On Aug 21, 2022, at 12:24 PM, Tam Hanna <tamhan@...> wrote:

?Hello,

thank you all so much. It was my honour that the OpenSCAD book was helpful.


Would you be willing to share a picture or two with me for Instagram?


Tam

With best regards
Tam HANNA

Enjoy electronics? Join 21k4 other followers by visiting the Crazy Electronics Lab at https://www.instagram.com/tam.hanna/

On 2022. 08. 21. 0:44, Paul Amaranth wrote:

That's great! ?Nice work, and thanks for publishing the openscad source.

Is this the same lever used in the 8640b?

On Sat, Aug 20, 2022 at 01:07:47PM -0700, Glydeck via groups.io wrote:

Gang,

Just shy of a year I can happily report that my HP 8007B is now back in service.? The big break through was acquiring a 3D printer.? A friend of mine had purchased a Creality Ender 3 during the pandemic, and after printing his fill of Dungeon and Dragon characters asked me if I wanted it. Of course I said yes. Armed with the Printer, Wilko’s sample lever and Tam’s book I was able to print the needed part. I’ve updated and will continue to update the details on this web page:

http://glydeck.com/hp_switch.html

Thanks again to Wilko and Tam for the help. Here is a photo of the 8007B back in action.

That's great! Nice work, and thanks for publishing the openscad source.

Is this the same lever used in the 8640b?

On Sat, Aug 20, 2022 at 01:07:47PM -0700, Glydeck via groups.io wrote:

Gang,

Just shy of a year I can happily report that my HP 8007B is now back in service.? The big break through was acquiring a 3D printer.? A friend of mine had purchased a Creality Ender 3 during the pandemic, and after printing his fill of Dungeon and Dragon characters asked me if I wanted it. Of course I said yes. Armed with the Printer, Wilko’s sample lever and Tam’s book I was able to print the needed part. I’ve updated and will continue to update the details on this web page:



Thanks again to Wilko and Tam for the help. Here is a photo of the 8007B back in action.

On Aug 21, 2022, at 6:39 AM, Wilko Bulte <wkb@...> wrote:

?Nice to see that the part that I saved from the dumpster has passed on its genetic makeup ?

Wilko

On Aug 20, 2022, at 3:44 PM, Paul Amaranth <paul@...> wrote:

?That's great! Nice work, and thanks for publishing the openscad source.

Is this the same lever used in the 8640b?

On Sat, Aug 20, 2022 at 01:07:47PM -0700, Glydeck via groups.io wrote:
Gang,

Just shy of a year I can happily report that my HP 8007B is now back in service. The big break through was acquiring a 3D printer. A friend of mine had purchased a Creality Ender 3 during the pandemic, and after printing his fill of Dungeon and Dragon characters asked me if I wanted it. Of course I said yes. Armed with the Printer, Wilko’s sample lever and Tam’s book I was able to print the needed part. I’ve updated and will continue to update the details on this web page:



Thanks again to Wilko and Tam for the help. Here is a photo of the 8007B back in action.

--
Paul Amaranth, GCIH | Manchester MI, USA
Aurora Group of Michigan, LLC | Security, Systems & Software
paul@... | Unix/Linux - We don't do windows

Gang,

Just shy of a year I can happily report that my HP 8007B is now back in service.? The big break through was acquiring a 3D printer.? A friend of mine had purchased a Creality Ender 3 during the pandemic, and after printing his fill of Dungeon and Dragon characters asked me if I wanted it. Of course I said yes. Armed with the Printer, Wilko’s sample lever and Tam’s book I was able to print the needed part. I’ve updated and will continue to update the details on this web page:



Thanks again to Wilko and Tam for the help. Here is a photo of the 8007B back in action.

Hi,

the article was in Microwaves & RF in April 2013. There is some discussion about its accuracy but I'm uncertain about the actual validity of the suggestion. The article can be found in a few places:

regards

Charles Edmonds VK3CLE
Mob: 0418309921
charles.edmonds@...

------ Original Message ------
From: "Conrad, PA5Y" <g0ruz@...>
To: "[email protected]" <[email protected]>
Sent: Saturday, 20 Aug, 2022 At 7:01 AM
Subject: Re: [HP-Agilent-Keysight-equipment] Noise head ENR calibration - how do keysight do it? A question that was put to Keysight.

Having re-read the David Stockton presentation again, that along with the fact that these days we have high IP3 MMICs with very low noise figures and good return loss, it makes sense to look more ?closely at these devices. Tuning for minimum on the bench is much less risky and negative noise figures should be a thing of the past.

?

I can see that my winter will be a little less boring.

?

Interesting discussion, thanks everyone. The expensive box that Keysight sell will be rather like the R&S FSWP, nothing more than a dream.

?

Regards

?

Conrad PA5Y

?

From: [email protected] <[email protected]> On Behalf Of n8zmTWH via groups.io
Sent: 19 August 2022 21:14
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] Noise head ENR calibration - how do keysight do it? A question that was put to Keysight.

?

Hi Conrad…

?

Actually, even the expensive box that Keysight sells to do the cal boils down to just comparing the unknown source to one that is traceable,? and simply adding the ?difference to the known ENR. So you are on the right track. As you know, the problem at low NF’s is quite simply that the magnitude of the accumulated uncertainties can become equal to or greater than the value of the NF.

?

You moonbounce guys also already know that an impedance mismatch between the antenna and the preamp input can really offset the benefits of a preamp tuned to perfection ?on the bench. Stockton hinted at this in his paper.

?

Tom, N8ZM

?

From: [email protected] <[email protected]> On Behalf Of Conrad, PA5Y
Sent: Friday, August 19, 2022 12:50 PM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] Noise head ENR calibration - how do keysight do it? A question that was put to Keysight.

?

Hello Tom, yes, I already read all this material (again) as well as the SM5BSZ stuff. As usual Leif’s pages are well worth a read. I will just compare with the calibrated Noise Com NC-346A that I have. It is good enough. The stuff that ?I do is sub-0.4dB which as you know is very tricky. Above 432 system analysis with celestial sources seems a whole lot more reliable. I am fortunate to live in a quiet location.

?

Anyway, it was good to refresh my memory. All brought about due to the acquisition of an HP-8790B and to help a friend with his home brew noise source.

?

Regards

Conrad PA5Y

?

From: [email protected] <[email protected]> On Behalf Of n8zmTWH via groups.io
Sent: 19 August 2022 17:21
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] Noise head ENR calibration - how do keysight do it? A question that was put to Keysight.

?

This link will take you to a paper by David Stockton, GM4ZNX, the architect of the HP 8973 series Noise Figure analyzers, and and Ian White GM3SEK . In it, they ?discuss the errors in NF measurements, including ENR calibration.

?

?

The title of the paper to look for is:

?

GM4ZNX-GM3SEK_Noise-Figure-Measurment_EME2012-Long.pdf

?

There is also a procedure for NF measurement using a network analyzer that does not require knowing the ENR, as the VNA determines the DUT gain, thus eliminating ?the need for the Y-factor. It can be a bit more tedious, and there is, as always, a devil in the details, but it is very accurate. Dr. Dunsmore covers it in his microwave measurements handbook.

?

?

Tom, N8ZM

?

From: [email protected] <[email protected]> On Behalf Of Tom Lee
Sent: Friday, August 19, 2022 7:17 AM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] Noise head ENR calibration - how do keysight do it? A question that was put to Keysight.

?

Hi Charles,

Can you point us to where you saw this claim? Like David Kirby, I'm skeptical, but I'd like to see the details of the argument. It is true that, since noise factor is dimensionless, a purely ratiometric measurement process is in principle possible. But details ?matter.

-- Cheers,
Tom

-- 

Prof. Thomas H. Lee

Allen Ctr., Rm. 205

350 Jane Stanford Way

Stanford University

Stanford, CA 94305-4070

On 8/19/2022 01:33, charles.edmonds@... wrote:

Hi, about 18 months ago I put the below on a Keysight forum expecting some helpful replies. Sadly I have not had a single reply as yet. (The concept of doing the measurement without the ENR ?being known is to compare derivatives of things not absolute values. This is the point where my mathematical cabilities implode).

Measuring the ENR of a Noise Source

Hi, I have read that it is possible to accurately measure the noise figure of a device without having a calibrated ?noise source. This is done by including an extra amplifier and an attenuator in the process. If the amplifier gain and the attenuator loss are very accurately known then knowing the exact ENR of the noise source is not necessary. The?device noise figure can?be?then ?determined as accurately as doing the normal Y-factor method with a calibrated noise source.

?

If this is correct then surely the next step would be to do the normal Y-factor process and change the ENR of the ?un-calibrated noise source in the calculation until the result given is the same as in the above procedure. So now the ENR of the un-calibrated noise source is known.

?

So how accurate could this result be? Could it be claimed that the un-calibrated noise source is now calibrated or ?only measured?

?

Would it be possible to create a spreadsheet to calculate all this using only the noise marker readings from something ?like an old 859xE or 856xE spectrum analyzer? (As an aside I don't think this would work using an E440xB spectrum analyzer would it?)?

?

My thought is that a hobbyist could buy 3 of the small amplifier modules seen on auction sites, the best being the ?ones that use the SBB5089 MMIC, as it have the right gain and a fairly flat frequency response. Also needed would be a termination and 2 attenuators. On one of the amplifiers the termination would be placed on the input and one of the attenuators placed on ?the output. This would be the un-calibrated noise source. The other preamplifiers would be the one normally used on the front end of the spectrum analyzer for a Y-factor method? measurement and the last is the DUT to be measured.

?

? ? ? ?