Test Equipment Anonymous (TEA) group therapy thread

[duckduck]

@Vince - man are you really serious, wtf is happening here, I mean compared with the usual medical reports, "those stinky hobo hams" and the other stuff, your stuff was nice and refreshing in a beginners way, including the fridge timer and components sorting.

Please reconsider, don't let idiots win  !!!

The $64,000 question is..., who might the idiots be then 

Idiot here, checking in!

Also, I'm a new RF hobbyist. For RF power meters (let's say 1 MHz - 500 MHz) it looks like my options are:

• Cheap used HP meter and a fairly expensive sensor head. Calibration is possible.
• Various ham power meters: MFJ, Bird, etc.
• Cheap ebay/AliExpress Golden Dragon PCB / OLED / SMA meters

Am I missing anything?

What power and frequency range?
There are other "professional" used power meters similar to the HP 43#X range. Marconi make a range including some (6460 etc) based on the General Microwave TfT sensors.

Typical amateur radio powers and frequencies: 1 W to 100 W, 1 MHz to 500 MHz.

[Robert763]

Oh boy these old HP handles really just kept breaking, they made them out of glass FFS ! 

Thin cross section of die cast zinc/alu alloy versus crap packaging (I blame people copying amazon) and/or shipping gorilla(s) unfortunately. 

See this almost three year old post for the replacement sideframe. https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/msg2719034/#msg2719034

A lot has happened since then....

The milling machine & another lathe that were at my Grandads place, are now in my Dads workshop, unfortunately some of my TE & other stuff, is all around both machine tools & we can't get to either to actually use them. I see no end to this problem yet, as the storeroom is pretty much full (they have no larger rooms available) and I'm struggling to find an affordable property, with enough space for the TE. 

David

Thanks, I understand now.... was not familiar with the HP way of doing things, didn't know the handles were an integral part of the sides 

Lucky you could find spare sides with that seller.

As for milling, Robert just got his fancy shiny new mini milling machine. Might be good enough for what you have to do ?
Maybe you can subcontract the job to him, maybe he can give you a TEA discount on his usual 200 quid hourly labour rate ?! 

My mill is just big enough to do the job with some repositioning. However the frames are standard. I'd buy a BER or stripped unit and use the frame from that.

[factory]

I agree the HP side-frames were standard parts, but in the 5240A they have the fold-out handle section completely machined out, this is because the 5240A consists of the heavy die-cast box from a 5260A, with a 8 digit counter stuck on top and the wiring looms are feed through the space where those handles normally are. Look closely and you might find others with little modifications.

There have been no stripped out units of a similar size in the last three years, the sellers that strip them throw them away before listing the parts, very hard to find a cheap BER unit these days on ePay, plus that comes with the 50/50 risk that the side will get smashed, by crap packing & poor delivery.
Same problem when I asked a UK seller that parted out a 5340A, if they had the empty frame with transformer, "nope it's gone" was pretty much the response, I did get a set of the small boards for 5340A number 3 (which is missing two), for a reasonable price, so can't complain too much.
I also have a 5321B with missing side cover panels, I've yet to see anything the same size listed for cheap, my only option at the moment is to cut down the two side covers from a commonly found 435A/B.
All these frame parts are usually too expensive to obtain from outside the UK.

A roundtuit & space to use the mill here, will be found eventually.

David

[Robert763]

Wel I survived my 412 mile road trip Too late to give details but the quick version is
Telford hamfest, glad I didn't make a dedicated trip
Haul 3x R&S, 2x HP 1x Thurlby Thandar plus some small bits.
Outlander PHEV, great for a road trip

[Brumby]

Haul 3x R&S, 2x HP 1x Thurlby Thandar plus some small bits.

Pics, man.  Pics!

(You can sleep later) 

[Brumby]

Grabbed a pen to make some notes - and then I saw it.

I just had to grab my phone with the other hand to take this:



 

[McBryce]

Grabbed a pen to make some notes - and then I saw it.

I just had to grab my phone with the other hand to take this:



 

And?? Did you detect a charge in the paper?

McBryce.

[Robert763]

Haul 3x R&S, 2x HP 1x Thurlby Thandar plus some small bits.

Pics, man.  Pics!

(You can sleep later) 

Ok OK,

Two R&S SFZ these are 2GHz generators that can generate 3 TV signals, total 6 carriers at once. Can do various modulations.
One R&S SFQ digital TV signal generator to 3GHz This may be a bit of a sleeper if one of the options does what I think. Need to play.
One HP 3708A Noise tst set (75R 10 to 150 MHz baseband.
One HP 3784A Digital transmission analyser.
One Thurlby Thandar TG1304 programmable function generator. This is full function non DDS unit with TWO generators the main up to 13MHz the Aux up to 100kHz either as moulation for the main, on it's own or summed with the main.

The two units on top are a Avantech Atom based industrial PC and a Motorolla MW800 mobile PC from a fire engine. No interconnect lead for THe MW800. They are only $30 in the USA but that triples when you add shipping and tax. I may have a couple of plugs (micro centronics style) I'll have to check.

The to HP units are really only fit for parts.

[capt bullshot]

And now for some creative abuse of TE - Fresh from the "Fun with TEA" department:

It might be known to some of you that one can use a Tek 7000 scope with two timebase plugins plus some external circuitry to display a TV picture. You'll be disappointed right now, as I won't show this. I just can't be bothered to make up the required external circuits right now.

What might be lesser known follows right here:

Using these adaptors is considered blasphemy in vast areas of TE world, as these allow to connect all kind of crap to impedance controlled (Ok, it's just BNC) coxial lines:



In this case, it's an ordinary consumer electronics device, a satellite TV set top box with composite video output.



Anyway, modern (or maybe not that recent) digital oscilloscopes have a video trigger mode:



This video trigger allows to pick and show one line out of the video signal. Normal triggering wouldn't allow a stable trigger on one line, just would show a more or less random line each time the scope triggers. One can manually scan through all the lines and maybe get an idea of the actual video picture, or just searching for anomalies ...

See the video for a short demonstration of how to scan through the lines:
https://cb.wunderkis.de/wk-pub/eevpic/video.ogg

Wandering through the various menus of this scope, one might find this function here:



The scope shows the video image (or something that at least looks like the actual image) without any external hardware  

For comparison, here's the image on a monitor:

[Vince]

I don't understand how you did it, but it's uber cool...

My analog Philips / Fluke Combiscope has video trigger like any decent analog scope of course, and IIRC it lets you select the line number as well. Picture might look better on an analog scope ?

But I just don't understand how you did it... I would say it's April fool, but we are not April 1st so.... I guess it must be a real thing....

[capt bullshot]

It's a fancy digital scope. It just has a button somewhere in its menus that says "Picture On/Off" - part of the video trigger option. No trick and no kidding involved - just connect the video signal to the input and push some buttons. It also does some video vector scope displays, but I don't know how they're intended to be used.
Picture quality is poor, I'd guess one can make up a better image on an analog scope - as I said, I don't have the stuff ready to use, I would have to build some sync separator and video amplifier and really cannot be bothered ...
Maybe there's something on the net ... indeed, there is:

[themadhippy]

And we go full circle,years ago people were converting there obsolete black n white  tv into a basic oscilascope,and now  their  converting scopes back to a tv

[Vince]

It's a fancy digital scope. It just has a button somewhere in its menus that says "Picture On/Off" - part of the video trigger option.

Oh OK ! That's too easy ! 

Didn't know some scopes had that fancy option... now I know.

Maybe there's something on the net ... indeed, there is:

Yeah I am subscribed to his channel, I remember that video of his from a while ago... was well impressed. I had kinda planned one day on following his instructions / schematic, and try to replicate his feat.

[factory]

Also watched that one years ago and have some parts to build it, assuming they are not fakes, as some parts were from ePay.

David

[factory]

Haul 3x R&S, 2x HP 1x Thurlby Thandar plus some small bits.

Pics, man.  Pics!

(You can sleep later) 

Ok OK,

Two R&S SFZ these are 2GHz generators that can generate 3 TV signals, total 6 carriers at once. Can do various modulations.
One R&S SFQ digital TV signal generator to 3GHz This may be a bit of a sleeper if one of the options does what I think. Need to play.
One HP 3708A Noise tst set (75R 10 to 150 MHz baseband.
One HP 3784A Digital transmission analyser.
One Thurlby Thandar TG1304 programmable function generator. This is full function non DDS unit with TWO generators the main up to 13MHz the Aux up to 100kHz either as moulation for the main, on it's own or summed with the main.

The two units on top are a Avantech Atom based industrial PC and a Motorolla MW800 mobile PC from a fire engine. No interconnect lead for THe MW800. They are only $30 in the USA but that triples when you add shipping and tax. I may have a couple of plugs (micro centronics style) I'll have to check.

The to HP units are really only fit for parts.

I quite like that TTI function gen, we had two of them at work, along with two of the TG1010A. Was it expensive?

One of the mods at the UK vintage radio forum worked on parts of the HP 3708A, there are a couple of posts mentioning parts used in it.

David

[factory]

...snip...

The BCD switch only does 0 to 9, to test the blanking I abused one of the dead (salvaged parts) 7404 ICs  , soldered four pins together, may have to find another switch in the future & replace the 10 position one.



I'm happy to say the prototype works fine. 

This leaves me with one question, why do the salvaged 1820-0215 ICs not work, well I suspect they are a different BCD code or pinout. I've ordered a manual from Artek, that will hopefully answer this, the Agilent one is unreadable crap as usual.

David

Well I didn't need to solder those IC legs together, there was an easier way to check the BCD above 9, link the BCD 8 resistor to the +5V pin that was already on my board and use the switch to do BCD 10 to 15.



The other pair of 1820-0215 ICs ended up testing the same as the 1820-0092 did, no idea why HP had another part number if it's the exact same functionality & pinout (pinout confirmed with the Artek pdf), the one I tested before was definitely borked.

Some progress on learning KiCAD to make an adaptor, the schematic editor wasn't too bad, never learned to add the component footprints before (I wrongly assumed they were already assigned when you picked the symbols), the tutorial helped with a few bits I missed along the way.
The PCB editor is currently a work in progress, just need to play with the track layout some more and find out what stuff the manufacturers allow in the board setup V cost. Need to find the right angle headers too.



David

[Robert763]

Haul 3x R&S, 2x HP 1x Thurlby Thandar plus some small bits.

Pics, man.  Pics!

(You can sleep later) 

Ok OK,

Two R&S SFZ these are 2GHz generators that can generate 3 TV signals, total 6 carriers at once. Can do various modulations.
One R&S SFQ digital TV signal generator to 3GHz This may be a bit of a sleeper if one of the options does what I think. Need to play.
One HP 3708A Noise tst set (75R 10 to 150 MHz baseband.
One HP 3784A Digital transmission analyser.
One Thurlby Thandar TG1304 programmable function generator. This is full function non DDS unit with TWO generators the main up to 13MHz the Aux up to 100kHz either as moulation for the main, on it's own or summed with the main.

The two units on top are a Avantech Atom based industrial PC and a Motorolla MW800 mobile PC from a fire engine. No interconnect lead for THe MW800. They are only $30 in the USA but that triples when you add shipping and tax. I may have a couple of plugs (micro centronics style) I'll have to check.

The to HP units are really only fit for parts.

I quite like that TTI function gen, we had two of them at work, along with two of the TG1010A. Was it expensive?

One of the mods at the UK vintage radio forum worked on parts of the HP 3708A, there are a couple of posts mentioning parts used in it.

David

It seems very nice, I don't suppose you kept a copy of the manual? I can't find one. I paid £50 which is pretty good.
There is one possible issue, but it might lack of operation information. The rotary knob does not do anything and there does not seem to be any indication of what function it is linked to. Can you rememder how it operates?
I've done some checks of the control and it seems OK. Surprisingly it's not a rotary encoder. It's  dual gang pot with the CW ends of each track connected to +5V and the anti-clockwise end to -5v (I mighr have mixed up the polarities) There are no stops. electrical travel is around 300 degrees but the two wipers are physically 180 degrees apart so there is always one on a track.
Wiper voltages look about right. I want to find out how it is suposed to be operated befrore digging deeper. I've asked TTI if they have a manual. They are just down the road from me in Huntingdon. Even if the knob doesn't work it will replace the Wavetek 278 that has a weird user interface e.g. you enter valurs in scientific notation say 1.2Ex4 for 12kHz and 1Ex-1 for 100mV 

The R&S SFQ seems to work fine for basic functions just have to play a bit more.

[factory]

We definitely had an operators manual, I couldn't tell you where it is now, since the lab at work downsized, or if the people I work with chucked it.  They all have zero interest in electronics, or the redundant TE.

Fairly certain the parameters could be adjusted with both the pot and the two up/down buttons next to the pot.

David

[Zoli]

...
The other pair of 1820-0215 ICs ended up testing the same as the 1820-0092 did, no idea why HP had another part number if it's the exact same functionality & pinout (pinout confirmed with the Artek pdf), the one I tested before was definitely borked.
...
David

Different supplier maybe?

...
 Need to find the right angle headers too.



David

Hirose A2-8PA-2.54DS(71) would be a choice; 0.8mm pins, so it will fit without the need to drill up the original PCB.
Another find is at LCSC: https://lcsc.com/product-detail/Pin-Headers_XFCN-MH254R-11-40-1376_C529316.html ; 40 pins(0.5mm) roughly for the price of 1pc of 8pin Hirose.
Of course, you can take a look for Preci-Dip, but those are even more expensive.

[Neper]

My analog Philips / Fluke Combiscope has video trigger like any decent analog scope of course, and IIRC it lets you select the line number as well.

At the risk of preaching to the choir...

In the days of analog TV, there were a number of lines within the vertical blanking period, i.e. outside of the normally visible picture frame, the so-called test lines. These lines contained various signal patterns used to check the transmission quality, bandwidth, ringing etc.

Those were the lines usually selected on those scopes in order to have a closer look at the signal.

[Brumby]

And?? Did you detect a charge in the paper?

McBryce.

There was a charge of $9.21 on the paper, but the pen didn't detect it!  Turns out I still had the isolating sleeve in the way of the clip - which I hadn't pressed.  Mea culpa.

[Brumby]

At the risk of preaching to the choir...

In the days of analog TV, there were a number of lines within the vertical blanking period, i.e. outside of the normally visible picture frame, the so-called test lines. These lines contained various signal patterns used to check the transmission quality, bandwidth, ringing etc.

Those were the lines usually selected on those scopes in order to have a closer look at the signal.

The TELETEXT service also used lines in the vertical blanking period.


I've always found it fascinating to see latent potential in a technology that gets exploited when new ideas and new techniques can tap into previously existing services.  Teletext being one, ADSL being another.

[Brumby]

That single video line capture, though, is one neat trick you could never expect from an analogue scope.   

[TERRA Operative]

Looks like my TDS784D with TV trigger option won't display an image, I didn't expect it but was half hoping it would somehow....

However, I'm preeettyy sure I have a few of those LM1881 chips shown in the linked video above. Might have to have a poke around and see if I can have some fun.

[RolandK]

That single video line capture, though, is one neat trick you could never expect from an analogue scope.   

As video is much older than digital scopes, they invented video sync before digital scopes, eg. the tektronix 524 had this in 1953:

https://w140.com/tekwiki/wiki/524

https://www.w140.com/RCA-Test-Equip-1966.pdf

Page 33: ... any portion of the television picture may be observed - from complete frames to small portions of individual lines ...