Some Vintage Test Gear Madness
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mayfly
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Hey Kevin! It determines how much harmonic distortion there is in a sign wave. Up to 3MHz harmonics apparently. It has some funky inputs/controls for dealing with modulated signals, so my guess it's intended for radio. Stuff like making sure your transmitter carrier is real clean and such.
But I intend to use it for audio!! I'm gonna do some total harmonic distortion measuring
According to the manual it can measure down to 0.01% THD.
... Assuming it works that is... We're gonna find out!
and yes, it was a lot cheaper than the Precision Audio we had at my old work.
BTW, for the interested the manual is here: https://www.keysight.com/upload/cmc_upload/All/333A_334A_Final.pdf
But I intend to use it for audio!! I'm gonna do some total harmonic distortion measuring
According to the manual it can measure down to 0.01% THD. ... Assuming it works that is... We're gonna find out!
and yes, it was a lot cheaper than the Precision Audio we had at my old work.
BTW, for the interested the manual is here: https://www.keysight.com/upload/cmc_upload/All/333A_334A_Final.pdf
Cagey
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I just looked up a cheap (<$100) Onkyo CD player and its THD was only .0029%, and in looking at a few inexpensive power amps found that most don't even post a number for THD, which sorta says the state of the art for that spec has been more or less solved. Kinda like frequency response, wow & flutter, etc. Most of those things have been relegated to the realm of the obsolete or vanishingly insignificant.
Of course, if you're designing things, like you do, then it could probably come in handy. Something sounds weird, you can always check to see if you've got some strange distortion thing happening.
Of course, if you're designing things, like you do, then it could probably come in handy. Something sounds weird, you can always check to see if you've got some strange distortion thing happening.
Seamas
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Off topic, but I had to take notice of the Addresses of the companies on the instruments at the beginning of the thread.
I get a kick out of things from that era will list Glendale LI, NY (PACO)--making sure Long Island is mentioned (Glendale is in Queens). I don't know why but you don's see that much anymore.
Then having lived in LIC for some years I looked up EICO, and sure enough it was in a building where I once had a storage unit.
I get a kick out of things from that era will list Glendale LI, NY (PACO)--making sure Long Island is mentioned (Glendale is in Queens). I don't know why but you don's see that much anymore.
Then having lived in LIC for some years I looked up EICO, and sure enough it was in a building where I once had a storage unit.
Seamas
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Yeah.
Though all those old warehouses and factories made perfect locations for self-storage--especially with the SQ footage price of most apartments in NYC, there is a huge demand for cheap space to keep your stuff.
I would like to time travel back to when all those places were making stuff.
Just saw that the old Gretsch factory in Brooklyn is now houses fancy Condos.
Though all those old warehouses and factories made perfect locations for self-storage--especially with the SQ footage price of most apartments in NYC, there is a huge demand for cheap space to keep your stuff.
I would like to time travel back to when all those places were making stuff.
Just saw that the old Gretsch factory in Brooklyn is now houses fancy Condos.
Cagey
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I don't know what you would call "cheap" storage space, but I suspect having lived in NYC, your idea of "cheap" is substantially different than most folks. Here, even 40 miles out of the city, they're still charging ~$250/mo for a 10' x 20' space, which they call a bargain but most consider borderline usury. Especially when you can buy land for ~$20K/acre. Buy 5 acres, throw up a buncha pole barns with internal dividers and bay doors on 'em but no power/water/gas/sewage, and if all you offered was the size I just mentioned you're looking at renting out at least 300 units at $250/mo for a return of $75K/mo. Any other configuration only increases that number, and there's almost always a waiting list to get the damned things. I can't even imagine what something like that would cost in NY.
As for old warehouses/factories, I'm sure if you saw 'em in action back when they were lively you'd only get depressed :laughing7:
As for old warehouses/factories, I'm sure if you saw 'em in action back when they were lively you'd only get depressed :laughing7:
Seamas
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LOL
Yeah, I meant "cheap" compared to living space.
Which city? NYC?
I am now (and have been for about 9 years) 40 miles from NYC.
Anything closer was impossible for us to buy.
We actually bought our house (and mortgage) the day before the market went ka-blooey in 2008.
Yeah, I meant "cheap" compared to living space.
Which city? NYC?
I am now (and have been for about 9 years) 40 miles from NYC.
Anything closer was impossible for us to buy.
We actually bought our house (and mortgage) the day before the market went ka-blooey in 2008.
mayfly
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Gentlemen. Back to our original program.
It's time to put the HP through it's paces and see what it can do! First off, let's run the output from the recently restored heathkit sine wave generator and see what we get.
Here's the setup: The heathkit into the scope and into the distortion analyzer. The laptop is so I can watch the tutorial on how to use the distortion analyzer - it's a bit finicky!
My scope has a handy dandy FFT / spectrum analysis setting. Here's what it shows on the output. Note the prominent 2nd, 3rd, and even 4th harmonics on there.
aaaand here's what the distortion analyzer shows us.
Yep that's right. 6% THD!! That's a killer number
ok, given the spectrum of the poor old Heathkit, I figured we better pull out the big guns. So I grabbed my stanford research signal generator, sorry Synthesized function generator, and fired it up instead.
Here's the spectrum. Note the dramatic reduction of the harmonics and the strong fundamental.
and here's what the HP shows us. I put the range switch in the shot so we can see it.
Yep 0.13% THD. That's more like it
It's time to put the HP through it's paces and see what it can do! First off, let's run the output from the recently restored heathkit sine wave generator and see what we get.
Here's the setup: The heathkit into the scope and into the distortion analyzer. The laptop is so I can watch the tutorial on how to use the distortion analyzer - it's a bit finicky!
My scope has a handy dandy FFT / spectrum analysis setting. Here's what it shows on the output. Note the prominent 2nd, 3rd, and even 4th harmonics on there.
aaaand here's what the distortion analyzer shows us.
Yep that's right. 6% THD!! That's a killer number
ok, given the spectrum of the poor old Heathkit, I figured we better pull out the big guns. So I grabbed my stanford research signal generator, sorry Synthesized function generator, and fired it up instead.
Here's the spectrum. Note the dramatic reduction of the harmonics and the strong fundamental.
and here's what the HP shows us. I put the range switch in the shot so we can see it.
Yep 0.13% THD. That's more like it
