Test Equipment Anonymous (TEA) group therapy thread

[beanflying]

Seems I brought some cheap RF crustiness, 75 and 50  Attenuators for $5AU pesos for the pair. Anyone got a clue what sort of bandwidth they may be good for? eBay auction: #173910552994



also tacked on a 100:1 Philips probe and a HP 100Mhz one for good measure from the same seller.

[mnementh]

Well, it's 75Ω/500mW, so my best educated guess would be analog broadcast/CATV frequencies. Probably the lower bands. But then, my mental processes are pretty much crunk; I'm still waiting for my coffee to cool off, since I'm out of milk & HWC.   

[EDIT] NM.... you said you got 50Ω AND 75Ω models. AND they're BNC. Looks to me like it's time for some Noise Source abuse.  Hey, I said I wasn't conscious yet.  [/EDIT]

mnem
I can haz caffeine...?

[bd139]

Gah in that hole as well. My coffee machine just pissed out water and coffee all over the place

Going out to find a coffee for a bit 

[mnementh]

Yeah... the older I get, the deeper that hole seems to get... and the more and stronger coffee I need to lift me out of it. Before long, I'll be drinking barrels of coffee thick enough to walk out on top of it. 

mnem

[bd139]

That’s what we call marmite here 

[mnementh]

...also tacked on a 100:1 Philips probe and a HP 100Mhz one for good measure from the same seller.

Dude... you cleaned the guy OUT! Well and truly TEA'd!!!     

mnem

[VK5RC]

@beanflying - that atten unit seems to have some fans in an antique radio blog and some cal services offer calibration of it - I think you have done well.
It has bnc connections so I would guess up to vhf and maybe uhf - so would be very useful.
+++
Rob

[mnementh]

That’s what we call marmite here 

Says here... "Guaranteed to raise your blood pressure to hazardous levels, or twice your kidneys back..." 

mnem
Hmmm... with four five kidneys, a dwagon like me could take over the WORLD...!

[mnementh]

@beanflying - that atten unit seems to have some fans in an antique radio blog and some cal services offer calibration of it - I think you have done well.
It has bnc connections so I would guess up to vhf and maybe uhf - so would be very useful.
+++
Rob

Oh... so my original half-conscious guess wasn't half-bad after all, eh? 

mnem
I need to do more of my thinking while asleep.

[beanflying]

Yep mopped up the three listed items  100:1 probe will be handy playing with my Valhalla Calibrator in the next few weeks and the HP  just because.

UHF/VHF will be plenty I did find one reference to 1Ghz from the same case but not much on these two.

Coffee - Black like your Dwagon Heart man up and skip the Cow

[mnementh]

Naaaahhh.... I've mellowed a bit in my old age; and my indigestion demands a little buffering. Now I have to squeeze the cow before I put it on a slow roast for dinner. 

mnem
mmmm.... bovine mammary drippings and caffeine-bearing bitter herb infusion... 

[bd139]

Black, no sugar here.

Have fixed the coffee machine. The issue was human error on the part of my eldest who didn't stick the cartridge in properly causing it to piss out everywhere, then she covered that up by cleaning it up and partially dismantling and cleaning it and putting it back together wrong. Of course I came along and coffee everywhere. The truth has been extracted, the machine cleaned and assembled properly and coffee in service again 

[mnementh]

One single word in that whole scenario tells me that no actual coffee was harmed in your charlie-foxtrot... "cartridge". 

mnem
I'd rather drink ranch-style and strain it through my teeth.

[bd139]

It's not terrible. Costa americano via Tassimo. The trick is that it's got the best tradeoff on laziness, flavour and cost. It's actually pretty close to the stuff you get in the actual shop as it's actually vacuum sealed coffee grinds rather than that horrid syrup shit.

[Kosmic]

Talking about HP 8566B, Found another unit for sale locally. Unit seem to be in good shape this time, screen is bright. Will try to lowball    Something like 500$.

Hmm was able to negotiate down to 450$US. Will collect it later today 

Edit: Correction it's a 8566B not 8569B.

[med6753]

Capacitor replacement on the OL-1.

Underside, before.



Underside, after. Lots of flying leads. I know I have sleeving somewhere but I couldn't find it. So I made do without. But everything is secure and not moving so I'm going to leave as is.



Topside circuit board, before.



Topside circuit board, after.



The HV supply. Yes Matilda, that terminal strip has approx 1KV on it out in the breeze ready to Darwinize the unsuspecting.



After. New Panasonic .1uf/1.25KV caps.



And here's the trash.



Left to do: still have to rework the B+ aluminum can. Once that's done I can do some initial power on testing. Stay tuned. 

[tggzzz]

@   tggzzz

https://www.ultimatebootcd.com/ 

You should still be able to repair your partition table or reprovision the drive for GRUB. If you're built on a RAID, you're probably still well & truly fooked, though. Good luck, my friend.

mnem

After many blind alleys using things on that disc, I decided the MBR/GRUB/etc was well and truly hosed. So I followed my initial inclination: find out what partitions are there and where, and reinstall xubuntu. Worked like a charm, no data lost.

Oh the wonders of knowing I have all the data I've generated on a different partition to the OS: beat that MS. Actually they might be going along the track to end up where MS was with their first multitasking multiuser OS, i.e. having everything in /users on Xenix.

Now back to playing with the results of GAS...

[tggzzz]

So, what have I been playing with? Lots of cheap stuff, naturally.

A newly acquired HP8562B, which I am using to explore the other stuff, and vice versa.

An old fleabay 4351 based synth:

• up to 4.4GHz
• USB powered, optional 5V via 0.1" headers
• eval kit software that runs in XP in VirtualBox in Xububtu

A newer TI LMX2594EVM eval kit that I picked up for £20 in an auction:

• 10MHz-15Ghz
• I'm only looking at one unbalanced outputs (two balanced outputs are available)
• onboard 100MHz source, or external balanced or unbalanced signal source - selectable by changing SMD resistors (hey, it is an eval board!)
• USB interface with another 100MHz differential output source, but a separate 3.3V 400mA PSU via an SMA connector (what else?)
• eval kit software only runs in Win7 or later. Changing frequency involves:
  
  • changing a textbox embedded in the block diagram
  • changing any other parameters that have "turned orange" because of inappropriate values
  • forcing the 2594 to change frequency

So, what does the 2594 look like?

At 15GHz, no spurs visible, and noise level is set by the 8562:


At 4GHz, spurs at +-32kHz, noise is not limited by the 8562:


At 55MHz, also spurs at +-32GHz; is this in the source or the analyser?:


EDIT: see https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/msg2471700/#msg2471700


So what does the 4351 look like?

By comparison the 4351 looks dreadful at 4GHz, with lots of strong spurs which are sufficient to visibly degrade the stability:


But is that noise from the USB interface? What happens if the 4351 is powered from a bench PSU?

Much better at 4GHz and 55MHz:




Unsurprising moral: don't power a synth from  USB power supply!

[mnementh]

@   tggzzz

https://www.ultimatebootcd.com/ 

You should still be able to repair your partition table or reprovision the drive for GRUB. If you're built on a RAID, you're probably still well & truly fooked, though. Good luck, my friend.

mnem

After many blind alleys using things on that disc, I decided the MBR/GRUB/etc was well and truly hosed. So I followed my initial inclination: find out what partitions are there and where, and reinstall xubuntu. Worked like a charm, no data lost.

Oh the wonders of knowing I have all the data I've generated on a different partition to the OS: beat that MS. Actually they might be going along the track to end up where MS was with their first multitasking multiuser OS, i.e. having everything in /users on Xenix.

Now back to playing with the results of GAS...

Well, at least UBCD helped with that part, right?    


You can specify where your data goes. Apps and their data, that requires paying attention at installation time, but usually still can be done. Or just let Winblows back it all up to OneDriveBy... 
Yeah, everybody thinks their app is fucking special and MUST be integrated into Windoze.  While MS encourages this behavior, app developers still CAN make simple executables that run where you plant them.

mnem
mrrp?

[Specmaster]

Anyone fancy a Pizza? I wanna go here and eat a lovely fresh pizza and just soak up all of that lovely atmosphere and gorgeous rich sound. I had thought that the age of pipe organs had long gone. The last one I can remember seeing and hearing it being played was when I was a teenager IIRC, it was a Wurlitzer 3/19 built into the car showroom of a garage in Diss, Norfolk, UK, owned by the Kitchener Bros. Garage. I remember that well as I given a tour behind the scene to see the massive pipes and actual real life instruments like drums, piano, chimes etc., all hooked up to the massive main keyboard console.

It was just sheer joy to experience first hand the beautiful deep bass of those huge pipes, wasn't just hearing that bass, but actually feeling it as well as the entire showroom (could be turned into a theatre for live performances by visiting organists, and even featured on the BBC radio program "The Organist Entertains") was pressurised by this low frequency air coming from the pipes.

Enjoy the attached clips of the pizza stop in Meza, Arizona.

[kj7e]

Ive been to Organ Stop Pizza a few times.  The Pizza is just okay from what I remember, but the big organ is impressive (she said).

[Specmaster]

@med, that really is looking like a good project and what a massive size difference between the old caps and the new replacements. It should go on to give many years of use and enjoyment to you once completed, well done sir. 

Edit.
Are you going to test the old caps just to see how bad they are after all these years?

[Specmaster]

Ive been to Organ Stop Pizza a few times.  The Pizza is just okay from what I remember, but the big organ is impressive (she said).

With a stunning centre piece like that to observe and listen to, who cares if the pizza is not even editable (I do actually, love pizza every now and then  ) but seriously, that has to be an amazing occasion dining there. 

[xrunner]

The Drake SPR-4 arrived! I have to say it really works great at the moment and is in really good condition. The blue LEDs are as bad as the pictures showed. But the good news is the tinting plastic seems to be just fine. My plans for that at this time are to just revert back to type 47 bulbs for the original look.

The rest of the progress will be in the thread I started on the RF, Microwave, and Ham Radio board. 

[Carl_Smith]

all my Macs (including the one I'm typing on) are PCs running MacOS.

I've wanted to install MacOS into a VM on my Windows PC just to play around with it a bit, but every web page I've found with instructions on how to do so starts with something to the effect of "Go to a Mac and download the OS install ISO..."   If I had a Mac to do that on I wouldn't be wanting to install MacOS in a VM.   Grrrr....

Erm, I don't think you can complain that pirating a copy of MacOS requires you to jump through some hoops to start from a legitimate copy from a machine where it's supposed to be running. Given you've already decided to cross the line, why don't you just download a torrent of the many hooky copies that are already out there?

Partly because I just haven't got around to trying it yet.  And partly because I am a bit hesitant to download some random torrent of an operating system.

I don't see it so much as crossing a line as wandering into a large gray area.  I'm not going to pay a large sum of money for a Mac just so I can try it out.  So I thought it would be a sort of "try before you buy" situation to just install MacOS in a VM and play around a bit.  If it ever turned out that I decided I liked it and wanted to use it for more than just a few minutes or hours of playing around then I would buy a Mac.