My Brand New CTC-7!

[SwizzyMan]

OK adjusted T704 and it looks great. I still need to do some convergence adjustments. Here is a picture of what I have now. Is there any problems with any of the bars to any of you?

[SwizzyMan]

One more thing. Would it be a bad idea to use this as my daily watcher? All guns test great and the life test is good.

[roundscreen]

Originally Posted by SwizzyMan

One more thing. Would it be a bad idea to use this as my daily watcher? All guns test great and the life test is good.

You should be able to use the set. Keep a eye on the line voltage. This set was designed to run on 117v ac. and you DO NOT want to run the set any higher than 117v ac. It can cause problems with the horz circuit and burn out tubes.

[MRX37]

Originally Posted by SwizzyMan

OK adjusted T704 and it looks great. I still need to do some convergence adjustments. Here is a picture of what I have now. Is there any problems with any of the bars to any of you?

image looks really tilted. Perhaps adjust the yoke?

[Phil Nelson]

Those are good color bars.

Before messing with convergence, I'd look at a crosshatch test pattern (or dot pattern) to judge whether it really needs improvement. Read about convergence in the manuals. Convergence is a multi-step procedure, not just one little tweak. On a color "roundie," it's difficult to get perfect convergence around the edges of the screen.

You can also look at regular programming to judge convergence. Look at the edge areas of the screen -- left, right, top, bottom -- and note whether there is "color fringing" around the edges of objects. This may be more obvious where there's lettering on the screen.

Some small amount of mis-convergence is pretty common in my experience. Ask yourself if your picture would bother you in everyday watching. If the answer is "not really," you could skip convergence for the time being. If your convergence is already pretty good, and you screw it up with hasty adjustments, it could be hard to make it that good again.

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

[roundscreen]

Here is a picture of my variac. This unit is 20 yo and is rated at 10 amps.

[SwizzyMan]

I really dont have the money for a variac. Is there any other possible alternatives?

[roundscreen]

Originally Posted by SwizzyMan

I really dont have the money for a variac. Is there any other possible alternatives?

A thermistor surge resistor on one side of the ac line would help. but you really need a variac. It is as important as a volt meter when working on vintage tv.

[SwizzyMan]

Hmmm, OK I will try to find a cheap variac. Does anyone here have a variac I could take off their hands?

[Electronic M]

I've been running a CTC-15 clone as a daily driver straight from the line for about 5 years. The first two were in an area where the line voltage ran high probably 120-125, since then it is usually 117 give or take 6 volts. I've never had a problem with the fly going into over-current....Granted I did monitor and dip the cathode current by adjusting the linearity coil (which is probably a better way to control it than a variac).

If you are worried about overheating the fly adjust the lin. coil for min H out Tube cathode current and leave the HV cage door open for ventilation.

[SwizzyMan]

I dont see a linearity coil but I do see a horizontal efficiency coil that looks like it is connected to pin 3 which is the cathode on the H out tube. Should I adjust that one?

[roundscreen]

Originally Posted by Electronic M

I've been running a CTC-15 clone as a daily driver straight from the line for about 5 years. The first two were in an area where the line voltage ran high probably 120-125, since then it is usually 117 give or take 6 volts. I've never had a problem with the fly going into over-current....Granted I did monitor and dip the cathode current by adjusting the linearity coil (which is probably a better way to control it than a variac).

If you are worried about overheating the fly adjust the lin. coil for min H out Tube cathode current and leave the HV cage door open for ventilation.

You are right. The cathode current must be adjusted for proper dip. If this is not done, The current will run high no matter what the line voltage is. Still, Why beat on the set if you don't have too. He want's to use the set as a daily driver and the variac will give him some added protection. Running the set at the line voltage it is rated at.

[Electronic M]

It is labeled Horizontal efficiency in some sets, H linearity in others. Sams horizontal adjustment procedure and schematic should list max safe current and how to adjust....Skip the osc. adjustment and the more complex HV reg adjustments unless the current can't be reduced, or those stages show signs of misadjustment.

Originally Posted by roundscreen

You are right. The cathode current must be adjusted for proper dip. If this is not done, The current will run high no matter what the line voltage is. Still, Why beat on the set if you don't have too. He want's to use the set as a daily driver and the variac will give him some added protection. Running the set at the line voltage it is rated at.

I'm not telling him to beat up his set, just noting my observation that MY set that has been in regular often heavy use since I restored it has done fine without any line input voltage control....Heck the cathode current was running WELL below the max safe value when adjusted running on high line voltage.

In many places the line voltage fluctuates so if you truly want to get OCD on line voltage get a VRT/saturable reactor/(insert other aliases for it here) isolation transformer that puts out a constant 120V, and buck that down......
I've been approaching that setup recently. The place I've lived in for the last few years has intermittent sudden brief and rapidly reoccurring voltage dips that cause highly annoying blooming. I've been using a 120V out VRT to regulate out these dips, and on the '71 Zenith I've been using it on I've been contemplating using a variac or bucking transformer with it so I can dial in the vertical over scan to minimum.

IMHO the best way to power a low voltage DC fan in a TV set is to connect a bridge rectifier to the heaters and a filter cap to the bridge. Then depending on the DC voltage it puts out how quiet the fan needs to be and the air flow desired select either a 5 or 12V fan.

[SwizzyMan]

Going to just try a bucking transformer. My AC is stable at 120.6v and rarely moves down a volt. What exact transformer should I get for the bucking transformer? I thought I heard a 2.2kva one was right? Also planning on refinishing the cabinet on Sunday after I build the bucking transformer Saturday.

[SwizzyMan]

Would this one work? Secondary out is 10v so If I buck it the output will be 110v right? Or is that too low or am I wrong about my theory? http://www.skycraftsurplus.com/f6-10...vct120pri.aspx