On 10/31/2018 6:21 PM, Szabolcs Szigeti wrote:

Hi,

I just managed to get a 3325b for a very good price. I still have to investigate a Fail 026, but otherwise it is in a nice shape and seems to work in general.

It has Opt 1, the oven oscillator, but lacks Opt 2 the high voltage output, which would really be useful for me.

I was wondering if either some of you has one for sale (part no 03325-66508, same for the A and B model. Also I'm in Europe).

Or, go the hard way a build one. I could copy the original design but I pretty sure that some modern high voltage opamp could be used instead.
What do you think?

Szabolcs

On 10/31/2018 6:22 PM, Richard Coberly via Groups.Io wrote:

I have several dozen, some 9122C, others 9122D, that have been in my barn for many years. They were bought in one lot at a DRMO sale so their operational condition is unknown.? Anyone need any? I live in south central Pennsylvania.

On 10/30/18 4:27 PM, Kuba Ober wrote:

That’s correct as far as amplitude modulations go, and also the sampling close to the Nyquist limit only works when it’s synchronous with the input signal: the Nyquist limit isn’t some general “sampling works up to here” frequency. Without synchronous sampling, there will be large amplitude errors, getting lower in frequency as the signal approaches the limit. If you, say, modulate at 4.9kHz, and sample at 10kHz, the envelope itself will have a secondary envelope at 100Hz, and only its peaks will have the correct amplitude:
image1.png
Cheers, Kuba
30 okt. 2018 kl. 15:59 skrev John Ackermann N8UR <jra@... <mailto:jra@...>>:

I'm trying to educate myself about the newer USB power sensors. ?When I look for example at the U2043XA (average) and U2044XA (peak and average) specs, I see that both can do at least 20K measurements/second. ?The 2044XA has a video bandwidth of 5 MHz, while that's not specified for the 2043XA.

My question is whether the averaging sensor can still provide a peak reading, if the modulation is slow enough.

If I can make 20K measurements per second, it seems I should be able to follow a modulation envelope of up to 10 kHz (Nyquist sampling) and use the computer to process that data stream to catch and report the peak level over some time period. ?In fact, in theory I could process all the samples to fully reconstruct the modulation.

Is that correct, or am I missing something?

Thanks,
John

On 2018-10-30 7:52 PM, Paul Berger wrote:

With a little work certain 1.44 drives can be made to work in a 9122C the usual stumbling block is the controller in the 9122 wants to see the ready signal, but I did manage to make a couple drives work, but don't have the models handy.

The 9122D is a different story, it uses 720K drives that turn at 600 RPM and unlike most other 3.5 diskette drives.? There where two versions of drives used. The earlier models used a full high drive with a square eject button on the bottom right of the drive, about the only place you can get replacements for this drive is from other 9122S/D units or there where also a couple disk/ diskette combo units that used these drives.? The newer version is a half high drive with a rectangular eject button at the bottom right, this drive was used in a lot of HP equipment so replacements are easier to find.? One of the prevalent problems with these drives and especially the full high versions is lubricants used on the load/eject mechanism dry and becomes gummy and the diskettes do not load or eject properly and it is dangerous because the upper head may not retract properly and if you pull out the diskette when it is like this the upper head will come out with it.? I would strongly recommend you open the units and do a general inspect, clean and lube.

Paul.


On 2018-10-30 7:39 PM, David Feldman via Groups.Io wrote:

I ended up with both HP 9122C and 9122D (dual floppy drive) units. Both are recognized by my 8753 network analyzer (up to the point that setting incorrect GPIB address and setting incorrect disc/volume number has the expected error message results), all four drives make familiar sounds during power-up and normal operation, however, only one of the drives (in the 9122C) can read a diskette (list files on the media), and none can write or initialize diskettes. I am uncertain whether the onboard controllers are fully functional, but both appear complete and physically undamaged.

My question is this - can a contemporary (i.e., a 3-1/2" 1.4MB floppy drive) be adapted for use in either of these units? The 9122C uses a single (0.05" pitch) ribbon cable between the drives and the controller board; the 9122D has a somewhat narrower (0.05" pitch) ribbon cable and a 4-pin power connector. None of the connectors are identical to those used in contemporary floppy drives. I haven't looked for/at service documentation (yet). My last exposure to floppy drive equipment (at engineering, hardware and firmware level) was in the mid-late 1970s (!), so I'd not be adverse to a modest engineering project if there's a sign that this sort of thing has been successfully attempted in the past.

My other question - do you happen to have any drives (of either type) you'd be willing to part with?

Thanks,

Dave

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of David Feldman via Groups.Io
Sent: Tuesday, October 30, 2018 6:39 PM
To: [email protected]
Subject: [HP-Agilent-Keysight-equipment] HP 9122C & 9122D floppy drive units - adapt to use a contemporary (3.5" 1.4MB) diskette drive?

I ended up with both HP 9122C and 9122D (dual floppy drive) units. Both are recognized by my 8753 network analyzer (up to the point that setting incorrect GPIB address and setting incorrect disc/volume number has the expected error message results), all four drives make familiar sounds during power-up and normal operation, however, only one of the drives (in the 9122C) can read a diskette (list files on the media), and none can write or initialize diskettes. I am uncertain whether the onboard controllers are fully functional, but both appear complete and physically undamaged.

My question is this - can a contemporary (i.e., a 3-1/2" 1.4MB floppy drive) be adapted for use in either of these units? The 9122C uses a single (0.05" pitch) ribbon cable between the drives and the controller board; the 9122D has a somewhat narrower (0.05" pitch) ribbon cable and a 4-pin power connector. None of the connectors are identical to those used in contemporary floppy drives. I haven't looked for/at service documentation (yet). My last exposure to floppy drive equipment (at engineering, hardware and firmware level) was in the mid-late 1970s (!), so I'd not be adverse to a modest engineering project if there's a sign that this sort of thing has been successfully attempted in the past.

My other question - do you happen to have any drives (of either type) you'd be willing to part with?

Thanks,

Dave

On 2018-10-30 7:39 PM, David Feldman via Groups.Io wrote:

I ended up with both HP 9122C and 9122D (dual floppy drive) units. Both are recognized by my 8753 network analyzer (up to the point that setting incorrect GPIB address and setting incorrect disc/volume number has the expected error message results), all four drives make familiar sounds during power-up and normal operation, however, only one of the drives (in the 9122C) can read a diskette (list files on the media), and none can write or initialize diskettes. I am uncertain whether the onboard controllers are fully functional, but both appear complete and physically undamaged.

My question is this - can a contemporary (i.e., a 3-1/2" 1.4MB floppy drive) be adapted for use in either of these units? The 9122C uses a single (0.05" pitch) ribbon cable between the drives and the controller board; the 9122D has a somewhat narrower (0.05" pitch) ribbon cable and a 4-pin power connector. None of the connectors are identical to those used in contemporary floppy drives. I haven't looked for/at service documentation (yet). My last exposure to floppy drive equipment (at engineering, hardware and firmware level) was in the mid-late 1970s (!), so I'd not be adverse to a modest engineering project if there's a sign that this sort of thing has been successfully attempted in the past.

My other question - do you happen to have any drives (of either type) you'd be willing to part with?

Thanks,

Dave

I'm trying to educate myself about the newer USB power sensors. ?When I look for example at the U2043XA (average) and U2044XA (peak and average) specs, I see that both can do at least 20K measurements/second. ?The 2044XA has a video bandwidth of 5 MHz, while that's not specified for the 2043XA.

My question is whether the averaging sensor can still provide a peak reading, if the modulation is slow enough.

If I can make 20K measurements per second, it seems I should be able to follow a modulation envelope of up to 10 kHz (Nyquist sampling) and use the computer to process that data stream to catch and report the peak level over some time period. ?In fact, in theory I could process all the samples to fully reconstruct the modulation.

Is that correct, or am I missing something?

Thanks,
John

On Oct 30, 2018, at 13:37, bownes <bownes@...> wrote:

And a time nut did a beagle bone based replacement for the 6809 board that is quite nice.?

On Oct 30, 2018, at 14:35, Glen Hoag <hoag@...> wrote:

I have both a 5370A (upgraded by HP to 5370B) and a 5370B at home. I can check, but don’t recall a separate RAM board.?

Early 5370s used a Fairchild F8 family CPU. When the F8 reached end of life, HP redesigned the CPU around the Motorola 6800 or 6809; I don’t remember offhand. IIRC, consolidation of the ROMs onto the CPU board occurred at this time.?

—Glen Hoag

? hoag@...