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#76
02-04-2020, 12:05 AM
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The way caps are interlace wound they would have both film layers(plates) very close to the same AC potential. In essence both foil layers come to the outside, only separated by the thickness of the dialectic. What am I missing?
Last edited by Kevin Kuehn; 02-04-2020 at 12:08 AM. 
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#77
02-04-2020, 06:00 AM
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for the first time in over 40 years ( guess ) heaters be heating!
https://imgur.com/aaQgLaA Bias is disabled, just a transformer / heater test.
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=^-^= Yasashii yoru ni hitori utau uta. Asu wa kimi to utaou. Yume no tsubasa ni notte. いとおしい人のために Last edited by Yamamaya42; 02-04-2020 at 06:12 AM.
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#78
02-04-2020, 08:38 AM
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Quote:
__________________
Tom C. Zenith: The quality stays in EVEN after the name falls off! What I want. --> http://www.videokarma.org/showpost.p...62&postcount=4
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#79
02-04-2020, 05:10 PM
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__________________
=^-^= Yasashii yoru ni hitori utau uta. Asu wa kimi to utaou. Yume no tsubasa ni notte. いとおしい人のために
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#80
02-05-2020, 08:43 AM
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Adding an amp stage is another valid option.
__________________
Tom C. Zenith: The quality stays in EVEN after the name falls off! What I want. --> http://www.videokarma.org/showpost.p...62&postcount=4
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#81
02-05-2020, 09:37 AM
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Quote:
 https://imgur.com/oFR1Zab hard to see in that, but if you look close, you can see a metal plate over the place where the socket for audio out v16 should be, audio amp v15 is there under that plate, but I have no clue how it's wired up w/o volume control. There is a long audio cable coming out of where audio output v16 would have been that ran to the radio/amp. At this point I'm thinking it's easier just to build an ext amp than to figure out how they modded it.
__________________
=^-^= Yasashii yoru ni hitori utau uta. Asu wa kimi to utaou. Yume no tsubasa ni notte. いとおしい人のために
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#82
02-05-2020, 10:02 AM
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Rewiring everything after the detector isn't the worst...I have a certain fondness for phonos that contain RCAs 45RPM only mini changer the RP-168/190. One of my units was a 1 tube wonder that required a high output cartridge more expensive than the phono as a whole...So to adapt it to the $1 eBay crosley knock off carts I favor in these I converted the amp to the 3 tube version found in other models....I pretty much had to recreate it from scratch and do some engineering changes to deal with series heater differences. The result was quite decent.
I can be lazy sometimes...I know there's the Texas vintage radio and phonograph society in your state...If they are not too far away I'd probably just go to a swap meet and pick up the most appealing/affordable table set with a phono input and use that. That said what everyou are comfortable with should be fine. This set has the most value to you so you are the only one that needs to be happy with it.
__________________
Tom C. Zenith: The quality stays in EVEN after the name falls off! What I want. --> http://www.videokarma.org/showpost.p...62&postcount=4
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#83
02-08-2020, 01:25 AM
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__________________
=^-^= Yasashii yoru ni hitori utau uta. Asu wa kimi to utaou. Yume no tsubasa ni notte. いとおしい人のために
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#84
02-08-2020, 01:28 PM
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Mutha Puss-bucket....
I expected the DC voltage to be a bit high with no load, but 480v?  It's hooked up to the 300 Vac center tap point on the power x-former, and I was not expect it to go that high when converted to DC. :/ I'm gonna have to stick some kind of voltage divider resistors on there to get it down :/
__________________
=^-^= Yasashii yoru ni hitori utau uta. Asu wa kimi to utaou. Yume no tsubasa ni notte. いとおしい人のために
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#85
02-09-2020, 09:39 AM
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IT'S ALIVE!! IT'S ALIVE! HAHAHAHAHA!
 https://www.youtube.com/watch?v=xos2MnVxe-c https://imgur.com/8dudmlg https://imgur.com/lM2ROjM running off a variac as I don't have the resistors for the voltage divider yet. https://www.youtube.com/watch?v=SM5g...ature=youtu.be YES, the pot on my signwave generator is VERY dirty but it's working! 
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=^-^= Yasashii yoru ni hitori utau uta. Asu wa kimi to utaou. Yume no tsubasa ni notte. いとおしい人のために
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#86
02-10-2020, 09:36 AM
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A music playing test sort of worked, :/
but did not play very loudly, no surprise, as in order to keep B+ bias down, I have the input voltage quite low, and so the heaters are hardly getting 5 volts and so the 12AX7 is hardly lit. I'm guessing it will get better once I get the resistors for the voltage divider and get things a bit more stable. Using a modded version of this, https://tinyurl.com/stn9984 Will just have to play with it to get the voltage correct. One thing noticed, the 6V6GT gets DAMN HOT :O, which, from what I have looked up is apparently normal for it. All in all, once complete, and all the tweaking is done, this thing should fit in nicely in the Jensen speaker compartment in what ever is the final enclosure of this TV.
__________________
=^-^= Yasashii yoru ni hitori utau uta. Asu wa kimi to utaou. Yume no tsubasa ni notte. いとおしい人のために
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#87
02-10-2020, 09:48 AM
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You could probably harvest the heater voltage off the TV chassis for testing....odds are it has the same transformer as the models with an audio amp, and even if it doesn't there should still be some headroom for it.
__________________
Tom C. Zenith: The quality stays in EVEN after the name falls off! What I want. --> http://www.videokarma.org/showpost.p...62&postcount=4
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#88
02-12-2020, 11:04 AM
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Sigh...
Trying to use that old 1955 era Sansui power transformer is giving me too much trouble, unstable voltage & weird AC leakages where there should be none, ( I have shocked the crap out of myself many times now cause of that. ), perhaps there was something wrong with them in the first place, and that's why they were donated to my class. :/ Trying another approach, I have an old beat up Sansui 1000 that used to work that I won't ever get to rebuilding, not worth it, it was in bad shape to start with, but I know the x-former in it is good, so I'm gonna pull that and use it, slightly adjusting the circuit that was in there, as it seem quite close to what I need. I still may have to adjust for load, but I'm sure the weird ac leak problem will be gone with it, and I won't get 300+ ac shocks anymore! :p https://imgur.com/7loNTco orig Sansui 1000 https://imgur.com/8CTU69K planned v2 power supply edit/ add on https://imgur.com/pteUqEl Yeah, I should have looked more closely, I would have noticed there was something odd with these... input power 0-85-100-110 0 – 5v3A up top, filament windings 0- 2.5 -2.5 -6.3 - 6.3 3A 0- 6.3 – 8.5 -15A 0- 6.3 – 8.5 -15A hv sec out ( what I overlooked ) 350 – 300 – 0 – 300- 350 but says DC130MA... meaning, this SHOULD have built in rectification, if I am understanding this right, but it must be damaged, cause its putting out ac, and the winding leaks to the case when hooked up .
__________________
=^-^= Yasashii yoru ni hitori utau uta. Asu wa kimi to utaou. Yume no tsubasa ni notte. いとおしい人のために Last edited by Yamamaya42; 02-12-2020 at 11:30 AM.
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#89
02-12-2020, 11:42 AM
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Quote:
Sometimes old transformers randomly develop leakage between windings....I used to use a 50's isolation transformer for working on not chassis radios 'safely'....one day the primary and secondary developed STRONG leakage on me while I was using it. I discovered that the hard way, then retired it...
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Tom C. Zenith: The quality stays in EVEN after the name falls off! What I want. --> http://www.videokarma.org/showpost.p...62&postcount=4 Last edited by Electronic M; 02-12-2020 at 12:07 PM.
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#90
02-12-2020, 11:53 AM
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Can you see the octal tube socket hole right next to the tuner? That was punched for an optional 6K6 audio output amp. You'd need to add an audio output transformer and volume pot, but man this would be so simple to add the amp stage right on your TV chassis. There may even be an extra control mounting hole on the front of your chassis? Fada made a model 925 TV only chassis that I'm pretty sure used the same basic chassis layout as your 895, which is why the hole for the optional audio output is there next to the tuner. I can post the schematic section from the 925 and you can wire it accordingly, that is if you're up for the challenge?
https://i.imgur.com/oFR1Zab.jpg
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