Test Equipment Anonymous (TEA) group therapy thread

[tautech]

https://en.wikipedia.org/wiki/Five_Eyes

[bd139]

“Five Eyes” intelligence sharing community. Australia, Canada, New Zealand, the United Kingdom and the United States. Basically massive fuckery behind the scenes.

[Specmaster]

Oh, I see, I thought it was something awful that we were about to drop in 

[Mr. Scram]

Most countries don't really allow indiscriminate spying on their own citizens on a large scale so you ask a friendly neighbour to do it for you. You spy on their citizens in return and you both legally share the data through international agreements and that's how you circumvent pesky laws telling you what you can't do. It's a travesty.

[med6753]

I ran across this picture of the London Underground and I'm very curious about the unusual track arrangement. I noticed a center rail like Lionel trains. Does that carry power? And if so, what is the purpose of the side, what we call here "3rd rail", that apparently the trains have a shoe to contact.

I'm thinking one side is voltage and the other ground? Yes?

[0culus]

https://en.wikipedia.org/wiki/London_Underground_infrastructure#Electrification


Looks like a 4 rail DC system. The center rail is negative and the "third rail" is positive.

[med6753]

OK makes sense....4 rail system. Unlike typical subway here where the 3rd outside rail that the shoe contacts is +600VDC and the riding rails are grounded or the return path.

[Specmaster]

I ran across this picture of the London Underground and I'm very curious about the unusual track arrangement. I noticed a center rail like Lionel trains. Does that carry power? And if so, what is the purpose of the side, what we call here "3rd rail", that apparently the trains have a shoe to contact.

I'm thinking one side is voltage and the other ground? Yes?

You are correct in your thinking, the trains work on 630VDC with 1 rail at +420 and the centre rail at -210VDC

[Specmaster]

OK makes sense....4 rail system. Unlike typical subway here where the 3rd outside rail that the shoe contacts is +600VDC and the riding rails are grounded or the return path.

Yes, apparently in the early days LUL I believe the 3 rails system with the actual running tracks being the ground return contacts as well but this caused corrosion of the running rails especially in the exposed sections of the track. So they experimented and came up with the 4 rail system and mounted both the power rails mounted on insulators which cured the problem.

[mnementh]

No, actually, the thing commonly called "duct tape" (or my favorite, NASCAR tape) was originally created for the US Military by Anderson tape MFG during WWII, on request for a waterproof sealing tape that could be used for temporary repair of tents and tarps, etc. This came to be known as "Duck tape" from the saying that it sealed "tighter than a duck's arse, and that's watertight", and would even seal when wet. It came to be used for sealing metal ductwork after the war, and then came about the whole "Duck Tape/Duct Tape" argument.

During the evolution of the companies involved, different colors evolved from the original GI Tan & Olive Drab to grey and silver for its popular use in ductwork, to black/white/blue for its use in music, theatrical and film productions. It was sometime around the age of Star Wars that descendant company MANCO made the "Duck Tape" name official and introduced a variety of colors for the consumer market.

mnem
Tape that duck!!!

As charming as that story is it's apparently called after duck cloth. That story won't quite make the same impact on birthdays though.

https://en.m.wikipedia.org/wiki/Duct_tape

The "Duck's arsehole" part was a direct quote from my grandfather, who served in WWII. While he was prone to some colorful stories, I do believe he knew why he and his fellow soldiers called it duck tape.  The rest of the story as I've related it is pretty well supported by that same wiki.

I suspect there may be some confusion in the wiki between what is known as duct tape vs what used to be known as "adhesive tape" or "medical adhesive tape", which was extremely sticky cotton duck tape used to hold gauze pads in place on skin as bandages, and was used will into the 70s or 80s in all manner of hospitals and clinics. THAT was one of J&J's staple products for over a century; the descendant of which is still used to wrap fighters' fists and hockey sticks. The primary difference being that "adhesive tape" is made in 1/2", 3/4" & 1" widths on a small core so it can be stored in a pocket or 1st Aid kit while duck tape, etc comes in 2-3" widths and are usually made on a core big enough to put your hand through so you can pull it tight to seal around objects.

OTOH... ehhh. It's fucking tape. 

mnem
*poring over schizzmatics on a 15-year-old TV* *tzzzzt*

[Kosmic]

Bought another frequency counter 

In general I appreciate the product made by BG7TBL (Chinese HAM ?). The Gpsdo, noise source and low freq upscaler I bought are all working fine and were really affordable. He recently created a high resolution frequency counter. Got 2 inputs (0-200Mhz and 30Mhz-6Ghz), 11 digits resolution, integrated power meter, switchable 50/1M  termination and USB (for data logging and automation). You can feed 10Mhz in the back or use the internal Ocxo. Best of all, it make absolutely no noise 





You can adjust the internal OCXO with a trimpot accessible at the back. The 6Ghz prescaler is on a different board.

[Kosmic]

I did some tests already and the internal OCXO is a little bit off. I guess it was not calibrated really well. No problem since I can tweak it to agree with my 10Mhz rubidium reference.

2.5Ghz on the second port. Look at all those digits !! 



10Mhz



Can also gather some useful stats. In this mode, characters on screen are really small though.



DIGITS !!! 

[mnementh]

Oh, I see, I thought it was something awful that we were about to drop in 

nope... we were dropped knee-deep in that particular pool of hoopla decades ago against our will and with little recourse.

It's the reason "cold-war" became an archaic concept... now all that psychological terrorism, cloak & dagger BS & illegal surveillance is just business as usual; the internet pretty much just handed them all wey more intel than they know what to do with. 

mnem
So of course, it all goes to the highest bidder...

[xrunner]

Bought another frequency counter 

In general I appreciate the product made by BG7TBL (Chinese HAM ?). The Gpsdo, noise source and low freq upscaler I bought are all working fine and were really affordable. He recently created a high resolution frequency counter. Got 2 inputs (0-200Mhz and 30Mhz-6Ghz), 11 digits resolution, integrated power meter, switchable 50/1M  termination and USB (for data logging and automation). You can feed 10Mhz in the back or use the internal Ocxo. Best of all, it make absolutely no noise 

Very cool. Integrated pwr meter too? Man I might have to pony up for one myself. 

How do you rate the accuracy of the pwr meter?

[Kosmic]

How do you rate the accuracy of the pwr meter?

at 0dBm it was spot on but on the lower range (-40dBm) it was something like 2 dBm off. So over all it's pretty good considering that this is not the primary function 

[Kosmic]

Also the power meter is only on port #1 from 0 - 200Mhz. Ha and while testing port #1 I realized it has no problem displaying a frequency up to 300Mhz 

[mnementh]

So... how long does it run on a 9V battery...?

mnem
 

[Kosmic]

So... how long does it run on a 9V battery...?

mnem
 

Nahh was for scale 

But since it's taking 12V DC in, would be easy to run that thing on battery.

[worsthorse]

Two component recommendations needed:

I have to replace some of the tiny tantalum electrolytics (mostly 1uf and 0.1uf, 35VDC) in the Tek 184 and one of the TMxxx modules. They are all being used as filter capacitors on the DC rails. I am inclined to use the Vishay 173D series solid tants, which fit, aren't terribly expensive and seem to have good enough specs but... any of the Tek restoration folks here want to make a different recommendation?

Second thing... I am going to upgrade the alligator clip connector on my DE-5000R, which means I'd like to find some decent quality two conductor shielded test lead cable. Doesn't have to be expensive or six point five digit special. It does have to be test lead flexible and probably 18 or 20 gauge.  Anyone have any recommendations?  Oh yeah, I'd prefer to not buy 100' of anything. 

Thanks all!

[worsthorse]

OTOH... ehhh. It's fucking tape. 

mnem
*poring over schizzmatics on a 15-year-old TV* *tzzzzt*

Thank you, i was typing, dudes its just freakin tape, right? when I saw your post. 

[worsthorse]

DIGITS !!! 

Is it just me, or is that much "precision" just, well, a little bit suspect?

[med6753]

Two component recommendations needed:

I have to replace some of the tiny tantalum electrolytics (mostly 1uf and 0.1uf, 35VDC) in the Tek 184 and one of the TMxxx modules. They are all being used as filter capacitors on the DC rails. I am inclined to use the Vishay 173D series solid tants, which fit, aren't terribly expensive and seem to have good enough specs but... any of the Tek restoration folks here want to make a different recommendation?

Second thing... I am going to upgrade the alligator clip connector on my DE-5000R, which means I'd like to find some decent quality two conductor shielded test lead cable. Doesn't have to be expensive or six point five digit special. It does have to be test lead flexible and probably 18 or 20 gauge.  Anyone have any recommendations?  Oh yeah, I'd prefer to not buy 100' of anything. 

Thanks all!

Either Vishay or Kemet tants will work just fine. 

[Kosmic]

DIGITS !!! 

Is it just me, or is that much "precision" just, well, a little bit suspect?

Peoples are talking about this counter on the metrology section. The resolution is supposed to be legit. https://www.eevblog.com/forum/metrology/bg7tbl-fa1-frequency-analyzer/

Will try to do some comparaison with my HP 53310a.

[mnementh]

<~~~ Yeah... aboot dat hoser over dere... Anytime you see him sign widdat little debbil grin, you can be double-damn certain he's just agitatin' fer the sake of agitatin'. 

So... how long does it run on a 9V battery...?

mnem
 

Nahh was for scale     But since it's taking 12V DC in, would be easy to run that thing on battery.

mnem
 

[Brumby]

<~~~ Yeah... aboot dat hoser over dere... Anytime you see him sign widdat little debbil grin, you can be double-damn certain he's just agitatin' fer the sake of agitatin'. 

I never noticed.   *cough*  *splutter*