View Single Post
Old 25th Jun 2013, 8:46 pm   #1
davidgem1406
Heptode
 
davidgem1406's Avatar
 
Join Date: Feb 2011
Location: Sheerness, Kent, UK.
Posts: 936
Default Tektronix 465B Scope - Some problems.

I have recently acquired a Tektronix 465B scope. Although it is in working order on running it and making some checks I have found some problems.

I will run through them, also there are pictures for all but one item.

1/. Not a fault really but something that threw me until I read the service manual. Although the vertical Volts/Div switches are marked up to 50V per Div the 3 top ranges 10, 20 & 50 V/Div are not usable. The switches do not rotate any further than the 5V/Div position. I found that rather strange, why mark them up to 50V/Div? (Image 002)

2/. The two traces are fuzzy with the Astig and Focus controls set to their best positions. Image 001)

3/. With a slow timebase it can be seen that the spot is distorted. The Focus and Astig controls change the shape of the spot more than focus it. (Images 3 & 3a)

4/. With an input signal to the vertical inputs the fuzzy traces can clearly be seen. (Image 4)

5/. The effect of the Focus control shows distortion quite clearly. Rather more than just defocusing. (Images 5 & 5a)

6/. The beam find does not show a clean round spot, it shows a short line with distortion at the centre of the screen. (No Image)

I was wondering if I may have a dirty/faulty power supply?

Would be grateful if anybody could point me in any direction regarding the above faults.
Also of any known faults that I should look at.

I have the service manuals, but it would be good to have the operators manual if anybody knows where this may be found.

Thanks
Dave.
Attached Thumbnails
Click image for larger version

Name:	Image_001.jpg
Views:	419
Size:	35.0 KB
ID:	81206   Click image for larger version

Name:	Image_002.jpg
Views:	1915
Size:	35.3 KB
ID:	81207   Click image for larger version

Name:	Image_003.jpg
Views:	400
Size:	34.1 KB
ID:	81208   Click image for larger version

Name:	Image_003a.jpg
Views:	377
Size:	35.0 KB
ID:	81209  
davidgem1406 is offline