Knobs and buttons for old Tek 2465 scopes

Just when finishing up a project at a client the old Tek 2465 over there
croaked. And I hate working with their digital scopes. Wanted to switch
from delayed trigger to normal and it felt like a broken clutch. The
plastic actuator fell into pieces. Upon disassembly some of the little
knobs also fell apart, they had also become brittle.

Couldn't find any of this at Sphere's web site and others, only custom
chips and stuff for these scopes. Is there a reliable place that has
such knobs? These scopes are certainly out of support but so widespread
that there should be a market. Thing is, the knobs have partially turned
from gray to "nicotine brown" and hardened up. It's only a matter of
time until the next ones crumble. So I guess "new old stock" wouldn't
help much unless it was really newer than the scopes and stored in a
cool place.

 

Take off a few good knobs,use modeling mold materials to cast new ones.

Not that I'm aware of.

Not really.

"nicotine brown";you SMOKE around your gear?
That's not going to help it any.Nor will direct sunlight/UV.
(BTW,plastic outgasses plasticizers naturally,becomes more brittle.)

I don't agree with this.

IIRC,the lever switches used for triggering modes is part of the switch
itself,not separate.


My guess is that you need a parts scope to cannabalize.

 

Several people on routinely make
replacement knobs. Look for Jeff Angus. He is in California. There
are a number of others doing this work, as well:

<http://groups.google.com/group/rec....group=rec.antiques.radio+phono&q=making+knobs>


--
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

 

That's hard with the time base / trigger mode knob. Very thin and no
clearance to speak of behind the panel.

Nah, no smoking here. This was at a client, also non-smoking of course.
It's just age. Wish they had used metal for that switch ring.

Well, I had my (not so good) experiences with plastic parts that were NOS.

They are separate. A SPDT switch "standing up" and the gray plastic part
cradles the rocker with some clearance.

Yes, the client will do that but it would need to be a younger scope.

Or we'll drill a hole and hang a plunger onto the switch. It will look
ugly but work ;-)

 

Thanks, Michael! That's the kind of info I was looking for. Might not
work for the trigger mode ring because it's a flimsy design to begin
with but it may work for all the other little knobs that crumbled. The
trigger mode might become a "kludge stick" out a hole drilled into the
front panel ;-)

 

Try this:
http://www.qservice.info/TEK_SPARES8.htm

;-)

 

The main problem is molders who run the parts too fast into molds that are
too cold. They're OK for a while but will crack over time.

 

Thanks, Stefano! Great, they seem to have quite a few of the knobs that
broke. Couldn't find any street address on the site, that always has me
a bit concerned but if they have the right stuff it may be ok. Did you
use this company before?

 

Just told my client about qservice. They had already found that company
on the web and the knobs are on order. To my surprise they even had that
weird delayed-trigger clutch which started all this grief. Since that
seems to be something that easily breaks here is the photo in case
anyone else runs into the same problem:

Thanks again.

 

The last I heard, jeff was machining new brass inserts for his replica
knobs. Jeff is a bit rough around the edges, but I think he can do what
you need. If he can duplicate them, I'm sure he'll make extras to keep
on hand.


--
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

 

Well, just talked to my client and they have already ordered from the
source Stefano mentioned. But thanks anyway, I am going to write this
into my database for parts sources in case a knob or button turns out to
be truly unobtanium.

 

If you are going to cast, why not use metal?
OTH, if that ring must be clear, use a sheet of polycarbonate of
similr thickness (rather rigid and robust) as a "base" for the cast section.

 

Hi Joerg,
I'm glad to read that you find useful this information, I've just
acquired some items on eBay from qservice and I'm waiting to receive
these in the next days.

 

Polycarbonate would be an option. Metal wouldn't be because a lot of the
scope's knobs have spring action parts molded into them. I wish
Tektronix hadn't done that.

Anyhow, the client has already ordered from a spare knob manufacturer.
So there does seem to be a sizeable market for that old 2465 scope. IMHO
it was one of the best Tektronix ever made which is why I convinced that
client to buy some. This client has several newer digital TDS scopes but
they don't even come close to the old 2465 when chasing noise on pulsed
signals. What does work nicely is the 7000 series mainframes which I am
using here. Much better "knob quality", none of this plastic snap action
stuff that breaks off, all nicely done with metal core and set screw.
But they are too large and too heavy for field work.

 

My client had found this source the night before and ordered right away.
But you'll probably win the race to receive the parts because they said
the company is in Greece and you are only a few hundred miles from
there. It's over 6000 miles for us here.

 

There was a time when TEK field engineers "carried" 500 series tube scopes
around for troubleshooting and repair.They repaired the customers TEK
scopes on site.

 

The clutch you refer to is a detent ball and spring. These have always
been a sore spot on the 2465. When you get the replacement apply a
drop of oil ( I use silicone oil) on the flat side of the aluminum
center collar and work it back and forth. The detent gets dry and
sticks and then when pulled on too much pressure is required. This
usually breaks the knob skirt and sends the detent off into orbit. I
have used the old JB weld to fashion a new skirt and miniture ball
bearing for the detent. The knobs are getting scarce. You can usually
buy a dead 2465 on ebay and use the knobs from it.

Roy