller CRT. These will definitely be a challenge. The bakelite cabinet is really NICE!
Now Answer.
Interesting set Bob, this is my first glimpse of the Philco 50T-701/-702. I find the electrostatic deflected sets a bit more interesting. This set was somewhat "old tech" in 1950 but, probably targeting the entry level, low cost customer.
With a 6V6 for a power oscillator for the high voltage power supply, I suspect 2 to 3 watts was the output rating. I heard one comment about high voltage drifting quite low as the set warms up. Looking at the design, I think the voltage rating of R58, R59, and R60 is being exceeded. These resistors are 4.7 meg, 1 watt carbon comp. I think they may have a maximum voltage rating of 500 volts, yet they (from my calculation) appear to have 870 volts across each one. Excess voltage, heat, humidity, and time does some weird things to carbon comp resistors.
Interesting power supply; a half wave rectifier to achieve 120 volts, then a half wave voltage doubler to achieve 310 volts. I think that is the speaker field coil as the filter choke in the 120 volt supply.
I was surprised to see .0047uF caps used to couple the sweep signal to the deflection plates for both the horizontal and vertical. I assumed the vertical coupling cap would be at least 10X the value to minimize distortion of the sawtooth wave.
For L1 and L2, 3 henry coils are hard to come by in a solid state world. I was going to suggest using the primary of a 6 to 9 watt, 120 Vac, 60 Hz power transformer, which should have about 3 henries. I suspect it wouldn't work very well due to the excessive winding capacitance.
Loctal tubes; the first high frequency tube base. Philco must have had a hand in that design, as they were a common site in Philco radios since 1937. Loctals were the tube of choice in the British WWII radar sets for the receiver IF amp.
I can't wait until you start on these Philcos ! These have a notorious High voltage fade and after they warm up, the high voltage dips down to about 2kv instead of the 5 kv needed. According to the forum, they even had some coils wound to the original specs and they too fade. It is a mystery to them. Several A.R.F. members stated they used the coils off old junker Motorola sets. I have not started on mine, but I have a Miller 4525 5 kv coil hoping that will work. Fun vid as always Bob !
Yeah, I've heard about the HV problem. I'm inclined to leave it original. I wonder if it was an issue back then? I can't imagine someone spend all that money on a lemon
@@bandersentv One of the old timer techs posted they were fine back in the 50's, that's why its such a mystery. Secondly, the new coils they wound fade as well.
Bob, that bakelite case is beautiful.
Interesting that one is badged Philco and one Philco Television
I love it awesome find Bob will love to it work again
I love them! Throw caution to the wind and do a Shango on it!
Yes, I'm joking but those are some cool finds. It's good thing I'm not closer to visit the swap meet or my truck would go home full. Living the mountain west, we didn't have TV till about 1954 so I rarely find anything as fun as you did. Enjoy them!
Bob, If you don't have any luck finding replacement knobs you could have some 3D printed. I have printed knobs for stereos in the past with great success. Cheers, Kelly
Hallo Bob, her is Radio Rainer, neues von Gestern youtube. From Germany, ei have a great Museum of Radio and TV Colaction, 1938,HMV.and a many Tv's vrom1952German made Russian TV Great Britain. Color TV from 1968 it is a lot off Tv's 150,and Radio400. Nice to meet you. 😊
Hopefully you end up with enough parts to make one nice one.
I'd try to restore the wooden cabinet. Much more attractive. As you know, keep checking auction sites and Marketplace.
If it was not for the ascetics of the Philcos I would not give them the time of day. There engineers spent more time skirting patents than making a functionally superior performing set. I did like their early solid state color TVs. Very easy to service. Good picture too...
I have one recapped and working in decent shape but there are scratches on the top front.
Hello again, been watching alot of these b&w restorations now but i seem to have a bit of a snag on the 8-301w sets currently
So i replaced a majority of the caps and a few resistors but theres a weird flickering now happening to the screen when it plays a video of something flashing and im wondering if you had any experience with something similar
So what it looks like is the horizontal bending towards the center before the vertical rolls like a flutter but right after that its locked back in with no defects (besides some warpage due to the set having bad linearity from its construction)
I believe its either some sort of short or a problem in the coil tuning but id like a good opinion before messing with the coils
If i had a good way of contacting i could send a small video clip of what i mean but thats really all i have so far holding them back for their restoration
Sorry. No idea. I've never worked on a Sony
@bandersentv well i meant it as sort of a general question as i have had a few other sets do it in the past as well but i could never find out the cause of it
how did you put the cutoff in a different range is that what the bias switch is for -58 volts, -63 volts ect?
Yes, exactly
Quite an interesting challenge! Where did you get the adapter with clip leads for the CRT tester, or did you have to make it yourself?
It comes with the Sencore CR70 tester
Glad it you not me (: :)
Hello big TV love Brazil 🥰💕💞💓✌️👊
Hallo Bob here is Radio Rainer Neues von Gestern, Radio and Television MUSEUM Germany TH-cam.
when I went to get schematics.... on the etf...........it automatically sent me to the sams website , was this just a glitch and the service info is still available on the e.t.f.?
Yes, it's still available. Try going to the Philco page and click on 50T-702. www.earlytelevision.org/tv_schematic_diagrams_philco.html
service information Call shango ! I real like his mining videos
So lets see if I ve been paying attention.
1950 7" set ?
Oh ya my glass cleaning trick
No water 0000 steel wool ...
Then windex. Give it a try
No mud
Oh bing! Thankx Im learning
Ya that was great
Alway like a good look
At the set itself.
Big fan of Our Miss Brooks
52-56 I think.
The big crossover years
From radio to tela plays
So you still get the jokes
Without looking...
listen to old time radio since the 70's
And they did a bunch of
Tv related shows on both
Formats
Rammbling now
But love what you do
Just like to see more glamor shots of these old beauties.
Thanks for saving history!
That some used to think of
As old garbage. A fan.