tektronix 465b problem

[jsblues81]

My 465b has the following problem...the waveform is reduced with the waveform in from the left side of the screen (it doesnt stretch across the screen from end to end) it starts and end never reaching the far left and far right of the screen. As if it was displayed on a smaller screen than the one its currently on. I hope I explained that right...any ideas...the -2450v is ok.

[tggzzz]

My 465b has the following problem...the waveform is reduced with the waveform in from the left side of the screen (it doesnt stretch across the screen from end to end) it starts and end never reaching the far left and far right of the screen. As if it was displayed on a smaller screen than the one its currently on. I hope I explained that right...any ideas...the -2450v is ok.

Insufficient information.

How much experience with scopes do you have?

Is this a change?

Can you use any controls to move the beam to the left/right/top/bottom of the CRT?

Picture of screen plus control settings would be sensible.

[jsblues81]

I am a trained electronic tech with experience of over 50 yrs...I have serviced scopes both vacuum tube ,analog and digital for many years...as far as the controls...no the waveform do not reach the far left or right horozontaly but vertically it goes all the way up or down. The horz sweep is fine and matches perfectly with another unit I have that functions perfectly. I'm beginning to think there is an issue with either a dirty trimmer or worse, the hv anode supply. I will post a screenshot soon.

[tggzzz]

I am a trained electronic tech with experience of over 50 yrs...I have serviced scopes both vacuum tube ,analog and digital for many years...as far as the controls...no the waveform do not reach the far left or right horozontaly but vertically it goes all the way up or down. The horz sweep is fine and matches perfectly with another unit I have that functions perfectly. I'm beginning to think there is an issue with either a dirty trimmer or worse, the hv anode supply. I will post a screenshot soon.

That's a more useful characterisation of the situation.

I presume the vertical deflection is roughly correct, since you don't mention anything to the contrary.

I presume all the PSU voltages are correct, since you don't mention anything to the contrary.

Since the beam can reach the top and bottom of the screen I doubt it is the HV supply.

In that case it is only the horizontal calibration that is faulty. Follow the procedures on p4-53 of the service manual.

[jsblues81]

I'm sure you are not far off. Yes all pwr supplies are perfect. I scoped tp4217 on the horz crt circuit and the waveform ( a 50% duty cycle square wave) on the working unit is not the same on the unit in question. It has approx 2x the repetition rate, is lower in amplitude by half and the DC levels are smaller...by about half. I tried to photograph the waveforms but the freq caused the waveform to flash and I couldnt get a proper shot. Here however is screenshots of what the problem looks like...hope this helps.