Test Equipment Anonymous (TEA) group therapy thread

[beanflying]

You haven't seen the goody bag yet you may want to retract that thanks

There is a few videos on youtube about converting Video distribution Amps for 50 for GPSDO use too.

[Brumby]

You haven't seen the goody bag yet you may want to retract that thanks

    

[mnementh]

Yesterday, I picked up a used BluRay player for $10 at the local thrift; figured I'd put it in the kids' bedroom with their movie archive HDD plugged into it. It still had the BluRay disc in it I found on the shelf to use for a quick "no DOA" reality check at the store; Disney's 101 Dalmatians. So today I plug it in on the bench and it starts playing automatically; now I can actually see it because there's a screen plugged in.

It's in 4:3 aspect ratio. 

mnem
Disney is a festering cesspool of complete & utter fuckwits.

[Kosmic]

You haven't seen the goody bag yet you may want to retract that thanks

There is a few videos on youtube about converting Video distribution Amps for 50 for GPSDO use too.

Yeah well that was my plan until I discovered today that the amplifier used in my small video distributer top at something like 4 Mhz 

[beanflying]

Found it. Worth a look. And I paid for the extra outputs on mine after watching it

https://youtu.be/chrzrod3tQY

[Kosmic]

Found one of those Extron video distributer on eBay. Not sure if there's enough output though 

https://www.ebay.com/itm/EXTRON-CROSSPOINT-SERIES-FULL-INPUT-and-Output-CARD/253951846695?ssPageName=STRK:MEBIDX:IT&_trksid=p2060353.m1438.l2649&redirect=mobile

[beanflying]

Nearly enough outputs if your name is Keysight Calibration Labs 

I had a vague memory of buying some PLL Multipliers a while ago and yep I was right https://www.mouser.com/ds/2/308/NB3N501-D-90980.pdf Breadboard won't be ideal but 2MHz from the Ublock X 5 and see how it comes up.

[Cubdriver]

US$100 for a 5221A? Granted, it has options 02 and 03, badge, and feet, but wowzers.

https://www.ebay.com/itm/Vintage-1969-Hewlett-Packard-Model-5221A-Electronic-Frequency-Counter-Nixie-Tube-/264205009124?nordt=true

   Guess we were both watching that one, huh?

-Pat

My, my. What a coincidence. We even posted about it consecutively.

The other one I was watching just went for $110 + shipping, and had only five digits.   
https://www.ebay.com/itm/Vintage-1969-Hewlett-Packard-Model-5221A-Electronic-Frequency-Counter-Nixie-Tube-/153391041638?epid=1203846994&hash=item23b6d18c66%3Ag%3AL0IAAOSwC5RccGLG&nma=true&si=ksURvHkEbUjEyehq1EVhnisKuOo%253D&orig_cvip=true&nordt=true&rt=nc&_trksid=p2047675.l2557

That's a bit nuts, and *I* say that as a certified nut!

-Pat

<edit to add auction URL>

[Brumby]

You haven't seen the goody bag yet you may want to retract that thanks

I saw our parcel delivery guy down at the post office this afternoon.  He has been warned.

[bd139]

Just got a DHL delivery notification. Hopefully my second Racal 9915 counter.

Think the backlight on my TDS210 is starting to give out. Took a hell of a long time to warm up last night. May get an LED retrofit at some point next month.

[tggzzz]

Forgot - The other option is you take one of the lower frequencies and feed it into a PLL Multiplier to get a 10MHz. Only a few $ for a lot of them.

And then you'll have to assess the noise introduced into the 10MHz by the PLL multiplier. TAANSTAFL.

On the bright side, that means more use for your test equipment.

[tautech]

Think the backlight on my TDS210 is starting to give out. Took a hell of a long time to warm up last night. May get an LED retrofit at some point next month.

Check the backlight HV inverter frequency. IIRC either the service manual states it in Circuit operation and typically is a couple of 10's of KHz.
In a TDS1002 I had the RC network for the push pull bipolars on the primary, well the C had drifted into the pF's. 
But that's all it was and an easy fix.

[Specmaster]

From the same seller eBay auction: #254152420977 without the extra outputs. Seems Very Very cheap but might be worth a crack just make sure you use Paypal as belts and braces protection. If it is based on a similar design to mine construction is better than most. The seller does know something about the product too.

I've put that on my watch list - and I always use PayPal for eBay purchases.  I know I'll probably prefer extra outputs somewhere down the track - but with a decent reference and a decent PLL design, I should be right for a while.



Edit: Bean the enabler, yet again ... but this time I'm in the mood to thank him....?

This rabbit hole is starting to feel comfortable.  Move over Faust.

Rabbit hole starting to feel comfortable, that's a bad sign, means that you'll not rest till you reach the bottom. Then if you upgrade to even more digits it starts again.

[bd139]

Think the backlight on my TDS210 is starting to give out. Took a hell of a long time to warm up last night. May get an LED retrofit at some point next month.

Check the backlight HV inverter frequency. IIRC either the service manual states it in Circuit operation and typically is a couple of 10's of KHz.
In a TDS1002 I had the RC network for the push pull bipolars on the primary, well the C had drifted into the pF's. 
But that's all it was and an easy fix.

Thanks for the tip. Will check that 

[beanflying]

Tail chasing for sure. Given up on the Breadboard with the PLL as it was all over the shop and noisy but it did force me to make my U-Blox setup look nicer including a little SMA breadboard adapter.

Terminated into 50 Ohms with the nicer wiring layout sees it giving a decent squarewave on the integer divisible frequencies. Screen Capture is full bandwidth no averaging. So maybe useful as a low frequency source and plaything. Good use for one of three stupid split power rail breadboards too

[tautech]

Think the backlight on my TDS210 is starting to give out. Took a hell of a long time to warm up last night. May get an LED retrofit at some point next month.

Check the backlight HV inverter frequency. IIRC either the service manual states it in Circuit operation and typically is a couple of 10's of KHz.
In a TDS1002 I had the RC network for the push pull bipolars on the primary, well the C had drifted into the pF's. 
But that's all it was and an easy fix.

Thanks for the tip. Will check that 

Oh and you know you can check the oscillator frequency with just a probe held close to it. 

[bd139]

Yep already sussed that  . I do that with Tek HT stuff.  Just clip the ground wire onto the end and use it as a pick up.

[tggzzz]

Given up on the Breadboard

That's a good decision, no matter what you are planning to use it for. Hate the damn things, because inevitably more time is spent debugging the breadboard than debugging the circuit.

If you want to breadboard low noise circuits, start with manhattan or rat's nest techniques (depending on highest frequency present in circuit), and once it is basically functional, add shielding.

[bd139]

Totally agree. I occasionally use a breadboard but it's for low frequency stuff and playing with bias points usually and not a lot else.

Manhattan FTW though. This week's experiment - RF diode switching...

[Specmaster]

Think the backlight on my TDS210 is starting to give out. Took a hell of a long time to warm up last night. May get an LED retrofit at some point next month.

Check the backlight HV inverter frequency. IIRC either the service manual states it in Circuit operation and typically is a couple of 10's of KHz.
In a TDS1002 I had the RC network for the push pull bipolars on the primary, well the C had drifted into the pF's. 
But that's all it was and an easy fix.

Thanks for the tip. Will check that 

Oh and you know you can check the oscillator frequency with just a probe held close to it. 

Thanks guys for the tips here, my display is a little yellow I think judging by some other photos I have seen so I might just check these caps and see if that has anything to do with it. Mine is still eminently usable though, its just I feel the display could be brighter and clearer than it is                                                                                                                                                                           

[tggzzz]

Totally agree. I occasionally use a breadboard but it's for low frequency stuff and playing with bias points usually and not a lot else.

Even then you might encounter problems with components that are capable of hooting. The inevitable inductance (~1nH/mm for a wire) and stray capacitance can produce entertaining results.

Some people don't realise a prime benefit of SMD components: the leads are very short.

[bd139]

Indeed that is an issue for sure. The fixture above actually has a flaw in that the inductors are self resonant at around 3.6MHz (measured) which causes all sorts of hell to break loose. That'd happen anywhere with those. So I've got a bunch of ferrites ordered from RS so I can wind my own (both beads and toroids) and see if I can get the stray capacitance of the inductors down and the SRF up past the 15MHz operating ceiling of this test.

I did a finger in the air calculation of stray reactances on wire length and PCB capacitance and this should be 20x the min system impedance so should be ok in theory. Shame about the inductors!

Point I found with SMD inductors is that the SRF can be much lower than the equivalent leaded unit.

[mnementh]

Found one of those Extron video distributer on eBay. Not sure if there's enough output though 

https://www.ebay.com/itm/EXTRON-CROSSPOINT-SERIES-FULL-INPUT-and-Output-CARD/253951846695?ssPageName=STRK:MEBIDX:IT&_trksid=p2060353.m1438.l2649&redirect=mobile

That's not a distribution Amp; it's a 128 series Matrix A/V switcher. Older models are relay-based, not sure about newer models; it's been about a decade since I worked for Crestron. That is actually a smaller one; it "only" does 12 x 8 x 5 channels matrix. They make much larger; the biggest I've worked with was a 16 x 16 matrix. These early models are almost perfectly flat to approx 10MHz; then gain varies with load up to approx 200MHz. The Ultra series are rated to 450MHz in up to a 32x32 matrix, and they now have HDMI and 4K-rated models as well.

mnem
"coffee.... grr.... arrg..."

[bd139]

Got my second Racal 9915. OCXO works in this one. OCXO isn't as stable as the Bliley one so this will be retrofitted with a new one. I may leave it for a couple of hours to do its thing though.

[Kosmic]

Totally agree. I occasionally use a breadboard but it's for low frequency stuff and playing with bias points usually and not a lot else.

Manhattan FTW though. This week's experiment - RF diode switching...

Woo look really good. Good Job