Back to the VT-71H

[timmy]

Originally Posted by bandersen

've restored a couple TS-4H and took a bunch of reference photos. Which tube and which pin are you referring to?

There’s nothing in particular just some areas are not what the schematic shows compared to an area that was not touched, it’s odd.

[Chris K]

In other words…strangeness and oddities but not from what Chris did!!!

[Yamamaya42]

Originally Posted by Chris K

In other words…strangeness and oddities but not from what Chris did!!!

Strangeness and oddness = referring to yourself in the third person!

[bandersen]

Are you using the original Motorola service info? It's very accurate.

[Chris K]

Originally Posted by Yamamaya42

Strangeness and oddness = referring to yourself in the third person!

Who him? I mean who me? I mean…?????

[timmy]

Using the Motorola schematic and the power supply shows b+ 150v and b++ 300v however all that’s there is 276v and 111v so this low b+ could be the reason why the vertical and horizontal seems to be fighting each other at least that’s what it looks like on the screen. The first and second clipper has 2 pins looks like 2&6 that b+ feeds but it’s to low so hot to find out why and it looks like either something in the ballast or a defective power supply cap that feeds the b+.

[Electronic M]

Originally Posted by Chris K

In other words…strangeness and oddities but not from what Chris did!!!

Motorola shared engineering between divisions, so the average Moto TV is part car radio (look at the UHF presets on a late 60s-mid 70s color set and a period car radio if you doubt me), part mobile communications reciever, part TV in the design approach...

[timmy]

I’m getting schematic fog if someone has a ts-4h I cannot find r80 E on the ballast pins 6&8 omg lol.

[Yamamaya42]

Originally Posted by timmy

I’m getting schematic fog if someone has a ts-4h I cannot find r80 E on the ballast pins 6&8 omg lol.

junction of V7 & V15 at the bottom of the VERY blurry Moto schematic, has a clear arrow for gnd.

[bandersen]

Originally Posted by timmy

I’m getting schematic fog if someone has a ts-4h I cannot find r80 E on the ballast pins 6&8 omg lol.

It is not present. The TS-4H does not use that section of the ballast.

Seems like something is dragging the supply voltage down. Probably why the ballast is hot.

[timmy]

Originally Posted by Yamamaya42

junction of V7 & V15 at the bottom of the VERY blurry Moto schematic, has a clear arrow for gnd.

I can’t find it anywhere.

[timmy]

Originally Posted by bandersen

It is not present. The TS-4H does not use that section of the ballast.

Seems like something is dragging the supply voltage down. Probably why the ballast is hot.

Why would it be shown on the ballast if it’s not in the circuit? I am putting a ballast together with resistors to rule out any trouble with the one in there now. So only 8-6 is not used?

[Yamamaya42]

I can see it on the schematic, but Bob just stated that it's not wired into this version. so if you are looking for it in the set, it's not there! :O

[Yamamaya42]

There are many revisions shown in the moto service manual, I'm not sure, but the one for this set may be on page 103, all seem to have the same ballast, but page 103 shows that part NOT being used.

[Yamamaya42]

I see what's going on here, it states in the table of contents that this moto service manual only covers up to TS-4D, therefore changes made on TS-4H won't be in there.

You will have to be very careful going forward with this.