sylvania gt matic

[DavGoodlin]

Originally Posted by wkand

Oil filled capacitor? Did i read that right? Is it also considered electrolytic?

Oil-filled is an AC-rated capacitor in a round or oval can with push-on terminals, normally 2-15 mfd used for motor-starting applications. Definitely not an electrolytic.

Zenith CCII sets also used them. I need to look up a 17EC45 schematic to see how it was applied.

Edit: I have a Zenith training binder (the casettes are gone) showing the power supply and explained the function of C213, aka oil-filled cap (remember, its not PCB oil, so it may be flammable) It was explained in this book to wit:
The capacitor is across the entire power transformer secondary. It is tuned to resonate at 60 Hz, thereby increasing the secondary voltage and saturating the secondary winding. This effectively isolates voltage variations on the primary from being proportionately induced in the secondary winding. The pass regulator transistors further this advantage.

I can attest to this feature as I knew folks on rural fringes of electric utility lines whose Zenith CCIIs performed well despite the voltage sags, which showed obviously with dimming incandescent lamps and shrinking vertical and horizontal on most other sets, notably series-string tube sets.

[zeno]

On its own winding that is part of the main B+ windings.
The "ends" IIRC. If it goes short will pop main breaker / fuse.
If opens pix will be unstable & pulsate. If good the sets
that use it will run apx 85-140VAC normally. Dont change it on
a re-cap. In fact dont recap this set ! Bad idea.....

GT-Matics were the first sets to use a master h/v osc.
It eliminates H&V hold & became industry standard. Came in
13", 17"IIRC, 19" & 25". 19 & 25' that used the 3 board chassis
had short lived CRT's. The key came with all sets but a
screwdriver worked fine. The "dark lite" CRT's could give a
spectacular pix with totally black blacks, not grays. Well built
but not quite Zenith or RCA PCB quality. Enjoyed by all
the techs I knew.

73 Zeno

Originally Posted by DavGoodlin

Oil-filled is an AC-rated capacitor in a round or oval can with push-on terminals, normally 2-15 mfd used for motor-starting applications. Definitely not an electrolytic.

Zenith CCII sets also used them. I need to look up a 17EC45 schematic to see how it was applied.