Test Equipment Anonymous (TEA) group therapy thread

[mnementh]

their addiction to fuxxoring E17 base bulbs in every damned thing. 

You mean E14, innit? Goes to wikipedia to read up on the Edison thread system.  Blimey.   



Obviously, IKEA has a different product offering regarding lights in northern America. It's like McD in Italy or France. "Same" but clearly different.

Our IKEA visit was the most effective yet. Order was pre-booked, when we had 300m left, at the last traffic lights, Wife started the check-in, and once we were parked, told the app license plate and parking spot number. I barely had time to tip the rear seats and clear out the Kökkenmödding of my cargo area before a gentleman arrived with the goods on a cart.  Very convenient, no time wasted. We got straight on to the Christmas tree shopping, literally within minutes.

Yeah, I've never done "curbside" with IKEA; Amazon is more convenient to my door with similar turnaround (even same-day if I shop over the morning cuppa) so seems a total "why bother?"  scenario to me.

The main reason I would ever consider them is stuff I need to measure/fit/fondle before I part with my hard-earned monies... tho I'll admit, as Wally World customer service gets worse and worse (last one was trying to find a store which actually had a certain nukebox in stock, which every question asked was met with a dumb blank stare), and less and less mindful of how they waste their customers' valuable time, the more and more I loathe "shopping at the company store"... 

I suspect IKEA chooses those threads based on regional availability to drive customers back to them for replacements; obviously the IKEA-branded bulbs don't last hugely longer than the competition, as most of the IKEA lamps I've bought come from the Thrift, and have dead bulbs. Doubtless the reason they wound up at the Thrift is the owner got annoyed over poor availability of suitable replacements and... the cycle continues.

mnem
 

[Cerebus]

Wanted to finally receive SAQ on christmas,

One presumes that's some Ho-ho-horrific Ha-ha-hamateur radio callsign that only goes on the air for Christmas? 

[mnementh]

Gaffer Tape Saves The World... again.         
...I did, however, find a generic fender-pop... but nothing suitable to use for a backing plate except this fender washer. A couple layers of Gaffer-tape later, and I'm pretty sanguine about this repair... we'll see how it holds up.

Of course, I'll get the correct bits on the way ASAP; but as we have only the one vehicle and kids who must be Christmas-shopped for... we're going to go with this for now.

mnem
"Daddy fix it!!!"

No cable-ties? pfft

Of course I had them on hand, in 3 different sizes... AND a roll of dead-soft mechanic's wire too. However, they were not needed. This time. 

mnem
 

[PA0PBZ]

Wanted to finally receive SAQ on christmas,

One presumes that's some Ho-ho-horrific Ha-ha-hamateur radio callsign that only goes on the air for Christmas? 

https://alexander.n.se/en/

[ch_scr]

Got a quick question....

I have a 10MHz OXCO that after a bandpass filter etc, is putting out 595mV P-P into 50ohms, how to best and simply get this to 0dB (0.775V) for a bit of a general reference? I'm thinking a buffer amp, but is there a best practice for this?
I just want a simple way to do it, for a little USB powered 'pocket 10MHz reference' I'm making for laughs.

Not sure how high your supply voltage is, but at 5V I would think a transistor amp should do it? At 3.3V that might get challenging regarding voltage swing.
Design wise, a gain stage with feedback to tame it down and a buffer stage for the current? 
Surely, there are integrated solutions (but can you get the IC at this day and age?) Maybe two gates from a 74VHCU04 with lower feedback to have the tiny gain?
In general not the most energy efficient, but at 3.3V a 74LVCU04 might be easier to get going than the transistor circuit.

The OCXO runs at 12V, so I have a boost converter running that. So, I have +5V and +12V available to use.
I want to get a sine wave output rather than square wave, so TTL stuff might not be ideal unless I put the bandpass filter after?

At 12V voltage swing on the transistor amplifier should be easy. But look closely, I proposed 74VHCU04!
These are unbuffered gates, that truly have only one inverter inside, not three with increasing size like a normal "CMOS" '04. With that gain (but also drive strength and also delay) is reduced some from the get go.
These are made specially as "linear" gain elements with a feedback resistor for stuff like "discrete" pierce oscillators. They can stay in linear mode so you get a sine out, but take their linear style current draw as penalty.
I'm just not sure if you can get the gain low enough! 
Look at these app notes for inspiration:
https://archive.eetasia.com/www.eetasia.com/STATIC/PDF/200906/EEOL_2009JUN04_EDA_AN_01.pdf?SOURCES=DOWNLOAD
https://www.ti.com/lit/an/scha004/scha004.pdf

[Zucca]

Yes.
Sorry forgot you are no longer in Italy. You still have a tricolour flag on your profile.

I will never change it. I am Italian 100%.
Anyway, I could install water cooled LEDs on the truck and open a mobile tanning center.

Nobody will give a shit, "no even Nixie the cat"

[ch_scr]

Yes.
Sorry forgot you are no longer in Italy. You still have a tricolour flag on your profile.

I will never change it. I am Italian 100%.
Anyway, I could install water cooled LEDs on the truck and open a mobile tanning center.

Nobody will give a shit, "no even Nixie the cat"

I think "Nixie the cat" will be most interested! Interested to take a nap in the spotlight of "artificial sunshine", so very warm and cozy, and put there just for her 

[Zucca]

Why good AC power source are so expensive?
I am looking for a 3000VA unit, but even a decent 500VA for parts costs half of my leg.

[Neper]

https://alexander.n.se/en/

A really magical place. Unfortunately, I'm in a high-noise environment and gone are the days when I could receive SAQ.

Still, all those without own equipment can always have a go via the SDR receiver at Twente University in the Netherlands:
http://websdr.ewi.utwente.nl:8901/

@mansaxel: what is a Underhålls- & Trivselkväll?

[mnementh]

Yes. Sorry forgot you are no longer in Italy. You still have a tricolour flag on your profile.

I will never change it. I am Italian 100%. Anyway, I could install water cooled LEDs on the truck and open a mobile tanning center.

Nobody will give a shit, "not even Nixie the cat"

Oh dear... this pitiful commentary def calls for a "Sad Wario"...



mnem
*nibbles quietly on some Columbus brand red wine & garlic dry salame with his leftover coffee*

[mnementh]

Why good AC power source are so expensive?   I am looking for a 3000VA unit, but even a decent 500VA for parts costs half of my leg.

You need to be a leetle beet more specific Z... otherwise, some wiseass-dwagon is gonna tell you to just drive around until you find a couple old microwaves on the curb at ~1400VA each.

mnem
*tzzzzzt*

[TERRA Operative]

Got a quick question....

I have a 10MHz OXCO that after a bandpass filter etc, is putting out 595mV P-P into 50ohms, how to best and simply get this to 0dB (0.775V) for a bit of a general reference? I'm thinking a buffer amp, but is there a best practice for this?
I just want a simple way to do it, for a little USB powered 'pocket 10MHz reference' I'm making for laughs.

Not sure how high your supply voltage is, but at 5V I would think a transistor amp should do it? At 3.3V that might get challenging regarding voltage swing.
Design wise, a gain stage with feedback to tame it down and a buffer stage for the current? 
Surely, there are integrated solutions (but can you get the IC at this day and age?) Maybe two gates from a 74VHCU04 with lower feedback to have the tiny gain?
In general not the most energy efficient, but at 3.3V a 74LVCU04 might be easier to get going than the transistor circuit.

The OCXO runs at 12V, so I have a boost converter running that. So, I have +5V and +12V available to use.
I want to get a sine wave output rather than square wave, so TTL stuff might not be ideal unless I put the bandpass filter after?

At 12V voltage swing on the transistor amplifier should be easy. But look closely, I proposed 74VHCU04!
These are unbuffered gates, that truly have only one inverter inside, not three with increasing size like a normal "CMOS" '04. With that gain (but also drive strength and also delay) is reduced some from the get go.
These are made specially as "linear" gain elements with a feedback resistor for stuff like "discrete" pierce oscillators. They can stay in linear mode so you get a sine out, but take their linear style current draw as penalty.
I'm just not sure if you can get the gain low enough! 
Look at these app notes for inspiration:
https://archive.eetasia.com/www.eetasia.com/STATIC/PDF/200906/EEOL_2009JUN04_EDA_AN_01.pdf?SOURCES=DOWNLOAD
https://www.ti.com/lit/an/scha004/scha004.pdf

How about something like an LT1814?
It can do bandpass filter duties and directly drive a coax cable apparently. Might help to simplify things.
https://www.analog.com/media/en/technical-documentation/data-sheets/18134fa.pdf
I'll just have to figure out how to calculate reasonable resistor/capacitor values for 10MHz.

I can probably power it directly from USB 5V using a MAU106 DC/DC converter too?:
https://akizukidenshi.com/download/MAU106.pdf

[Cubdriver]

Yes.
Sorry forgot you are no longer in Italy. You still have a tricolour flag on your profile.

I will never change it. I am Italian 100%.
Anyway, I could install water cooled LEDs on the truck and open a mobile tanning center.

Nobody will give a shit, "no even Nixie the cat"

I think "Nixie the cat" will be most interested! Interested to take a nap in the spotlight of "artificial sunshine", so very warm and cozy, and put there just for her 

Like most cats, he does thoroughly enjoy his naps, and considers sleeping a high art form...




-Pat

[capt bullshot]

The OCXO runs at 12V, so I have a boost converter running that. So, I have +5V and +12V available to use.
I want to get a sine wave output rather than square wave, so TTL stuff might not be ideal unless I put the bandpass filter after?

Maybe you can find some inspiration here:
http://www.ko4bb.com/~bruce/CE_TransformerFeedback_BufferAmplifier.html
http://www.ke5fx.com/norton.htm

Another rather simple approach would be:
Use standard logic to buffer the OCXO output, then filter to sine wave.
If the amplitude is too low, use more gates in parallel and a simple transformer to increase the amplitude.

[mnementh]

@mansaxel: what is a Underhålls- & Trivselkväll?

Gurrgle Translate returned: Evening Maintenance & Well-being, so I'd guess transmissions related to bringing their all-original pre-hollow-state transmitter online and tuning up...?

mnem
pre-hollow-state... copper-state...?

[capt bullshot]

How about something like an LT1814?
It can do bandpass filter duties and directly drive a coax cable apparently. Might help to simplify things.
https://www.analog.com/media/en/technical-documentation/data-sheets/18134fa.pdf

I'd guess 100MHz GBW isn't enough to make an active 10MHz R/C/OpAmp bandbass. I'd rather go for L/C filters. There's some quite easy to use filter design S/W around to easily calculate a higher order L/C filter. Same kind of S/W exists for active filters, too. I'll have to fire up the other computer where I have it installed.

Edit:
https://www.rfcafe.com/miscellany/factoids/Mother-All-Free-Filter-Software-Iowa-Hills.htm

The site linked (iowahills.com) appears to have disappeared

By some lucky coincidence, I've got a local copy here:
https://cb.wunderkis.de/wk-pub/www.iowahills.com/

Note: As too often, this S/W is for windows, but works nicely with wine on my linux desktop PC.

[mnementh]

...I think "Nixie the cat" will be most interested! Interested to take a nap in the spotlight of "artificial sunshine", so very warm and cozy, and put there just for her 

Like most cats, he does thoroughly enjoy his naps, and considers sleeping a high art form...         -Pat

Hmmmm... it would appear Nixie has been tutoring others while you weren't watching. 



mnem
https://pethero.co.za/8-signs-that-cats-are-plotting-to-take-over-the-world/

[Cerebus]

Why good AC power source are so expensive?
I am looking for a 3000VA unit, but even a decent 500VA for parts costs half of my leg.

Oh, come on; you'd get more than that for Prosciutto di Zucca!   

[AVGresponding]

@Cerebus did you bag the LCR? It went for nearly double what I expected. That 34401A seems to have been withdrawn from sale too.

[Zucca]

Oh, come on; you'd get more than that for Prosciutto di Zucca!   

during Xmas break I will install the 220VAC in my US home in schuko plugs and finally put my european meat slicer in use.
Until then no "prosciutto amico mio".

Anyway.

eBay auction: #233034286419

eBay auction: #373803025167

are you effing me?

not kewl...

I just learned a new word today: "Kewl". I wanted to use it... 

[dl6lr]

With regard to LED bulbs - cooling is king, and as a rule of thumb in that regard, heavier bulbs are better.

Yes but the G9 is a very small form factor, so cooling is difficult.

A "corn cob" LED-bulb is an excellent example for a design where it is very hard to get the cooling right - best to avoid them in general.
Still, only the most cunning designs (of what I have seen) have the LEDs itself fail - usually the power supply fails before.

At the time I bought the G9 retrofit, there were no other than corn type bulbs for G9 available. Still a lot of the latest Osram and Philips LED G9 do have several SMD-LEDs mounted on a Al-PCB, no COB.
Failing LEDs: I have several lamps that exhibit failing LEDs with a black spot. I suppose this is due to spikes in the mains? Often those LEDs are conducting a very faint current, so the others are flickering very dim.

[dl6lr]

https://alexander.n.se/en/

A really magical place. Unfortunately, I'm in a high-noise environment and gone are the days when I could receive SAQ.

I was planning to visit Grimeton this year, but Covid made this a non-option.
I have to test reception. Living on the countryside, there is a chance that not too far from home I can receive it outside.

[Cerebus]

@Cerebus did you bag the LCR? It went for nearly double what I expected. That 34401A seems to have been withdrawn from sale too.

No, I didn't. I was aiming much closer to the half-way mark; we had similar expectations.

[Robert763]

Oh, come on; you'd get more than that for Prosciutto di Zucca!   

during Xmas break I will install the 220VAC in my US home in schuko plugs and finally put my european meat slicer in use.
Until then no "prosciutto amico mio".

Anyway.

eBay auction: #233034286419

eBay auction: #373803025167

are you effing me?

not kewl...

I just learned a new word today: "Kewl". I wanted to use it... 

You still have not said what you want the AC supply for. It can't be for the meet slicer can it? That just needs an auto transformer. It will run 20% faster but that's not a problem.
The cheap option if you really want 50Hz is an on-line UPS (batteries not required). Most have a setting, switch or link for 50Hz output. Worse case change the crystal. Stillneed an autotransfomer of course. 

[Zucca]

You still have not said what you want the AC supply for. It can't be for the meet slicer can it? That just needs an auto transformer. It will run 20% faster but that's not a problem.
The cheap option if you really want 50Hz is an on-line UPS (batteries not required). Most have a setting, switch or link for 50Hz output. Worse case change the crystal. Stillneed an autotransfomer of course.

oh no no no meat slicer behind an AC6800...

It is just for my lab, I am in USA and sometime I believe I can now get broken stuff for cheap and repair it.
I posted here because I did not expect the prices to be so effing high.
Pure TEA, no precise project yet. I am missing a decent ac power source brick, like a child miss ice cream sometime.

Sorry I am so TEA sick.