Help wanted with TEK 2445 oscilloscope

[Mike Henry]

Hi all,

I bought 3 'used' TEK 2445 scopes ($60 for all) from a local company that
just wanted to clear some space in their warehouse. I was able to get two
of them up and running by swapping some of the components that were damaged.
The third was obviously dropped against the HIGH voltage board that drives
the CRT. Both power up fine now, and one seems to be working just fine.
The second one gives a strange output with nothing connected to it. The
trace seems Ok near 0 on the vertical scale, but if I adjust the vertical
position, the trace get wide, and will trigger a sawtooth profile. The
amplitude for this profile gets larger the further away form 0 I get. It is
too repeatable for noise. Is there an adjustment for this? Or is it a bad
component/board? Any help would be appreciated.

This link connects to Snapfish screen shot photos.
http://www2.snapfish.com/thumbnailshare/AlbumID=239706448/a=114757653/t_=114757653

02 is No signal connected to Ch 2 - V pos centered
01 is No signal connected to Ch 2 - V pos up max
04 is No signal connected to Ch 2 - V pos down half
03 is No signal connected to Ch 2 - V pos down max
00 is Ch 2 - calibration signal

I'm also curious what value it is to have them "calibrated". There is a
local shop that will do it for $110. Any thoughts?

I know the HV dangers that are posed inside the scope and take all
precautions to prevent electric shock.

Thanks in advance for your help.

Mike Henry

 

[Mike Henry]

Here is Flickr pix in case you don't have Snapfish acct.

http://www.flickr.com/photos/15503604@N06/?saved=1

 

[Cees Keyer]

Hi all,

I bought 3 'used' TEK 2445 scopes ($60 for all) from a local company that
just wanted to clear some space in their warehouse. I was able to get two
of them up and running by swapping some of the components that were damaged.
The third was obviously dropped against the HIGH voltage board that drives
the CRT. Both power up fine now, and one seems to be working just fine.
The second one gives a strange output with nothing connected to it. The
trace seems Ok near 0 on the vertical scale, but if I adjust the vertical
position, the trace get wide, and will trigger a sawtooth profile. The
amplitude for this profile gets larger the further away form 0 I get. It is
too repeatable for noise. Is there an adjustment for this? Or is it a bad
component/board? Any help would be appreciated.

This link connects to Snapfish screen shot photos.
http://www2.snapfish.com/thumbnailshare/AlbumID=239706448/a=114757653/t_=114757653

02 is No signal connected to Ch 2 - V pos centered
01 is No signal connected to Ch 2 - V pos up max
04 is No signal connected to Ch 2 - V pos down half
03 is No signal connected to Ch 2 - V pos down max
00 is Ch 2 - calibration signal

I'm also curious what value it is to have them "calibrated". There is a
local shop that will do it for $110. Any thoughts?

I know the HV dangers that are posed inside the scope and take all
precautions to prevent electric shock.

Thanks in advance for your help.

Mike Henry

Try the tek scopes group on Yahoo...
TekScopes2 in yahoogroups.com