I've been offered both a HP3580A and HP3582A at an attractive price.
I'm definitely going to buy one of them but can't decide which is the better bet. On the one hand I'm tempted to think that the 3580A will be easier to repair and keep working but the 3582A is the newer and more powerful tool.
Which would you go for and why?
I'm definitely going to buy one of them but can't decide which is the better bet. On the one hand I'm tempted to think that the 3580A will be easier to repair and keep working but the 3582A is the newer and more powerful tool.
Which would you go for and why?
That is a hard call. I've had both and they both present significant limitations. If this will be your only analyzer, it kinda depends on your primary use. The 3582A is only 12-bits, so its usefulness for electronics is limited. For speakers/acoustics, 12 bits is just "good enough". For electronics, the 3580A would be the better choice.
Why not use a computer sound card and some free software?
The 3582 appears to use the HP 1345 vector display. There are modern replacements for these. Some even feature colour TFT displays. That could be an advantage if the CRT ever goes.
Tom
The 3582 appears to use the HP 1345 vector display. There are modern replacements for these. Some even feature colour TFT displays. That could be an advantage if the CRT ever goes.
Tom
How attractive is that price? Do you need RF analysis? Ads I found are about $1K, for which you could buy a decent modern scope that includes a FFT spectrum analysis and probably a signal generator. As others have pointed out, you can do audio analysis with a sound card in on PC. If they are selling it for $100, then go for it, otherwise I wouldn't touch it. Modern instruments have USB and LAN c/w HTML interfaces which make it easy to remote control them and capture test results. The only issue is that some scopes do not have a high-resolution capture, but that is not true of sound cards. I have done a lot of work with GPIB/HPIB instruments, and I don't think you want to go there. Old tech belongs in museums.
BTW, you can download the service manual for 3582 from Keysight.
BTW, you can download the service manual for 3582 from Keysight.
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Looking at the 3582 service manual, I find that it is a 12 bit ADC @ 102KHz with 16 bit processing. This does not compare well with a 24 bit 192KHz sound card (~$100 on Amazon) and your computer's 64 bit processing. Of course you need some software, which may be freeware but even professional software will likely be cheaper than a 3582.
That's a bit over the top.
The 3580A has a really nice front end, with 18 full-scale input ranges from 0.1uV to 20V RMS. Option 2 adds a balanced input. Compared to what, one input range on a soundcard?
You can also use the 3580A as a TDS analyzer with variable delay and spacial bandwidth. It uses a 100kHz IF, which can be replaced with an external reference by the "Ext Ref" switch and input on the rear panel. Use a stable signal source with 0.1Hz resolution and slip it below 100kHz to correct for the airpath delay between transducer and microphone. The Resolution Bandwidth control then becomes a "Spacial Bandwidth" control in conjunction with the sweep rate.
The 3580A has some unique features and is a real pleasure to use.
A preamp with low enough noise for 0.1uV is not trivial but a balanced input and whatever gain you like is easy. You can probably buy one ready-made but it's a "no-brainer" circuit to DIY. Sound cards always have at least two channels.
About the time these were new, a friend of mine was playing with TDS, popping balloons in various rooms and halls. But he was renting an expensive piece with a phosphorous "storage" display. Remember those "storage scopes"? I'm not sure exactly who is writing TDS software today but I'm sure it's available, if you are not inclined to write your own. If you are not a DIY person, then sure, professional solutions let you get results quickly and confidently. It just cost a lot of money. I see a U8903B is $25.6K. I'll spare you my rant about entitlement.
About the time these were new, a friend of mine was playing with TDS, popping balloons in various rooms and halls. But he was renting an expensive piece with a phosphorous "storage" display. Remember those "storage scopes"? I'm not sure exactly who is writing TDS software today but I'm sure it's available, if you are not inclined to write your own. If you are not a DIY person, then sure, professional solutions let you get results quickly and confidently. It just cost a lot of money. I see a U8903B is $25.6K. I'll spare you my rant about entitlement.
Nice. Update us when you get it and check it out.
Is the 3580A "easier to repair"? I dunno. I have three of them that I have poured way too many hours into troubleshooting. The "adaptive sweep" really complicates things in the sweep circuitry.