Date   
Yahoo Groups are deleting all files in December

 

Hi Richard,
Thank you for the notice. I never received any notice from Yahoo about this (that was typical for Yahoo!) so your heads up was appreciated.

We moved everything over to Groups.io a long time ago and we have no connection with Yahoo ever since. So we will not be affected by anything Yahoo does.

Dennis Tillman W7PF
TekScopes Co-owner and Moderator

-----Original Message-----
From: Richard Tyner
Sent: Thursday, October 17, 2019 6:19 AM

I was not sure if any of the old group files might be be on Yahoo or not. Just wanted to let others know just in case

-----Original Message-----
From: Richard Tyner
Sent: Wednesday, October 16, 2019 12:06 PM

Yahoo has made the decision to no longer allow users to upload content to the Yahoo Groups site. Beginning October 21, you won't be able to upload any more content to the site, and as of December 14 all previously posted content on the site will be permanently removed. You'll have until that date to save anything you've uploaded.

73 Richard W4MCD



--
Dennis Tillman W7PF
TekScopes Moderator

Re: 175 Curve Tracer Rear 9-Pin Connector

Craig Sawyers
 

I have a 175. It is pins

Craig

Does anyone know for certain if the 9-Pin connector on the rear of the 175 curve tracer is pins or
sockets? Photos I have seen are not clear enough, and none of the manuals describe non-Tektronix
Amphenol connector part numbers.

Re: "liquid crystal driver" sighting

p mc
 

...or someone who got the postage down to reasonable.

Bravo, sir.

Re: "liquid crystal driver" sighting

Mlynch001
 

We will all be waiting To hear all about this little item.

--
Michael Lynch
Dardanelle, AR

Re: "liquid crystal driver" sighting

Glenn Little
 

I bought it.
I got the postage down to $15.00.
When it gets here I will get some better pictures, inside and out.

Glenn

On 10/17/2019 9:48 PM, p mc wrote:
Yeah, that.

But someone snagged it. Someone willing to pay for delivery by angel choir so I doubt they just wanted the 5A1xN plugins.

Someone here, perchance? TekWiki would like to hear from you...


--
-----------------------------------------------------------------------
Glenn Little ARRL Technical Specialist QCWA LM 28417
Amateur Callsign: WB4UIV wb4uiv@... AMSAT LM 2178
QTH: Goose Creek, SC USA (EM92xx) USSVI LM NRA LM SBE ARRL TAPR
"It is not the class of license that the Amateur holds but the class
of the Amateur that holds the license"

Re: "liquid crystal driver" sighting

Glenn Little
 

I bought it.
I got the postage down to $15.00.
When it gets here I will get some better pictures, inside and out.

Glenn

On 10/17/2019 9:48 PM, p mc wrote:
Yeah, that.

But someone snagged it. Someone willing to pay for delivery by angel choir so I doubt they just wanted the 5A1xN plugins.

Someone here, perchance? TekWiki would like to hear from you...


--
-----------------------------------------------------------------------
Glenn Little ARRL Technical Specialist QCWA LM 28417
Amateur Callsign: WB4UIV wb4uiv@... AMSAT LM 2178
QTH: Goose Creek, SC USA (EM92xx) USSVI LM NRA LM SBE ARRL TAPR
"It is not the class of license that the Amateur holds but the class
of the Amateur that holds the license"

Re: 175 Curve Tracer Rear 9-Pin Connector

Mlynch001
 

They are male pins on the one that I saw.

--
Michael Lynch
Dardanelle, AR

Re: "liquid crystal driver" sighting

p mc
 

Yeah, that.

But someone snagged it. Someone willing to pay for delivery by angel choir so I doubt they just wanted the 5A1xN plugins.

Someone here, perchance? TekWiki would like to hear from you...

Re: Smoking 2465B (Rifa/30-ohm) + Recap = PS will not start

Roy Thistle
 

On Thu, Oct 17, 2019 at 02:31 PM, Chuck Harris wrote:


Faston connectors are supposed to be rarely
mated
Hi Chuck:
Yes... I don't know about Pandas... but Fastons can bite back when you try to interrupt their mating!
Just the same, the Real McCoy, TE Faston is supposed to conform to UL-310... and so is speced as to the insertion and withdrawal force, for multiple insertions and withdrawals.The speced withdrawal force is hefty...about the same as the speced insertion force, which is about 20 pounds.
I've done the prying thing, when necessary... with mixed results...using a screwdriver, or pliers... or both...but, its sometimes hard to generate that kind of force, in tight fits, or without breaking something. And, I've never seen a sold tool to help do the withdrawal in the field. At least, TE doesn't seem to sell, or make one.
Does anyone know if their is an appropriate tool available?

175 Curve Tracer Rear 9-Pin Connector

Gary Robert Bosworth
 

Does anyone know for certain if the 9-Pin connector on the rear of the 175 curve tracer is pins or sockets? Photos I have seen are not clear enough, and none of the manuals describe non-Tektronix Amphenol connector part numbers.

Gary

Re: Smoking 2465B (Rifa/30-ohm) + Recap = PS will not start

tekscopegroup@...
 

Just finished reprogramming the FRAM with backup data and put it back into the scope, its once again working fine.
Time to put the cover back on.

Re: Smoking 2465B (Rifa/30-ohm) + Recap = PS will not start

tekscopegroup@...
 

Happy to report that I just swapped out the FRAM for the old original 1990 NVRAM, which I had completely forgotten about, and the error code went away.
Will try to erase and reprogram the FRAM, otherwise will just order a new one, plus another Aries adapter.

Re: Smoking 2465B (Rifa/30-ohm) + Recap = PS will not start

tekscopegroup@...
 

On Thu, Oct 17, 2019 at 02:41 PM, Chuck Harris wrote:
Is your supply loaded, or unloaded? Unloaded, all the
voltages will be low as the supply works feverishly trying
not to destroy itself.

-Chuck Harris
Chuck I only powered the supply while it was connected to the scope, never unloaded.

Anyway, I found a problem and now the power supply is working again. But I am being greeted now by a 04 11 error message which indicated a faulty cal constant checksum. Maybe the FRAN did not like the lower power supply voltages or spikes etc. When I swapped out the old NVRAM I also programmed a fresh one and put it away just in case the FRAM would not work out. But so far the FRAM had been in the scope for almost a year without any problems until now. Guess I could just swap in that new programmed NVRAM to confirm the error goes away, and then try to reprogram the data back into the FRAM.

What happened with the power supply? Well as said I had double/triple checked all caps, but... against my OWN NOTES which I had taken prior to start removing and replacing caps one by one. Turns out that in the case of C1220 and C1240 I read 10uF 100V but wrote down 100uF 10V. Then when it came to replace those two I grabbed a bag with two extra and somewhat different looking 100uF 25V separate from the other 100uF 25V caps that I was correctly using for the other spots. So I figured I had ordered these two extra ones just to "upgrade" those pesky 10V units up to 25V.

Found out when I left the power on for a few minutes and heard another pop. Upon inspection C1220 had vented its top. It was obliviously pulling down the 87V rail. Oooops...

Re: Smoking 2465B (Rifa/30-ohm) + Recap = PS will not start

Chuck Harris
 

The caps each should have about 1.4 x 117V = 163V on them.

In the 110V position, the bridge rectifier, and the
capacitors are arranged to be a half-wave voltage doubler.
In the 220V position, they form a full wave rectifier.

Being half-wave, I would expect the voltage to be have
a lot more ripple, and be a little lower than it would be
as a full wave bridge... So, they are about right.

Is your supply loaded, or unloaded? Unloaded, all the
voltages will be low as the supply works feverishly trying
not to destroy itself.

-Chuck Harris


tekscopegroup@... wrote:

On Thu, Oct 17, 2019 at 11:50 AM, Chuck Harris wrote:
Check the connection of the faston connectors that
connect the 110/220V selection switch. It looks like
you forgot to connect them back up when you connected
the supply back up.

-Chuck Harris
Hi Chuck, with the switch connected I can measure zero ohms across R1013 a 68K resistor that is in parallel with the voltage selection switch, so it seems all is ok in that respect. I just measured again the voltages across C1021 and C1022 the main input caps at J231A and each measures 144V across each, and total 287V. Does that sound right? I am using an isolation transformer that also drops the AC down to 117V, so those cap voltages are now a bit lower than what I reported earlier when connected directly to the AC line.



Re: Smoking 2465B (Rifa/30-ohm) + Recap = PS will not start

Chuck Harris
 

Roy, Faston connectors are supposed to be rarely
mated... Kind of like panda bears.

There is no way to de activate the dimple that latches
them together.

You can remove them more safely by using something to pry
them apart carefully. Yanking usually only busts your
knuckles, or gashes your hand in some way.

-Chuck Harris

Roy Thistle wrote:

On Thu, Oct 17, 2019 at 11:50 AM, Chuck Harris wrote:


faston connectors
Hi All:
Speaking of Faston Connectors (TE Connectivity)… what's the favorite way people have of removing the female "plugs"?... you know the crimp-on ones with indents or tabs, that lock somehow... and that pull the male lug off the pcb, or right out of the speaker... when you yank on them, in frustration. (I use a small screw driver, thin metal blade [or appropriate width]… or sometimes I do just yank like hell, if I want to see it the thing will let go before it, or something breaks.
Best regards. Best wishes.
Roy



Re: 2465A channel 2 problems

 

Chuck Harris wrote:
"Two quick ways to kill the attenuators are to give
them a spray with contact cleaner, or to wash them with
water.  The manual warns you not to do either."
I stand corrected and educated.  Thanks, Chuck, I missed that in the manual.  

GerryR wrote:

Chuck,
        Are you saying that the scope CH 1 & 2 inputs will be in 50 ohm mode for all
the Cal procedures?  I did check the inputs in normal mode when switched to 50 ohms,
and they are both OK, right at 50 ohms..  I haven't checked their state when in the
different Cal procedures; I'll be back at it a little later.

        Also, I don't hear CH 2 relays clicking when going from the 500 mV to the 1 V
scale; OK from 50 mV to 100 mV.  The inputs stay at 1 M throughout the ranges for
both CH 1 and CH 2, but I expect that particular relay isn't being activated for CH
2, so it is stuck in the 500 mV range and showing a "good" 1 M input.

        I'll have to look at the schematic and see if I can jumper the proper relay to
activate the 1 V scale change.  They are OC Darlington's, so that may tell me whether
it is the attenuator module relays or if the software or the drivers are the
problem.  Any other suggestions are welcome!
Thanks.

Gerry

Re: Smoking 2465B (Rifa/30-ohm) + Recap = PS will not start

tekscopegroup@...
 

On Thu, Oct 17, 2019 at 11:50 AM, Chuck Harris wrote:
Check the connection of the faston connectors that
connect the 110/220V selection switch. It looks like
you forgot to connect them back up when you connected
the supply back up.

-Chuck Harris
Hi Chuck, with the switch connected I can measure zero ohms across R1013 a 68K resistor that is in parallel with the voltage selection switch, so it seems all is ok in that respect. I just measured again the voltages across C1021 and C1022 the main input caps at J231A and each measures 144V across each, and total 287V. Does that sound right? I am using an isolation transformer that also drops the AC down to 117V, so those cap voltages are now a bit lower than what I reported earlier when connected directly to the AC line.

Re: Smoking 2465B (Rifa/30-ohm) + Recap = PS will not start

Roy Thistle
 

On Thu, Oct 17, 2019 at 11:50 AM, Chuck Harris wrote:


faston connectors
Hi All:
Speaking of Faston Connectors (TE Connectivity)… what's the favorite way people have of removing the female "plugs"?... you know the crimp-on ones with indents or tabs, that lock somehow... and that pull the male lug off the pcb, or right out of the speaker... when you yank on them, in frustration. (I use a small screw driver, thin metal blade [or appropriate width]… or sometimes I do just yank like hell, if I want to see it the thing will let go before it, or something breaks.
Best regards. Best wishes.
Roy

Re: Smoking 2465B (Rifa/30-ohm) + Recap = PS will not start

Roy Thistle
 

On Thu, Oct 17, 2019 at 10:14 AM, <tekscopegroup@...> wrote:


So maybe now would be a good time to recap, not just fix the damage
Hi Alex, Hi All!
First a disclaimer: The following are not.. for sure... the "words of the wise"... or maybe not even the words of the competent.
Next, and suspiciously, I noticed that all the voltages in your table are about 2/3 of what they are supposed to be. (Could you have created some kind of capacitive divider, or something causing a line drop, in the "primary" of the SMPS)… will the SMPS even start at 80VAC?
Also, did you check the SMPS part number correction on Tekwiki?
Lastly, did you check the "new" caps before installing them? (And, have you checked the removed ones to see if they are bad?)
Best regards and wishes.
Roy

Re: 2465A channel 2 problems

Chuck Harris
 

When calibration is under computer control, the computer
will automagically set all of the pertinent controls to their
proper settings for you. If the inputs need to be 50 ohms,
they will be set to 50 ohms.

Just like the manual says.

If your preamp attenuators are broken, they won't do what
they are told to do, and calibration will fail.

Two quick ways to kill the attenuators are to give
them a spray with contact cleaner, or to wash them with
water. The manual warns you not to do either. Somehow
everyone knows better than the engineers that designed
this stuff.

The relays are not made to be water resistant, and will rust
solid if you wash them, and their plastic structure is not
guaranteed to be compatible with anything but isopropyl alcohol.

The relays are a latching variety that was devised and made by
tektronix. They are set or reset by giving the appropriate coil
a little pulse of current. They are not strong enough to release
if there is oil (contact cleaner) between the armature and the
pole piece. The surface tension will for all intents and purposes
glue them into one position.

-Chuck Harris

GerryR wrote:

Chuck,
Are you saying that the scope CH 1 & 2 inputs will be in 50 ohm mode for all
the Cal procedures? I did check the inputs in normal mode when switched to 50 ohms,
and they are both OK, right at 50 ohms.. I haven't checked their state when in the
different Cal procedures; I'll be back at it a little later.

Also, I don't hear CH 2 relays clicking when going from the 500 mV to the 1 V
scale; OK from 50 mV to 100 mV. The inputs stay at 1 M throughout the ranges for
both CH 1 and CH 2, but I expect that particular relay isn't being activated for CH
2, so it is stuck in the 500 mV range and showing a "good" 1 M input.

I'll have to look at the schematic and see if I can jumper the proper relay to
activate the 1 V scale change. They are OC Darlington's, so that may tell me whether
it is the attenuator module relays or if the software or the drivers are the
problem. Any other suggestions are welcome!
Thanks.

Gerry