Date   

Re: 155-0035-00

Dave Casey
 

Page 3-6 of the 1982 Semiconductor common design parts catalog lists the
Tek made (155) ICs.

Dave Casey



On Tue, Aug 4, 2020 at 7:09 PM Dennis Tillman W7pF <dennis@ridesoft.com>
wrote:

Hi pitti_pu,
I am puzzled by this part number. The 7L5 service manual confirms it is
correct but there are no 155-0035 ICs. In fact there are no ICs starting
with 155 in any of the Tek Semiconductor or IC parts catalogs I have.

Can someone point me to a list of Tek ICs that does have the 155-xxxx IC
in it?

Dennis Tillman W7pF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of
pitti_pu@hotmail.com
Sent: Tuesday, August 04, 2020 11:27 AM
To: TekScopes@groups.io
Subject: [TekScopes] 155-0035-00

The spectrum analyzer 7L5 contains two 155-0035-00 quad op amps. One of
the four was faulty. No direct replacement was available. Therefore, I
disconnected the three affected pins, then piggy-backed a LM324 in place
with ±15V lines attached to the 115-0035 and added three wires for the
socket. The remaining three op amps in the LM324 are not used.
Works nicely. The gain/bandwidth product of the LM324 is much smaller, but
that does not affect the performance.





--
Dennis Tillman W7pF
TekScopes Moderator




Re: 155-0035-00

 

Hi pitti_pu,
I am puzzled by this part number. The 7L5 service manual confirms it is correct but there are no 155-0035 ICs. In fact there are no ICs starting with 155 in any of the Tek Semiconductor or IC parts catalogs I have.

Can someone point me to a list of Tek ICs that does have the 155-xxxx IC in it?

Dennis Tillman W7pF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of pitti_pu@hotmail.com
Sent: Tuesday, August 04, 2020 11:27 AM
To: TekScopes@groups.io
Subject: [TekScopes] 155-0035-00

The spectrum analyzer 7L5 contains two 155-0035-00 quad op amps. One of the four was faulty. No direct replacement was available. Therefore, I disconnected the three affected pins, then piggy-backed a LM324 in place with ±15V lines attached to the 115-0035 and added three wires for the socket. The remaining three op amps in the LM324 are not used.
Works nicely. The gain/bandwidth product of the LM324 is much smaller, but that does not affect the performance.





--
Dennis Tillman W7pF
TekScopes Moderator


eBay / PayPal Changes and our alternatives

 

I believe the following excerpts from a Feb. 1, 2018 eBay announcement
should be viewed with skepticism until the details become clear. I thought
that it was important to repeat these parts of the announcement since many
members of TekScopes are current users of eBay and of PayPal and may not be
aware of the upcoming changes on eBay.
------
On Feb. 1, 2018 eBay announced that it will be replacing PayPal with Adyen
as its primary payments provider.
Ebay will continue to let customers use PayPal as an option for checking out
until July 2023, but most of eBay's payments will be processed by Adyen by
2021. Adyen, a start-up based in the Netherlands, is an online payment
company that provides businesses with backend payment services including
credit card processing and point-of-sales (POS) systems.

Ebay explained that its decision to integrate Adyen's payment processor
would result in lower costs and more control of finances for its merchants.
EBay said its partnership with Adyen's technology would enable sellers to
have a more central view of their data, and to manage and track all
transactions and customer interactions via eBay. EBay said that the
integration of Adyen would also provide customers with "greater choice" when
checking out. "We believe that we can offer a more seamless experience while
giving buyers and sellers more choice for payment and payout options," eBay
Chief Executive Devin Wenig said on a conference call with analysts. The
move is a part of eBay's strategy to "transition to full payments
intermediation," the firm said.
------

One member already mentioned there is a Groups.io site dedicated to the
exchange of Test equipment. If you are interested the link is here:
https://groups.io/g/Test-Equipment-For-Sale-Wanted-or-Exchange

If there are other alternative sites we should know about please let us know
about them. Please provide a link in your reply and indicate if you have any
actual experience with them.

Dennis Tillman W7pF


Re: Preventing SPAM from new members

Michael A. Terrell
 

Shoulder of Pork And ham.

On Tue, Aug 4, 2020, 4:52 AM Carsten Bormann <cabocabo@gmail.com> wrote:

(FYI, you were talking about “spam”. “SPAM”® is a brand for a delicious,
inexpensive precooked canned meat product, held by Hormel Foods Corporation.

Thank you for listening to this Public Service Announcement.
We now return you to the regular program.)

Grüße, Carsten





Re: Preventing SPAM from new members

 

Hi David,
I think the answer is clear from what happened after I banned him, or more
correctly as you pointed out after I banned the email-ID associated with the
spam.

Nothing happened!

On the other hand if this email-ID was from someone whose email had been
hacked he knows how to get in touch with me through the home page of the
TekScopes web site to explain the situation.

I would have restored his membership the best way possible under a new email
address, or, after he protected his existing email address from further
hacks.

I think the fact that I never heard from him is a pretty clear indication he
was a spammer.

Dennis Tillman W7pf

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of David C.
Partridge
Sent: Tuesday, August 04, 2020 1:38 AM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Preventing SPAM from new members

I didn't raise the point at the time, and 'm really not trying to tell you
"how to suck eggs": Did you check with the person involved? It is
possible that his email had been hi-jacked, and that he wasn't the spammer.

Why do I say this - it happened to me a long time ago to a different email
from the one I now use. Not much spam was sent and I was not (luckily)
banned anywhere.

David

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Dennis
Tillman W7pF
Sent: 04 August 2020 01:24
To: TekScopes@groups.io
Subject: [TekScopes] Preventing SPAM from new members

Prior to the SPAMMER I accepted and approved as a member a few weeks ago
anyone who wanted to post a message to TekScopes had to be approved by me. I
read each of their pending messages to be sure they passed my "smell" test.
If they did, then I approved them as a member and unmoderated them at the
same time.
Unfortunately spammers are now getting better at hiding their intentions and
it is becoming harder to separate them from legitimate future members.
From this point forward I will no longer be un-moderating new members
automatically. I apologize in advance for any inconvenience this may cause
new members.
Thanks to the member who alerted me to that spammer he was immediately
banned, all of his posts were removed, and all of the posts by others in
response the topic(s) he initiated were removed.

Dennis Tillman W7pF







--
Dennis Tillman W7pF
TekScopes Moderator


Re: DC503 Not Working

Stephen
 

On Tue, Aug 4, 2020 at 11:17 AM, Harvey White wrote:


Once you get the extender, check the strobes on each of the digits. 
Strobes???


Re: DC503 Not Working

Harvey White
 

Once you get the extender, check the strobes on each of the digits.  Then check the source of those strobes.  Then check the chip that's driving those (likely) transistors.  A typical way is to have a counter driving a decoder which then drives the digits individually.  You may find that this counter does all of that in one chip.  If it's a complicated chip, then look for a reason (if no strobes) that the chip is being inhibited.

Anything where digits freeze or are irregularly displayed indicates the scanning electronics.  Anything where there's a missing segment on ALL displays indicates the common 7447 decoder or the like.  Anything where you have one segment on one display missing tends to indicate a problem on that display.

Even if the display is wonky, you might see (and perhaps should see) digits indicating counting.  The counter is very sensitive to the input settings even on a good day.

You're going to need the JAMMA extender.  My research suggests that if you have all the lower pins connected on both sides, equivalent to 1 to 13 when you turn the extender upside down, all you need to do is mark both connectors promently, and reverse the connectors.  On the JAMMA connectors I saw, pin 7 was missing on both sides.  No other pins were missing, which suggests the reversal.

I wouldn't do much more until you can get that counter out on an extender.  Make the extension wires long enough to get the plugin at least one plugin length away from the front of the frame.

Harvey

On 8/4/2020 5:59 PM, Stephen wrote:
I got to working on bit on this unit today again. I rechecked all the voltages, and they’re all good.
For good measure, I replaced all the tantalums on the lower board. 2 with electrolytics, the 15uF/50V and the 6.8uF, which I couldn’t find. And of course nothing has changed, I yet have to find time to modify the JAMMA extender. After all that has been changed, there is close to no improvement...



FG 502 Adjustment and Possible New Issue

Stephen
 

I’m trying to adjust my FG 502 to factory specs as per the manual.
So far there are a couple of things that have popped up as being of concern to me:

1- R170 (Sym) has absolutely no visible effect whatsoever.
2- C287 (Triangle Peak) has absolutely no visible effect either.
3- There is a -25mV DC bleeding when no DC offset is engaged.
4- When the switch is set to triangle, settings 10(-6) and .1 on the dial, this is what I see on a 466:

https://groups.io/g/TekScopes/album?id=251651


Apology for my message to satbeginner and Saroj Pradhan re: Tektronix 2230

 

To satbeginner and Saroj Pradhan,

I apologize for requesting you take your discussion off line. I did not realize it was something other members were finding useful.
Please continue as if I had not intervened.

Dennis Tillman W7pF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Dennis Tillman W7pF
Sent: Monday, August 03, 2020 4:33 PM
To: TekScopes@groups.io
Subject: [TekScopes] Message to satbeginner and Saroj Pradhan re: Tektronix 2230

Gentlemen:
You are creating an excessive amount of unnecessary message traffic, consuming significant bandwidth, and taking up precious storage on TekScopes.
I believe the best way for you to explore your mutual interests regarding the 2230 is to communicate directly to each other rather than through TekScopes.
If you need further assistance please contact me directly.
Thank you,
Dennis Tillman W7pF





--
Dennis Tillman W7pF
TekScopes Moderator





--
Dennis Tillman W7pF
TekScopes Moderator


Re: DC503 Not Working

Stephen
 

I got to working on bit on this unit today again. I rechecked all the voltages, and they’re all good.
For good measure, I replaced all the tantalums on the lower board. 2 with electrolytics, the 15uF/50V and the 6.8uF, which I couldn’t find. And of course nothing has changed, I yet have to find time to modify the JAMMA extender. After all that has been changed, there is close to no improvement...


Re: Message to satbeginner and Saroj Pradhan re: Tektronix 2230

 

Hi Chuck,
The first thing I can say is I always appreciate you input.

I did receive a complaint about it so I took a closer look. What I saw was an awful lot of messages with only two individuals involved. I was concerned that others might find it annoying.

It was a judgement call. But since many others indicate they are benefitting from it please accept my apology.

Dennis W7pF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Chuck Harris
Sent: Monday, August 03, 2020 6:55 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Message to satbeginner and Saroj Pradhan re: Tektronix 2230

Dennis,

Are you serious? Why is the 2230 not worthy of long threads, but every damn thing else is?

Yes, it is bit of a chit/chat fest, but the messages all seem to me on topic. Bandwidth (ha ha!) is minimal, perhaps less than 40K for the entire thread.

I admit that I care nothing for the 2230, but others do.

So, why?

-Chuck Harris



Dennis Tillman W7pF wrote:
Gentlemen:
You are creating an excessive amount of unnecessary message traffic, consuming significant bandwidth, and taking up precious storage on TekScopes.
I believe the best way for you to explore your mutual interests regarding the 2230 is to communicate directly to each other rather than through TekScopes.
If you need further assistance please contact me directly.
Thank you,
Dennis Tillman W7pF








--
Dennis Tillman W7pF
TekScopes Moderator


Re: 7834 Missing Trace

sdferg7@...
 

Alright, good news. Turning R2135 about 1/8 of a turn to the right brought the trace back. Thank you! Both time bases seem to work properly. Unfortunately this is the only scope I own, I've only used them at school before; if I really need another one I might be able to take it to a lab at my college when I go back at the end of the month, but I'm not sure if they'd let me use one for personal purposes. Is there more checking I need to do with regards to the trace issue? Not sure what would cause it to suddenly go out of adjustment like that. I also don't know the proper calibration procedure.

With regards to the storage controls, I've never used a storage analog scope before so I'm not sure if I'm using them correctly and I'm a bit afraid of burning the CRT with them. They all seem to turn the screen green at varying intensities, some at a worrying brightness.

Thanks again,

Shane


Re: 7834 Missing Trace

Roger Evans
 

Turn the readout intensity fully anticlockwise, there should be a detent to turn the readout function off.

You need to turn R2135 slowly since if it does brighten up the missing trace you don't want to overdo it and damage the very rare 7834 storage CRT. It's probably clockwise to brighten the trace but if not try turning it slowly anti clockwise. You may see nothing at all or a trace with both X and Y signals or a dot or a line, it just depends on which of the X, Y and Z signals are missing by the time they get to the CRT. Make sure to return R2135 to its original position, you can do a final adjustment when everything is working. There are X, Y and Z signals to drive the readout, they clearly do get through to the CRT so the problem is to find the point where the main signals go missing.

Were both time bases working before the right one was removed?

Do you have a second scope for troubleshooting?

Roger


Re: Tektronix 2230

satbeginner
 

Hi Saroj,

It looks like the FET gate signal is good now.
I would not worry too much about the Vpp of 19V, because both the rise and falling flank show quite some overshoot.
It would not surprise me if that is caused by the probe not compensated optimally.

I would look into the temperature: my recent 2215A repair showed a long run temperature of 59 Celsius, the higher temperatures you are seeing worry me.

On the other hand, your scope is a 2230, so a higher current would be expected.

Some questions:

Is the FET you are using a plastic one?
What is the specified On-Resistance?
Are you able to use a TO-220 heatsink on both sides of the metal mounting plate?
Did you use heat conducting compound when you mounted the FET?

You're getting close I think.

Leo


Re: Message to satbeginner and Saroj Pradhan re: Tektronix 2230

Greg Muir
 

I’ll probably take some flak over this.

Yes, on-topic discussions are fine as far as I am concerned but it seems to be the nature of others to predictably wander off the path and start discussions about the creation of the universe, different brands of steel wool, the effectiveness of lawn fertilizer, swimming pool maintenance and other comparable dribble.

It would be nice if everyone kept in the back of their minds that these sites are created to share pertinent information related to the topic at hand, not as a “chat room” in which to wander on through the idiosyncrasies about the meaning of life. We’re here to share our technical knowledge to help others learn and, in return, find answers to our own questions in a semi-professional way.

I do understand that there may be a share of members who seen to be hopelessly trapped in their homes due to the ongoing pandemic but if the urge strikes one to post unrelated thoughts it best be done via off-list contact with the person you wish to share those thoughts with.

I may be wrong but I feel that Dennis may have developed a little impatience from looking at the entire picture, not just only the posts between “satbeginner” and Saroj Pradhan. I, myself see on goings in many posts every week that allude to unrelated conversation when a topic finally jumps the rails and ends up continuing for dozens more postings of no relational value whatsoever.

Dennis may have happened to reach that “point” where he felt it was time to say something. We all exhibit that behavior when something finally irritates the devil out of us and we finally have to take action and say something.

As for myself, I do receive the digest mode via email and seldom go to the website because of the numerous OT posts that follow. It gives me a quick indication as to when to stop looking at topics when they veer off course – which seems to be quite frequently. I personally do not have untold amounts of time to waste.

Greg

PS – Maybe it is time to create a “TekScopeschatroom@groups.io”


155-0035-00

 

The spectrum analyzer 7L5 contains two 155-0035-00 quad op amps. One of the four was faulty. No direct replacement was available. Therefore, I disconnected the three affected pins, then piggy-backed a LM324 in place with ±15V lines attached to the 115-0035 and added three wires for the socket. The remaining three op amps in the LM324 are not used.
Works nicely. The gain/bandwidth product of the LM324 is much smaller, but that does not affect the performance.


Re: FG502

Colin Herbert
 

Now I've tried it on my FG 503, I can see that it enables much better setting of the frequency.
Couldn't a static Lissajous pattern be obtained more simply by connecting the two function generators via "trigger out" and "gate in"? Maybe not....
Colin.

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Roger Evans via groups.io
Sent: 04 August 2020 15:56
To: TekScopes@groups.io
Subject: Re: [TekScopes] FG502

The fine adjustment knob gives about a factor of ten improvement in the precision with which you can set the frequency measured against a DC503 counter. The only reason that comes immediately to mind is that it would help to give an almost static Lissajous figure in XY mode against some other generator. Any other ideas?

Roger


Re: 7834 Missing Trace

sdferg7@...
 

Ok, sorry for my inexperience. Just to make sure, you're saying turn the readout knob all the way to the left to turn it off, then try twisting R2135 back and forth? Should I just move it a little or all the way? And I'm looking for something to appear on the display?

Thanks for the help,

Shane


Re: FG502

Stephen
 

On Tue, Aug 4, 2020 at 03:56 AM, Roger Evans wrote:


The fine adjustment knob gives about a factor of ten improvement in the
precision with which you can set the frequency measured against a DC503
counter. The only reason that comes immediately to mind is that it would help
to give an almost static Lissajous figure in XY mode against some other
generator. Any other ideas?

Roger

Hummm... Interesting. If only my FG503 was working...
I have to find the time to get back to it..


Re: AWG2005 Issues and Repair Question.

Stephen
 

On Tue, Aug 4, 2020 at 03:55 AM, Michael W. Lynch wrote:

Yes, I have a 2440 and that is one of the scopes that must be constantly
cooled to prevent overheating of the A/D Converters and the CCD Hybrids. I
think that Martin makes a good point.
Yep. Very good piece of advice indeed.
I don’t personally know that series, but I trust you guys on that.

9421 - 9440 of 179352