Topics

2465B Buying advice

Harold Foster
 

All:

I'm looking for a very good, fast analog scope and so far the 2465B seems to be the best choice; I would very much welcome any tips and advice before I go shopping. Options that are worth holding out for? Certain manufacturing dates/serial numbers? Fair prices? Different models?

TIA,

Hal

Jean-Paul
 

Hello Harold: Welcome to the 2465/7B fan club!

I have 5 of these (!) and the costs varied $200-$400. These were the last TEK CRT scopes and have the finest ease of operation, performance and repair ability!
Look for physical damage or abuse on front, and rear, as well as the initial behavior on startup, of the self test.
Options are CT, BCT, and probe power, and GPIB. Suggest the original TEK probes: P6137, also use the Zo probes P6156 (rare).

The 2467B has wider BW 400 MHz and a micro channel plate CRT, but has a beam time limiter and somewhat smaller screen. Its super for fast transients and very fast sweep rates and for scope photography.

The serial numbers SN >B050xxxx are best, the earlier SN are different revs and can be troublesome.
The late versions have a problem: 4 pcs SMD lytic cap leakage that corrodes the A5 control board, producing many odd behaviors, but this is usually easy to fix.

As all of these are now circa 30 -35 yrs old, recapping the PSU and replacing the battery backup NVRAM (Dallas 1227) is expected. Then a full caliobration!
Get the big service manual that applies to the model and serial you get.

I am sure that Chuck Harris and our TEK Guru Dennis Tillman W7PF will have many more useful tips!

Just the ramblings of an old retired EE!

GOOD LUCK!

Jon in Paris

Jim Ford
 

Do know that the 2465B knobs have a noticeable lag in response, due to their being rotary encoders sampled by the microprocessor.  That used to drive me nuts several decades ago when I had one on my bench in the lab.  I assume the other 2465 and 2467 scopes have the same issue.Jim Ford Sent from my Verizon, Samsung Galaxy smartphone

-------- Original message --------From: Harold Foster <@HalFoster> Date: 1/9/20 5:03 AM (GMT-08:00) To: TekScopes@groups.io Subject: [TekScopes] 2465B Buying advice All:I'm looking for a very good, fast analog scope and so far the 2465B seems to be the best choice; I would very much welcome any tips and advice before I go shopping.  Options that are worth holding out for?  Certain manufacturing dates/serial numbers? Fair prices?  Different models?TIA,Hal

amirb
 

I am a happy owner of 2465A and a (like new) 2465B with options 05 and 06.
I have never noticed the lag that Jim is talking about though. A noticeable lag must be in 10s of msec or even couple of 100 of msec
and even with crappiest CPU it is hard for me to believe that would cause a noticeable lag in knob response...anyways, it probably depends on tatse

however, I also have a mint condition Iwatsu SS-7840 A.K.A Lecroy LA314 which in some ways is similar to 2465B but I like it a lot
and in some respects a lot more than 2465B. The Japanese CRT on these scopes is much nicer than the Tek and it also has
a true DC offset (not just the regular trace vertical position) which is very helpful when looking at small AC on top of large DC
the nice CRT and the DC offset was the main reason I bought this. There is also a 470MHz version SS-7840H (lecroy LA314H) which otherwise is identical

there is a complete service manual and schematics available for LA314/H although I have not used it because the scope works perfectly

Jim Ford
 

Funny you should mention Iwatsu scopes, Amir.  I had 3 of them at one point, a 250 MHz, a 100 MHz, and a 60 MHz job.  Got them as payment for consulting services to a no longer in business startup company in 2002.   Sold the faster ones on eBay almost immediately and kept the slow one because it had a frequency counter built in.  Sold it on Craigslist for $180 a couple years ago.  It had a problem with the horizontal sweep not going all the way across the screen.Now I have 4 scopes, Tek 5110N D10, 7603, and 7904, and HP 54504A.  That last one came from a Raytheon (my current day job) vendor who went out of business.  Got a bunch of cool HP stuff from them.  Worth probably at least $50,000 when new!Man, is it a great time to buy test equipment, or what?!JimSent from my Verizon, Samsung Galaxy smartphone

-------- Original message --------From: amirb <@amirb> Date: 1/9/20 11:05 AM (GMT-08:00) To: TekScopes@groups.io Subject: Re: [TekScopes] 2465B Buying advice I am a happy owner of 2465A and a (like new) 2465B with options 05 and 06. I have never noticed the lag that Jim is talking about though. A noticeable lag must be in 10s of msec or even couple of 100 of msecand even with crappiest CPU it is hard for me to believe that would cause a noticeable lag in knob response...anyways, it probably depends on tatsehowever, I also have a mint condition Iwatsu SS-7840 A.K.A Lecroy LA314 which in some ways is similar to 2465B but I like it a lotand in some respects a lot more than 2465B. The Japanese CRT on these scopes is much nicer than the Tek and it also hasa true DC offset (not just the regular trace vertical position) which is very helpful when looking at small AC on top of large DCthe nice CRT and the DC offset was the main reason I bought this. There is also a 470MHz version SS-7840H (lecroy LA314H) which otherwise is identicalthere is a complete service manual and schematics available for LA314/H although I have not used it because the scope works perfectly

Siggi
 

I have a 2467 with the CTT option, and I like it a lot. It's my goto
spelunker scope, though it does feel almost sacrilegious to use an MCP CRT
for everyday troubleshooting. I find the controls very intuitive and usable
for the most part.

It's definitely noticeable control lag on the pots, especially if you read
the Theory of Operation, and know how the controls work behind the scenes
:). The lag only occurs in practice when you start moving a new pot, as the
firmware has a notion of a "current" pot. The "current" pot is scanned
frequently, so you don't experience any lag after the first little movement.

On Thu, Jan 9, 2020 at 2:05 PM amirb <@amirb> wrote:

I am a happy owner of 2465A and a (like new) 2465B with options 05 and 06.
I have never noticed the lag that Jim is talking about though. A
noticeable lag must be in 10s of msec or even couple of 100 of msec
and even with crappiest CPU it is hard for me to believe that would cause
a noticeable lag in knob response...anyways, it probably depends on tatse

however, I also have a mint condition Iwatsu SS-7840 A.K.A Lecroy LA314
which in some ways is similar to 2465B but I like it a lot
and in some respects a lot more than 2465B. The Japanese CRT on these
scopes is much nicer than the Tek and it also has
a true DC offset (not just the regular trace vertical position) which is
very helpful when looking at small AC on top of large DC
the nice CRT and the DC offset was the main reason I bought this. There is
also a 470MHz version SS-7840H (lecroy LA314H) which otherwise is identical

there is a complete service manual and schematics available for LA314/H
although I have not used it because the scope works perfectly




Gary Robert Bosworth
 

Be very careful when it comes to 2465B. MANY on the market are modified
units with a new handle that says 2465B but they did not start out as one.
I have been told that these modified units are fast, but they are not
authentic and you might have a difficult time reselling it in the future.

Gary

On Thu, Jan 9, 2020 at 5:03 AM Harold Foster <@HalFoster> wrote:

All:

I'm looking for a very good, fast analog scope and so far the 2465B seems
to be the best choice; I would very much welcome any tips and advice before
I go shopping. Options that are worth holding out for? Certain
manufacturing dates/serial numbers? Fair prices? Different models?

TIA,

Hal



--
Gary Robert Bosworth
@grbosworth
Tel: 310-317-2247

John Williams
 

Very true. I have seen rebadged 2465 units sold as 2465B. I would never buy a 2465B from eBay or anywhere I could not test it. The U800 failure can take hours to show up, not just minutes. There is no way to tell if that defect is present without testing. Just saying.

David DiGiacomo
 

On Thu, Jan 9, 2020 at 7:40 PM John Williams <books4you@...> wrote:

Very true. I have seen rebadged 2465 units sold as 2465B. I would never buy a 2465B from eBay or anywhere I could not test it.
I think you are misremembering... there's no way you can disguise a
2465 as a 2465B.

The eBay issue is the seller "2465b", who sells modified 2445Bs as 2465Bs.

It is very difficult to identify one of these units without looking inside.

The U800 failure can take hours to show up, not just minutes. There is no way to tell if that defect is present without testing. Just saying.
I have not seen an intermittent U800 failure. In my experience, once
it fails, it stays that way (unless you remove and "rebake" the part).

John Williams
 

David: I did not say they were “disguised.” I said they were sold as 2465b. They were listed as 2465B and when they arrived they were 2465. I have purchased for my store 2465b scopes that worked fine until they warmed up, and then the u800 would fail. This could take anywhere from a few minutes to an hour. After they cooled the cycle would repeat itself. This is a classic well known failure mode. Nothing “disremembered.”

Jean-Paul
 

Hello again: The U800 heatsink/failure/replacement seems to be controversial.

The designers did envisige a heatsink but after preproduction it was deemed unnneded.

Many of the homemade DIY mods damage the chip seals especially the nuts torque.

Some of the HS glued on fall off.

In my experience I have never had a U800 fail, and all my 246X/B are original TEK U800, not the later copies. ]

My IR prrometer tests show just a 10 deg C rise over ambient and fine operation all day even with case open and no fan.


Especially beware of Chinese U800 re brands and pulls, many exist!

"If ain't broke, don't fix it!"

Look up U800 in our forum to find long tips and discussions! I am sure Chuck Harris can say volumes more on this issue!


Jon

Jean-Paul
 

Hello Siggi: I have never had a lag issue on any of my 246X/B, and see about the same time response to controls as other digital scopes EG Yokogawa DL series.

Perhaps these lagging controls are a symptom of a deep fault? Does it pass all self test?

Jon

Siggi
 

On Fri, Jan 10, 2020 at 8:41 AM Jean-Paul <jonpaul@...> wrote:

Hello Siggi: I have never had a lag issue on any of my 246X/B, and see
about the same time response to controls as other digital scopes EG
Yokogawa DL series.
Sure, but compared to a 7K series or my 485, there's control lag that you'd
be able to notice. Doesn't bother me at all, but I still notice it.


Perhaps these lagging controls are a symptom of a deep fault?

No, this is a consequence of how the pots are scanned.
Try this:

1. Set channels 1 and 2 to GND coupling and enable both traces.
2. Move one of the traces around with the vertical positioning control.
3. Move the same trace again with the vertical positioning control, no
lag.
4. Now try and alternate the position controls, and you'll notice that
there's sometimes a bit of a lag until the trace picks up on the pot
movement. After the trace starts moving, there's no perceptible lag, it's
just a little laggy - sometimes - to pick up on the initial pot movement.

This is because the "current", or the most recently moved pot is scanned
quite frequently (every interrupt or every other interrupt - some such).
All the other pots are non-"current", and are scanned at a much slower
rate. If you're unlucky, and the non-"current" pot you go to move was just
previously scanned, you may wait a quarter of a second or so until the
firmware notices that the pot's been moved and makes it "current".


Does it pass all self test?
Yes it passes all self test and performance verification.

Chuck Harris
 

When tektronix went from the 2465 to the much more fly-by-wire
2465A and B, they kept the same 6802 microprocessor, running the
same speed. Though, they about doubled its load.

The delay is a funny thing, though. It certainly seems like the
processor is busy off doing other things before it notices that
you have turned the knob, but there is an additional "feature"
that makes the knobs appear to be "different".

Because of the relative coarseness of a knob that at best has only
256 steps (because of the DAC that is used to read it), tektronix
put in a special routine that shifts between coarse motion, and
fine motion, depending on how quickly you turn the knob.

So, if you give the knob a crank, it will hop, skip, and dither
across the screen, but if you turn it slowly, it will sync up, and
move smoothly with fine resolution.

It might serve to try the knobs again with that additional insight.

-Chuck Harris

Jim Ford wrote:

Do know that the 2465B knobs have a noticeable lag in response, due to their being rotary encoders sampled by the microprocessor. That used to drive me nuts several decades ago when I had one on my bench in the lab. I assume the other 2465 and 2467 scopes have the same issue.Jim Ford Sent from my Verizon, Samsung Galaxy smartphone
-------- Original message --------From: Harold Foster <@HalFoster> Date: 1/9/20 5:03 AM (GMT-08:00) To: TekScopes@groups.io Subject: [TekScopes] 2465B Buying advice All:I'm looking for a very good, fast analog scope and so far the 2465B seems to be the best choice; I would very much welcome any tips and advice before I go shopping. Options that are worth holding out for? Certain manufacturing dates/serial numbers? Fair prices? Different models?TIA,Hal