Date   
465B fan question

Robert Simpson
 

Trying to get the fan in a 465B working. Initially I noticed the PCB under the IC was dark brown as if the IC had overheated. So I replaced both the IC and the transistor, just in case. Also, the fan motor didn't spin freely, so I also pulled the fan motor, cleaned and lubricated the bearings with Silicon Oil. The fan motor now spins freely. I also checked the diodes with fan off the PCB and they seemed OK (forward reverse Ohm check).
However, The motor won't start turning on its own. If I manually spin it a couple of times, it will then keep spinning until I turn the power off. The fan will only spin if I start it manually.
Does indicate a problem with the motor, like, say, a bad winding thus not enough starting torque?
Bob

Re: Looking for 7104 crt , trade

oliver johnson
 

I an in the US, New York 11553 zip . I did get a crt shipped to me before , as long as its packed in multiple boxes , one larger than the other i should be fine . Let me know if you can 
Do a shipping. 
On Fri, Oct 11, 2019 at 1:11 PM, Steve Wiseman<sjwiseman@...> wrote: > I have a 7103 rack mount scope , my crt is bad and would like to replace
it with a good working crt . I would like to trade someone that has crts
and may want one that i have , i have some 5 series 4 series 7 series  and
other tek crt , in addition to that i have some hp and leader crt , if you
are  looking for something specific let me know and maybe we can help each
other .
I've got a 7103 with a pristine tube (no burn in visible at all, nice and
bright) but otherwise a bit battered. You don't say where you are - and
shipping's going to be the issue... I'm in Cambridge, England. Interested,
or not?

Steve

Re: Looking for 7104 crt , trade

Steve Wiseman
 

I have a 7103 rack mount scope , my crt is bad and would like to replace
it with a good working crt . I would like to trade someone that has crts
and may want one that i have , i have some 5 series 4 series 7 series and
other tek crt , in addition to that i have some hp and leader crt , if you
are looking for something specific let me know and maybe we can help each
other .
I've got a 7103 with a pristine tube (no burn in visible at all, nice and
bright) but otherwise a bit battered. You don't say where you are - and
shipping's going to be the issue... I'm in Cambridge, England. Interested,
or not?

Steve

Re: AM700

Giampi Redmond
 

Hi,
I have just posted the v1.05 firmware on the ko4bb website (www.ko4bb.com).
It will take a few days for it to be downloadable.
There are also the two boot roms I had posted some time ago.
The 8MBytes Simm Flash modules are still found on eBay although not of the same model mounted on the AM700.

Re: ths730a battery cover stuck

Scott Adams
 

The problem is the cover is in the closed locked position and it will not rotate, the o-ring might be broken down and is sticking, not sure.

Re: ths730a battery cover stuck

doyle.paul48
 

G'day Zenith,
The battery compartment relies on having a battery inserted to give enough
spring pressure to pop the cover off when it is rotated.
I use a medium sized bull nosed pliers to rotate the cover then pull it up.
Try not to pry it up with a sharp leaver you could crack it.
Paul Doyle
CRO-TEK

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Re: ths730a battery cover stuck

 

On Thu, Oct 10, 2019 at 09:42 PM, Scott Adams wrote:


I do not want to break anything so any ideas on how to remove the cover so I
can check the battery condition.
The normal way to open is to turn the cover 1/4 turn CCW and the cover should
come off. However there is a small o-ring on the cover which may make the cover
stick to the case especially if it hasn't been opened for a long time. Just try to
carefully pull and/or wiggle the cover in the open position and eventually it will come off.

/Håkan

ths730a battery cover stuck

Scott Adams
 

I just got a ths730a and it works fine, but the battery cover is frozen stuck. I do not want to break anything so any ideas on how to remove the cover so I can check the battery condition.

Re: In search of Impeller Fan Fastener For Tek 2465 - Part # 243104001

EricJ
 

Good question. I think probably Chuck was going off memory when he mentioned 6-32. I didn't even look at the print, just ran with it. 8-32 is likely correct.

--Eric

On Oct 9, 2019 4:15 PM, Paul Amaranth <paul@...> wrote:




The print in the files section shows 8-32, is that a mistake?

On Wed, Oct 09, 2019 at 11:40:40AM -0500, EricJ via Groups.Io wrote:
Chuck, the 6-32 thread won't be any stronger in brass than in aluminum -
in fact most likely weaker. Two benefits to brass as I see it are easier
machining and less likely to corrode and seize the thread - the likely
culprit if aluminum ones are breaking. What material are they screwed
into?

--Eric

On Oct 9, 2019 10:25 AM, Chuck Harris <cfharris@...> wrote:




Tom Jobe's were made of brass.

The collet is made from billet (eg solid rod).  If you
use aluminum, you are going to have trouble threading the
6-32 section without breaking it.  And, some future user
is likely to twist it off, or break the screw slot, when
they guess wrongly that the screw is turned to remove the
fan.

I would use brass or steel.

-Chuck Harris



EricJ via Groups.Io wrote:
Hi Chuck,

Found it. Slight discrepancy though - you mentioned these were made
of
brass and the print says 6061 (aluminum). Which is preferable for
these?

--Eric

On Oct 9, 2019 9:15 AM, Chuck Harris <cfharris@...> wrote:




Hi Eric,

There is already a blue print for the collets
in the files section of this group.  I have a
copy if you can't find it.







!DSPAM:5d9e469095791713744598!
--
Paul Amaranth, GCIH             | Manchester MI, USA
Aurora Group of Michigan, LLC   |   Security, Systems & Software
paul@...              |   Unix & Windows





Re: In search of Impeller Fan Fastener For Tek 2465 - Part # 243104001

Chuck Harris
 

It isn't a fan, per sei, but rather a squirrel cage blower.

Why reinvent the wheel? I could make this collet with a drill
press, slitting saw, and a file.

-Chuck Harris

Phil Wong via Groups.Io wrote:

Looking at it from another perspective: Are there currently available fans that would fit right into the drive shaft of the Siemens motor?


-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of EricJ via Groups.Io
Sent: Wednesday, October 09, 2019 12:41 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] In search of Impeller Fan Fastener For Tek 2465 - Part # 243104001

Chuck, the 6-32 thread won't be any stronger in brass than in aluminum - in fact most likely weaker. Two benefits to brass as I see it are easier machining and less likely to corrode and seize the thread - the likely culprit if aluminum ones are breaking. What material are they screwed into?

--Eric

Re: In search of Impeller Fan Fastener For Tek 2465 - Part # 243104001

Chuck Harris
 

Mine, follow the plan.

-Chuck Harris

Paul Amaranth wrote:

The print in the files section shows 8-32, is that a mistake?

On Wed, Oct 09, 2019 at 11:40:40AM -0500, EricJ via Groups.Io wrote:
Chuck, the 6-32 thread won't be any stronger in brass than in aluminum - in fact most likely weaker. Two benefits to brass as I see it are easier machining and less likely to corrode and seize the thread - the likely culprit if aluminum ones are breaking. What material are they screwed into?

--Eric

Re: In search of Impeller Fan Fastener For Tek 2465 - Part # 243104001

Chuck Harris
 

As an engineer who is very comfortable in the machine shop,
(I won't say I'm a machinist), I agree, but brass is still
better.

My reasoning is that any brass you find will be very good
for machining, and adequate for strength. I can't say the
same about any aluminum you find.... imagine the recycled
chewing gum they sell as aluminum stock in the hardware store.

If you really use 6061, and especially T6061, you will have
a working collet when you are done.

The original was a plastic collet with a 6-32 screw molded
into the plastic. So overall strength is not much of an issue.

I don't think it very much matters what you make it out
of... even some plastics would be fine, if you can cut the
threads to size.

The collet doesn't screw into anything. The threads are used
as the collet closer, and are pulled with an ordinary nut.
The collet's tapered cone is inside of the fan's hub.

-Chuck Harris


EricJ via Groups.Io wrote:

Chuck, the 6-32 thread won't be any stronger in brass than in aluminum - in fact most likely weaker. Two benefits to brass as I see it are easier machining and less likely to corrode and seize the thread - the likely culprit if aluminum ones are breaking. What material are they screwed into?

--Eric

On Oct 9, 2019 10:25 AM, Chuck Harris <cfharris@...> wrote:




Tom Jobe's were made of brass.

The collet is made from billet (eg solid rod). If you
use aluminum, you are going to have trouble threading the
6-32 section without breaking it. And, some future user
is likely to twist it off, or break the screw slot, when
they guess wrongly that the screw is turned to remove the
fan.

I would use brass or steel.

-Chuck Harris



EricJ via Groups.Io wrote:
Hi Chuck,

Found it. Slight discrepancy though - you mentioned these were made of
brass and the print says 6061 (aluminum). Which is preferable for these?

--Eric

On Oct 9, 2019 9:15 AM, Chuck Harris <cfharris@...> wrote:




Hi Eric,

There is already a blue print for the collets
in the files section of this group. I have a
copy if you can't find it.




Re: In search of Impeller Fan Fastener For Tek 2465 - Part # 243104001

Phil Wong
 

Looking at it from another perspective: Are there currently available fans that would fit right into the drive shaft of the Siemens motor?

-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of EricJ via Groups.Io
Sent: Wednesday, October 09, 2019 12:41 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] In search of Impeller Fan Fastener For Tek 2465 - Part # 243104001

Chuck, the 6-32 thread won't be any stronger in brass than in aluminum - in fact most likely weaker. Two benefits to brass as I see it are easier machining and less likely to corrode and seize the thread - the likely culprit if aluminum ones are breaking. What material are they screwed into?

--Eric

On Oct 9, 2019 10:25 AM, Chuck Harris <cfharris@...> wrote:




Tom Jobe's were made of brass.

The collet is made from billet (eg solid rod). If you use aluminum,
you are going to have trouble threading the
6-32 section without breaking it. And, some future user is likely to
twist it off, or break the screw slot, when they guess wrongly that
the screw is turned to remove the fan.

I would use brass or steel.

-Chuck Harris



EricJ via Groups.Io wrote:
Hi Chuck,

Found it. Slight discrepancy though - you mentioned these were made
of
brass and the print says 6061 (aluminum). Which is preferable for these?

--Eric

On Oct 9, 2019 9:15 AM, Chuck Harris <cfharris@...> wrote:




Hi Eric,

There is already a blue print for the collets in the files section
of this group. I have a copy if you can't find it.




Re: In search of Impeller Fan Fastener For Tek 2465 - Part # 243104001

Paul Amaranth
 

The print in the files section shows 8-32, is that a mistake?

On Wed, Oct 09, 2019 at 11:40:40AM -0500, EricJ via Groups.Io wrote:
Chuck, the 6-32 thread won't be any stronger in brass than in aluminum - in fact most likely weaker. Two benefits to brass as I see it are easier machining and less likely to corrode and seize the thread - the likely culprit if aluminum ones are breaking. What material are they screwed into?

--Eric

On Oct 9, 2019 10:25 AM, Chuck Harris <cfharris@...> wrote:




Tom Jobe's were made of brass.

The collet is made from billet (eg solid rod).  If you
use aluminum, you are going to have trouble threading the
6-32 section without breaking it.  And, some future user
is likely to twist it off, or break the screw slot, when
they guess wrongly that the screw is turned to remove the
fan.

I would use brass or steel.

-Chuck Harris



EricJ via Groups.Io wrote:
Hi Chuck,

Found it. Slight discrepancy though - you mentioned these were made of
brass and the print says 6061 (aluminum). Which is preferable for these?

--Eric

On Oct 9, 2019 9:15 AM, Chuck Harris <cfharris@...> wrote:




Hi Eric,

There is already a blue print for the collets
in the files section of this group.  I have a
copy if you can't find it.







!DSPAM:5d9e469095791713744598!
--
Paul Amaranth, GCIH | Manchester MI, USA
Aurora Group of Michigan, LLC | Security, Systems & Software
paul@... | Unix & Windows

Re: In search of Impeller Fan Fastener For Tek 2465 - Part # 243104001

EricJ
 

Chuck, the 6-32 thread won't be any stronger in brass than in aluminum - in fact most likely weaker. Two benefits to brass as I see it are easier machining and less likely to corrode and seize the thread - the likely culprit if aluminum ones are breaking. What material are they screwed into?

--Eric

On Oct 9, 2019 10:25 AM, Chuck Harris <cfharris@...> wrote:




Tom Jobe's were made of brass.

The collet is made from billet (eg solid rod).  If you
use aluminum, you are going to have trouble threading the
6-32 section without breaking it.  And, some future user
is likely to twist it off, or break the screw slot, when
they guess wrongly that the screw is turned to remove the
fan.

I would use brass or steel.

-Chuck Harris



EricJ via Groups.Io wrote:
Hi Chuck,

Found it. Slight discrepancy though - you mentioned these were made of
brass and the print says 6061 (aluminum). Which is preferable for these?

--Eric

On Oct 9, 2019 9:15 AM, Chuck Harris <cfharris@...> wrote:




Hi Eric,

There is already a blue print for the collets
in the files section of this group.  I have a
copy if you can't find it.




Re: In search of Impeller Fan Fastener For Tek 2465 - Part # 243104001

Chuck Harris
 

Tom Jobe's were made of brass.

The collet is made from billet (eg solid rod). If you
use aluminum, you are going to have trouble threading the
6-32 section without breaking it. And, some future user
is likely to twist it off, or break the screw slot, when
they guess wrongly that the screw is turned to remove the
fan.

I would use brass or steel.

-Chuck Harris



EricJ via Groups.Io wrote:

Hi Chuck,

Found it. Slight discrepancy though - you mentioned these were made of brass and the print says 6061 (aluminum). Which is preferable for these?

--Eric

On Oct 9, 2019 9:15 AM, Chuck Harris <cfharris@...> wrote:




Hi Eric,

There is already a blue print for the collets
in the files section of this group. I have a
copy if you can't find it.

Re: In search of Impeller Fan Fastener For Tek 2465 - Part # 243104001

EricJ
 

Hi Chuck,

Found it. Slight discrepancy though - you mentioned these were made of brass and the print says 6061 (aluminum). Which is preferable for these?

--Eric

On Oct 9, 2019 9:15 AM, Chuck Harris <cfharris@...> wrote:




Hi Eric,

There is already a blue print for the collets
in the files section of this group.  I have a
copy if you can't find it.

Tom Jobe took that print, and set up his CNC
shop to make them, and got exactly zero interest
from this group for his efforts.  He didn't want
all that much for them, just enough to cover the
cost of the brass and the wear on the tool bits.

When he was cleaning up loose ends before he died,
he sent me some.  Judging by how quickly they went,
free is apparently the correct price.

-Chuck Harris

EricJ via Groups.Io wrote:
Chuck, as an alternative to that approach, you could either make a
blueprint of the fan collet or send it my way so I can do so. Then I would
be happy to pass it on to the fellow in need. I could make a few up in my
spare time and send them back to you or on to whoever needed them. I was a
machinist and toolmaker for a couple decades before I ruptured a disc in
my back. Now I just make things for fun - can't stand at the machines all
day anymore.

--Eric




Re: In search of Impeller Fan Fastener For Tek 2465 - Part # 243104001

Chuck Harris
 

Hi Eric,

There is already a blue print for the collets
in the files section of this group. I have a
copy if you can't find it.

Tom Jobe took that print, and set up his CNC
shop to make them, and got exactly zero interest
from this group for his efforts. He didn't want
all that much for them, just enough to cover the
cost of the brass and the wear on the tool bits.

When he was cleaning up loose ends before he died,
he sent me some. Judging by how quickly they went,
free is apparently the correct price.

-Chuck Harris

EricJ via Groups.Io wrote:

Chuck, as an alternative to that approach, you could either make a blueprint of the fan collet or send it my way so I can do so. Then I would be happy to pass it on to the fellow in need. I could make a few up in my spare time and send them back to you or on to whoever needed them. I was a machinist and toolmaker for a couple decades before I ruptured a disc in my back. Now I just make things for fun - can't stand at the machines all day anymore.

--Eric

Re: In search of Impeller Fan Fastener For Tek 2465 - Part # 243104001

EricJ
 

Chuck, as an alternative to that approach, you could either make a blueprint of the fan collet or send it my way so I can do so. Then I would be happy to pass it on to the fellow in need. I could make a few up in my spare time and send them back to you or on to whoever needed them. I was a machinist and toolmaker for a couple decades before I ruptured a disc in my back. Now I just make things for fun - can't stand at the machines all day anymore.

--Eric

On Oct 9, 2019 7:50 AM, Chuck Harris <cfharris@...> wrote:




This issue is caused by not reading the manual, and
incorrectly assuming how the fan is constructed.  The
slotted screw is not ever supposed to be turned.  The
slot is there to allow you to turn the nut without
putting any torque on the screw.

The correct way to remove the fan is to put a screwdriver
in the slot.  Holding the screwdriver firm, and using a
wrench, loosen the nut.  Remove the screwdriver, and turn
the nut by finger until it is flush with the top of the
screw slot.  Finally, tap the nut a couple of times...
lightly... until the screw goes into the FAN hub a little
bit.  The internal collet (the broken thingy) will have
released, and the fan will come off easily.

Send me your address, and I will send you my absolutly last
Tom Jobe collet.  I was saving it for my own use, but you
need it more than I do.

-Chuck Harris

Phil Wong via Groups.Io wrote:
I got hold of a Tek 2465 (the one with the Siemens motor), but the
inside
fan is cracked.

I could get epoxy and glue it back (suggestion appreciated), but this
fastener piece is in 4-5 small pieces. Could somebody here suggest a
place
where I could order one of these?












Re: In search of Impeller Fan Fastener For Tek 2465 - Part # 243104001

Chuck Harris
 

This issue is caused by not reading the manual, and
incorrectly assuming how the fan is constructed. The
slotted screw is not ever supposed to be turned. The
slot is there to allow you to turn the nut without
putting any torque on the screw.

The correct way to remove the fan is to put a screwdriver
in the slot. Holding the screwdriver firm, and using a
wrench, loosen the nut. Remove the screwdriver, and turn
the nut by finger until it is flush with the top of the
screw slot. Finally, tap the nut a couple of times...
lightly... until the screw goes into the FAN hub a little
bit. The internal collet (the broken thingy) will have
released, and the fan will come off easily.

Send me your address, and I will send you my absolutly last
Tom Jobe collet. I was saving it for my own use, but you
need it more than I do.

-Chuck Harris

Phil Wong via Groups.Io wrote:

I got hold of a Tek 2465 (the one with the Siemens motor), but the inside
fan is cracked.

I could get epoxy and glue it back (suggestion appreciated), but this
fastener piece is in 4-5 small pieces. Could somebody here suggest a place
where I could order one of these?