Date   

Re: Payment; Thanks

Byron Hayes, Jr.
 

Dennis,

I just sent $20 to Marian to add my share to the fund. I echo the sentiments of others, to thank you and Michael for your diligent work in making TekScopes the great group it is.

Byron, WA6ATN


Re: MEMBERS PLEASE READ: Our annual Group.io payment is due in 2 weeks.

Gary Robert Bosworth
 

I am totally confused as to where I send money to annual group payment.
Gary


On Thu, Jan 2, 2020, 18:37 victor.silva via Groups.Io <daejon1=
yahoo.com@groups.io> wrote:

Barry,

Marian must be Dennis' wife.

--Victor




TDS694C 50 Ohm Overload

George Langston
 

Hi All,

I have a tds694c that will not pass SPC due to a previous "50 ohm overload" error on Ch2. All other channels appear to be working properly. This scope does not utilize the attenuator hybrids that all other TDS 500/600/700 models use. It has only 50 ohm DC coupling available. The input goes through a rigid coax line directly to a relay and from there it's not clear but looks like it goes to a massive heat-sinked ADC. The trace shows up on the screen but is attenuated compared to the other channels and looks noisy. Also, the trace looks good at the output of the relay. If anyone is familiar with this circuit, please let me know. I have a feeling I'm on my own, but when/if I track this down I'll be sure to post. Thank you!

George


Re: Push-push switch repair (need some theory of operation)

 

Hi Ke-Fong,

YIKES! That is not a very common switch! I searched everything I have and didn't find one on any parts board I have.

You will be delighted to hear there is an alternative however: C&K makes a 6 pole double-throw switch for less than $4.00 in single quantities. The part number is F6UEETB. It is sold by many distributors. I got mine from Mouser. The pinouts are an exact replacement for the one in the 5CT1N and 7CT1N. I just checked. I also believe the same extender rods will connect correctly to the push button shaft on the front of it.

That leaves the really big problem of getting the old switch out. That will not be easy. Since there is a little space under the switch I would recommend you cut the switch off its pins and leave the pins in place until the switch is out of the way. At that point you can remove each pin one at a time and clean out that hole before going on to the next pin. You might even be able to do this without removing the board from the plugin if you are really clever and careful.

Dennis Tillman W7PF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Ke-Fong Lin
Sent: Thursday, January 02, 2020 1:05 AM
Subject: Re: [TekScopes] Push-push switch repair (need some theory of operation)

Hi everyone,

Thanks for your tips.
The repair document is exactly what I'm looking for.
I'll keep you posted.
Again thank you.

Best regards,




--
Dennis Tillman W7PF
TekScopes Moderator


Re: Tektronix 2245a Flickering Trace

KB6NAX
 

Yup, I have to agree with Siggi. The "OSD," meaning the vertical
sensitivity callout in the lower left hand corner and the sweep time in the
lower right hand corner also are jumping sideways along with the
sine wave. So the jitter is occurring in the horizontal amplifier chain, not
the triggering circuit. With power off, carefully reseat anything that plugs in.
Don't slip up and plug anything back in wrong that you pulled out - no bent
pins, etc.

Arden


I think it's safe to say that you have more than just a triggering issue,
as your OSD (on-screen display) is jumping around as well as the traces
(see e.g. around here https://youtu.be/j6Dqke1CIRE?t=74). This could be as
simple as a marginally plugged-in connector somewhere, but you should be
looking at points common to the OSD and sweeps. This includes power
supplies and e.g. the horizontal amplifier. Your vertical appears
unaffected, however.
If you haven't read this:
https://www.sphere.bc.ca/test/tek-parts/troubleshooting-scopes.pdf already,
you may want to take a gander. Do you have a second scope you could turn on
your 2245A?

Siggi <


Re: 577D1 itching issue - Haven't touched since, currently in storage

DW
 

Thanks for the reply Dave, I will take that into consideration

I had a thought about line voltage selection. I believe the 577 is set for 120V and I even checked and it appears to be. But just out of curiosity would having the line voltage selector set to 110 on 120V mains possibly overdrive the collector supply thus explaining my issue? Maybe if it was in the 110 selection I would see maybe 130V wide open from the variac which tell me to check the power supply line voltage selection, in which case I only saw 120 so I believe I am fine, just a thought.


Re: MEMBERS PLEASE READ: Our annual Group.io payment is due in 2 weeks.

victor.silva
 

Barry,

Marian must be Dennis' wife.

--Victor


Re: Tektronix 2245a Flickering Trace

Siggi
 

Hey Bill,

I think it's safe to say that you have more than just a triggering issue,
as your OSD (on-screen display) is jumping around as well as the traces
(see e.g. around here https://youtu.be/j6Dqke1CIRE?t=74). This could be as
simple as a marginally plugged-in connector somewhere, but you should be
looking at points common to the OSD and sweeps. This includes power
supplies and e.g. the horizontal amplifier. Your vertical appears
unaffected, however.
If you haven't read this:
https://www.sphere.bc.ca/test/tek-parts/troubleshooting-scopes.pdf already,
you may want to take a gander. Do you have a second scope you could turn on
your 2245A?

Siggi

On Thu, Jan 2, 2020 at 8:23 PM William Schuler <guitardad1967@...>
wrote:

Thanks Arden, I’ll give that a whirl this weekend.

On Thu, Jan 2, 2020 at 2:04 PM KB6NAX <gumbear@...> wrote:

Hi Bill,

Sounds like Panos has a clue. Switch in the 20 MHz bandwidth filter to
see
if the erratic triggering stops or lessens. Too much bandwidth can be a
problem in a noisy environment. If the triggering in 20 MHz mode still
acts
up there's something noisy in the triggering circuits.

Arden

-----Original Message-----
From: guitardad1967@...
Sent: Thursday, January 02, 2020 5:58 AM
To: TekScopes@groups.io
Subject: [TekScopes] Tektronix 2245a Flickering Trace

Hey guys, newbie here. First of all I want to say thanks for what a great
resource this place is! Made my donation two days ago.

I have a Tektronix 2245a, which I bought about a year ago. This is my
first
scope, and I’m still learning how to use it. I have replaced all the
power
supply capacitors, and all the voltages test out OK., and the unit runs
OK
when I first power it on. After about 10 minutes though, I start to get
ghost traces and a jumpy, flickering image. Here is a link to a video I
made
of the unit. https://youtu.be/j6Dqke1CIRE

It is usable for what I do, which is just viewing a signal after it’s
gone
through a tube amp, but I would like to track down the issue. Any
suggestions on where to look?

Thanks everyone, Bill









Re: Tektronix 2245a Flickering Trace

William Schuler
 

Thanks Arden, I’ll give that a whirl this weekend.

On Thu, Jan 2, 2020 at 2:04 PM KB6NAX <gumbear@...> wrote:

Hi Bill,

Sounds like Panos has a clue. Switch in the 20 MHz bandwidth filter to
see
if the erratic triggering stops or lessens. Too much bandwidth can be a
problem in a noisy environment. If the triggering in 20 MHz mode still
acts
up there's something noisy in the triggering circuits.

Arden

-----Original Message-----
From: guitardad1967@...
Sent: Thursday, January 02, 2020 5:58 AM
To: TekScopes@groups.io
Subject: [TekScopes] Tektronix 2245a Flickering Trace

Hey guys, newbie here. First of all I want to say thanks for what a great
resource this place is! Made my donation two days ago.

I have a Tektronix 2245a, which I bought about a year ago. This is my
first
scope, and I’m still learning how to use it. I have replaced all the power
supply capacitors, and all the voltages test out OK., and the unit runs OK
when I first power it on. After about 10 minutes though, I start to get
ghost traces and a jumpy, flickering image. Here is a link to a video I
made
of the unit. https://youtu.be/j6Dqke1CIRE

It is usable for what I do, which is just viewing a signal after it’s gone
through a tube amp, but I would like to track down the issue. Any
suggestions on where to look?

Thanks everyone, Bill







Re: MEMBERS PLEASE READ: Our annual Group.io payment is due in 2 weeks.

Craig Cramb
 

Thank you Dennis for letting us know the situation. Contrubution sent.

Craig


Re: MEMBERS PLEASE READ: Our annual Group.io payment is due in 2 weeks.

Geoffb
 

Thanks for all your efforts, Dennis.
Happy New Year to All!


Re: MEMBERS PLEASE READ: Our annual Group.io payment is due in 2 weeks.

 

Donation sent Dennis.....

Ancel


Re: MEMBERS PLEASE READ: Our annual Group.io payment is due in 2 weeks.

Reginald Beardsley
 

On Thu, Jan 2, 2020 at 04:22 PM, Rogerio O wrote:


Sent a contribution to te email informed in a previous tread. I started with
$10.00 as a first trial. I will donate more if we don’t meet the quota.
I wasn't going to post, but I sent $10 ASAP. I am pretty sure many others did the same without posting anything.

Now, so long as Dennis does not run off to a private island with all that loot, I think the list is well funded for some time to come.

Have Fun!
Reg

FWIW A number of people I buy stuff from have a PayPal account in the name of SWMBO@...


Re: 577D1 itching issue - Haven't touched since, currently in storage

Dave Hills
 

What you are seeing may just be stray signal pickup from the open input of the horizontal
amplifier when no DUT is present. Try connecting a 1K resistor from the collector to emitter terminals
of the 177 and move the left-right switch to the appropriate side. On mine this drives the line to a dot
on any voltage range of the peak voltage range switch with the variable collector set to zero%.

Dave

On Wed, Jan 1, 2020 at 12:37 PM, DW wrote:


I agree with your response Arden, a resistance measurement is less risky and
preferable, good call!

When I can pull the 577 out of storage I will perform these checks

I will check the resistance from the neutral to the first winding, then I will
check the resistance from the hot to the last winding and see what the
differences are. Then repeat the tests with the probe on the wiper instead of
the winding.

Thanks for the reply


Re: MEMBERS PLEASE READ: Our annual Group.io payment is due in 2 weeks.

Renée
 

Dennis- now that many interesting issues have settled-a contribution has been sent. Thanks to you and Michael for the superb stewardship!
The knowledge is immense to say the least.
Happy New Year to all!
Renée, K6FSB

On 2020-01-02 3:06 p.m., Dennis Tillman W7PF wrote:
Hi Leo, and everyone else,

First to Leo:
I am stunned by your generosity but this creates a huge dilemma for me because I asked for small contributions. I cannot accept you most generous offer because it is far too much. My goal in asking for small contributions was to give everyone who has gotten some value out of belonging to TekScopes an opportunity to say thanks based on their ability to pay and the value they have received.

For Leo and everyone else:
For reasons neither Marian nor I remember, beca use it happened so long ago, the PayPal account was set up in her name. That only came to our attention the other day when it caused confusion. We are in the process of adding my name to the account to clear up any future confusion. We have been married for 35+ years. What's hers is mine and what's mine is hers (except she doesn't want the Tektronix things).

So far Michael Dunn and I have received over 150 contributions through PayPal, one through Vimeo, and I believe one will be coming through Zelle. As soon as the donations drop to a trickle which I expect by the beginning of next week I will post a notice that anyone who still wants to contribute has 24 hours left. Then it will take me a day to make a spreadsheet of who contributed and what the contribution was. I believe the safest way to do this will be to list just the PayPal transaction numbers and the amounts personal information is revealed for privacy reasons. This way everyone can check that their contribution was received and entered.

For the long term Michael Dunn and I have discussed what should be done next and how to insure the contributions will be safe and secure if something should happen to either one of us. I have also contacted Groups.io to find out if they allow paying a few years in advance.

Dennis Tillman W7PF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Leo Bodnar
Sent: Thursday, January 02, 2020 2:03 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] MEMBERS PLEASE READ: Our annual Group.io payment is due in 2 weeks.

Dennis,

Given the mess with account name and group.io emails handling could you please post the list of names you have received the donations from?

On the 31st of December, moments after your appeal was posted, I have sent you the whole $340 - enough to cover all immediate costs for 2019 and 2020.
PayPal said It went straight into Marian Tillman account. I was slightly bemused to see it's not yours.
Since then - for the last three days - I have not heard anything - neither from you nor the PayPal account owner. This does not sound right.

On Tue, Dec 31, 2019 at 03:42 AM, Dennis Tillman wrote:
I plan to give an accounting of the total to the group once the contributions stop. Anything over $340 will be set aside.
What if they never stop? How do we know you have received the funds?

Leo





Re: TDS694C nvram DS1486

George Langston
 

OK, I solved the ++processor and ++acquisition failures. The scope now shows Voltage Reference PASS, Frequency Response PASS, Pulse Trigger PASS on powerup. I found a single pin on one of the QFP256 devices on A10 that had been nudged into shorting with a neighboring pin. This took care of MANY errors. However, it will not pass SPC because of a 50 ohm overload (my original problem before I got careless when reinstalling the A10 board). I'll start a new topic ...

Many thanks for suggestions!

George


Re: Push-push switch repair (need some theory of operation)

KB6NAX
 

Wow. Tek actually recommended WD40 even to use on pot resistive surfaces. <
WD-40 has wooed a lot of folks into believing their stuff was heaven sent. Nope, I learned the hard way WD-40 is not good for pots or switches. It eventually dries to the point that contacts ride over it instead of it assuring metal to metal contact.

Never put WD-40 next to a roll of duct tape. The two are mutual enemies and will annihilate each other. That has been proven by scientific experiment. Duct tape sticks things. WD-40 unsticks things. It's a fight to the death....

Arden


Re: MEMBERS PLEASE READ: Our annual Group.io payment is due in 2 weeks.

Scott Walters
 

TYVM $20.00 to dennis at ridesoft


Re: MEMBERS PLEASE READ: Our annual Group.io payment is due in 2 weeks.

 

Hi Leo, and everyone else,

First to Leo:
I am stunned by your generosity but this creates a huge dilemma for me because I asked for small contributions. I cannot accept you most generous offer because it is far too much. My goal in asking for small contributions was to give everyone who has gotten some value out of belonging to TekScopes an opportunity to say thanks based on their ability to pay and the value they have received.

For Leo and everyone else:
For reasons neither Marian nor I remember, because it happened so long ago, the PayPal account was set up in her name. That only came to our attention the other day when it caused confusion. We are in the process of adding my name to the account to clear up any future confusion. We have been married for 35+ years. What's hers is mine and what's mine is hers (except she doesn't want the Tektronix things).

So far Michael Dunn and I have received over 150 contributions through PayPal, one through Vimeo, and I believe one will be coming through Zelle. As soon as the donations drop to a trickle which I expect by the beginning of next week I will post a notice that anyone who still wants to contribute has 24 hours left. Then it will take me a day to make a spreadsheet of who contributed and what the contribution was. I believe the safest way to do this will be to list just the PayPal transaction numbers and the amounts personal information is revealed for privacy reasons. This way everyone can check that their contribution was received and entered.

For the long term Michael Dunn and I have discussed what should be done next and how to insure the contributions will be safe and secure if something should happen to either one of us. I have also contacted Groups.io to find out if they allow paying a few years in advance.

Dennis Tillman W7PF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Leo Bodnar
Sent: Thursday, January 02, 2020 2:03 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] MEMBERS PLEASE READ: Our annual Group.io payment is due in 2 weeks.

Dennis,

Given the mess with account name and group.io emails handling could you please post the list of names you have received the donations from?

On the 31st of December, moments after your appeal was posted, I have sent you the whole $340 - enough to cover all immediate costs for 2019 and 2020.
PayPal said It went straight into Marian Tillman account. I was slightly bemused to see it's not yours.
Since then - for the last three days - I have not heard anything - neither from you nor the PayPal account owner. This does not sound right.

On Tue, Dec 31, 2019 at 03:42 AM, Dennis Tillman wrote:
I plan to give an accounting of the total to the group once the contributions stop. Anything over $340 will be set aside.
What if they never stop? How do we know you have received the funds?

Leo





--
Dennis Tillman W7PF
TekScopes Moderator


535 front panel corrosion/staining?

Bruce Atwood
 

I the corrosion/staining shown in the photos below a known problem? Can it be cleaned or has the finish been eaten? It is CL about an hour away and I'd like to know what to look for.

thanks

[cid:part1.058BC5C9.5C0D07A4@...]

[cid:part2.DEE06756.A1E3335E@...]


[cid:part3.707807CC.F224D056@...]


--
Bruce Atwood PhD
Department of Astronomy
The Ohio State University
100 West 18th Ave., Room 4055
Columbus, OH 43210

Phone 614.314.0189
FAX 614.292.2928