Admiral 19A1-S-A troubles

[robert1]

Hi All. i did a recap on this Admiral 19A1-S-A set. i also checked every resistor that i could think of that would cause this trouble & i did not find any resistors that had drifted to affect the horizontal osc circuit like this.



would the horizontal blocking transformer cause this? HV Transformer?
the horizontal hold control just makes the picture narrower.

i do not have a working scope here at this time. i am just wondering if anybody else here seen this problem with this particular chassis.
thanks

[Kamakiri]

I've been through hell and back on that chassis

Horizontal sweep transformer is suspect. Sams says 50 ohms primary, 150 ohms secondary. It shows the same part number is used for both horizontal and vertical transformers, which makes things easy to compare.

EDIT: Be very careful when moving the leads around on these transformers. They tend to be brittle, and can go open if you look at them the wrong way.

[timmy]

possible mica cap in the yoke ?

[Kamakiri]

It's an electrostatic 7" set....there is no yoke on this model....

[Notimetolooz]

Do you have a video signal going in? I kind of looks like video is mixed into the horizontal sweep.

[robert1]

Originally Posted by Kamakiri

I've been through hell and back on that chassis

Horizontal sweep transformer is suspect. Sams says 50 ohms primary, 150 ohms secondary. It shows the same part number is used for both horizontal and vertical transformers, which makes things easy to compare.

You would not by chance mean the Horizontal blocking transformer T4 (the one that looks like a large I.F. can located next to the horizontal oscillator tube (v-12b 6SN7).

i did notice that i am getting some wrong voltages on a couple of the pins on that section of the horizontal osc tube. however, all i have got to work with is the ryders schematic that i downloaded from the E.T.F site & there are some descrepancies with that schematic & this particular admiral model.

if it turns out that the problem is that transformer, where can i find one.

[robert1]

Originally Posted by Notimetolooz

Do you have a video signal going in? I kind of looks like video is mixed into the horizontal sweep.

yes, i do have the cable connected to the antenna input. it also has good sound.
funny though when i disconnect the cable input, the set shows a blank raster.

[robert1]

i will get more pics of this tonight as well as some voltage readings in the horizontal oscillator circuit.

[Kamakiri]

Originally Posted by robert1

You would not by chance mean the Horizontal blocking transformer T4 (the one that looks like a large I.F. can located next to the horizontal oscillator tube (v-12b 6SN7).

i did notice that i am getting some wrong voltages on a couple of the pins on that section of the horizontal osc tube. however, all i have got to work with is the ryders schematic that i downloaded from the E.T.F site & there are some descrepancies with that schematic & this particular admiral model.

if it turns out that the problem is that transformer, where can i find one.

Nope, I believe it's T2, at least in the Sams. Here's what mine looked like with a bad T2. Look familiar?

If you have the chassis sitting on its side with the underneath facing you, and the picture tube facing left, the transformer will be just below the chassis cutout for the picture tube, on the left side of center down low.

[Kamakiri]

Originally Posted by robert1

i did notice that i am getting some wrong voltages on a couple of the pins on that section of the horizontal osc tube. however, all i have got to work with is the ryders schematic that i downloaded from the E.T.F site & there are some descrepancies with that schematic & this particular admiral model.

I hate Riders anything, but that's me

Try this.

http://www.earlytelevision.org/pdf/A...-sams-59-2.pdf

[Notimetolooz]

Originally Posted by robert1

yes, i do have the cable connected to the antenna input. it also has good sound.
funny though when i disconnect the cable input, the set shows a blank raster.

Do you mean it has a rectangular raster with no video in? If so, maybe the SYNC. SEP. circuit is passing video to the horizontal section. Can you put a scope on the horizontal sync input to the oscillator? You should just see pulses there. That would be pin 2 of V13 in Sams.