Date   
Re: Guernsey Island 2445

Chuck Harris
 

Everything you want to know about serial numbers is in
the front of the 2445 manual, usually on the copyright
page.

I was using "8" as a sample prefix, Beaverton is "B",
Gurnsey is "1", UK is "2", Sony is "3", and Holland
is "7"

The primary thing I was trying to relate is the last
5 digits determines which engineering change orders
apply to your instrument.

-Chuck Harris

n4buq wrote:

Okay. Apparently I inferred too much from the example.

Thanks,
Barry - N4BUQ

----- Original Message -----

Re: Guernsey Island 2445

Chuck Harris
 

I am mix mashing Holland and Gurnsey.

But my point still stands. There was undoubtedly
a connection between all of the tek factories that
made a given instrument. I am certain that they
linked the serial numbers so that the engineering
changes apply to the last 5 digits of the serial
number, regardless of which factory made it.

-Chuck Harris

Colin Herbert via Groups.Io wrote:

I believe that all of the manuals were printed in Beaverton, but I might be talking rubbish. The Guernsey products had either no beginning letter or the letter "G", where Beaverton-made items are "Bxxxxxx".

I think that the part-numbers are the same, wherever the equipment is made. Otherwise, I think Deane Kidd would have had something to say about it!

Colin.

Re: Guernsey Island 2445

n4buq
 

Okay. Apparently I inferred too much from the example.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "cmjones01" <chris@...>
To: TekScopes@groups.io
Sent: Sunday, January 26, 2020 2:39:47 PM
Subject: Re: [TekScopes] Guernsey Island 2445

On Sun, Jan 26, 2020 at 8:51 PM n4buq <n4buq@...> wrote:

Did all the Guernsey serial numbers begin with 8? Mine has a six-digit
serial number that begins with 1.
Most of my Tek equipment was built in Guernsey, and it all has serial
numbers starting with 1. My 535A is right in front of me, serial
number 101936, and my 7904A (built in Guernsey even though I bought it
in the USA) is (I think) 100084.

Chris



Re: Guernsey Island 2445

cmjones01
 

On Sun, Jan 26, 2020 at 8:51 PM n4buq <n4buq@...> wrote:

Did all the Guernsey serial numbers begin with 8? Mine has a six-digit serial number that begins with 1.
Most of my Tek equipment was built in Guernsey, and it all has serial
numbers starting with 1. My 535A is right in front of me, serial
number 101936, and my 7904A (built in Guernsey even though I bought it
in the USA) is (I think) 100084.

Chris

Re: 11801 questions - funny fan noise and light

Leo Bodnar
 

Quiter fan would mean that 11801 can be used more and for longer.
And this is exactly what I don't want!
Leo

Re: Your generosity is STUNNING!

Michael A. Terrell
 

Why not set up a bank account for it, and Autopay for Groups.io? It could
also be used to fund group purchases for custom made replacement parts,
when you are short a person or two. Put the money back into the account
when the extras are sold. We did this for a computer club, in the '80s. It
was registered as a non profit, but it wouldn't be difficult to do that for
a group this size.

On Sun, Jan 26, 2020 at 12:46 AM Dennis Tillman W7PF <@Dennis_Tillman_W7PF>
wrote:

Hi Raymond,

You are one of the few people who did correctly identify your contribution
in my list.
This is the information I have on your contribution:
### DENNIS' LOCAL TIME $$$ STATUS CONTRIBUTOR
PAYPAL TRANSACTION
128 Wed 1/1/2020 2:50 PM $22.57 TO BE RETURNED Raymond Domp
Frank 9SK435895B100851N

Yes, Siggi is correct PayPal did this for everyone. They also obscure the
time you made your contribution because they strip out your UTC offset
(time zone) so I can’t tell the hour of the day you sent it. The minutes
are close however.

Thank you for your contribution. We received too much money to keep it all
so we will be refunding anything above $10.00 as soon as I have had a
chance to contact everyone who asked for confirmation that I received their
contribution.

Dennis

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of
Raymond Domp Frank
Sent: Monday, January 20, 2020 9:45 AM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Your generosity is STUNNING!

Dennis,
My transaction could well be
9SK43*******0851N $22.57 TO BE REFUNDED
That's the only transaction in your list for the amount that I transferred.
Siggi may be right in assuming that Paypal references change between
sender and receiver (nice!) for international transactions.

Raymond




Re: Tek CRTs supplied to competing manufacturers

Bob Koller
 

I believe that the AN/UPM-137 IFF Test Set, at least the units made by Teledyne Electronics back in the day, had a Tek made CRT.

Re: Tek CRTs supplied to competing manufacturers

george gonzalez <grg2gonzalez@...>
 

I think it was the other way around, Tek used to buy CRTs from Dumont and
RCA but found out they were getting the below average CRTs. This came to
light when some university bought like 50 CRTs and some alert Tek person
noticed the tubes were not in serial number order and they all were
extremely bright and sharp, better than the ones sent to Tektronix. This
spurred Tek to start up their own CRT factory. Expensive but had superb
results.

On Friday, January 24, 2020, Greg Muir via Groups.Io <big_sky_explorer=
yahoo.com@groups.io> wrote:

Thanks, Dennis.

I did think it came from a fairly reputable source. But the years that
passed after reading of it made it rather fuzzy in the ol' brain.

As for another title, i would add "...and why was it subject to such
suffering under control of a holding company?"

("Big fish eating smaller fish")

Greg



Re: Guernsey Island 2445

n4buq
 

Did all the Guernsey serial numbers begin with 8? Mine has a six-digit serial number that begins with 1.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Chuck Harris" <cfharris@...>
To: TekScopes@groups.io
Sent: Sunday, January 26, 2020 1:34:58 PM
Subject: Re: [TekScopes] Guernsey Island 2445

I am pretty sure that the last 5 digits between Guernsey
and Beaverton units are not unique, but rather, are sync'd
to each other so the change orders apply.

In other words, you can have a B012345 and an 8012345 scope,
and each will use the revisions specific to B012345.

They were in communication with each other.

-Chuck Harris

n4buq wrote:
My 2445 was made in Guernsey Island. In the manual I have, I notice there
are references to certain serial numbers for certain parts, etc., and that
that made me wonder if/how those would apply to the Guernsey model
numbers. I presume there was not a separate manual for those models,
correct, and, if not, I wonder which serial numbers might apply?

Thanks,
Barry - N4BUQ






Re: 2400 series Test 4 Fail 3,13, 1

Craig Cramb
 

It would probably be fine.

Thanks Chuck, it looks like there are some used and new ones from private sellers.

Craig

On Jan 26, 2020, at 1:20 PM, Chuck Harris <cfharris@...> wrote:

It would probably be fine.

Re: Guernsey Island 2445

Chuck Harris
 

I am pretty sure that the last 5 digits between Guernsey
and Beaverton units are not unique, but rather, are sync'd
to each other so the change orders apply.

In other words, you can have a B012345 and an 8012345 scope,
and each will use the revisions specific to B012345.

They were in communication with each other.

-Chuck Harris

n4buq wrote:

My 2445 was made in Guernsey Island. In the manual I have, I notice there are references to certain serial numbers for certain parts, etc., and that that made me wonder if/how those would apply to the Guernsey model numbers. I presume there was not a separate manual for those models, correct, and, if not, I wonder which serial numbers might apply?

Thanks,
Barry - N4BUQ




Re: Guernsey Island 2445

Colin Herbert
 

I believe that all of the manuals were printed in Beaverton, but I might be talking rubbish. The Guernsey products had either no beginning letter or the letter "G", where Beaverton-made items are "Bxxxxxx".

I think that the part-numbers are the same, wherever the equipment is made. Otherwise, I think Deane Kidd would have had something to say about it!

Colin.

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of n4buq
Sent: 26 January 2020 19:07
To: TekScopes@groups.io
Subject: [TekScopes] Guernsey Island 2445

My 2445 was made in Guernsey Island. In the manual I have, I notice there are references to certain serial numbers for certain parts, etc., and that that made me wonder if/how those would apply to the Guernsey model numbers. I presume there was not a separate manual for those models, correct, and, if not, I wonder which serial numbers might apply?

Thanks,
Barry - N4BUQ

Re: 2400 series Test 4 Fail 3,13, 1

Chuck Harris
 

It would probably be fine.

-Chuck Harris

Craig Cramb wrote:

The NEC uPD4364-20L draws 100ua max standby current.
The NEC uPD4364-20LL draws 50ua max standby current.

The D4464C-20 only draws 10ua standby current so maybe this would be a good choice to replace it with.

Craig

Guernsey Island 2445

n4buq
 

My 2445 was made in Guernsey Island. In the manual I have, I notice there are references to certain serial numbers for certain parts, etc., and that that made me wonder if/how those would apply to the Guernsey model numbers. I presume there was not a separate manual for those models, correct, and, if not, I wonder which serial numbers might apply?

Thanks,
Barry - N4BUQ

Re: 11801 questions - funny fan noise and light

Gudjon Gudjonsson
 

Hi list

I bought a TM5000 and nearly started crying when I heard the noise :)
But I replaced the fan with a new 24V fan and the instrument is quiet
and lovely.
Plugged it directly to the 25V supply.

Has anyone replaced the 11801/CSA803 fan with a more quiet one?

Regards
Gudjon

TDS210 trigger pick-off

boid_twitty
 

Probably asked this before, but has anyone found a trigger pick-off method for TDS210-type scopes?

Although not the best where low levels are concerned, it's a hell of a lot easier to use than other scopes I'm dealing with. I'd like to wire a trigger output to drive more elaborate but less triggerable devices.

RL

Re: 2400 series Test 4 Fail 3,13, 1

Craig Cramb
 

The NEC uPD4364-20L draws 100ua max standby current.
The NEC uPD4364-20LL draws 50ua max standby current.

The D4464C-20 only draws 10ua standby current so maybe this would be a good choice to replace it with.

Craig

On Jan 26, 2020, at 11:40 AM, Craig Cramb via Groups.Io <electronixtoolbox=gmail.com@groups.io> wrote:

This post was originally was on 3 units that I was working on. The 2465a after replacing its ram, calibration issues were corrected.
This 2465B was doing the same things after going thru it’s calibration sequence so I changed it following the same path as the 2465a unit. The second post earlier in this thread is where I thought this must be the issue with both units. I couldn’t seem to locate the LL chip so just went with the L thinking it would be ok. I still have the original chip I removed.
The 2465A and 2465DM Ram chip were a D4464-20.

Craig


On Jan 26, 2020, at 10:29 AM, Chuck Harris <cfharris@...> wrote:

Why did you replace the original RAM chip?s

Re: 2400 series Test 4 Fail 3,13, 1

Craig Cramb
 

This post was originally was on 3 units that I was working on. The 2465a after replacing its ram, calibration issues were corrected.
This 2465B was doing the same things after going thru it’s calibration sequence so I changed it following the same path as the 2465a unit. The second post earlier in this thread is where I thought this must be the issue with both units. I couldn’t seem to locate the LL chip so just went with the L thinking it would be ok. I still have the original chip I removed.
The 2465A and 2465DM Ram chip were a D4464-20.

Craig

On Jan 26, 2020, at 10:29 AM, Chuck Harris <cfharris@...> wrote:

Why did you replace the original RAM chip?s

Re: 11801 questions - funny fan noise and light

Ragnar S
 

Thank you gentlemen for your replies!

So it is unclear if it is supposed to do this, but it is at least not
unheard of.

I checked the voltages on the feed wires to the fan relative chassis ground.
From start, the positive wire has about +6.3 V and the negative about +0.7 V.
When the fan revving occurs, the negative wire goes to about -6 V for about
35 ms, making a total voltage over the fan of about 12 V. For some reason
the pulses come irregularly, around 1 or a few times per second.

My current hypotheses is that the intention is to regulate the speed of
the fan, but I would be surprised if this actually is how it was designed
to work. It is somewhat annoying. :-)

Are there any schematics on these boxes to be found?


Also - the neon (?) light in the power supply, right behind the fan, that
starts to flicker as soon as it has power (also in standby mode) - do you
guys have that too?


Thanks for you help and best regards,

Ragnar

On 25 Jan 2020, at 16:01, Chuck Harris <cfharris@...> wrote:

Mine is normal until after the scope has been turned on for
about 30 minutes, and then it starts going "Brummm..... Brummm..."

I suspect a capacitor failure, as it is annoying, and would have
caused notice if it were a "normal" condition.

Annoying, though it may be, I can't see how it would cause any
harm... unless it presages a total failure.

What it isn't is a bearing failure, or lack of lubrication. My
fan spins for what seems like half a minute after power is turned
off.

-Chuck Harris

Reginald Beardsley via Groups.Io wrote:
I don't recall mine ever doing that. I'm very sensitive to noise as I investigate anything I can't identify, so I think I would have noticed it.

A fan on one of my HP Z400 workstations was doing that. I shut it down to reduce the heat in the room and when I tried to boot it the fan was dead. I've not had time to correct it yet.

Good luck,
Reg



Re: P6201 probe Q100 FET replacement

Nenad Filipovic
 

Thanks for your inputs, the probe is working, I decided to go with the
datasheet and mounted the FET upside down. R150 had to be decreased from
2kOhm to about 1.45kOhm for proper biasing. It needs calibration though,
but for that I'd need to assemble a proper rig.

Best Regards,
Nenad