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  #16  
Old 01-19-2015, 10:14 AM
dieseljeep dieseljeep is offline
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Originally Posted by Electronic M View Post
I don't know what you mean by helper magnets. They are the static convergence magnets....You know how on the newer yokes how there is a knob on each petal of the convergence clover (yoke) to adjust the static convergence?....Well mine has those dumb white plastic sticks with magnets on the ends instead of knobs....They are less smooth to adjust than knobs too, and I can see why once the new kind was created they fell out of use FAST.

Zeno: I never knew Sylvanias had 20' cords. I can see that being useful for lugables and movable cart/stand dwellers, but it was probably terribly awkward on consoles.

I hate when wires are too short on table sets to use the set as it's own test jig!




I still have not found the damn magnet! But if I do I'm gluing it into the plastic like I'm in the process of doing on the remaining two.
I might have the whole assembly!
PM me in a few days.
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  #17  
Old 01-19-2015, 02:35 PM
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Electronic M Electronic M is offline
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Quote:
Originally Posted by dieseljeep View Post
I might have the whole assembly!
PM me in a few days.
That would be nice.
I have cobbled together a temporary solution. There was a toy marketed about a decade ago called Supermag it was like legos only you were building with magnets...I eventually found that if I cut one of the small magnets from that toy down it's strength would be reduced enough (and it would fit the plastic mount) that it would be usable in place of the original....It is still much stronger than it should be, but I can at least dial the static convergence in now...

Seems my video fade problem was a bad connection on the AGC tube socket.

I have it back together now (as of last night), and hope my patch job will hold until my next school break week or after graduation. Next time I have the back off I think I need to refresh the H sweep tubes, and fully align the H sweep and color osc, and deal with my convergence kludge if you can find that assembly.

To try to be a bit on topic, one design I never cared for was 'wire wrap terminals'. They are a pain in the but to undo (completely), and unless by some miracle one has the proper tool to create the wrap, it just ends up being redone as a shorter solder joint any way.
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  #18  
Old 01-19-2015, 07:50 PM
walterbeers walterbeers is offline
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Sony color trinitron sets made in the 80s that used the SG613 switching triac (or what ever the device was called). One little problem, like a bad connection in the horizontal or in the power supply, or a bad cap, etc, and poof, both of them would short out. Spend a bunch of money on new ones, solder them in, and thinking you've got all the problems taken care of, and then you plug it in and again, poof, another $40 or more bucks down the drain. And besides that, only the exact original Sony SG613s would work. Some other manufacturers (including ECG) made copies of them, and if they worked at all, they only lasted for at the most a month or two. Most TV repair guys tried to avoid those sets like the plague. I had one here that was working beautiful, and then it lost the picture due to an open transformer providing filament voltage to the CRT. Disconnected the leads to the filament and supplied filament voltage from an external supply, and had a great picture. Tilted the boards back into place, and a connection or something either shorted or broke loose, and yes, poof, the SG613s were history. Never the less the set got junked out.
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  #19  
Old 01-22-2015, 10:20 AM
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Zenith26kc20 Zenith26kc20 is offline
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The rotary VHF tuners that used conductive paint (like the stuff used on remote buttons) instead of metal contacts. The local tuner rebuilder hated working on them. He would bend the contact fingers to a spot that wasn't worn. And all of the contact area was covered by a white round piece of plastic, forcing the rebuilder to disassemble the entire horror!
Ball Grid Array ICs! JUNK!
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  #20  
Old 01-22-2015, 11:23 AM
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Findm-Keepm Findm-Keepm is offline
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Quote:
Originally Posted by walterbeers View Post
Sony color trinitron sets made in the 80s that used the SG613 switching triac
Um, they stopped using SG-613 and SG-264 Silicon Controlled Switches in 1978. After that, conventional transistor deflection with 2SC1116s and those funky TX-series transistors...

We had very little trouble with them - the trick was to replace the (leaky) SID30-15 (GH3F) diodes, and check all the sub-10K carbon resistors in the gate circuit for opens. You also had to check for a presence of the drive signal to the gate - some CX-numbered chip provided it, and without it, you'd eat the SG-613, as the SG-613 would be on all the time. Most of the sets we saw were lightning strike sets.

We bought SG-613's direct from Sony National parts, as they had improved the SG-613 to the SG613-A (marked with an A below the SG613). The ECG276 replacements were remarked non-improved SG-613s, and would fail with certainty.
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  #21  
Old 01-22-2015, 11:28 AM
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Quote:
Originally Posted by Zenith26kc20 View Post
The rotary VHF tuners that used conductive paint (like the stuff used on remote buttons) instead of metal contacts. The local tuner rebuilder hated working on them. He would bend the contact fingers to a spot that wasn't worn. And all of the contact area was covered by a white round piece of plastic, forcing the rebuilder to disassemble the entire horror!
Ball Grid Array ICs! JUNK!
Ugh, how I hated those tuners! Printed tuner stator contacts, and limited life. Korean sets had them, and we saved every Japanese tuner to replace them - the little Sanyo and Hitachi BW sets had tuners that were solid. PTS had a universal DIN tuner that would work, but it was 24 bucks - too much to use a replacement.
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