A few things with the usual IIRC's & IMHO's.
Only remember 2 kinds of the big xtals one had a third
ground wire soldered to the case. All 2 legged ones were
the same, even sold under ECG. They did go bad more often
than components.

If you have sets infested with 6GH8's you need to keep some
NOS BRAND NAME ( no rat shack) ones around. They are also very touchy
as to the circuit they are in. They can work fine as a sync
separator but not work for color osc as an example. If you
shuffle them around usually you will change symptoms.
They were so bad that we bought them by the gross 2-3
times a year for 29 cents.
I could tell you more stories abt 5 & 6GH8's.....

Most coils in TV's never even need tweaking. If you do it
put a flag on the tool. This way you can put it back where it
was. Count & write down & keep the note. I used to note it
on the slip " L703 3/4 CCW" if it came back again I could go
back & find the problem.

For your problem your freq is way off so start with 6GH8,
several if used even from a known working set. Next the
xtal. Then easy voltage & resistance checks. After that
caps one at a time ! But thats me...........

73 Zeno:smoke:

I saw a comment on your youtube channel in regards to your sylvania. Some guy wrote "i live in NY and never see these kinds of sets for sale."

oh, the irony.

For any color sync issue, i would also routinely sub the burst amp with a known good one (6EW6, IIRC).

For the heck of it, check L702 (reactance coil) for continuity. Back in the day, i do remember a few instances of that coil being open.
The chroma circuitry here is common to CTC-15, '16, '17, '25 and their clones.

The color stripes will stay with the grid grounded.

Do not adjust T703 at this time.
If you get the color to sync but can't get a good flesh tone at the center of the tint/hue control we can address that issue then.

not sure what may have done it, i pulled the power booster, let the set for the first time for more than an hour, had it running for almost three hours, then played with the tone and color controls.

She finally locked color. Clearly she could use a recap still, but for the time being i'm calling this done.

Now to get on the rca roundie combo, and my 300 lb sylvania combo monster.

Power booster?? Are you talking about the CRT brightener? Removing the brightener will not help or hurt your color lock issue. Sounds like after a few hours of running, the heat buildup in there changed the value of something... cap, resistor, coil... maybe even caused a ground connection to make better contact.

Tomorrow, you may have to start all over again... take a few hours to lock.

At least now you know it WILL lock... it's just a matter of finding the part causing the problem. I think it's a cap or resistor changing value.

The 3.58 oscillator tube (V703) could still be borderline weak even if you've changed it. There's a 'quick and dirty' way of determining whether the tube is weak or not..
With the set fully warmed up and the color in-lock, turn the set off for about 7 seconds and then back on. Is the color still in sync? If so, the tube is good. Or is it back to stripes, taking a while to re-acquire lock? If the latter, the tube is borderline.

(This method can also reveal a borderline hor. osc tube, osc/mixer tube in the tuner, etc.)

have swapped out several tubes in the color circuit no major difference.

Good.
Make the adjustment anyway. You won't screw anything up.
Are you getting flesh tone at mid-range on tint control? (on a live broadcast)
Phil

Another thing that can happen is with a set sitting unused and/or in an unconditioned place for a long time, moisture can creep into coils, etc. and throw off proper operation. Heat from operation can dry that out. Also you can put a light bulb inside the cabinet to maintain gentle heat for a few days to speed the process. Be sure to clean all tube pins and sockets, too, as contact can be "iffy."

I sure would not be in a hurry to adjust anything. Like Reece said, it needs to thoroughly dry out.

You may be seeing this in it's now locking.

Believe me, you will use the adjustment tools, eventually.

Back when I was in high school, we had ONE TV in the school, a big black and white table model, and every fall we had to turn it on during the World Series to drive out any moisture it might have accumulated during the summer. :D