Date   

Re: Solved: 575 line voltage noise source

Peter Gottlieb
 

You could make a filter for it, but why not simply have it unplugged when not in use, or on a timer?

Are those tests even called for in a pure power consuming device? I thought they were more for grid-connected power conversion systems such as solar inverters and large energy storage system inverters. Remember, you can go to Home Depot and buy fully approved triac phase control dimmers.

In any case, flicker is not the problem with that kind of disturbance (much slower, multi-cycle phenomenon), and it doesn't look like it will be anywhere near the 5% THD limit. Looking on the label will show you what agency certifications it has. If you have one of those FFT or even swept audio frequency spectrum analyzers from HP or SRL you can look at the line and see the harmonic levels and do the calculations, or borrow a more modern Fluke or Yokogawa which directly reads that out.

Peter

On 1/10/2015 11:37 AM, Stefan Trethan stefan_trethan@... [TekScopes] wrote:

I don't think a ferrite will do the trick here, sounds like a low
frequency disturbance.

I'm surprised this coffee maker passed flicker and harmonics tests,
but the mains probably looks a lot worse these days than it did when
the 575 was developed.

Oh well, I guess you'll just have to throw it out then, after all
what's coffee if you can have a working curve tracer.

ST

On Sat, Jan 10, 2015 at 4:13 PM, Merchison Burke merchison@...
[TekScopes] <TekScopes@...> wrote:
Option 1: Turn off the Bunn when using the 575.

Option 2: If the Bunn coffee maker uses a line cord similar to
computers, you might want to replace the line cord with a line cord that
has a toroid core on it. Some computers had line cords with the toroid
cores heat-shrunk onto them.

Option 3: Add a toroid core to the line cord of the Bunn. This might
help to reduce the noise.

Option 4: You may want to try a line filter similar to the line filters
on test equipment, mounted in a small metal box with the metal box
connected to the ground wire and the Bunn coffee maker plugged into the
filter or, if there is room, mounted inside the Bunn coffee maker.

Option 5: If the Bunn coffee maker uses a line cord similar to
computers, you might want to replace the connector with a filtered
connector such as the ones used in test equipment.

Option 6: Buy a coffee maker which does not make mains noise.

Option 7: Use a kettle to make coffee one cup at a time.

Option 8: Stop drinking coffee.

Merchison


On 2015-Jan-10 9:22 AM, Barry Densch fretsbiz@... [TekScopes] wrote:
Thanks Matt. Your diagnosis was correct!

The engineer at Bunn company said they know the coffee maker makes mains
noise. He said they use a triac to monitor the hot water reservoir
temperature. This means 2 SCRs back to back that switch on or off at zero
crossing. Too bad the engineer didn't mention any plans to fix the noise.
So I am disappointed with the Bunn company.....especially since they know
the coffee maker makes line voltage noise as well as coffee!


Best regards,
-Barry


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Posted by: Merchison Burke <merchison@...>
------------------------------------


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Yahoo Groups Links



Re: Solved: 575 line voltage noise source

stefan_trethan
 

I don't think a ferrite will do the trick here, sounds like a low
frequency disturbance.

I'm surprised this coffee maker passed flicker and harmonics tests,
but the mains probably looks a lot worse these days than it did when
the 575 was developed.

Oh well, I guess you'll just have to throw it out then, after all
what's coffee if you can have a working curve tracer.

ST


On Sat, Jan 10, 2015 at 4:13 PM, Merchison Burke merchison@...
[TekScopes] <TekScopes@...> wrote:
Option 1: Turn off the Bunn when using the 575.

Option 2: If the Bunn coffee maker uses a line cord similar to
computers, you might want to replace the line cord with a line cord that
has a toroid core on it. Some computers had line cords with the toroid
cores heat-shrunk onto them.

Option 3: Add a toroid core to the line cord of the Bunn. This might
help to reduce the noise.

Option 4: You may want to try a line filter similar to the line filters
on test equipment, mounted in a small metal box with the metal box
connected to the ground wire and the Bunn coffee maker plugged into the
filter or, if there is room, mounted inside the Bunn coffee maker.

Option 5: If the Bunn coffee maker uses a line cord similar to
computers, you might want to replace the connector with a filtered
connector such as the ones used in test equipment.

Option 6: Buy a coffee maker which does not make mains noise.

Option 7: Use a kettle to make coffee one cup at a time.

Option 8: Stop drinking coffee.

Merchison


On 2015-Jan-10 9:22 AM, Barry Densch fretsbiz@... [TekScopes] wrote:
Thanks Matt. Your diagnosis was correct!

The engineer at Bunn company said they know the coffee maker makes mains
noise. He said they use a triac to monitor the hot water reservoir
temperature. This means 2 SCRs back to back that switch on or off at zero
crossing. Too bad the engineer didn't mention any plans to fix the noise.
So I am disappointed with the Bunn company.....especially since they know
the coffee maker makes line voltage noise as well as coffee!


Best regards,
-Barry


------------------------------------
Posted by: Merchison Burke <merchison@...>
------------------------------------


------------------------------------

Yahoo Groups Links



Re: Solved: 575 line voltage noise source

Peter Gottlieb
 

I am just glad Broadband over Power Lines failed on its own.

On 1/10/2015 11:18 AM, geoffrey thomas geoffreythomas@... [TekScopes] wrote:

Not so long ago they wouldn't have been able to sell this rubbish, the
wonders of de-regulation.

Geoff.


On 2015-Jan-10 9:22 AM, Barry Densch fretsbiz@... [TekScopes] wrote:
Thanks Matt. Your diagnosis was correct!

The engineer at Bunn company said they know the coffee maker makes mains
noise. He said they use a triac to monitor the hot water reservoir
temperature. This means 2 SCRs back to back that switch on or off at zero
crossing. Too bad the engineer didn't mention any plans to fix the noise.
So I am disappointed with the Bunn company.....especially since they know
the coffee maker makes line voltage noise as well as coffee!


Best regards,
-Barry


Re: Solved: 575 line voltage noise source

Geoffrey Thomas
 

Not so long ago they wouldn't have been able to sell this rubbish, the wonders of de-regulation.

Geoff.


On 2015-Jan-10 9:22 AM, Barry Densch fretsbiz@... [TekScopes] wrote:
Thanks Matt. Your diagnosis was correct!

The engineer at Bunn company said they know the coffee maker makes mains
noise. He said they use a triac to monitor the hot water reservoir
temperature. This means 2 SCRs back to back that switch on or off at zero
crossing. Too bad the engineer didn't mention any plans to fix the noise.
So I am disappointed with the Bunn company.....especially since they know
the coffee maker makes line voltage noise as well as coffee!


Best regards,
-Barry


Re: Solved: 575 line voltage noise source

Buzz Boxx
 

Merchison,

Thank you. I assume that you are drinking a caffeinated beverage as
evidenced by your numerous suggestions. Now, how do those toroidal
thing-a-ma-bobs work?

-Barry
On Jan 10, 2015 9:13 AM, "Merchison Burke merchison@...
[TekScopes]" <TekScopes@...> wrote:



Option 1: Turn off the Bunn when using the 575.

Option 2: If the Bunn coffee maker uses a line cord similar to
computers, you might want to replace the line cord with a line cord that
has a toroid core on it. Some computers had line cords with the toroid
cores heat-shrunk onto them.

Option 3: Add a toroid core to the line cord of the Bunn. This might
help to reduce the noise.

Option 4: You may want to try a line filter similar to the line filters
on test equipment, mounted in a small metal box with the metal box
connected to the ground wire and the Bunn coffee maker plugged into the
filter or, if there is room, mounted inside the Bunn coffee maker.

Option 5: If the Bunn coffee maker uses a line cord similar to
computers, you might want to replace the connector with a filtered
connector such as the ones used in test equipment.

Option 6: Buy a coffee maker which does not make mains noise.

Option 7: Use a kettle to make coffee one cup at a time.

Option 8: Stop drinking coffee.

Merchison

On 2015-Jan-10 9:22 AM, Barry Densch fretsbiz@... [TekScopes] wrote:
Thanks Matt. Your diagnosis was correct!

The engineer at Bunn company said they know the coffee maker makes mains
noise. He said they use a triac to monitor the hot water reservoir
temperature. This means 2 SCRs back to back that switch on or off at zero
crossing. Too bad the engineer didn't mention any plans to fix the noise.
So I am disappointed with the Bunn company.....especially since they know
the coffee maker makes line voltage noise as well as coffee!


Best regards,
-Barry


Re: OT - Solder Pot and Wire solder

John Griessen
 

On 01/10/2015 02:19 AM, Stefan Trethan stefan_trethan@... [TekScopes] wrote:
I've heard tales that you can just twist them together, coat with
borax, and they will weld themselves.
For a metal like iron, that would work fine. For NiChrome, not so sure, but worth
attempts. Any dissimilar metals at heater temperture will probably not work with all the temperature cycling
near melting points. The end crimps stay cool is why they work.

I have some salvaged NiChrome wire in larger coils. It could be tightened up on a smaller rod mandrel
and become an uninterrupted coil to fit the old heater ceramic grooves.


Re: Solved: 575 line voltage noise source

Merchison Burke
 

Option 1: Turn off the Bunn when using the 575.

Option 2: If the Bunn coffee maker uses a line cord similar to computers, you might want to replace the line cord with a line cord that has a toroid core on it. Some computers had line cords with the toroid cores heat-shrunk onto them.

Option 3: Add a toroid core to the line cord of the Bunn. This might help to reduce the noise.

Option 4: You may want to try a line filter similar to the line filters on test equipment, mounted in a small metal box with the metal box connected to the ground wire and the Bunn coffee maker plugged into the filter or, if there is room, mounted inside the Bunn coffee maker.

Option 5: If the Bunn coffee maker uses a line cord similar to computers, you might want to replace the connector with a filtered connector such as the ones used in test equipment.

Option 6: Buy a coffee maker which does not make mains noise.

Option 7: Use a kettle to make coffee one cup at a time.

Option 8: Stop drinking coffee.

Merchison

On 2015-Jan-10 9:22 AM, Barry Densch fretsbiz@... [TekScopes] wrote:
Thanks Matt. Your diagnosis was correct!

The engineer at Bunn company said they know the coffee maker makes mains
noise. He said they use a triac to monitor the hot water reservoir
temperature. This means 2 SCRs back to back that switch on or off at zero
crossing. Too bad the engineer didn't mention any plans to fix the noise.
So I am disappointed with the Bunn company.....especially since they know
the coffee maker makes line voltage noise as well as coffee!


Best regards,
-Barry


Re: Solved: 575 line voltage noise source

Buzz Boxx
 

Hi Herbert. They are all vampires!

-Barry
On Jan 10, 2015 8:25 AM, "Measurement measurement@...
[TekScopes]" <TekScopes@...> wrote:



Hi Barry,

that is the secret live in darkness of the always standby devices ?!

Remember the Critters ..... do not feed after midnight and and do not
let them get wet !

Herbert

Am 09.01.2015 15:11, schrieb Barry Densch fretsbiz@... [TekScopes]:


Hi all,

I went through my breaker box this morning and found the circuit that was
causing a noise spike on my 575 curve tracer. The culprit is a Bunn My
Cafe
coffee maker. I'll try to get in touch with an EE at Bunn and find out
what's going on. In the meantime, I'll just flip off circuit breaker
number
10 if I start getting annoyed.....or, maybe I'll make a cup of coffee and
think about what is really bothering me!

-Barry

[Non-text portions of this message have been removed]





Re: Solved: 575 line voltage noise source

Herbert
 

Hi Barry,

that is the secret live in darkness of the always standby devices ?!

Remember the Critters ..... do not feed after midnight and and do not
let them get wet !

Herbert


Am 09.01.2015 15:11, schrieb Barry Densch fretsbiz@... [TekScopes]:



Hi all,

I went through my breaker box this morning and found the circuit that was
causing a noise spike on my 575 curve tracer. The culprit is a Bunn My
Cafe
coffee maker. I'll try to get in touch with an EE at Bunn and find out
what's going on. In the meantime, I'll just flip off circuit breaker
number
10 if I start getting annoyed.....or, maybe I'll make a cup of coffee and
think about what is really bothering me!

-Barry




Re: Solved: 575 line voltage noise source

Buzz Boxx
 

Thanks Matt. Your diagnosis was correct!

The engineer at Bunn company said they know the coffee maker makes mains
noise. He said they use a triac to monitor the hot water reservoir
temperature. This means 2 SCRs back to back that switch on or off at zero
crossing. Too bad the engineer didn't mention any plans to fix the noise.
So I am disappointed with the Bunn company.....especially since they know
the coffee maker makes line voltage noise as well as coffee!

Alzo, I bought another 575. This one is the 122C model. Time to clean it.
I'll post some photos for you on the Deutsch site.

Best regards,
-Barry
On Jan 10, 2015 8:00 AM, "matt8@... [TekScopes]" <
TekScopes@...> wrote:



sorry, i must laughing, :-)

( your Text is posting in wellenkino.de )

Best regards and making a good coffee
Matt





Re: Solved: 575 line voltage noise source

mattko87
 

sorry, i must laughing, :-)

( your Text is posting in wellenkino.de )

Best regards and making a good coffee
Matt


Re: OT - Solder Pot and Wire solder

stefan_trethan
 

So if you can crimp the ends, how come you can not crimp the break?

I might try welding, like a thermocouple bead, since that is a similar material.
Thermocouples are typically welded by striking an arc on a carbon
electrode, under inert gas.

Brazing would also work, but you'd need a flux (borax) and a suitably hot torch.

I've heard tales that you can just twist them together, coat with
borax, and they will weld themselves. I consider these tales rather
tall.

ST

On Fri, Jan 9, 2015 at 11:45 PM, 'Dennis Tillman' dennis@...
[TekScopes] <TekScopes@...> wrote:
Hi Stewart,

A crimp joint won't work. The crimp doesn't heat evenly compared to the rest of the hot wire around it and it fails quickly. You never see two nichrome wires crimped together. They must always be one continuous strand of wire. You can crimp the ends to ordinary copper stranded wire (like a line cord.

Dennis Tillman W7PF


Re: Manuals Plus going out of business...

Sergey Kubushyn
 

On Fri, 9 Jan 2015, 'Dennis Tillman' dennis@... [TekScopes] wrote:

I'm not Lyle but I'll respond :)

You make an offer by sending then an email or giving them a call. I've just
got a whole bunch of manual shipped to me today, kinda like "Last Buy" --
got manuals for everything I do own and even just plan to buy :)

I don't know what you mean by "nothing was listed by product name". Go to
http://www.manualsplus.com and just enter your instrument number in the
search box. E.g. enter "494ap" and you will get a list of manuals for Tek
494AP with manufacturer's name, model, manual type, manual part no,
condition, and price. What else do you need? Search box is right in the
center of the page and it clearly says "Search by manufacturer and/or model
number".

Where did you find a list? I can not see any... Have you been to the right
site?

Their email is sales@... BTW. That will come to Becky and she
will respond in a day or so. Just list all the manuals you want to purchase
and make your offer.

Too bad they are going out of business... That was a very good place with
tons of manuals including many rare ones that you wouldn't be able to find
anywhere else, they were a pleasure to work with, manuals always were in
very good condition, prompt shipping, everything one could wish...

Lyle,

It doesn't look like they are going out of business on their web site. There
was no indication that you could make an offer on anything.

I also found it very frustrating that nothing was listed by product name.
All the manuals seem to be listed only by their part number with no hint of
what product they were for. If I already have a manual I can tell what part
number it is, but then I don't need the manual. On the other hand if I need
a manual there is no easy way to tell the part number in advance so how do I
search their site without the manual number.

What am I missing?

Dennis Tillman W7PF

-----Original Message-----
From: TekScopes@... [mailto:TekScopes@...]
Sent: Friday, January 09, 2015 10:42 AM
To: TekScopes@...
Subject: [TekScopes] Manuals Plus going out of business...

I got a letter a couple of weeks ago that "Manuals Plus"
http://www.manualsplus.com/ is going out of business. I verified that by
phone yesterday.

They are having a "make me an offer" sale - and I understand they are being
swamped with orders. If you need/want original service/op manuals for test
equipment, etc., now is the time to buy.

I've bought a lot of manuals from Manuals Plus - and I'm really sorry to see
them go. Unfortunately, the owner of their building is raising their rent
next month - and they can't afford to stay - or move...

Lyle

------------------------------------
Posted by: Lyle Bickley <lbickley@...>
------------------------------------




------------------------------------
Posted by: "Dennis Tillman" <dennis@...>
------------------------------------


------------------------------------

Yahoo Groups Links


---
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* KSI@home KOI8 Net < > The impossible we do immediately. *
* Las Vegas NV, USA < > Miracles require 24-hour notice. *
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Re: Manuals Plus going out of business...

 

Did you not see the big box in the middle of the page with the caption above it saying "Search by manufacturer and/or model number: "?

It's a pretty good search tool... you can enter just part of a mfr name or model and get hits on all the manuals containing your search terms. Then you can browse through them and find the manual that you want (if they have it).

Try it again
Dave M



---In TekScopes@..., <dennis@...> wrote :

Lyle,

It doesn't look like they are going out of business on their web site. There
was no indication that you could make an offer on anything.

I also found it very frustrating that nothing was listed by product name.
All the manuals seem to be listed only by their part number with no hint of
what product they were for. If I already have a manual I can tell what part
number it is, but then I don't need the manual. On the other hand if I need
a manual there is no easy way to tell the part number in advance so how do I
search their site without the manual number.

What am I missing?

Dennis Tillman W7PF

-----Original Message-----
From: TekScopes@... mailto:TekScopes@... [mailto:TekScopes@... mailto:TekScopes@...]
Sent: Friday, January 09, 2015 10:42 AM
To: TekScopes@... mailto:TekScopes@...
Subject: [TekScopes] Manuals Plus going out of business...

I got a letter a couple of weeks ago that "Manuals Plus"
http://www.manualsplus.com/ http://www.manualsplus.com/ is going out of business. I verified that by
phone yesterday.

They are having a "make me an offer" sale - and I understand they are being
swamped with orders. If you need/want original service/op manuals for test
equipment, etc., now is the time to buy.

I've bought a lot of manuals from Manuals Plus - and I'm really sorry to see
them go. Unfortunately, the owner of their building is raising their rent
next month - and they can't afford to stay - or move...

Lyle

------------------------------------
Posted by: Lyle Bickley <lbickley@... mailto:lbickley@...>
------------------------------------


Re: Silver Oxide batteries in 7S14 Sampling Gate

 

Hi KW,
What distributor or parts supplier did you buy the batteries from in Canada?
Dennis Tillman W7PF

-----Original Message-----
From: TekScopes@... [mailto:TekScopes@...]
Sent: Friday, January 09, 2015 2:05 PM
To: TekScopes@...
Subject: RE: [TekScopes] Silver Oxide batteries in 7S14 Sampling Gate

Greetings
I live in Canada and we still have mercury batteries that work fine in the
5S14 and 7S14 sampling plugins.
Made by 'Renata' part number 313 1.35 volts /cross ref pt no MR44 Made in
Switzerland.
I had tabs spot welded onto them by a local shop. total cost 20$ including
cells (4).
Should last 10 years +
KW

------------------------------------
Posted by: nosprime@...
------------------------------------


Re: Manuals Plus going out of business...

 

Lyle,

It doesn't look like they are going out of business on their web site. There
was no indication that you could make an offer on anything.

I also found it very frustrating that nothing was listed by product name.
All the manuals seem to be listed only by their part number with no hint of
what product they were for. If I already have a manual I can tell what part
number it is, but then I don't need the manual. On the other hand if I need
a manual there is no easy way to tell the part number in advance so how do I
search their site without the manual number.

What am I missing?

Dennis Tillman W7PF

-----Original Message-----
From: TekScopes@... [mailto:TekScopes@...]
Sent: Friday, January 09, 2015 10:42 AM
To: TekScopes@...
Subject: [TekScopes] Manuals Plus going out of business...

I got a letter a couple of weeks ago that "Manuals Plus"
http://www.manualsplus.com/ is going out of business. I verified that by
phone yesterday.

They are having a "make me an offer" sale - and I understand they are being
swamped with orders. If you need/want original service/op manuals for test
equipment, etc., now is the time to buy.

I've bought a lot of manuals from Manuals Plus - and I'm really sorry to see
them go. Unfortunately, the owner of their building is raising their rent
next month - and they can't afford to stay - or move...

Lyle

------------------------------------
Posted by: Lyle Bickley <lbickley@...>
------------------------------------


Re: Video update 1/9. Tektronix 475A x-y discussion and triggering/sweep

Siggi
 

Yes, I have a plethora of other scopes..
Believe it could be a problem with either Q904, 920, or 920.

Sweet - it should be easy to sort this with a second scope. If you look at the shape and extents of your sweep, you should be able to characterize the failure (once you get your trigger back).


I have to say I love the way most of the test points on my 485 are brought out to a handy eyelet. Perfect for hooking a probe on.
Also they're all labeled, in copper, as there's no silk screen on the PCB IIRC.


Re: Video update 1/9. Tektronix 475A x-y discussion and triggering/sweep

Siggi
 

Hey Keith,

maybe you can scan or snap a picture of the sweep gen schematic and post in photos. That'd help, as I don't think there are any good (free) schematics available for folks here to refer to.


Good luck,
Siggi


Re: 577 Curve Tracer Problem

henasau@...
 

No, R754 didn't shorted through. Part of the resistor touching -30V trace burnt. Its resistance decreased. I think it changed to about 150k.


Re: Video update 1/9. Tektronix 475A x-y discussion and triggering/sweep

Leanna Erickson <lle@...>
 

Thanks,



But now Murphy came calling as I lost all triggering, so have to back up
several steps!



Keith



From: TekScopes@... [mailto:TekScopes@...]
Sent: Friday, January 09, 2015 3:09 PM
To: TekScopes@...
Subject: RE: [TekScopes] Video update 1/9. Tektronix 475A x-y discussion and
triggering/sweep





On the collector of Q904, I have -0.865 volts when I should have +0.5
volts.


In the 465 and 485 scopes the A and B sweeps are identical. If the 475A is
the same, you can try switching components from one to the other, one by by
one, and see which one causes the problem.

81661 - 81680 of 194681