Re: Oscope advice

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Jim Lux by way of Terry Fritz <teslalist-at-qwest-dot-net>" <jimlux-at-earthlink-dot-net>


----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Tuesday, August 12, 2003 9:54 PM
Subject: Re: Oscope advice


 > Original poster: "Chris Arnold by way of Terry Fritz
<teslalist-at-qwest-dot-net>" <chris_arnold-at-msn-dot-com>
 >
 > A while back I got a decommissioned Tektronix 7704 A 'scope, and it seems
 > one of the channels is in need of callibration - square waves aren't so
 > much square ;).


That's a probe or amplifier compensation thing.. Is there just a tilt in the
square wave, or slow rise times, or overshoot?

  Where can I dig up information on how to recalibrate
 > it.  One other thing, on the lower horizontal timescale settings - like
 > into the nanosecond ranges the scope seems to become unstable and the
 > display will suddenly become unreadable.  What is causing this?

Is the sweep speed unstable, or is it the triggering?
 >
 > Thanks a bunch,
 >
 > Chris
 >
 >
 > >From: "Tesla list" <tesla-at-pupman-dot-com>
 > >To: tesla-at-pupman-dot-com
 > >Subject: Re: Oscope advice
 > >Date: Mon, 11 Aug 2003 13:18:01 -0600
 > >
 > >Original poster: "Jim Lux by way of Terry Fritz <teslalist-at-qwest-dot-net>"
 > ><jimlux-at-earthlink-dot-net>
 > >
 > >465s are great scopes (as indicated by the remarkably high Ebay prices
for
 > >a way obsolete (commercially) scope)..
 > >
 > >One gotcha, though... make sure the tube is good and not burned.  I'll
bet
 > >a replacement CRT for these is quite expensive.  The other thing is to
not
 > >even bother buying one of these that isn't working, thinking you'll fix
 > >it.  You'll have a tough time finding replacement parts (particularly
 > >transistors and such for the vertical amps).
 > >
 > >However, if it's working, and just needs readjustment, or recalibration,
 > >then, have at it...
 > >
 > >
 > >At 05:29 PM 8/6/2003 -0600, you wrote:
 > >>Original poster: "Peter Lawrence by way of Terry Fritz
 > >><teslalist-at-qwest-dot-net>" <Peter.Lawrence-at-Sun.COM>
 > >>
 > >>Terry,
 > >>       I'm thinking of getting a used Tek 465 scope for tesla coil
 > >>measurements. Do you have any comments on that model, or any related
 > >>advice.
 > >>
 > >>-Pete Lawrence
 > >>
 > >>(ps, feel free to post response to tesla list if you think others will
 > >>be interested).
 > >>================
 > >>Hi Pete,
 > >>
 > >>Tektronix has never made a bad scope ;-))  Avoid those giant ones that
 > >>are bigger than a cow.  Any of the smaller (12x18x8) style CRT scopes
are
 > >>great.  I have long forgot which is the 465...  I looked on ebay and
 > >>those are great scopes!  They don't have fancy microprocessors ore
 > >>anything but they don't let you down.  Try and get the service manual if
 > >>you can incase you ever have to fiddle with it.  But they made zillions
 > >>of those things so everyone knows how to fix them if they ever were to
break.
 > >>
 > >>Cheers,
 > >>
 > >>         Terry
 > >
 >