Motorola ts907 low hv

[Yamamaya42]

Originally Posted by timmy

Maybe this helps about this dvm

but it does not say 10m impedance.
that is the important difference here, and why it can give faulty readings for some tube measurements.

https://xdevs.com/doc/Fluke/FLUKE%20...%20Service.pdf

note page 12 of this manual above.

input impedance
this is critical.

[timmy]

The link for Amazon I can’t get it says there’s a problem can you send they link again maybe it will work

[timmy]

Or the model number and I can look it up in Amazon

[Yamamaya42]

Originally Posted by timmy

or the model number and i can look it up in amazon

msr-r500 MSR-A600 i have both

[timmy]

Msr - r500 is the one that is 10m impedance because it don’t say or show that I can find

[Yamamaya42]

jr_tech also has it, and he did the input impedance test on it, and it was 10m.

it a rather complicated thing to do with a voltage source and a 2nd DVM.

most DVMs of this type are, but most clamp meters are 1m.

[timmy]

So the msr- r500 is the one to grab

[timmy]

I guess that would explain why when I touch the probe I see a little tiny spark.

[Yamamaya42]

Originally Posted by timmy

I guess that would explain why when I touch the probe I see a little tiny spark.

It's almost like adding an extra resistor to ground.

[timmy]

Well I don’t know how much this meter was affecting the voltage outcome a guess maybe 10-12 volts lower then what it is normally.

[timmy]

Ever since I accidentally let the hot red plate for like 40 seconds this is what I’m left with. Does this look like a bad damper. I am going to try a damper but I have both boost voltages so what’s this it looks like a bar generator but it’s not. Stumped again.

[timmy]

Already tried 2 new horizontal output tubes of course no change. One thing after another. So I need to find out what gives up when these tubes red plate to long.

[Yamamaya42]

A weak damper can cause low HV & insufficient horizontal width, but can also be a symptom of the horizontal osc being at the wrong freq, or a damaged HOT.

A new damper is a rather low cost first step in working out the problem.

[timmy]

Originally Posted by Yamamaya42

A weak damper can cause low HV & insufficient horizontal width, but can also be a symptom of the horizontal osc being at the wrong freq, or a damaged HOT.

A new damper is a rather low cost first step in working out the problem.

So if the frequency is low then that’s why the bars are there and are you referring to hot as tube or flyback. I have 2 new dampers coming tomorrow.

[Yamamaya42]

HOT = horizontal output tube FBT = flyback transformer.

Wait till you get the new damper, then once again do the setup for direct video input at test point B, and then adjust horizontal hold to try to get lock, once you get lock, there should be no need to adjust it again.