EEVblog #769 - Mailbag

[EEVblog]

More mailbag, from a few countries we haven't had before!



SPOILERS:
Isolated Current Measurement Interface from PM Test Equipment
http://pm-te.com/current_meas.html
PAL TV Pattern & RF Generator Teardown
LED Panel meter teardown.
Mail from Antarctica!
Sandmarc GoPro Selfie Stick & Pole:
http://www.sandmarc.com/products/pole
Sandmarc Armour GoPro bag:
http://www.sandmarc.com/products/sandmarc-armor-bag
Rockband 3 Stratocaster Guitar Controller Teardown:

[tech5940]

Always love the mailbag video's, thanks Dave. And +1 on the request for more repair video's! You have to get lucky eventually... You know even if the repair isn't successful I always seem to learn something from the attempt to repair it.



Sent from my iPad using Tapatalk

[RickieSalad]

Check it out! I made it on the EEVBlog. 

Yes, there are 2 bars down here at McMurdo.  Southern Exposure and Gallaghers Pub, but only Gallaghers is open in the winter.

It is like a little town. Here is a better picture from the air.

[M4trix]

McMurdo ?? 

[RickieSalad]

McMurdo ?? 

I never actually saw the movie. When I came down here the first time the second most popular question was "Wow have you seen The Thing?"  The most popular of course being "Antarctica? Seriously, are you nuts why would you do that?!"  Haha

[TSL]

A couple of things...

Arlunya is Aboriginal for "The Sun"

Australia's Antarctic base have webcams

http://www.antarctica.gov.au/webcams

[daqq]

Hi Dave,

Thanks for the video.

Concerning the Czechoslovakian panel meter:

The connectors are not IDC, they are solder on pins. As to the Czech manual - the two languages (Slovakian and Czech) are very similar, if you know one, you will understand the second one without problems. Most everything on that meter was made by Tesla - the state owned electrotechnical monopoly ( https://en.wikipedia.org/wiki/Tesla_%28Czechoslovak_company%29 ), a few parts seem to be East German. I would be very surprised had you recognized the IC inside - very few products were traded between the west, let alone Australia - pretty much every part was made locally (the giant trim pot including) - good times from one point of view, not as good from another... The 74xx and 40xx logic is the same (note that Soviet Russia had their own parts with different numberings... although pin compatible most of the time), some analog stuff had similar numbers etc.

Should you ever visit Slovakia and visit Bratislava, drop me a note for a free guided tour  We do have some very beautiful sites, both natural and historical.

David

[M4trix]

McMurdo ?? 

I never actually saw the movie. When I came down here the first time the second most popular question was "Wow have you seen The Thing?"  The most popular of course being "Antarctica? Seriously, are you nuts why would you do that?!"  Haha

It's a John Carpenter's classic ! You have to watch it. 

[Deathwish]

"from a few countries we haven't had before!" . Not sure if Dave was being sarcastic as his first parcel was from someplace called stralia.... Maybe that part of Oz is the land that time forgot or such 

[RickieSalad]

A couple of things...

Arlunya is Aboriginal for "The Sun"

Australia's Antarctic base have webcams

http://www.antarctica.gov.au/webcams

We have webcams too. Naturally they wouldn't be working at the moment, but stay tuned.  It's been dark for months so not much to look at except lights on buildings anyway. The sun is coming back though! Happy dayssss!  O0

http://www.usap.gov/videoclipsandmaps/mcmwebcam.cfm

[george graves]

I never actually saw the movie. When I came down here the first time the second most popular question was "Wow have you seen The Thing?"  The most popular of course being "Antarctica? Seriously, are you nuts why would you do that?!"  Haha

The remake was bad.

Awesome that your post here.  Welcome! 

[BloodyCactus]

I never actually saw the movie. When I came down here the first time the second most popular question was "Wow have you seen The Thing?"  The most popular of course being "Antarctica? Seriously, are you nuts why would you do that?!"  Haha

The remake was bad.

it was a prequel. i didnt think it was bad. interesting but not the impact the original had, which is one of my favourite movies next to big trouble in little china

[delmadord]

Also, a free guided tour near the Slovak mountains (Vysoké Tatry - High Tatras) shown on the postcards. Should anyone be visiting Slovakia, drop me an email

[hli]

Concerning the Czechoslovakian panel meter:

...a few parts seem to be East German...

I think that most of it comes from east Germany. I instantly recognized the electrolytic caps (should be from 'Frolyt', but I have similar looking ones from Tesla), the ceramic caps and the green resistors - I still have many of them in my parts bin... The VQE 7-segment displays are east Germany, as well as the C520. To be sure you can look at the schematic.
The C520 is comparable to the AD2020 / CA3162. Its a 3-digit converter, ranging from -99 to +999mV. It was quite popular in east Germany at my time as it was really simple to use. And I still have some boards with it around.

[daqq]

The green resistors are of the TR191 or a similar type - I believe they were made by Tesla, but I could be mistaken. But parts from the TR series of resistors seem to be made by Tesla, see http://www.classical-stereo.wz.cz/image/tr161-64.jpg .

The blue electrolyte caps seem to be Tesla as well - see: http://www.elektrobazar.com/items/154%20Kondenz%C3%A1tor%201mF%2016V.jpg - either that or they used the same/very similar/compatible technology.

[hli]

The caps and resistors might be standardized throughout the communist block. I have similar resistors (just in blue) originating in Germany, same for the caps. And I even still have the book defining the standards. (My east-german electrolytic caps even mention the number of the corresponding standard on them).
But without more pictures its just guessing - the Tesla caps look quite similar. For me the LED drivers would be a clear indication where it was designed, since they were (AFAIK) produced both by Tesla and in east Germany (For Tesla with a MHxxxx designation IIRC, for east germany it would be a D348 or something like that).

[Halcyon]

Dave, you mention you haven't had much luck regarding things you can repair. Have you thought about opening it up to EEVblog members (of a certain contribution level) who can send stuff in for you to fix (for a fee/donation)? Maybe like your very own 'Antiques Roadshow' type segment with a twist? (Film it off-site to your office so you don't get stalkers).

I've got an old Apple Macintosh Classic which keeps tripping the circuit breaker in the house, but works otherwise. You're welcome to look at it :-)

Maybe even chuck on a barbie, charge members $10 a head or something. We'll see how good mini Dave goes handling BBQ tools :-)

[Yansi]

Hi Dave,

Thanks for the video.

Concerning the Czechoslovakian panel meter:

The connectors are not IDC, they are solder on pins. As to the Czech manual - the two languages (Slovakian and Czech) are very similar, if you know one, you will understand the second one without problems. Most everything on that meter was made by Tesla - the state owned electrotechnical monopoly ( https://en.wikipedia.org/wiki/Tesla_%28Czechoslovak_company%29 ), a few parts seem to be East German. I would be very surprised had you recognized the IC inside - very few products were traded between the west, let alone Australia - pretty much every part was made locally (the giant trim pot including) - good times from one point of view, not as good from another... The 74xx and 40xx logic is the same (note that Soviet Russia had their own parts with different numberings... although pin compatible most of the time), some analog stuff had similar numbers etc.

Should you ever visit Slovakia and visit Bratislava, drop me a note for a free guided tour  We do have some very beautiful sites, both natural and historical.

David

You shoud not be surprised, because the C520D is a deutsch copy of AD2020 (CA3162). It is a quite well known ADC.

//Hello for my Slovakian neighbours.

[Fungus]

Does it matter if things are beyond economical repair?

This is the EEVBLOG, not a company which only wants a working instrument.

[GoneTomorrow]

Check it out! I made it on the EEVBlog. 

Yes, there are 2 bars down here at McMurdo.  Southern Exposure and Gallaghers Pub, but only Gallaghers is open in the winter.

It is like a little town. Here is a better picture from the air.

How much interaction is there with the New Zealand Antarctic base just over the hill there?

[RickieSalad]

We do our own things but we do interact quite a bit.  I know our phone, internet, and power systems are tied together to some degree.  Sometimes we'll hitch rides on the Kiwi aircraft and sometimes they ride with us.  Our SAR teams train and work together sometimes to track down missing people and things like that.  They invite us over for dinner for "American" nights and they'll come over when we have celebrations.  We all work really well together.

[poot36]

If Dave doesn't think that it is worth his time to fix the piece of test gear with the blown components from the bad voltage regulator I think that he could give it away to one of the users of this forum who had the time to fix it instead of collecting dust (me for example although shipping to Canada might be expensive).

[Jeroen3]

Do we already know more about the current sensor used in the isolated current interface?

[radix]

Concerning the Czechoslovakian panel meter:

...a few parts seem to be East German...

I think that most of it comes from east Germany. I instantly recognized the electrolytic caps (should be from 'Frolyt', but I have similar looking ones from Tesla), the ceramic caps and the green resistors - I still have many of them in my parts bin... The VQE 7-segment displays are east Germany, as well as the C520. To be sure you can look at the schematic.
The C520 is comparable to the AD2020 / CA3162. Its a 3-digit converter, ranging from -99 to +999mV. It was quite popular in east Germany at my time as it was really simple to use. And I still have some boards with it around.

Yet everyone ignored the "Iskra" logo on the electrolytic capacitor... Iskra was the Yugoslav equivalent of the Czechoslovak Tesla. A state owned company, that produced much of the electonic components, small appliances and basic test equippment. Tere may have even been some cooperation between Tesla and Iskra because I've seen some examples of gear with an Iskra logo and a Tesla nameplate.

[AF6LJ]

Mailbag is good even the less than great ones have some great content.
Love Them Dave.

[Jay_Diddy_B]

Do we already know more about the current sensor used in the isolated current interface?

I have found it:

http://www.gmw.com/magnetic_sensors/asahi/current-sensors-HA.html?gclid=CK-LsZmQ8sYCFQwyaQoddEsA-w#330x

and

http://www.gmw.com/magnetic_sensors/asahi/documents/CQ2093_e.pdf


Here are some extracts from the datasheet:





They very reasonable at $5.33 USD EA. for Qty 5-9.


Regards,

Jay_Diddy_B

[Jeroen3]

Looks promising. Much like the more famous Allegro ACS sensors, but more accurate and higher bandwidth. 

[poot36]

You could always repair the Tek scopes that a fan sent in in a previous mailbag.