wrote in
:

On Dec 1, 8:50 am, Jim Yanik wrote:
well,I can't recall specifically if it does,but I believe it does.
I think you have to put the time/div switch into X position,then use
Ch2 for it's input.I'd have to see a front panel pic to be sure.

I don't see any indication for X position on the time/div switch...?

http://a763.g.akamai.net/7/763/1644/...img/image/fp/e
xtra/2/VPID/4462013

http://a763.g.akamai.net/7/763/1644/...img/image/fp/e
xtra/3/VPID/4462013/


sorry,it says ext.horiz.

--
Jim Yanik
jyanik
at
kua.net

On Nov 29, 4:56 pm, Jim Yanik wrote:
Fred Bartoli " " wrote :



Jim Yanik a écrit :
Doug McDonald wrote in
:

Sam Goldwasser wrote:

Reasons why I should maybe stay with my 485:

1) Better proprietary IC availability (?, don't beat me up; I
thought this was what I read...)
2) Easier to service/repair than the 2465
3) More robust for the beginner

Obviously if I am thinking like this, I have no idea what I
should ultimately do. What does everyone think? ducking
I'm an expert on these things.

Oh?

The 485 is the best portable
analog scope ever made. It is arguably the best analog scope ever
made, though the 7904 series competes well on the bench. Do anything
you can to keep one working. There is no substitute for a 485/7904,
and I've used them all, including $50,000 digital ones. For
repairing analog electronic oddities, digital frequently simply
doesn't work.

A 485 is 350 MHz scope.

The 2465 is a very poor substitute, though a good scope.

Doug McDonald

IMO,the 485 is much worse than a 2465,having lots of flaky attenuator
problems,a bitch of a power supply repair-wise,and less accuracy than
the 2465 series.And you get a better CRT display with the 2465.
The 2465 was the best portable scope TEK ever made.What killed it was
TEK selling off the ICO/Hybrid plant to Maxim,and Maxim cutting TEK's
throat by forcing a last-time buy on TEK-made ICs.
The 485s are getting really old,the HF switch contacts are degrading
and unavailable.
The 2465 is more serviceable -if you can get the parts.
the 485 has the same problem.

I worked for TEK for 21.5 years in their Field Service centers
repairing and calibrating these scopes.I'd much rather work on a 2465
than a 485. 485s were a PITA even when TEK was still issuing the mod
summaries on fiche.There were SO many ECO changes,you couldn't keep
up with them all.

I agree about the 7904 lab scopes being great.Had one on my bench.

Totally agree on the 2465.

As for the DSOs, the OP clearly don't know what good ones can do. See
the DSA/11k plugins series. That's simply the best scope I've seen.
Period.

I currently have a setup with a DSA and one 11A34 and one 11A33 diff
plug-in from which I *measure* signals at the 10uV level with
excellent accuracy (has been checked against some calibration
tooling). But the truely amazing parts are the plug-ins (11A33 & 11A34
checked) recovery from deep saturation.
Right now after a 200mV step down to 0V (on a 1mV/div scale), both
plug-ins show not more than 40uV thermal tail and recovers from
saturation in under 50ns. All this being very well behaved and hence
can
be well compensated for, pushing the performances one step further.

We're trying to find a 'modern' DSO doing that: nada, nothing.
The last we've tested (DPO7054 @ euro 15K) showed near 2mV thermal
tailing after a 200mV step.

What I wonder is what did make Tek losing the art of those exceptional
input stages...

Ignorant beancounters and overpaid upper management.
They thought they could sell off the ICO/hybrid division,and then buy the
same parts from the new owner,but Maxim decided TEK was not buying in
enough volume to make Maxim happy,and forced a last-time buy before
shutting down the production of TEK ICs/hybrids.


IIRC Maxim made them available to all comers, but no one else wanted
very many of them.

Tek could have had another vendor make them:they just did not want to
spend the money.

Unless and until someone decides to make third party parts to FULLY
support at least some Tek models (some replacement assemblies using
merchant parts would be needed) the best solution is leave old Teks to
Tek collectors and support someone who will commit to the analog
oscilloscope business.

IMO,the 485 is much worse than a 2465,having lots of flaky attenuator
problems,a bitch of a power supply repair-wise,and less accuracy than the
2465 series.And you get a better CRT display with the 2465.
The 2465 was the best portable scope TEK ever made.What killed it was TEK
selling off the ICO/Hybrid plant to Maxim,and Maxim cutting TEK's throat
by forcing a last-time buy on TEK-made ICs.
The 485s are getting really old,the HF switch contacts are degrading and
unavailable.
The 2465 is more serviceable -if you can get the parts.
the 485 has the same problem.


What about the 2245, 2247?

Bret Ludwig wrote in
:



IMO,the 485 is much worse than a 2465,having lots of flaky attenuator
problems,a bitch of a power supply repair-wise,and less accuracy than
the 2465 series.And you get a better CRT display with the 2465.
The 2465 was the best portable scope TEK ever made.What killed it was
TEK selling off the ICO/Hybrid plant to Maxim,and Maxim cutting TEK's
throat by forcing a last-time buy on TEK-made ICs.
The 485s are getting really old,the HF switch contacts are degrading
and unavailable.
The 2465 is more serviceable -if you can get the parts.
the 485 has the same problem.


What about the 2245, 2247?



I have been out of this message loop but have a question on the 2465.

This is the model I have, however, it has a bad chip - I believe U800.

This is the famous chip that is no longer made, failed due to heat, and
isn't replaceable.

I found another 2465 that has a different board (without this chip). Are
the boards compatible? Another words, can I swap boards without a problem?

On Sun, 02 Dec 2007 20:17:53 -0600 Steve wrote in
Message id: :

Bret Ludwig wrote in
:



IMO,the 485 is much worse than a 2465,having lots of flaky attenuator
problems,a bitch of a power supply repair-wise,and less accuracy than
the 2465 series.And you get a better CRT display with the 2465.
The 2465 was the best portable scope TEK ever made.What killed it was
TEK selling off the ICO/Hybrid plant to Maxim,and Maxim cutting TEK's
throat by forcing a last-time buy on TEK-made ICs.
The 485s are getting really old,the HF switch contacts are degrading
and unavailable.
The 2465 is more serviceable -if you can get the parts.
the 485 has the same problem.


What about the 2245, 2247?



I have been out of this message loop but have a question on the 2465.

This is the model I have, however, it has a bad chip - I believe U800.

This is the famous chip that is no longer made, failed due to heat, and
isn't replaceable.

I found another 2465 that has a different board (without this chip). Are
the boards compatible? Another words, can I swap boards without a problem?

AFAIK, ALL the 2465's had a U800...

Steve wrote in
6:

Bret Ludwig wrote in
:



IMO,the 485 is much worse than a 2465,having lots of flaky
attenuator problems,a bitch of a power supply repair-wise,and less
accuracy than the 2465 series.And you get a better CRT display with
the 2465. The 2465 was the best portable scope TEK ever made.What
killed it was TEK selling off the ICO/Hybrid plant to Maxim,and
Maxim cutting TEK's throat by forcing a last-time buy on TEK-made
ICs. The 485s are getting really old,the HF switch contacts are
degrading and unavailable.
The 2465 is more serviceable -if you can get the parts.
the 485 has the same problem.


What about the 2245, 2247?

Different animals,LOTs of TEK-madeICs,and not very serviceable.
I'd never own one.



I have been out of this message loop but have a question on the 2465.

This is the model I have, however, it has a bad chip - I believe U800.

This is the famous chip that is no longer made, failed due to heat,
and isn't replaceable.

I found another 2465 that has a different board (without this chip).
Are the boards compatible? Another words, can I swap boards without a
problem?



no such animal as a 2445/65 without the horizontal output IC;TEK never made
any substitute.

Now some guy contacted me a few years ago wanting me to evaluate his "U800"
replacement board,but I didn't have the means to do any evaluation. I
suggested he post to the sci.electronics NGs,he would have gotten lots of
testers,maybe even someone with real cal standards to do a decent
evaluation.

--
Jim Yanik
jyanik
at
kua.net

JW wrote in
:

On Sun, 02 Dec 2007 20:17:53 -0600 Steve wrote in
Message id: :

Bret Ludwig wrote in
:



IMO,the 485 is much worse than a 2465,having lots of flaky
attenuator problems,a bitch of a power supply repair-wise,and less
accuracy than the 2465 series.And you get a better CRT display with
the 2465. The 2465 was the best portable scope TEK ever made.What
killed it was TEK selling off the ICO/Hybrid plant to Maxim,and
Maxim cutting TEK's throat by forcing a last-time buy on TEK-made
ICs. The 485s are getting really old,the HF switch contacts are
degrading and unavailable.
The 2465 is more serviceable -if you can get the parts.
the 485 has the same problem.


What about the 2245, 2247?



I have been out of this message loop but have a question on the 2465.

This is the model I have, however, it has a bad chip - I believe U800.

This is the famous chip that is no longer made, failed due to heat,
and isn't replaceable.

I found another 2465 that has a different board (without this chip).
Are the boards compatible? Another words, can I swap boards without a
problem?

AFAIK, ALL the 2465's had a U800...

Yes.


the only thing different between a 2445 and a 2465 was the main PCboard
itself;that is what determined the BW of the scope,it's internal PC
elements.(intentionally)

All the ICs and hybrids were the same on both scopes.

--
Jim Yanik
jyanik
at
kua.net

Michael A. Terrell posted to
sci.electronics.equipment:

Bret Ludwig wrote:

I no longer recommend owning or using Tektronix analog scopes,
period. Yes, they were very well built, but none of them are 100%
supported and they all lose the same parts. The hybrid issue is a
big one, but CRTs, attenuators, and high voltage parts on all solid
state Teks are getting unavailable even through the back channels.

If some company decided to FULLY SUPPORT certain Tek models,
guaranteeing availability of every part from new production-or at
least every part that is getting scarce-I'd say yes.

Ironically you can still get every possible part for many tube
Teks,
but the size, weight, power draw and heat make them nonstarters.
That is why the parts are available.

Buy a new scope.


I agree 100%!!!!!!!! Buy a brand new chinese scope with no
support,
and throw it away when it dies. Repeat till you're tired of using
crap, then buy a used US made scope.



What US made scopes? Both Tek and HP moved their manufacturing to
Taiwan, Malaysia and China over a decade ago.

JosephKK wrote:
What US made scopes? Both Tek and HP moved their manufacturing to
Taiwan, Malaysia and China over a decade ago.

And Singapore too.

Even so, scopes have not changed a whole lot in a decade. Hell, I
regularly use an old Tek from the mid-sixties and it's just fine
even if the calibration lab at work hates me for it.

The one thing that HAS changed is that digital storage systems have come
along, and they are much, much better for finding transient glitches than
the old storage tube scopes were. However, for just about anything else
there's nothing wrong with an old analogue scope.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

"JosephKK" wrote ...
Michael A. Terrell posted :
and throw it away when it dies. Repeat till you're tired
of using crap, then buy a used US made scope.

What US made scopes? Both Tek and HP moved their
manufacturing to Taiwan, Malaysia and China over a
decade ago.

So then "a used US made scope" would mean one that was
made in the US more than 10 years ago (by your method).

I frequently drive by the Tektronix campus in Beaverton, OR
and most of the buildings seem to be leased to companies
for other uses (daycare centers, offices, warehouses, etc.)
The eastern edge was sold to the adjacent strip-mall to
make a significant expansion and up-scale including a
nice multiplex movie theater.

Their semiconductor fab (on the northwest corner of the
campus, right next to the fire station) was sold to Maxim
and has their name on the building and the signs at that
entrance to the campus.

JosephKK wrote:

Michael A. Terrell posted to
sci.electronics.equipment:

Bret Ludwig wrote:

I no longer recommend owning or using Tektronix analog scopes,
period. Yes, they were very well built, but none of them are 100%
supported and they all lose the same parts. The hybrid issue is a
big one, but CRTs, attenuators, and high voltage parts on all solid
state Teks are getting unavailable even through the back channels.

If some company decided to FULLY SUPPORT certain Tek models,
guaranteeing availability of every part from new production-or at
least every part that is getting scarce-I'd say yes.

Ironically you can still get every possible part for many tube
Teks,
but the size, weight, power draw and heat make them nonstarters.
That is why the parts are available.

Buy a new scope.


I agree 100%!!!!!!!! Buy a brand new chinese scope with no
support,
and throw it away when it dies. Repeat till you're tired of using
crap, then buy a used US made scope.



What US made scopes? Both Tek and HP moved their manufacturing to
Taiwan, Malaysia and China over a decade ago.


I said 'buy a used US made scope', but I didn't specify a date. I
still have two older tek alanog scopes, one US made, the other is a
small battery powered portable made by Sony, for Tektronix.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida