Re: E4406A MATLAB Application
Please correct me if I'm wrong, but looking at Dick Benson's description of his MATLAB application (as described in the PDF included with his MATLAB files) and comparing his features with those in John Miles' SSM.EXE, it looks to me as though SSM.EXE is quite a different beast from Benson's MATLAB application.?
Benson's application mimics the controls of a basic spectrum analyzer (and includes bells and whistles such as the ability to do Harmonic and IMD analysis, as well as trace memory), while Miles' program seems to me to be much more of a spectrum surveillance tool.
- Jeff
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Re: E4406A MATLAB Application
Yes, I am aware of John's excellent work and use it often.
This offering complements his work.
Dick
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Re: E4406A MATLAB Application
KE5FX (aka John Miles) has a program to do this (SSM.EXE) as part of his GPIB toolkit and for details. ? Dave ?
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From: [email protected] [mailto:[email protected]] On Behalf Of Dick Benson
Sent: 19 November 2018 15:34
To: [email protected]
Subject: [HP-Agilent-Keysight-equipment] E4406A MATLAB Application ? Greetings,
?There appears to be a continuous wave of decommissioned Agilent E4406A "VSA Series Transmitter Tester" boxes hitting eBay.?
?They have a lot of bang-per-buck but have some limitations when being used as general purpose spectrum analyzers.
? A MATLAB application was created to address a few of them:
?Some of you folks might find this useful as well.
Best regards,
Dick (w1qg)
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Re: Issue with homemade diode power sensor for HP meters
Tobias, You will see, not easy task to linearze and to compensate this kind of detector if you need a accuracy.? 1. I sugest you to use some of SPDT switches (well matched, small leakage and small on/off charge transfer)? like ADG819. In this case you will need some power supply from 436 but you need only one 220Hz line. 2. Put some bias trough your voltage doubler diodes, something like 10-20 uA; 3. Replace ground path of the chopper with same diode doubler configuration also biased on the same way like active one. Same capacitors around this one like a "active" doubler. This one doubler configuration (no RF input to this one) will be a new virtual ground and will compensate for temperature drift.? Milan
Hey Jeff,
I didn't see your message, it was not in the other thread!
But thanks anyway, I had the same idea as you suggested - I will soon receive some sensors with a blown thermocouple, and there I probably can replace the thermocouple with my own circuit.
As for now, autozero seems to work, and the sensor provides more or less accurate readings, but it is not terribly accurate. I hope to improve that soon, probably by adding the shaping network HP mentioned.
Best
Tobias HB9FSX
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E4406A MATLAB Application
Greetings,
?There appears to be a continuous wave of decommissioned Agilent E4406A "VSA Series Transmitter Tester" boxes hitting eBay.?
?They have a lot of bang-per-buck but have some limitations when being used as general purpose spectrum analyzers.
? A MATLAB application was created to address a few of them:
?Some of you folks might find this useful as well.
Best regards,
Dick (w1qg)
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Re: Issue with homemade diode power sensor for HP meters
Hey Jeff,
I didn't see your message, it was not in the other thread!
But thanks anyway, I had the same idea as you suggested - I will soon receive some sensors with a blown thermocouple, and there I probably can replace the thermocouple with my own circuit.
As for now, autozero seems to work, and the sensor provides more or less accurate readings, but it is not terribly accurate. I hope to improve that soon, probably by adding the shaping network HP mentioned.
Best
Tobias HB9FSX
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Re: A homemade diode power sensor for HP meters
Hi all,
I made some further progress. I discarded my previous prototype and made a new one using better JFETs, this time the 2N4856A. According to its datasheet it is especially designed for chopper applications (well, I don't quite understand in which parameters a chopper JFET should differ from an ordinary JFET).
And with the new JFETs, indeed, the waveforms at the chopper output look much cleaner and nicer. However it is difficult to measure because my scope (Agilent 54832B) is very noisy with those small voltages.
I was able to get more stable and reliable readings, and the zeroing of the sensor also works more reliable. However, the linearity is still quite bad; at low input power, it is okay but towards increasing output power, linearity degrades quickly and at the worst point (0 dBm input into the detector) it is almost 3dB off. My detector can measure -30dBm to 0dBm with usable accuracy. Above it becomes a bit nonlinear - could be due to the diode no longer operating in the square law region. But I will further investigate in the subject. Probably I also need to add the shaping network mentioned in the 8484D service manual.
@ Dave NR1DX
I am testing the diode detector with the HP 436A calibration output. And I also test at various frequencies down to 1MHz and up to 2.6GHz with the 8663A signal generator. However, I think later it would be desirable that my detector works to, say, 6 to 10 GHz. I think otherwise it is not very useful. On the other hand it would also be good if it works to below 1MHz.
@ Rainer DF6NA
Thanks for the links. I will probably order some of those connectors when I am ready for a 'real' prototype! looks not toooo expensive.
@ Mike N2MS
I think for the diode sensors (like 8484A, 8481D) it is not possible to replace the diode without a highly sophisticated workshop and tools. I have never seen one of these sensors from the inside, but I expect wire bonded black magic inside; the service manual even says that the position and shape of certain wires is important, otherwise the calibration goes nuts.
@ Dave NR1DX
The thermocouple has the advantage that it really measures power dissipation, i.e. RMS. Since it does the measurement via temperature, it is basically independent of the waveform and even independent of the frequency - as long as the mechanics is reliable and precise enough, you can measure each frequency with this, even DC. The HP sensors have an internal DC blocking capacitor, so this is why they don't work down to DC.
@ bownes
yes, like AD8307 or so would be nice as well. However, I am not sure whether it is possible to connect these somehow to a HP meter like the 436A. For instance, the AD8307 (or some other LogAmps) need a power supply, which is not available on the existing interface to the sensors, except if you abuse some signals, e.g. the chopper signals and then rectify them etc.
Besides that, you need to mimic the behaviour of the thermocouple/diode detector signals.
This is why I stuck to the 8484A/8481A design.
@Dave McGuire, AK4HZ
You said you have already done what bownes suggested? was it working? could you tell a bit more about this? :-)
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Re: Readings from 436A power meter using 82357B USB-GPIB?
Steffan...
Maybe I missed you saying so, but with the Keysight IOLibraries installed the 82357A/B should be essentially transparent to you. Connection Expert will let you assign it a name such as GPIB0 and then you just send commands to the 436's address.
I don't recall the exact details but there is a box to check to use 488.2 vintage protocol but that's about it. Unless there is something amiss with it, I doubt that the adapter is the problem. Since it appears to be at least sending commands, that doesn't seem likely.
From Tom Holmes, N8ZM
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Re: A homemade diode power sensor for HP meters
Thermocouple detectors are definitely more linear, RMS, and have been around very long time. Some of the peak power meters use the diode versions. These typically have lower dynamic range. The HP8900D uses diode detectors for peak reading. Analog Devices bought Linear Technology but they are still selling independent product lines so the power detector IC's are there. We designed a detector based on one of their log-amp based power detectors that reads linear voltage for dB RF. It was a mistake and so I found the ADL5511 which has both voltage for dB in and also envelope. It also has temperature compensation to first order. Envelope is perfect for peak reading. We have built over 60 of these in a small pod, that has a PIC to take care of curve fit and they track our Keysight and Boonton meters on single frequency (which is what we needed). There are numerous companies now making USB power heads that go direct into a PC, like R&S, LadyBug (ex HP), Keysight, MiniCircuits. They all use the new generation ICs.
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Re: A homemade diode power sensor for HP meters
A long time ago, I remember an eBay seller offering NOS HP replacement thermocouples, with calibration labels, at incredibly low starting bid prices.? I really don't think he knew what he was selling.? I can only imagine the seller's surprise at the ensuing bidding frenzy.? Those silly little pieces of bent wire were worth a lot of money!??
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Re: 8642B displays A6A1 transient failure F3 when audio peaks at FM mod input
Update
I figured out a way to make the 8642B stop reporting A6 counter fault in FM mode when I go from internal to external dc. I turn on AM modulation and set it to internal then turn on FM and there is no problems switching from int to ext dc, weird. I have a A3 processor board on the way, from the troubleshooting I have done in the manual it suggests swapping out the A3 board after I already swapped out A4.
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Re: A homemade diode power sensor for HP meters
On Sun, Nov 18, 2018 at 12:48 PM Artekmedia < manuals@...> wrote: Mike
almost all of the 848x series power sensor heads use a thermocouple and
not a diode. The replacement thermocouples were at one time available?
directly from HP/Agilent. They were crazy expensive (like $750) as I
remember) plus you needed an eye loop and the nerves of a? Swiss
watchmaker to replace them. What is essentially being attempted here is
to make a diode version of the power sensor head as a replacement since
the heads have become scarce and expensive in their own right.
"parkertest" on ebay seem to have bought a lot of replacement thermocouples and are selling them at $7200 obo for 20!
They will also repair an 8481A for $465 or sell a refurbished one for $475 obo.? Kind of puts a limit on the value of these things.
?
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Re: WANTED: HP 606B Sig Gen RF Output Attenuator Module A10
Hi Jeremy,
Thanks for your suggestions. I've searched without success so far. Can't find a non-working 606B at this time. I'll keep monitoring.
Hi Kim,
Thank you for the offer of the unit. I'd be most happy to try it in my 606B.
I'm unsure how to send you the postage costs and my postal address. Perhaps you could advise me.
With my thanks
Graeme
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Re: A homemade diode power sensor for HP meters
On 11/18/18 4:30 PM, wrote: I’ve long thought about using one of the Linear Tech or Analog Device RF sensor ICs as a front end to an HP power sensor head with blown thermistor/diode.
They have a great frequency and sensitivity range, come in a tiny package that could fit in an existing head, and come in linear and log versions. A local friend and I have done a lot of work on exactly that. The idea has great potential, but there are some dragons hiding. -Dave -- Dave McGuire, AK4HZ New Kensington, PA
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Re: A homemade diode power sensor for HP meters
I’ve long thought about using one of the Linear Tech or Analog Device RF sensor ICs as a front end to an HP power sensor head with blown thermistor/diode.
They have a great frequency and sensitivity range, come in a tiny package that could fit in an existing head, and come in linear and log versions.
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On Nov 18, 2018, at 15:48, Artekmedia <manuals@...> wrote:
Mike
almost all of the 848x series power sensor heads use a thermocouple and not a diode. The replacement thermocouples were at one time available directly from HP/Agilent. They were crazy expensive (like $750) as I remember) plus you needed an eye loop and the nerves of a Swiss watchmaker to replace them. What is essentially being attempted here is to make a diode version of the power sensor head as a replacement since the heads have become scarce and expensive in their own right.
Why you might ask did the then HP choose a thermocouple? I suspect that the thermocouple is more linear than a diode sensor and generally flatter over a wide frequency range. If your willing to trade off dynamic range and wider bandwidth of the thermocouple then the diode may be a a useful solution to lack of power heads available these days .. .I am hopeful that Tobias is successful.
Hope that helps
Dave
NR1DX
On 11/18/2018 2:35 PM, n2msqrp wrote:
I've been following this discussion about diode power sensors.
I assume the diode sensors fail because of blown diodes form overload. Has any repaired the faulty sensors by replacing diodes?
Mike N2MS
On November 17, 2018 at 6:33 PM "Ed Breya via Groups.Io" <edbreya@...> wrote:
Hi Tobias, I looked at the OP again, and realized that you already knew about the "mount" resistor - I didn't notice that the first time. I grabbed that 8484A manual pdf that Orin linked - thanks Orin, I have lots of 8484As, and the manual somewhere, but can never seem to find it. Now I have a fresh copy.
Anyway, after refreshing my memory on these sensors, and looking also at the 8481A schematic, I'd recommend studying both types - the TC and diode models have a different arrangement for the auto-zeroing function. The circuit you posted puts the AZ feedback to the detector, as in the 8481A TC circuit, but that won't work right. With the TC type, it is a low impedance source, so the AZ current can go through, and offset the signal. With a diode detector, you should use a circuit like in the 8484A, which applies it to the ground-side JFET switch in the chopper. The diode detector is a high impedance source, so you don't want to put the AZ feedback current there.
Good luck,
Ed --
Dave
Manuals@...
www.ArtekManuals.com
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Re: Readings from 436A power meter using 82357B USB-GPIB?
Hello,
Short update. Just recalling I had an Arduino setup for GPIB-USB (many thanks to Emanuele Girlando!). It works using that one to do a ++read and get a response, but then I don't seem to be able to write to the instrument...
Any hints on doing everything on 82357 would be much appreciated...
Regards,
? Staffan
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Re: A homemade diode power sensor for HP meters
Mike
almost all of the 848x series power sensor heads use a thermocouple and not a diode. The replacement thermocouples were at one time available? directly from HP/Agilent. They were crazy expensive (like $750) as I remember) plus you needed an eye loop and the nerves of a? Swiss watchmaker to replace them. What is essentially being attempted here is to make a diode version of the power sensor head as a replacement since the heads have become scarce and expensive in their own right.
Why you might ask did the then HP choose a thermocouple? I suspect that the thermocouple is more linear than a diode sensor and generally flatter over a wide frequency range. If your willing to trade off dynamic range and wider bandwidth of the thermocouple then? the diode may be a a useful solution to lack of power heads available these days .. .I am hopeful that Tobias is successful.
Hope that helps
Dave
NR1DX
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On 11/18/2018 2:35 PM, n2msqrp wrote:
I've been following this discussion about diode power sensors.
I assume the diode sensors fail because of blown diodes form overload. Has any repaired the faulty sensors by replacing diodes?
Mike N2MS
On November 17, 2018 at 6:33 PM "Ed Breya via Groups.Io" <edbreya@...> wrote:
Hi Tobias, I looked at the OP again, and realized that you already knew about the "mount" resistor - I didn't notice that the first time. I grabbed that 8484A manual pdf that Orin linked - thanks Orin, I have lots of 8484As, and the manual somewhere, but can never seem to find it. Now I have a fresh copy.
Anyway, after refreshing my memory on these sensors, and looking also at the 8481A schematic, I'd recommend studying both types - the TC and diode models have a different arrangement for the auto-zeroing function. The circuit you posted puts the AZ feedback to the detector, as in the 8481A TC circuit, but that won't work right. With the TC type, it is a low impedance source, so the AZ current can go through, and offset the signal. With a diode detector, you should use a circuit like in the 8484A, which applies it to the ground-side JFET switch in the chopper. The diode detector is a high impedance source, so you don't want to put the AZ feedback current there.
Good luck,
Ed
--
Dave
Manuals@...
www.ArtekManuals.com
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Re: A homemade diode power sensor for HP meters
I've been following this discussion about diode power sensors.
I assume the diode sensors fail because of blown diodes form overload. Has any repaired the faulty sensors by replacing diodes?
Mike N2MS ?
On November 17, 2018 at 6:33 PM "Ed Breya via Groups.Io" <edbreya@...> wrote:
Hi Tobias, I looked at the OP again, and realized that you already knew about the "mount" resistor - I didn't notice that the first time. I grabbed that 8484A manual pdf that Orin linked - thanks Orin, I have lots of 8484As, and the manual somewhere, but can never seem to find it. Now I have a fresh copy.
Anyway, after refreshing my memory on these sensors, and looking also at the 8481A schematic, I'd recommend studying both types - the TC and diode models have a different arrangement for the auto-zeroing function. The circuit you posted puts the AZ feedback to the detector, as in the 8481A TC circuit, but that won't work right. With the TC type, it is a low impedance source, so the AZ current can go through, and offset the signal. With a diode detector, you should use a circuit like in the 8484A, which applies it to the ground-side JFET switch in the chopper. The diode detector is a high impedance source, so you don't want to put the AZ feedback current there.
Good luck,
Ed
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Re: Readings from 436A power meter using 82357B USB-GPIB?
Hello,
Thanks for the suggestions. I tried to figure out how to do low-level communication, but don't seem to find any way.?
I hope I'm just missing something trivial here. If anyone has an example of communicating with the 436 (or similar - old HP-IB) using 82357 USB-GPIB, preferably using the VISA library, that would be the best - that would give a good starting point for digging further.
Regards,
? Staffan
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Re: A homemade diode power sensor for HP meters
-------- Weitergeleitete Nachricht --------
Mouser also shoes the wrong picture.
I use these:
Lumberg Series 03 - Circular connectors with threaded joint M16
acc. to IEC 61076-2-106, IP40/IP67/IP68
But not cheap either.
73, Rainer
Am 18.11.2018 um 10:04 schrieb rmc321 via Groups.Io:
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The 12-pin circular connector used on the power sensors is an
Amphenol.? The old part number was 91-T-3638.
Now, it's part of their "C 091 A/B/D" series circular
connectors.? Several variations are listed in the Amphenol
catalog:
Mouser has several slightly expensive options (a few of which
appear in this link -- note that widening the Mouser search
filter will supply more results):
It appears that an eBay seller is selling them at a lower
price.? His text says they are the 12-pin versions, although his
photo shows the 14-pin version.? It's hard to tell which of the
two connectors he is selling.? However, it appears the two
additional pins shouldn't matter since it's the female part of
the connector -- you would leave those two extra pins
unconnected.
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Dick Benson
David C. Partridge
Dave McGuire
bownes