Added some slightly more serious Linear oomph to the bench with this 22kg beasty. Aussie made and tough as old boots. 35V @ 5A x 2. My couple of beefy SMPS can go back to just R/C use. $100 AU pesos plus 1/2 a truckload of $ for freight or maybe a 5 hour round trip to pick it up.
I like the dual suitcase handles.
The handles were always strange on them you finish up with 22kg sitting under the belt line
These and the matching era Scopes by the same local manufacturer were standard Secondary School gear 30-40+ years ago.
Added a slightly random (for most) bit of test gear to my collection as well at $20 AU pesos with postage. Impressive specs over my cheap one I have had for years for outdoor R/C flying use. Far more useful and accurate for low speed airflow in industrial work.
A few days ago I hit the mother load of equipment at auction. Paid a total of $205 for all listen equipment.
Fluke 45 Dual Display Multimeter $37
Hewlett Packard 66332A Dynamic Measurement DC Source $14
Agilent Technologies E3632A DC Power Supply $110
Kikusui PAB 18-1A Regulated DC Power Supply $7
HP 6825A Bipolar Power Supply/Amplifier Calibration:7/16/2013 $18.50
HP E3615A DC Power Supply, 0-20V, 0-3A; Calibration: 2/18/2000 $18.50
None of it was listed as nonworking so hopefully, when I'm able to get it in a home shop and do some testing it will all be good.
A few days ago I hit the mother load of equipment at auction. Paid a total of $205 for all listen equipment.
Fluke 45 Dual Display Multimeter $37
Hewlett Packard 66332A Dynamic Measurement DC Source $14
Agilent Technologies E3632A DC Power Supply $110
Kikusui PAB 18-1A Regulated DC Power Supply $7
HP 6825A Bipolar Power Supply/Amplifier Calibration:7/16/2013 $18.50
HP E3615A DC Power Supply, 0-20V, 0-3A; Calibration: 2/18/2000 $18.50
None of it was listed as nonworking so hopefully, when I'm able to get it in a home shop and do some testing it will all be good.
Especially the second and the second-last leave me speechless.
Been so long since I posted my acquisitions, I'll have to trickle them out as I use them.
The current one I am cleaning up ... Tektronix 576 Curve Tracer
if anyone has tricks for removing that blob of aged epoxy off the aluminum, let me know
Philips PM 3214
Hameg HM 203-6
Beckman industrial 9016
The lot for 50€, they all need repair and cleaning.
The PM 3214 has had a quick power-on so far, not looking too bad overall, but after a 5 min warm the traces loose intensity, the H.V. sags (trace length diminishes) this gets worse by turning the graticule illumination up.
I was hoping for a bad C203, that seems OK in circuit, the pottings looks atrocious, so now I'm starting to dread a leaky transformer or H.V. multiplier. Will have to make some measurements.
Been so long since I posted my acquisitions, I'll have to trickle them out as I use them.
The current one I am cleaning up ... Tektronix 576 Curve Tracer
if anyone has tricks for removing that blob of aged epoxy off the aluminum, let me know
Many kinds of epoxy will literally crumble to pieces when subjected to soldering iron temperature. I had a circuit board on which someone had dropped an ugly blob of epoxy - which incidentally was covering up a couple of components. I used a normal sized soldering gun with a thin spade tip and gently scraped it away. At a high enough temperature the epoxy just fell apart; by being gentle, I was able to remove nearly all of it without damaging the board or components. Yours being aluminum, it ought to be possible to get all the blob off pretty readily; I had to be careful with the glass-fiber board itself.
Tek 7904A with a 7A26, 7A19, 7B15 (hey might as well start getting stuff for a 7104
) and a 7B92A. I've got a few more plugins coming.
Tek 7904A with a 7A26, 7A19, 7B15 (hey might as well start getting stuff for a 7104 ) and a 7B92A. I've got a few more plugins coming.
Do you intend to buy this strange comparator plugin? Please do, and then tell me for what it is useful really!
In this case a Tek document just managed to cause a capital WTF moment in me.
Tek 7904A with a 7A26, 7A19, 7B15 (hey might as well start getting stuff for a 7104 ) and a 7B92A. I've got a few more plugins coming.
Do you intend to buy this strange comparator plugin? Please do, and then tell me for what it is useful really!
In this case a Tek document just managed to cause a capital WTF moment in me.
Which one are you talking about? Among the other plugins I'm going to be getting is another 7A26 dual trace amplifier. The 7A19 is a 600 MHz 50 ohm amplifier designed for reaching the rated bandwidth of the 7904A (500 MHz).
Tek 7904A with a 7A26, 7A19, 7B15 (hey might as well start getting stuff for a 7104 ) and a 7B92A. I've got a few more plugins coming.
Do you intend to buy this strange comparator plugin? Please do, and then tell me for what it is useful really!
In this case a Tek document just managed to cause a capital WTF moment in me.
Which one are you talking about? Among the other plugins I'm going to be getting is another 7A26 dual trace amplifier. The 7A19 is a 600 MHz 50 ohm amplifier designed for reaching the rated bandwidth of the 7904A (500 MHz).
I was referring to the 7A13 differential comparator plugin.
Ah. I think there is one in the box of plugins the fellow is sending me. No experience with it yet.
Ah. I think there is one in the box of plugins the fellow is sending me. No experience with it yet.
When I read the app note for it, it seemed very drawn by the hairs to me. I could not see where the real purpose of the thing is.
I'll let you know what I find once I have one...in the meantime, just for grins I tried pushing the 7A19 and 7B15 a little. While the 7B15 is really intended to go with a 7B10 in a 7104 mcp CRT scope, it works quite nicely and I was able to get a stable trigger at 1.1 GHz. Beyond that the frequency response of the 7A19 (rated at 600 MHz) drops off precipitously to nothing.
Now that is a pretty darn fast analog scope.
When I read the app note for it, it seemed very drawn by the hairs to me. I could not see where the real purpose of the thing is.
It's a differential amplifier with decent bandwidth and a nice common mode range. At 1mV/DIV it'll cope with +-10V common mode, which comes out to 10000 DIV common mode.
You can also used it as a single-ended input amp with a massive offset. You could e.g. look at a 3.3V rail with DC coupling at 1mV/DIV in 100MHz bandwidth.
You'd be able to see minute ripple, but also slow "DC" drift, which you wouldn't be able to see with AC coupling.
When I read the app note for it, it seemed very drawn by the hairs to me. I could not see where the real purpose of the thing is.
It's a differential amplifier with decent bandwidth and a nice common mode range. At 1mV/DIV it'll cope with +-10V common mode, which comes out to 10000 DIV common mode.
You can also used it as a single-ended input amp with a massive offset. You could e.g. look at a 3.3V rail with DC coupling at 1mV/DIV in 100MHz bandwidth.
You'd be able to see minute ripple, but also slow "DC" drift, which you wouldn't be able to see with AC coupling.
So there is no threshold or switching involved - the 10-turns or digital adjustment is just for the offset?
So there is no threshold or switching involved - the 10-turns or digital adjustment is just for the offset?
Yups - essentially you get to dial in a voltage and use it as input to either of the differential inputs, or you can both inputs for a differential measurement.
I got this HP54645A Oscilloscope for 45 euros from our uni. Last calibrated in '09 but seems accurate enough.
Made in 1996 in USA. It has 2 channels, negazoom and a sharp CRT tube.
It was "Broken". I just needed to clean the keys and glue one pcb in and it worked like new. I modded an usb port to it(sorry)
And I got a Hameg 20Mhz analog scope for free. from the 80's. Made in West Germany. I opened it up and it was in top notch condition. Nothing has leaked or broken. German engineering!
This may not be a big score but I went to a ham fleamarket a couple of days ago. It was much smaller than I had hoped but there was one seller there who had, along with other goodies, several small SMPSs, most were new and still wrapped. I asked how much and he said $1 each so I just grabbed them all, not even checking their ratings. A lot of equipment uses small power supplies like this and sometimes it's easier to replace than to try to repair.
I was a little surprised when I opened one and saw the brand name. I'll have to check it out to see if it really meets specs!
This may not be a big score but I went to a ham fleamarket a couple of days ago. It was much smaller than I had hoped but there was one seller there who had, along with other goodies, several small SMPSs, most were new and still wrapped. I asked how much and he said $1 each so I just grabbed them all, not even checking their ratings. A lot of equipment uses small power supplies like this and sometimes it's easier to replace than to try to repair.
I was a little surprised when I opened one and saw the brand name. I'll have to check it out to see if it really meets specs!
I bet it has tremendous specs and its really great!
This may not be a big score but I went to a ham fleamarket a couple of days ago. It was much smaller than I had hoped but there was one seller there who had, along with other goodies, several small SMPSs, most were new and still wrapped. I asked how much and he said $1 each so I just grabbed them all, not even checking their ratings. A lot of equipment uses small power supplies like this and sometimes it's easier to replace than to try to repair.
I was a little surprised when I opened one and saw the brand name. I'll have to check it out to see if it really meets specs!
Check twice. At least. And put the test records in a place where they can't reach them.
Wow, that's a good source for lots of jokes.