Rectify 500MHz Small Signal

Good man :-)

The usual scenario would be that either the power supply limits or a PVC stench develops.

What are they using? SCADA software?

--
Regards, Joerg

http://www.analogconsultants.com/

"gmail" domain blocked because of excessive spam.
Use another domain or send PM.

The jet engine and FADEC test folks usually write their own system software, using RT Linux or some such. Test runs are often script driven, may involve thousands of channels of stimulation and acquisition, and may run for days. They have to simulate 1553 busses, pitot tubes, thermocouples, tach pickups, vibration things, pressure sensors, LVDTs, all sorts of nonsense. And then faults on all of the above.

Hmmm, maybe I should do an LVDT simulator. Could be fun.

John

Wow, ok, that's a different caliber. One of my newer clients in in that biz as well. Luckily I'll only have to connect to their custom test rig, the programming will be done by others.

I just got DAQFactory back to work. Was like pulling teeth. Almost like an old engine that hadn't been started up in years.

--
Regards, Joerg

http://www.analogconsultants.com/

"gmail" domain blocked because of excessive spam.
Use another domain or send PM.

I've had fun with two hobbyist concepts:

The Lambda Diode:

The psuedo PUT:

In defense of the guy who runs 4QD, his golf cart controllers are really good.

And for those of you who bemoan the fact that you cannot get your hands on fast sampling bridges , these show up on ebay and use a all analog PLL with a sampling bridge picking off the 900-1600 mhz drive oscillator , before it goes into the SRD multiplier. The bridge is driven by a 90-120 mhz crystal oscillator. They come in 2.5 ghz, 5-6 ghz and 8-11 ghz flavors. The SRD is in a tiny pill package in a ridge waveguide. 20-40$ usually.

There is almost always a brick or two on ebay.

Tech data is here:

Frequency Sources (West Division) model MS-62XEL-52.

Just about all of them use the same circuit, but some have better sampling systems. The sampler almost always ties into a probe extended into the "sapphire rod" cavity oscillator.

Some performance data are here:

So if you do some digging at a good hamfest, you can come away with

2-3 bricks and some nice fast diodes :-)

I do 10 Ghz ham stuff, its more of a challenge then a store bought 2 meter rig. These days your expected to forgo the old Gunn diodes and have tunable SSB locked to GPS or or a used Rb oscillator from a old cell site.

Steve

Nice. And it refers to:

which has the operator manual. I have the 59 - now I have the manual, too. :-) Thanks!

Ed

Some of those links didn't make it to my last post:

ebay:

Collins, Frequency West, and Harris bricks, as well as others, are all just about the same inside. Out of 10 or so I've bought, only 1 has ever been dead. Made to old Bell System specs, and thus they don't die. Worse thing I've ever had to do was reseat a crystal and peak the tuning.

Steve

with RF on one

appropriately.

tunnel diodes, as

a dreadful IEEE

power engineers

slideback

certain party loved

it himself.

used to get them

is insane, and

essentially

for switching.

odes.pdf

oscillating, detection,

capacitance. The low

forward bias of

about 1 ohm,

makes a good

of stored=20

than the DC=20

don't

your spectrum=20

must be.=20

TD would

buy one I=20

Guess=20

avalanche-rated=20

buck.

send

drive

have a

from a 10

offer, but=20

there :-)

bar I

were very=20

I

in

order

8568B=20

this=20

$100000=20

of

sampling=20

=20

John L, Jeorg:

I am in the market for (in no particular order) a fast analog scope maybe a TEK 2465B. I could use an 11801/11802 with a few heads good to say 6 GHz, and some probes. A decent freq/interval counter. A

5-1/2 digit multimeter (with 4 terminal ohms, and true rms ac measurements up to 100 KHz). And an AM/FM modulatable function/sweep generator up to 20 MHz. Except for the good scopes, this is high hobbyist to low end or mid-range lab stuff. =20

20 years away from the lab and i don't remember what is good stuff any more. The stuff must be functional, but 20+ year old stuff is quite acceptable. For computer interactivity i expect to buy/use USB to GPIB converter(s). Serial is acceptable as well.

My proper email address is in the headers. I have an objection to dealing with e-prey or preypal myself.

Read the whole thread. I can see how your approach will work.

Just the same, i would consider range switching. Most anything like analog switches or transmission gate won't cut it for rectification at those levels and frequency. My idea is to use samplers, use a six or

8 way group of samplers and get a total sample rate of 3 or 4 GS/s. Then average/analyze the ratios of the six/eight sampler outputs. Maybe synchronizing them signal to be measured would be worthwhile. This could give you as much as 50 MHz detector bandwidth with the resolution of 2% or so.

On a sunny day (Wed, 30 Sep 2009 18:50:54 -0700 (PDT)) it happened snipped-for-privacy@uakron.edu wrote in :

Nice!

Yup, but if you have some sort of standard platform you could design a high bandwidth sampling front-end for it without much additional costs. That's how I setup my USB DSO project.

--
Failure does not prove something is impossible, failure simply
indicates you are not using the right tools...
                     "If it doesn't fit, use a bigger hammer!"
--------------------------------------------------------------

on one

diodes, as

dreadful IEEE

engineers

slideback

party loved

himself.

get them

insane, and

essentially

switching.

detection,

The low

bias of

ohm,

a good

stored

the DC

spectrum

be.

would

one I

but

:-)

Unfortunately EBay has monopolized the market for 2nd hand, they are almost like Walmart. So they call the shots, and thus also the fee levels.

The 2465 is a very good choice, this is the scope I always recommend to clients whom I feel are in dire need of a "real" scope. Can't go wrong. But remember that those things can be very tired.

For the generator check out modulateable DDS eval boards.

If you really don't want EBay your only options are 2nd hand re-sellers (expensive, usually), company auctions (very good deals, got some of my stuff that way) and another very good source are hamfests.

--
Regards, Joerg

http://www.analogconsultants.com/

"gmail" domain blocked because of excessive spam.
Use another domain or send PM.

FWIW here's my lab equipment list including what I paid for it on eBay. Some things I already had for awhile and forgot, or else didn't get on eBay. I've had really good luck on eBay--good stuff for a few cents on the dollar, almost zero duds.

Cheers

Phil Hobbs

-------------

ElectroOptical Innovations Equipment List

Phil Hobbs, September 29, 2009

HAVES

*****

Oscilloscopes: Price (Shipping)

--------------

Tek TDS744A 500 MHz 2Gs/s, 4 channel scope $ 849 ( 0)

Tek 11802 Sampling Scope SD-22 12.5 GHz dual low noise head SD-24 20 GHz dual TDR head SD-42 6.4 GHz OE converter $ 200 SD-14 dual-channel probe sampler 3 GHz $ 175 ( 16) (One channel mildly broken)

Tektronix 466 Analogue Storage Scope $ 100

Tektronix 475A Analogue Scope $ 100

Counters and Spectrum Analyzers

-------------------------------

HP 8568B Spectrum Analyzer, 100 Hz->1.5 GHz $ 900 ( 90)

HP 35665A dynamic signal analyzer $ 351 ( 120) (Options 1C1 (add 2MB memory), 1D4 (Arbitrary function source), and

1C2 (HP instrument BASIC)

HP 5315B Universal Counter $ 80

Signal Sources / Time & Frequency Generators

---------------------------------------------

HP 8013B pulser Highland P400 Digital delay generator

HP 3325A synthesizer $ 299 HP 8640B ultraquiet phaselocked generator $ 120 ( 60)

HP 8620C Sweeper mainframe $ 250 ( 50) HP 86222B 0.01-2.4 GHz plugin

Meters

-------

HP 400EL AC Voltmeter (10 MHz) HP 3403A True RMS Voltmeter (100 MHz) $ 95 ( 26)

Simpson Model 260 Series 3 multimeter Fluke 87 handheld DMM $ 249 ( 0)

Keithley 191 5.5 digit DMM #1 Keithley 191 5.5 digit DMM #2

Power Supplies

--------------

MIT PMT-2000 HV power supply $ 41 ( 13)

Power Designs TP343A triple DC power supply $ 48 ( 16) Power Designs TP325 triple DC power supply $ 47 ( 17)

HP 6112A Precision DC power supply (5 digit)

Amplifiers

----------

Highland J750 Amplifier Highland T860 Buffer/Driver

Optical Test Equipment

----------------------

Blue Sky model 200 Collimeter collimation tester

Uniphase 1137P He-Ne (needs 1202 $ 212 ( 21) power supply, 2.4 kV, 6.5 mA)

Furniture and Hardware

-----------------------

19-inch HP rack $ 300 ( 0) Vidmar 15-drawer cabinet $1382 ( 176) (new) Safco 5-drawer map cabinet, 30x48 $ 0 ( 0) Salvage

5 pcs 2M GPIB cables $ 32 ( 16)

--------------------------------------------------------------- Total 5830 ( 621)

-------------- WANTS ------------------

Tools

-----

Cooper 13006C 6-inch gas pliers (13006 OK too)--discontinued

Mantis microscope with 4x & 8X objectives $1500 Sherline--Small lathe/milling machine $3000 Metcal soldering/desoldering station $ 300 Small electric vacuum pump $ 150 Small electric compressor $ 150

Spares

------ Epson SMD-300 disc drive for HP 35660A (?) TEAC 300D disc drives for HP 35665A Sony MP-F52W-20 disc drives for HP 4145B

Interfacing and Control

-----------------------

Prologix GPIB-Ethernet module $ 200 new

Oscilloscopes & Accessories

---------------------------

Tek TDS684B 1 GHz, 5 Gs/s, 4 channels simultaneously, colour LCD Opt 13 serial/parallel hardcopy port Opt 1F Floppy drive Opt 2F Advanced waveform math

For Tek 11802 sampling scope: SD-46 20 GHz OE converter SD-48 30 GHz OE converter SD-32 50 GHz sampling head SD-51 20 GHz trigger head

1x 012-1220-00 1m sampling head extender 1x 012-1221-00 2m sampling head extender

Counters and Spectrum Analyzers

-------------------------------

HP 8444A Opt 59 Tracking Generator for 8568B HP 5372A Modulation domain analyzer

Meters

------

HP 435A analog power meter HP 8482A power meter head and cable (100 kHz - 4 GHz) HP 8484A diode power head and 11708A reference attenuator HP 4470A transistor noise tester

Signal Sources / Time & Frequency Generators

--------------------------------------------

HP 3325B or equivalent HP 8560D synth plus plugins

Highland Technology arbs

Furniture

---------

Lista or Vidmar two-pedestal workbench with lots of small drawers Workbench for Sherline

Optical

--------

3 x 4 foot Newport optical breadboard and bench

10 mW He-Ne

100-mW single frequency green DP YAG

Lots of mounts

Optical spectrum analyzer

Optical power meter

Pb salt camera

JDS Uniphase 1202-1 power supply

Computers

---------

26-processor pizza box cluster, 50G RAM, 10 TB disc, Rocks cluster Linux

Small server rack

1U 20-inch LCD/keyboard drawer

GbE router

Intel C++ and Fortran compilers

Business FIOS line--15/20Mb fixed IP

Firewall machine

NAS machine with mirroring

B-size laser printer with Postscript, Ethernet and duplex--HP 5000, about $300-400 refurb

B-size page scanner with ADF & duplex

--
Dr Philip C D Hobbs
Principal
ElectroOptical Innovations
55 Orchard Rd
Briarcliff Manor NY 10510
845-480-2058
hobbs at electrooptical dot net
http://electrooptical.net

I bet the Lecroy LH314H (rebranded Iwatsu SS-7847A) is just as good as the 2465 and more recent. Sometimes they come quite cheap on Ebay.

--
Failure does not prove something is impossible, failure simply
indicates you are not using the right tools...
                     "If it doesn\'t fit, use a bigger hammer!"
--------------------------------------------------------------

That seems very reasonable especially since the Dollar is so low. Shipping costs to Europe are still huge though.

--
Failure does not prove something is impossible, failure simply
indicates you are not using the right tools...
                     "If it doesn\'t fit, use a bigger hammer!"
--------------------------------------------------------------

;0 Those are just the prices for the plugins.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal
ElectroOptical Innovations
55 Orchard Rd
Briarcliff Manor NY 10510
845-480-2058
hobbs at electrooptical dot net
http://electrooptical.net

Got a link? Search engine didn't find it. So far I was less than impressed with LeCroy scopes but maybe they've got a gem somewhere. The epitome of ghastliness are Windows-based scopes ... yuck.

--
Regards, Joerg

http://www.analogconsultants.com/

"gmail" domain blocked because of excessive spam.
Use another domain or send PM.

levels.

If someone i knew somewhat, that did not have issues with eprey was interested in helping me out, i would not be so remiss as to not include some consideration for their assistance.

any

levels.

=20

=20

I can handle LeCroys, but they are samplers not real time scopes.

I can't help you there because (so far) I've never bid on EBay myself, only my clients, a lot. If you do need a lot of stuff I'd consider setting up an account. I guess you could always cancel it when done.

--
Regards, Joerg

http://www.analogconsultants.com/

"gmail" domain blocked because of excessive spam.
Use another domain or send PM.