Need some advice please(7704A)

[jolphil]

Hi All,
This is my first post to this group so i hope you will bear with me..
I recently purchased a Tek 7704A scope(embarrasingly cheap)...The only
problem was that it was not working..Having used tek scopes many many
years ago I decided to attempt the repair..Found a shorted cap in the
+17 volts source..Fixed that only to discover a week later that the
power supply would turn on then go off about once a second.."Months"
later fixed that...Now(finally) to the problem..
This scope has the7B53A Horiz time base,a 7A18A Vert plug in,and a
7A26 vert plug in...This scope deserved better treatment than it got
through the years..Broken mode Knob on the 7A18A PI and the lower BNC
probe connector broken on the 7A26 PI.. I have located a Mode knob but
the BNC connector puzzles me..Looks like it is a special isolated type
that I have not seen online..I do not have the service manual for the
PI so i do not have a part number..Can anyone shed some light as to if
the BNC is available online or if someone has one laying around that
wishes to sell one..Any help will be appreciated..Thank you for
reading this long rambling
post..J Phillips

 

[Jim Muehlberg]

jolphil wrote:

Hi All,
This is my first post to this group so i hope you will bear with me..
I recently purchased a Tek 7704A scope(embarrasingly cheap)...The only
problem was that it was not working..Having used tek scopes many many
years ago I decided to attempt the repair..Found a shorted cap in the
+17 volts source..Fixed that only to discover a week later that the
power supply would turn on then go off about once a second.."Months"
later fixed that...Now(finally) to the problem..
This scope has the7B53A Horiz time base,a 7A18A Vert plug in,and a
7A26 vert plug in...This scope deserved better treatment than it got
through the years..Broken mode Knob on the 7A18A PI and the lower BNC
probe connector broken on the 7A26 PI.. I have located a Mode knob but
the BNC connector puzzles me..Looks like it is a special isolated type
that I have not seen online..I do not have the service manual for the
PI so i do not have a part number..Can anyone shed some light as to if
the BNC is available online or if someone has one laying around that
wishes to sell one..Any help will be appreciated..Thank you for
reading this long rambling
post..J Phillips

Ebay is full of 7xxx modules... just get one for parts! (sounds like you
need 'em!) I bought a 7A26 for not much money....

good luck!


--
Jim Muehlberg
Electrical Engineer
LO/IF Group
National Radio Astronomy Observatory
P.O. Box O
1003 Lopezville Rd.
Socorro, NM 87801
P: 505-835-7140/7195
F: 505-835-7027
http://www.aoc.nrao.edu/~jmuehlbe



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[jolphil]

Jim Muehlberg <jmuehlberg@ieee.org> wrote in message news:<3f27d4b1$1_2@corp.newsgroups.com>...

jolphil wrote:
Hi All,
This is my first post to this group so i hope you will bear with me..
I recently purchased a Tek 7704A scope(embarrasingly cheap)...The only
problem was that it was not working..Having used tek scopes many many
years ago I decided to attempt the repair..Found a shorted cap in the
+17 volts source..Fixed that only to discover a week later that the
power supply would turn on then go off about once a second.."Months"
later fixed that...Now(finally) to the problem..
This scope has the7B53A Horiz time base,a 7A18A Vert plug in,and a
7A26 vert plug in...This scope deserved better treatment than it got
through the years..Broken mode Knob on the 7A18A PI and the lower BNC
probe connector broken on the 7A26 PI.. I have located a Mode knob but
the BNC connector puzzles me..Looks like it is a special isolated type
that I have not seen online..I do not have the service manual for the
PI so i do not have a part number..Can anyone shed some light as to if
the BNC is available online or if someone has one laying around that
wishes to sell one..Any help will be appreciated..Thank you for
reading this long rambling
post..J Phillips

Ebay is full of 7xxx modules... just get one for parts! (sounds like you
need 'em!) I bought a 7A26 for not much money....

good luck!


--
Jim Muehlberg
Electrical Engineer
LO/IF Group
National Radio Astronomy Observatory
P.O. Box O
1003 Lopezville Rd.
Socorro, NM 87801
P: 505-835-7140/7195
F: 505-835-7027
http://www.aoc.nrao.edu/~jmuehlbe



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-----== Over 80,000 Newsgroups - 16 Different Servers! =-----

Thanks Jim for the response,
That may be the only way I can find the part..Since you have the
7a26 would you by chance have the PN of the BNC ??
Thanks again
J Phillips

 

[jolphil]

Jim Yanik <jyanik@nullkua.net> wrote in message news:<Xns93C8E51AAE31Bjyanikkuanet@204.117.192.21>...

jolphil@hotmail.com (jolphil) wrote in
news:6327e639.0307301127.360541b1@posting.google.com:




Thanks Jim for the response,
That may be the only way I can find the part..Since you have the
7a26 would you by chance have the PN of the BNC ??
Thanks again
J Phillips


131-0679-02,if my sometimes faulty memory serves me. I'm not sure if TEK
still sells these as they are for items no longer supported.The BNC has a
ring for 10X probe ID.

BTW,the 7B53A is not perfectly compatible with the 7704A,due to delay line
length and 7B53A triggering,the leading edge of fast pulses cannot be
displayed.

Ahhh!
Thanks for the Part number..At least I'll know what I am looking for..
It may well be that I'll have to buy a "not working" amp to get the
BNC..
I looked online and cannot find one with the probe ring..I understand
what you mean about the delay line but will not use the scope for such
fast pulses..
Heck, Im just glad to get it working..
Thanks again
JP