Tech-Master NIB TV Kit #5516

[Crist Rigott]

Originally Posted by tom.j.fla

Yes I do have a T-M 5516 and it has a 17 inch CRT. All the best,Tom.J

Way cool!

I gotta see pictures!

[Crist Rigott]

I added the extra 220uf e-caps, on each to C44A and C44B. The picture seems more stable now.

I spent a little time centering the picture and adjusting the height and Vert. Lin and here is the picture a scene from Veggietales.

Seems pretty good. The width is much too wide even though at very near the end of the adjustment. Any ideas as to what can be done to shrink it some like change a cap or such.

[Crist Rigott]

Originally Posted by tom.j.fla

Yes I do have a T-M 5516 and it has a 17 inch CRT. All the best,Tom.J

Tom,
What is the number of the CRT? I have a list of typo errors and such I'll have to provide you. The TV essentially played right off the bat.

[tom.j.fla]

You can drop the screen voltage on the 25DN6 horz. tube to get the width under control. Don't have any way to take pics at this time, just coal in my stocking this year(lol). Don't have the CRT number at hand will have to get set out of storage to find out. All the best,Tom.J

[EdKozk2]

Great Job Crist
I noticed you used that black foam under the CRT. I used something just like that on the bottom of a Motorola VT-71 set a couple of months ago. After about 2 weeks of weight on it, about 25 pounds it flattened out. It lost almost all of it's ability to cushion the set. I ended up using heavy felt pads instead. I brought this up because I didn't want your CRT to get real loose in the tension strap.
Ed

[Crist Rigott]

Originally Posted by EdKozk2

Great Job Crist
I noticed you used that black foam under the CRT. I used something just like that on the bottom of a Motorola VT-71 set a couple of months ago. After about 2 weeks of weight on it, about 25 pounds it flattened out. It lost almost all of it's ability to cushion the set. I ended up using heavy felt pads instead. I brought this up because I didn't want your CRT to get real loose in the tension strap.
Ed

Thanks ED, I'll keep an eye on it.

[Crist Rigott]

Originally Posted by tom.j.fla

You can drop the screen voltage on the 25DN6 horz. tube to get the width under control. Don't have any way to take pics at this time, just coal in my stocking this year(lol). Don't have the CRT number at hand will have to get set out of storage to find out. All the best,Tom.J

Tom,
I increased R63 (pin 8 of the 25DN6) to 6.8K and it finally made a difference in width, however my HV went from 13.5Kv to 10Kv. That won't work. Did I get the right resistor?

[old_coot88]

You got the right resistor. If the width control (L17) doesn't help, there's something called a width sleeve that some sets actually came equipped with. It's basically a thin sheet (almost a foil) of brass or copper that's rolled into a cylinder and slipped partway into the yoke. You adjust the depth of insertion for width. Of course it needs to have an insulating coating so it doesn't short to the yoke windings. Some of the gurus on here can tell you more about width sleeves.

[Electronic M]

The sleeve is probably the only way to further change the width without reducing HV.

Part of me wonders if this set would benefit from a HV doubler circuit.

[Crist Rigott]

Originally Posted by Electronic M

The sleeve is probably the only way to further change the width without reducing HV.

Part of me wonders if this set would benefit from a HV doubler circuit.

Could you go into more detail as to a "HV Doubler" circuit? Thanks.

[tom.j.fla]

Crist, the crt in my set is a 17HP4 "C" as labeled by the rebuilder, most likely to show that the jug has a straight gun. Old_coot88 is correct that a width sleeve is needed to control the width on your set. The brass or copper is 1/2 to 3/4 the dia. of the neck and is sealed in thin sheet hi-temp plastic. Try to find a sleeve from a junker or make one. All the best,Tom.J

[old_coot88]

I've never done it, but wonder why not put a low resistance in series with the horiz yoke winding? Maybe try 20 ohms and go from there..? Seems like it wouldn't screw with the resonant point of the HV systen enuff to matter.

[Kevin Kuehn]

Regarding your concern of not being able to duplicate your earlier focus problem - It's possible the internal electrode connected to pin 6 is retaining a charge(because of capacitance) even after you remove the wire.

[Electronic M]

Originally Posted by Crist Rigott

Could you go into more detail as to a "HV Doubler" circuit? Thanks.

See the 3 HV rects in this circuit? They constitute an HV trippler. Saw off the third HV rect tube (and everything right of the second HV rect), and you have an HV doubler.
http://www.earlytelevision.org/pdf/R...-Sams-90-9.pdf

There were also SS HV doublers, tripplers, and quadrupplers in 70's SS color sets that could be used if period correct look is not a concern.

Any doubler will increase load on the flyback and reduce width....Monitor H Out tube cathode current and flyback temperature over an extended test run and if it gets excessive power down and try something else.

Tube doublers will draw more power due to the tube heaters.

[dieseljeep]

Originally Posted by Crist Rigott

Tom,
I increased R63 (pin 8 of the 25DN6) to 6.8K and it finally made a difference in width, however my HV went from 13.5Kv to 10Kv. That won't work. Did I get the right resistor?

Increasing the screen resistor to 6.8K is way too much of an increase. Maybe a 1.5K or so. Try putting the 25CD6 back in.