Date   
App that keeps track of "Or Best Offer" auctions on eBay to tell you what a seller will accept.

John Dickens
 

Please post this for everyone to see. Thanks, John

On May 21, 2019, at 5:19 PM, Daniel Koller via Groups.Io <kaboomdk=yahoo.com@groups.io> wrote:

Hi all, With all due respect to OP Dennis, this IS on topic, given that a lot of my Tek equipment came from e-bay, and I suspect that is also true of a lot of others here. Got my 7854 on e-bay, after watching prices for months, and I snagged it for under $200 including shipping.
Please add me to the list if anyone knows of such an app. I'm happy to take a reply off-line as well, but it's probably helpful to the group as a whole.
Dan

Re: App that keeps track of "Or Best Offer" auctions on eBay to tell you what a seller will accept.

ROLYNN PRECHTL K7DFW
 

Please post this for everyone to see. Thanks, John
================================================================


Not an app but this is what I use to purchase TEKTRONIX items.

<https://www.goofbid.com/ebay_best_offers_tool.html?gbo_username=&gbo_submit=>


Rolynn

Re: Old Tektronix Books

Dave Wise
 

Where? I found the Concepts series, but Typical Oscilloscope Circuitry is not a Concepts book.

Thanks,
Dave Wise
________________________________________
From: TekScopes@groups.io <TekScopes@groups.io> on behalf of ROLYNN PRECHTL K7DFW <k7dfw@...>
Sent: Tuesday, May 21, 2019 1:15 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Old Tektronix Books

I wonder what scope the schematic examples are taken from. They certainly look genuine.
========================================================================


1961 publication eliminates some.

The power supply might be a 531/535/541 but I'm not going to spend any time with this since the manuals are on TekWiki.



Rolynn

Tektronix 310A CRT issues

Brenda
 

Hello everyone! I have a Tektronix 310A serial number 016911 that I have had in my shop area for quite some time. When I first got it, I only got a very faint trace and was only sweeping 3 divisions instead of the full 10 divisions. I shut it down and most of the electrolytic caps were much hotter than the tubes themselves, so that was pretty much a full recap in my eyes. I finally got around to recapping this old 310A, dialed in all the power supplies (-150V, +100V and +300). The 300V was off by 1V when the -150 was set. At this point, I have a trace, not very bright, but the sweep was fairly accurate with my function generator along with the vertical amplifier. Not bad with all 6BQ7's instead of 6DJ8's! So this tells me that this scope is partially operational which I am happy about. But I digress now..

Onto the CRT circuit itself, when the scope is operating, The Focus control is turned all the way to the 3'o clock position, and my intensity is turned to about 10'o clock position and I have a dim, but very sharp trace. But the center 4 divisions around the middle where the vertical and horizontal with the smaller divisions is very dim. What I have done to check things is I checked all the resistors in the HV circuit, most were almost dead on with a few that where slightly high but well within the 20% tolerance as stated on the resistor. I did not mess with any of the capacitors as they are the ceramic type, but know that it's possible that 1 or more my be bad. After that, I took some voltage measurements according to the schematic for the CRT circuit, which is below:

V704 (6AQ5) Plate voltage: 477V
V704 (6AQ5) screen voltage taken at pins 1 and 7, Upper reading should be -41V and measured -44.4V (Intensity turned CCW)
" " Lower reading should be -45V and measured -49.2V (Intensity turned CW)

V701A (12AU7) Plate voltage taken at pin 1, Upper reading should be +47V and measured 44.8V (Intensity turned CCW)
" " Lower reading should be +75V and measured 136.7V (Intensity turned CW)
V701B (12AU7) Plate voltage taken at pin 6, Upper reading should be -1.8V and measured -1.4V (Intensity turned CCW)
" " Lower reading should be -3.5V and measured -116.7V (Intensity turned CW)
V701B (12AU7) Screen voltage taken at pin 7 should be -155V and measured -155V.

I did try substituting V701 for a know good working 12AU7 and the readings were pretty much the same, so I put the original back in. I am only a novice hobbyist, and slowly learning about electronics, but I am confused with the readings. I should also mention that in regards to the trace being dim and sharp, once you turn the intensity past 11'o clock position, the trace starts to defocus and dims out even more. I have also tried cleaning the pins on the CRT and the socket as well. I did however notice that the CRT is from Sylvania. I know that the earlier 310's, Tektronix had to outsource to Dumont for the CRT's until they could start making their own. So is this Sylvania a replacement that someone installed or did Tektronix outsource to them as well?

Sorry for the lengthy post, I wanted to get as much detail in as possible to help get this little guy up and running! Thanks so much for your help!

Brenda

Re: Old Tektronix Books

Dave Daniel
 

Where what?

DaveD

Sent from a small flat thingy

On May 21, 2019, at 20:26, Dave Wise <david_wise@...> wrote:

Where? I found the Concepts series, but Typical Oscilloscope Circuitry is not a Concepts book.

Thanks,
Dave Wise
________________________________________
From: TekScopes@groups.io <TekScopes@groups.io> on behalf of ROLYNN PRECHTL K7DFW <k7dfw@...>
Sent: Tuesday, May 21, 2019 1:15 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Old Tektronix Books

I wonder what scope the schematic examples are taken from. They certainly look genuine.
========================================================================


1961 publication eliminates some.

The power supply might be a 531/535/541 but I'm not going to spend any time with this since the manuals are on TekWiki.



Rolynn




497P frequency counter question? How to turn on?

radioconnection@...
 

I think the dip switches are set to enable the frequency counter option in 497P, but I do not have a clue as to how to tell whether it is working or not. What push button enables the counter on the 497P front panel, and what should I see when and if the counter is really enabled? I've never seen a function not defined error while randomly trying to figure out what does what.

Pete

Re: 497P frequency counter question? How to turn on?

John Miles
 

What's your serial #? Before B020000, the 497s were derived from the 492A hardware and didn't support the counter feature. If your front panel doesn't have a COUNT button, then that's the case with your unit.

What I'm not sure about offhand is whether the B020000 through B030000 series had counter support. Post-B030000 they definitely did, because those were basically relabeled 494As.

The good news is that while you may not be able to enable the counter with the firmware and/or hardware you have, the 492As were free of the nasty SMT electrolytics and are going to be more reliable as a result despite being a couple years older.

-- john, KE5FX

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of
radioconnection@...
Sent: Tuesday, May 21, 2019 6:25 PM
To: TekScopes@groups.io
Subject: [TekScopes] 497P frequency counter question? How to turn on?

I think the dip switches are set to enable the frequency counter option in 497P,
but I do not have a clue as to how to tell whether it is working or not. What
push button enables the counter on the 497P front panel, and what should I see
when and if the counter is really enabled? I've never seen a function not
defined error while randomly trying to figure out what does what.

Pete

Re: 497P frequency counter question? How to turn on?

radioconnection@...
 

B0202199

Looks like most parts are late 1990 date codes.

Spectrum Analyzers

Gary Robert Bosworth
 

Does anyone know the exact differences between a Tektronix 495P Spectrum Analyzer and a 496P Spectrum Analyzer? They have the same input frequency range, but apparently have a completely different front control panel.

Latest firmware for TDS210 and TDS2CM?

Jared Cabot
 

Hi,

I have an old TDS210 scope with TDS2CM comms/math module and I was wondering if anyone knows what the latest firmware revisions for these modules is, and if anyone has these firmware files?

I was reading that some changes were made in the later firmwares and I have itchy fingers if my unit is an earlier rev.

Thanks!

Re: Spectrum Analyzers

John Miles
 

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Gary
Robert Bosworth
Sent: Tuesday, May 21, 2019 7:11 PM
To: TekScopes@groups.io
Subject: [TekScopes] Spectrum Analyzers

Does anyone know the exact differences between a Tektronix 495P Spectrum
Analyzer and a 496P Spectrum Analyzer? They have the same input frequency
range, but apparently have a completely different front control panel.
The front panels aren't actually *that* different, but they are pretty different beasts under the skin. They are both 1.8 GHz models, but the 496 was the second model in the product line, released in the late 1970s/early 1980s timeframe after the original 492 came out. (The first 496s were sold as 492s with option 6, in fact.)

The 495, on the other hand, was one of the last models, produced as late as 1993 or so.

Like the 497 that radioconnection is talking about, there were early versions of the 495 that lacked some of the features like the signal counter that were added to the later-production ones. But the later-production examples with all the bells and whistles and post-B030000 serial numbers will also have capacitor leakage problems that will not be an issue in the earlier ones.

-- john, KE5FX

7B92A time-base plug-in odd behaviour

Colin Herbert
 

I have a 7B92A which is puzzling me. When turned on, it will only show the "ALT" time-base, which isn't altered by the time-base Time/Div knob, but after warming-up for probably only a minute or so, everything seems to work correctly. I have a feeling that this is associated with one or other of the switches on the "Pull for Alt / Push for Dly'd" switch. I am a bit puzzled about these two switches and the Service Manual isn't enlightening me too well. There is a micro-switch close to the front-panel, which I _think_ is S490 (the mechanical parts list refers to it as "SWITCH, SENS:(SEE S490 REPL)). This only operates when the "Time/Div or Dly Time" knob is pulled out with the two time-bases locked. It then stays in that position until the delaying and delayed time-bases are at the same Time/Div again and the knob pushed in. It seems to be connecting something to chassis ground when the knob is pushed in, but I can't locate it anywhere in the manual. The other switch that is operated by pulling/pushing the time-base knob looks to be a slider-switch on the Readout board, but it is on the inner face of this board and difficult to see without removing the board. I can't find out what it does, as I can't locate it in the manual.
Can anyone enlighten me as to the identity of these two switches and their function? Also, some idea as to what might be causing the odd behaviour before the time-base plug-in warms up?
TIA, Colin.

Re: 7B92A time-base plug-in odd behaviour

Albert Otten
 

Hi Colin,

S490 is shown at diagram <4> top-right (in my manual Rev. D, April 1976). Switching contact goes to GND, one choice is open, the other(LOCKED) connects it to P911 at/to the A6 Interface Board. From there also to R334 at <3>. Somewhat vague, as if R334 is in the wire , then to P936 and P204. I didn't look at the function (yet).

Albert

On Wed, May 22, 2019 at 02:10 PM, Colin Herbert wrote:


I have a 7B92A which is puzzling me. When turned on, it will only show the
"ALT" time-base, which isn't altered by the time-base Time/Div knob, but after
warming-up for probably only a minute or so, everything seems to work
correctly. I have a feeling that this is associated with one or other of the
switches on the "Pull for Alt / Push for Dly'd" switch. I am a bit puzzled
about these two switches and the Service Manual isn't enlightening me too
well. There is a micro-switch close to the front-panel, which I _think_ is
S490 (the mechanical parts list refers to it as "SWITCH, SENS:(SEE S490
REPL)). This only operates when the "Time/Div or Dly Time" knob is pulled out
with the two time-bases locked. It then stays in that position until the
delaying and delayed time-bases are at the same Time/Div again and the knob
pushed in. It seems to be connecting something to chassis ground when the knob
is pushed in, but I can't locate it anywhere in the manual. The other switch
that is operated by pulling/pushing the time-base knob looks to be a
slider-switch on the Readout board, but it is on the inner face of this board
and difficult to see without removing the board. I can't find out what it
does, as I can't locate it in the manual.
Can anyone enlighten me as to the identity of these two switches and their
function? Also, some idea as to what might be causing the odd behaviour before
the time-base plug-in warms up?
TIA, Colin.

Re: 7B92A time-base plug-in odd behaviour

Roger Evans
 

On my 7B92A, the microswitch near the front panel is connected by a single wire to P911 on the interface board. P911 is to be found on schematic <4>, 'Delaying Sweep', near the top right corner. It is marked as going to R334 on schematic <3> and the switch is marked as S490. S800 on 'Horizontal Logic', schematic <7> is marked with 'pull for alt, push for delay' and is surely the second switch on that shaft, it connects through to the Readout board.

I noticed while investigating my 7B92A that the whte plastic 'cotton reel' that activates the microswitch didn't seem to be an entirely tight fit on the shaft but settled down happily after a few iterations. I hadn't noticed any odd behaviour when it is operating in the mainframe.

Regards,

Roger

Re: Old Tektronix Books

Dave Wise
 

The "Typical Oscilloscope Circuitry" book. Rolynn said it was at w140 ("TekWiki"), but I couldn't find it so I asked him where it was in the w140 site.

Dave Wise
________________________________________
From: TekScopes@groups.io <TekScopes@groups.io> on behalf of Dave Daniel <kc0wjn@...>
Sent: Tuesday, May 21, 2019 5:54 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Old Tektronix Books

Where what?

DaveD

Sent from a small flat thingy

On May 21, 2019, at 20:26, Dave Wise <david_wise@...> wrote:

Where? I found the Concepts series, but Typical Oscilloscope Circuitry is not a Concepts book.

Thanks,
Dave Wise
________________________________________
From: TekScopes@groups.io <TekScopes@groups.io> on behalf of ROLYNN PRECHTL K7DFW <k7dfw@...>
Sent: Tuesday, May 21, 2019 1:15 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Old Tektronix Books

I wonder what scope the schematic examples are taken from. They certainly look genuine.
========================================================================


1961 publication eliminates some.

The power supply might be a 531/535/541 but I'm not going to spend any time with this since the manuals are on TekWiki.



Rolynn




Re: Old Tektronix Books

Dave Daniel
 

Thanks for clarifying that.

I thought there was copy on the TekWiki as well. When I saw that there wasn’t, I went to upload my copy. It was at that point that I discovered that (a) I don’t seem to have a copy and (2) I could not find a copy online.

I still think I had a PDF copy at one time.

FaveD

Sent from a small flat thingy

On May 22, 2019, at 12:09, Dave Wise <david_wise@...> wrote:

The "Typical Oscilloscope Circuitry" book. Rolynn said it was at w140 ("TekWiki"), but I couldn't find it so I asked him where it was in the w140 site.

Dave Wise
________________________________________
From: TekScopes@groups.io <TekScopes@groups.io> on behalf of Dave Daniel <kc0wjn@...>
Sent: Tuesday, May 21, 2019 5:54 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Old Tektronix Books

Where what?

DaveD

Sent from a small flat thingy

On May 21, 2019, at 20:26, Dave Wise <david_wise@...> wrote:

Where? I found the Concepts series, but Typical Oscilloscope Circuitry is not a Concepts book.

Thanks,
Dave Wise
________________________________________
From: TekScopes@groups.io <TekScopes@groups.io> on behalf of ROLYNN PRECHTL K7DFW <k7dfw@...>
Sent: Tuesday, May 21, 2019 1:15 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Old Tektronix Books

I wonder what scope the schematic examples are taken from. They certainly look genuine.
========================================================================


1961 publication eliminates some.

The power supply might be a 531/535/541 but I'm not going to spend any time with this since the manuals are on TekWiki.



Rolynn










Re: OT: App that keeps track of "Or Best Offer" auctions on eBay to tell you what a seller will accept.

tekscopegroup@...
 

Back a few years before ebay started to obfuscate all the information on bidders and sellers an app like that would still have been possible to work on the public information that was available on any ebay member. Back then I was even doing myself some manual background checks on other bidders I was competing with for an item. I used to check on their previous bids history what items they won/lost etc to try and find patterns, and also how they liked to send in their highest bid (some people like to send even amounts, others like weird patterns, like $12.34 or $111.11 and so on) to try to anticipate their next maximum bid. Also back then if you managed to get in your bid in the last 10-15 seconds before the end you usually won if your bid was high enough, and I was quite successful (inc synchronizing the PC clock with ebay clock, make sure to be freshly logged in, etc). I even had friends asking me to snag something of ebay for them. But nowadays they even automated sniping and sometimes you get beaten by a bid sent 1-2 seconds before the auction ends. Anyway gathering relevant information on other bidders or sellers is now for the most part no longer possible as it used to be. So unless this app has a way to sneak into ebay's servers and bypass whatever security they have in place to protect their databases I don't see how an app like that is still possible. Unless someone found a backdoor...

Re: Latest firmware for TDS210 and TDS2CM?

 

On Wed, May 22, 2019 at 06:56 AM, Jared Cabot wrote:


I have an old TDS210 scope with TDS2CM comms/math module and I was wondering
if anyone knows what the latest firmware revisions for these modules is,
If you by old mean the first generation that had BNC connectors with two pins and F/W in a removable 24C040 PROM the last version as far
as I know is 1.19. The next generation had BNC connetors with four pins and F/W in flash ROM. They were programmed by attaching a
special programming fixture into the I/O module compartment. I don't know the latest version for those.
F/W is the same for TDS210 and TDS220.
/Håkan

Re: OT: App that keeps track of "Or Best Offer" auctions on eBay to tell you what a seller will accept.

 

There are certainly a lot of people asking me to let them know if I ever find it again. I remember using all the strategies you describe when eBay was a lot less controlling of their own auctions. Everything you can learn about a seller, the price an item sells at, and other bidders behavior rpatterns is knowledge you can use to improve your odds of winning an auction. eBay has gradually caught on to this and has steadily placed restrictions on every bit of information that can be used to give you an edge.

You have seen the very same thing happening. I think I was very lucky to have been so active on eBay so many years ago. At the time I never realized that it wouldn't always be that way. This is unfortunate, but it explains why I turn to eBay for different things now than I did before. Gone are the exciting one of a kind items you can sometimes get for a ridiculous price because your put in a bid early and the sniping site had a meltdown moments before the auction ended and didn’t place any snipes. I remember a few times when I won something for the opening bid price that way.

Dennis Tillman W7PF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of tekscopegroup@...
Sent: Wednesday, May 22, 2019 10:04 AM
Subject: Re: [TekScopes] OT: App that keeps track of "Or Best Offer" auctions on eBay to tell you what a seller will accept.

Back a few years before ebay started to obfuscate all the information on bidders and sellers an app like that would still have been possible to work on the public information that was available on any ebay member. Back then I was even doing myself some manual background checks on other bidders I was competing with for an item. I used to check on their previous bids history what items they won/lost etc to try and find patterns, and also how they liked to send in their highest bid (some people like to send even amounts, others like weird patterns, like $12.34 or $111.11 and so on) to try to anticipate their next maximum bid. Also back then if you managed to get in your bid in the last 10-15 seconds before the end you usually won if your bid was high enough, and I was quite successful (inc synchronizing the PC clock with ebay clock, make sure to be freshly logged in, etc). I even had friends asking me to snag something of ebay for them. But nowadays they even automated sniping and sometimes you get beaten by a bid sent 1-2 seconds before the auction ends. Anyway gathering relevant information on other bidders or sellers is now for the most part no longer possible as it used to be. So unless this app has a way to sneak into ebay's servers and bypass whatever security they have in place to protect their databases I don't see how an app like that is still possible. Unless someone found a backdoor.




--
Dennis Tillman W7PF
TekScopes Moderator

Re: Old Tektronix Books

ROLYNN PRECHTL K7DFW
 

The "Typical Oscilloscope Circuitry" book. Rolynn said it was at w140 ("TekWiki"), but I couldn't find it so I asked him where it was in the w140 site.

===========================================================================================

Not even close.

Rolynn said that the:

1961 publication eliminates some.
(1961 publication date eliminates some of the scopes from where the schematics came from)

The power supply might be a 531/535/541 but I'm not going to spend any time with this since the manuals are on TekWiki.

(the manuals for the potential scope candidates are on TekWiki and to do your own detective work to find out which instrument schematics are in the book)

Clear as a bell - to me.

Rolynn