| Author |
Message |
egb
Guest
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 Posted:
Wed Jan 26, 2005 9:55 pm Post subject:
Help w/Tektronix 7905 Oscilloscope |
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I pruchased a used, non-working 7905. Have almost everything fixed
except:
When increasing the trace brightness to an acceptable level there is a
halo present. It is not a uniform halo, but is displaced slightly up
and to the right of the trace, probably 20% brightness at normal
brightness of main trace.
The focus and astigmatism controls work properly.
Your help will be appreciated,
Thanks,
Emil
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egb
Guest
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| Posted:
Wed Jan 26, 2005 10:53 pm Post subject:
Re: Help w/Tektronix 7905 Oscilloscope |
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| Correction... Model # is 7904 |
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Dr. Anton T. Squeegee
Guest
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| Posted:
Thu Jan 27, 2005 11:29 am Post subject:
Re: Help w/Tektronix 7905 Oscilloscope |
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In article <1106758430.404787.102350@c13g2000cwb.googlegroups.com>,
eborys@martinauto.com says...
| Quote: | Correction... Model # is 7904
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Hate to be the harbinger of bad news, but I see two possibilities
here. First, a bad CRT.
Second, it is possible that the high voltage is up too high. You
may have a defect in the HV section.
There is a mailing list dedicated to Tektronix O-scopes out of
Yahoo. Google for 'TekScopes mailing list.'
I also maintain a Tektronix-dedicated forum, in the form of a
PHPBBS install, at http://tekboard.bluefeathertech.com
Happy hunting.
--
Dr. Anton T. Squeegee, Director, Dutch Surrealist Plumbing Institute.
(Known to some as Bruce Lane, ARS KC7GR,
kyrrin (a/t) bluefeathertech[d=o=t]calm -- www.bluefeathertech.com
"If Salvador Dali had owned a computer, would it have been equipped
with surreal ports?"
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tekamn
Guest
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| Posted:
Thu Jan 27, 2005 2:17 pm Post subject:
Re: Help w/Tektronix 7905 Oscilloscope |
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egb wrote:
| Quote: | Correction... Model # is 7904
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Seems that your scope's tube is at the end of it's useful life.
You should check first the voltages in the LV and HV powersupplies - in
case you don't have a service manual, download one (e.g.
www.teknetelectronics.com)
hth,
Andreas |
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egb
Guest
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| Posted:
Thu Jan 27, 2005 6:59 pm Post subject:
Re: Help w/Tektronix 7905 Oscilloscope |
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Good Doctor, thank you for your comments, suggestions, and links. I
shall continue the odyssey of the $39 scope this weekend.
Emil
W9NM |
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