Test Equipment Anonymous (TEA) group therapy thread

[kleiner Rainer]

ok, I did pick up the THS720 - came with power supply, albeit not original, came with 2 150MHz Testec Probes, new battery, LCD fresh and crisp , even though it has one scratch that does not pose a real problem and checked out ok.

Also came with invoice which makes this tax deductable.

I realize it is not the over the top super duper gizmo and that there are better ones out there, but as a small general purpose portable gizmo for abroad this does not sound too bad an idea.

Still gotta take a couple of photos, but I was too tired today.

The THS720A is not very picky about its power supply - the original wall wart (transformer based, no switcher) has a 16V no load output and a capacitance between primary and secondary of 25pF.
I ran my THS720 off a cigarette lighter jack in my car - worked fine.

BTW the difference between a THS720 and the A type is that the A type can use the DMM input as extra trigger source.

Here the thread with the modification to "P": https://www.eevblog.com/forum/testgear/tek-ths720a-portable-scope-teardowndiscussion/msg1074016/#msg1074016

Schematic: http://kazus.ru/forums/attachment.php?attachmentid=25865&d=1315575619

Page 9 shows the magic jumpers. Remove R205 and put it onto the position for R204. Done.

Greetings,

Rainer

[bd139]

The single reason which answers all that, and the fact that it continues to persist even today, and still indirectly poisons all digital formats that have followed, is simple human greed. 

mnem
 

I'm talking about audio quality and manageability, and you are -- conveniently to your argument -- including metadata and politics.

Yes, with the hindsight of 2021, adding 1-10KiB or so of metadata is a no-brainer.

Given the technical solutions of 1982, that would mean ASCII or worse, just look at the GSM SMS charset, it is such a worse-ness; it's almost but not quite LATRINE-1, and what would Sony say? Dutch like English has hardly any characters outside 7-bit so neither one of the inventors nor most of the readers of this thread would even start thinking of this as a problem unless beaten with an internationalisation stick. Us Nordic people look at the 7-bit world and their Heavy Metal usage of umlauts and simply break down in a meleé of cringe and pity: "Mötley Crüe" "Tröjan")

(Creating that paragraph involved editing Wikipedia to insert "Tröjan", with references, just because.)

The thing with CD that has made it good beyond its useful life is that it is simple, well understood, open and not encumbered by stupid things like software "patents".  Given that CD is alive still -- according to you -- because of greed, that might seem like a controversial statement, but look at what came after it; MP3, AAC, Apple Lossless, WMA, Real, APT-X, et c. ad inf. All festering piles of greed. Compared to those, CDDA is immaculate conception pure. Not until the arrival of Ogg Vorbis, FLAC and Opus has the music compression landscape become something else than an industrial wasteland.

So, there!

Yes. My 2014 Citroen will not display the metadata for anything with Cyrillic Unicode runes. Go back to 1980 something and it was even worse.

This is ruining my Sovietwave playlist 

[McBryce]

Somebody here from Köln (Cologne)?

https://www.ebay-kleinanzeigen.de/s-anzeige/amateurfunk-konvolut-messgeraete-hewlett-packard-rohde-schwarz/1739640352-168-18670

They are still there... Just starring at me, willing me...

McBryce.

They're gone and it wasn't me. Tony??

McBryce.

[Peter_O]

There is a second advertisement from the same seller: Two garages full of components:     
https://www.ebay-kleinanzeigen.de/s-anzeige/elektronik-konvolut-elektronische-bauelemente-sortiment/1739649532-168-18670
   

[goaty]

Man, that makes me sad. Grandpa died and that´s whats left over. At least the stuff goes to some afficionado.

[McBryce]

There is a second advertisement from the same seller: Two garages full of components:     
https://www.ebay-kleinanzeigen.de/s-anzeige/elektronik-konvolut-elektronische-bauelemente-sortiment/1739649532-168-18670
   

Yes, but they don't tell you what's there and the pictures only show dusty boxes.

McBryce.

[bd139]

Man, that makes me sad. Grandpa died and that´s whats left over. At least the stuff goes to some afficionado.

Might not be. The dude I bought that Marconi 2019A off a few years back was having a mid life crisis and selling all his stuff to disappear off to the US with his new floozie. I thought it was an SK sale to start with 

[kleiner Rainer]

Yeah had one too that didn't work properly. Took some fixing that one!

https://www.eevblog.com/forum/testgear/hp-1740a-power-supply-burn-up/

This was my favourite diagnostic picture - spot the missing bond wire on the LM723:

Collector bond wire of the internal power transistor. Probably the main cause of death for this type of chip.

Greetings,

Rainer

[tonyalbus]

Somebody here from Köln (Cologne)?

https://www.ebay-kleinanzeigen.de/s-anzeige/amateurfunk-konvolut-messgeraete-hewlett-packard-rohde-schwarz/1739640352-168-18670

McBryce.

They're gone and it wasn't me. Tony??

McBryce.

Would have been cool to say YES! ... but it wasn't me


i am happy it is gone... and the wife now not killing me in my sleep after she would have find out 
i sleep much better not buying it

[med6753]

The single reason which answers all that, and the fact that it continues to persist even today, and still indirectly poisons all digital formats that have followed, is simple human greed. 

mnem
 

I'm talking about audio quality and manageability, and you are -- conveniently to your argument -- including metadata and politics.

You should know by now that everything surrounding Capitalism and free economy in dragon's mind is driven by profit, greed, and crooked politics. Doesn't matter what the subject matter is...he always manages to drag in his endless bantering and verbal diarrhea. So much so that 90% of his posting I either skim or skip entirely. Perhaps he should move to Cuba, or China, or perhaps even North Korea for a year or so and then report back how great it is.     

[Specmaster]

Med you want a HP scope ? 55$ for a HP 1740A, it's cheap right ?

https://www.ebay.com/itm/Hewlett-Packard-HP-1740A-Oscilloscope/154422216684



Edit: Just noticed it's sold for parts. Probably explain the price.

I just can't seem to warm up to HP scopes of that era.  The early tube ones are cool, and I have one of the later 90s era digitals, but that lot is just meh.  By and large I subscribe to the old wisdom that there are three names in oscilloscopes - Tektronix, Tektronix and Tektronix.  For all else there is HP.

-Pat

Actually, those HP scopes are not too bad, their weakness is in the board interconnects, unless these are kept in good condition, some contacts will oxidise  and will start to cause intermittent contacts and can as bd139 will testify burn out contacts if left. Apart from that they seem to be OK

[med6753]

Med you want a HP scope ? 55$ for a HP 1740A, it's cheap right ?

https://www.ebay.com/itm/Hewlett-Packard-HP-1740A-Oscilloscope/154422216684



Edit: Just noticed it's sold for parts. Probably explain the price.

I just can't seem to warm up to HP scopes of that era.  The early tube ones are cool, and I have one of the later 90s era digitals, but that lot is just meh.  By and large I subscribe to the old wisdom that there are three names in oscilloscopes - Tektronix, Tektronix and Tektronix.  For all else there is HP.

-Pat

Actually, those HP scopes are not too bad, their weakness is in the board interconnects, unless these are kept in good condition, some contacts will oxidise  and will start to cause intermittent contacts and can as bd139 will testify burn out contacts if left. Apart from that they seem to be OK

I've got nothing against them. I used older 180A's at work and they were decent scopes.

[tggzzz]

Med you want a HP scope ? 55$ for a HP 1740A, it's cheap right ?

https://www.ebay.com/itm/Hewlett-Packard-HP-1740A-Oscilloscope/154422216684



Edit: Just noticed it's sold for parts. Probably explain the price.

I just can't seem to warm up to HP scopes of that era.  The early tube ones are cool, and I have one of the later 90s era digitals, but that lot is just meh.  By and large I subscribe to the old wisdom that there are three names in oscilloscopes - Tektronix, Tektronix and Tektronix.  For all else there is HP.

-Pat

Actually, those HP scopes are not too bad, their weakness is in the board interconnects, unless these are kept in good condition, some contacts will oxidise  and will start to cause intermittent contacts and can as bd139 will testify burn out contacts if left. Apart from that they seem to be OK

I quite like mine, especially the 50ohm termination and the large screen. Unless space is a problem, I have a minor preference for it over a 465.

The only problem I had was that the plastic cover on the rotating part of the timebase abraded the teack on the PCB. Fixed by soldering a wire across the gap, being very careful not to allow solder to flow along the PCB tracks onto the gold ring contacts.

[mansaxel]

You should know by now that everything surrounding Capitalism and free economy in dragon's mind is driven by profit, greed, and crooked politics. 

I know. It's just more fun to keep at it that way. And, I think mnem is right on to something here.

Actually, I do.  Capitalism involves using the resources you have to rob others of their work or monies in order to further your own coin pile, all under a gauze-thin veil of "offered convenience" and "flourishing society". It is an industrial variant of the feudal conservative society and as such it shares the fundamentals of conservatism:

• Those who have shall continue to gain more, unproportionally.
• The rules limiting behaviour only apply to the ruled classes.

But such a fight needs to be fought with precision from a moral high ground of accurate statements -- it won't do to turn it into ranting. Therefore, I offer my support. 

[Specmaster]

If anyone is interested there is a live internet broadcast from RAF Lakenheath and RAF Mildenhall today from Airshow World.

[Robert763]

Anyway distractions aside from TE, a TE related post finally.

So I was going to work on a GPSDO so the plan was to do something fancy with microcontrollers as well but seeing as Cerebus thoroughly cornered the market with that one I thought I'd go back to basics and do something old school. Thus I have in my possession some 74hc4046's and 74hc390's and am going to build a good old fashioned PLL that will lock to a 1pps signal. I don't have anything that will kick out a 1pps signal at the moment so the plan is:

1. stuff the ref out on the 5384A into the back of the DG810 ref in so I have a consistent reference.
2. Get the DG810 to generate the 1pps signal.
3. Lock an independent OCXO module to it with a stack of 74hc390 dividers and the 4046 as the phase detector.
4. Observe the phase locking with a scope
5. Observe frequency difference with the 5384A
6. Try and develop a lock indicator for it.

Only horrible thing is the time constant for a 1pps loop filter is horrible so this is going to mean watching second long pulses shooting past each other like snails  .

Assuming worst case it's possible that the phase lock could take a couple of days to happen if both clocks are fairly close but out of phase

10KHz timing module would be nicer!!! Any suggestions?

I have a spare Rockwell Jupiter GPS module with a 10kHz output if that is useful. There are existing designs around this including one by James Miller G3RUH
 http://jrmiller.online/projects/ministd/frqstd0.htm http://jrmiller.online/projects/ministd/frqstd.htm
Another by Andy Talbot G4GNT
http://www.g4jnt.com/SimpleGPSDO.pdf

PM me if you want a GPS.

[bd139]

You should know by now that everything surrounding Capitalism and free economy in dragon's mind is driven by profit, greed, and crooked politics. 

I know. It's just more fun to keep at it that way. And, I think mnem is right on to something here.

Actually, I do.  Capitalism involves using the resources you have to rob others of their work or monies in order to further your own coin pile, all under a gauze-thin veil of "offered convenience" and "flourishing society". It is an industrial variant of the feudal conservative society and as such it shares the fundamentals of conservatism:

• Those who have shall continue to gain more, unproportionally.
• The rules limiting behaviour only apply to the ruled classes.

But such a fight needs to be fought with precision from a moral high ground of accurate statements -- it won't do to turn it into ranting. Therefore, I offer my support. 

Capitalism, as with all political ideology and religion, is poorly defined. Poorly defined things allow less than ethical individuals exploit others for personal gain. The problem is down to individuals not ideologies. Ideologies just distract from that conveniently and allow people to hide behind them.

[bd139]

Anyway distractions aside from TE, a TE related post finally.

So I was going to work on a GPSDO so the plan was to do something fancy with microcontrollers as well but seeing as Cerebus thoroughly cornered the market with that one I thought I'd go back to basics and do something old school. Thus I have in my possession some 74hc4046's and 74hc390's and am going to build a good old fashioned PLL that will lock to a 1pps signal. I don't have anything that will kick out a 1pps signal at the moment so the plan is:

1. stuff the ref out on the 5384A into the back of the DG810 ref in so I have a consistent reference.
2. Get the DG810 to generate the 1pps signal.
3. Lock an independent OCXO module to it with a stack of 74hc390 dividers and the 4046 as the phase detector.
4. Observe the phase locking with a scope
5. Observe frequency difference with the 5384A
6. Try and develop a lock indicator for it.

Only horrible thing is the time constant for a 1pps loop filter is horrible so this is going to mean watching second long pulses shooting past each other like snails  .

Assuming worst case it's possible that the phase lock could take a couple of days to happen if both clocks are fairly close but out of phase

10KHz timing module would be nicer!!! Any suggestions?

I have a spare Rockwell Jupiter GPS module with a 10kHz output if that is useful. There are existing designs around this including one by James Miller G3RUH
 http://jrmiller.online/projects/ministd/frqstd0.htm http://jrmiller.online/projects/ministd/frqstd.htm
Another by Andy Talbot G4GNT
http://www.g4jnt.com/SimpleGPSDO.pdf

PM me if you want a GPS.

Ooh nice. Might take you up on that. Will PM later when I get a min. PagerDuty just lit up like a fucking Christmas tree 

[Saskia]

re capitalism vs communism

communism means: only the party and its delegates have anything. This is the very same situation as the turbo capitalism that some of you are so irate about. Neither is a good thing in my opinion.

In my opinion work should pay off. I should be able to gain something if I have a good idea or work hard towards my goals. You cannot do that in socialism or communism. You cannot do this in the new world corporate feudalism either. At least not while not being a corporate critter on their food roster.

I hate the limitations on personal freedom and liberties that communism, socialism, and the "well meaning" nanny states impose.

Back in our old times you were forced to think for yourself. You learned that some stuff was a bad idea. You learned fast not to be a complete moron because doing so would end up in pain and some take aways for your future life. Nanny states deny you that experience and will make you unfit for a self sustained and responsible life.

It goes without saying that I do not condone unethical behavior such as exploiting kids for sex, others for personal gain, etc.

Fair pay for good work and mutual respect go a long way to lay the foundation to prevent such behavior. As for the psycho- and sociopaths: you will always have those in a society. And it is the responsibility of the society to weed out such behavior. You will however only detect it if you are allowed to have a non-state-imposed moral foundation and a feeling for good and evil. Which you will not develop if the state just tells you what to believe. You have to learn to think for yourself, otherwise you will just be another worker ant in the hive.


Now I would very much like to see the constant political rambling like "socialism is great, capitalism is evil" be dropped. Especially the "superior moral position" stuff. We are all trying to live our lifes without too much of a negative impact on the environment and on society and we all value our personal freedom to make our own choices in day to day life.

Let's keep it this way.

Just my 2c ...

[med6753]

Would it be possible if we could at least achieve a small sample of Utopia if we keep our political views OUT of this thread once and for all? 

Is it really asking too much? 

[Robert763]

The single reason which answers all that, and the fact that it continues to persist even today, and still indirectly poisons all digital formats that have followed, is simple human greed. 

mnem
 

I'm talking about audio quality and manageability, and you are -- conveniently to your argument -- including metadata and politics.

Yes, with the hindsight of 2021, adding 1-10KiB or so of metadata is a no-brainer.

Given the technical solutions of 1982, that would mean ASCII or worse, just look at the GSM SMS charset, it is such a worse-ness; it's almost but not quite LATRINE-1, and what would Sony say? Dutch like English has hardly any characters outside 7-bit so neither one of the inventors nor most of the readers of this thread would even start thinking of this as a problem unless beaten with an internationalisation stick. Us Nordic people look at the 7-bit world and their Heavy Metal usage of umlauts and simply break down in a meleé of cringe and pity: "Mötley Crüe" "Tröjan")

(Creating that paragraph involved editing Wikipedia to insert "Tröjan", with references, just because.)

The thing with CD that has made it good beyond its useful life is that it is simple, well understood, open and not encumbered by stupid things like software "patents".  Given that CD is alive still -- according to you -- because of greed, that might seem like a controversial statement, but look at what came after it; MP3, AAC, Apple Lossless, WMA, Real, APT-X, et c. ad inf. All festering piles of greed. Compared to those, CDDA is immaculate conception pure. Not until the arrival of Ogg Vorbis, FLAC and Opus has the music compression landscape become something else than an industrial wasteland.

So, there!

Not to mention YOU OWN the CD unlike a iTunes download.

[xrunner]

Would it be possible if we could at least achieve a small sample of Utopia if we keep our political views OUT of this thread once and for all? 

Is it really asking too much? 

I'm not sayin' anything or I'll get shot down.

Well I said that, but that's all. 

[Saskia]

I still like CDs and I still keep buying them.
Why ?
Because I hate streaming services and the bloody DRM stuff. I want to be able to listen to and watch my stuff when I like, where I like and as often as I like.
Without anybody charging me for it continuously.

[xrunner]

Tests from the bench: hp 437B power meter with hp 8481A sensor

Item 2: Icom IC-7300 HF Transceiver

Transmitting tuning tone from FT-8 software on USB, effectively a CW emission on 14 MHz band. Rig power setting was Max percent power, ~100 W (~ +50 dBm).  So we add 50 dB atten. in-line (a little extra for safety), (50 dB offset entered into meter). Expecting ~ 0 dBm at sensor. DMM connected to "recorder output" which is a 0 to 1 V linear power tracking signal. Output not expected to be exactly 100W. Reading was 90.0 W.

Need to measure more power? Add more attenuators. Now - what about the other direction?

Note 1: I can go into the service menu of the radio at a later time and go through the output power adjustment procedure, but I have to make a simple shorting plug for a connector at the back to allow access to the menu.

Note 2: Told some of my ham friends I got this power meter (they know what I do over here, some have visited). I said it isn't a "Ham" thing like MFJ stuff it's legit lab equipment and wasn't made for "casual" ham radio use. But it certainly can be used for that hobby if I wanted to. One of them asked me how much power it could measure. I said, well the sensor can measure from -30 dBm to +20 dBm without attenuation. He said that +20 dBm sounded like a lot of power.

I said - don't get one. That's me - saving power sensors for posterity - one day at a time. 

[med6753]

Note 2: Told some of my ham friends I got this power meter (they know what I do over here, some have visited). I said it isn't a "Ham" thing like MFJ stuff it's legit lab equipment and wasn't made for "casual" ham radio use. But it certainly can be used for that hobby if I wanted to. One of them asked me how much power it could measure. I said, well the sensor can measure from -30 dBm to +20 dBm without attenuation. He said that +20 dBm sounded like a lot of power.

I said - don't get one. That's me - saving power sensors for posterity - one day at a time. 

You actually let some of those Hobos in your house? Did you have to fumigate afterwards?