开云体育

Yes. My last visit to JB was just after they closed. Sitting on the
concrete table outside the store was a Tektronix 7623A, with a sign on it
that read "FREE". You can guess what happened next. JB was the local parts
source for common parts for us at Benchmark. As far as I know JB was the
last surplus store (of the four that existed back in the 90s) to close and
I'm guessing that no new ones have opened since.

My sister worked at Sandia and told me about the surplus store there.

And don't forget the StorageTek surplus store. My Simpson 260xi came from
there. It was basically free (maybe $5 or something like that).

DaveD
KC0WJN


On Mon, May 19, 2025 at 11:42 W0LEV via groups.io <davearea51a=
[email protected]> wrote:

Dave, we all miss J. B. !! I can't count the number of times we,
collectively, solved (unpaid consulting) design problem with unknown
designers in the isles of J. B. Saunders. And......, then found the parts
to buy. They are sorely missed ! ! !

And in New Mexico: The surplus sales at both Los Alamos and Sandia.

Dave - W?LEV

On Mon, May 19, 2025 at 3:33?PM Dave Daniel via groups.io <kc0wjn=
[email protected]> wrote:

And J. B. Saunders ....

DaveD
KC0WJN


On Mon, May 19, 2025 at 11:24 AG6CX via groups.io <edwmccann=
[email protected]> wrote:

And Yardley Beers, W0JF, a Boulder legend along with McGukins.

Ed McCann
AG6CX

On May 19, 2025, at 8:21?AM, Dave Daniel via groups.io <kc0wjn=

[email protected]> wrote:

?I severely miss McGuckins.

DaveD

On 5/19/2025 11:03 AM, W0LEV via groups.io wrote:
Any good hardware store may have them. Also a good electrical

supply

house. Likely, the chains will not have such items.

We have an excellent "have everything" and then some hardware store

in

Boulder. They are an independent.

Dave - W?LEV

On Mon, May 19, 2025 at 1:51?AM WB9YXA via groups.io <ahoffman1=
[email protected]> wrote:

Dave,

Where did you find the very large alligator clip shown in the

photos

in

the document? My usual sources aren't turning up anything big

enough

to

bite a bnc connector.

Just curious.

Andy

--
This email has been checked for viruses by Avast antivirus software.
www.avast.com

--

*Dave - W?LEV*


--
Dave - W?LEV

Dave, we all miss J. B. !! I can't count the number of times we,
collectively, solved (unpaid consulting) design problem with unknown
designers in the isles of J. B. Saunders. And......, then found the parts
to buy. They are sorely missed ! ! !

And in New Mexico: The surplus sales at both Los Alamos and Sandia.

Dave - W?LEV

On Mon, May 19, 2025 at 3:33?PM Dave Daniel via groups.io <kc0wjn=
[email protected]> wrote:

And J. B. Saunders ....

DaveD
KC0WJN


On Mon, May 19, 2025 at 11:24 AG6CX via groups.io <edwmccann=
[email protected]> wrote:

And Yardley Beers, W0JF, a Boulder legend along with McGukins.

Ed McCann
AG6CX

On May 19, 2025, at 8:21?AM, Dave Daniel via groups.io <kc0wjn=

[email protected]> wrote:

?I severely miss McGuckins.

DaveD

On 5/19/2025 11:03 AM, W0LEV via groups.io wrote:
Any good hardware store may have them. Also a good electrical supply
house. Likely, the chains will not have such items.

We have an excellent "have everything" and then some hardware store in
Boulder. They are an independent.

Dave - W?LEV

On Mon, May 19, 2025 at 1:51?AM WB9YXA via groups.io <ahoffman1=
[email protected]> wrote:

Dave,

Where did you find the very large alligator clip shown in the photos

in

the document? My usual sources aren't turning up anything big enough

to

bite a bnc connector.

Just curious.

Andy

--
This email has been checked for viruses by Avast antivirus software.
www.avast.com

--

*Dave - W?LEV*


--
Dave - W?LEV

And J. B. Saunders ....

DaveD
KC0WJN


On Mon, May 19, 2025 at 11:24 AG6CX via groups.io <edwmccann=
[email protected]> wrote:

And Yardley Beers, W0JF, a Boulder legend along with McGukins.

Ed McCann
AG6CX

On May 19, 2025, at 8:21?AM, Dave Daniel via groups.io <kc0wjn=

[email protected]> wrote:

?I severely miss McGuckins.

DaveD

On 5/19/2025 11:03 AM, W0LEV via groups.io wrote:
Any good hardware store may have them. Also a good electrical supply
house. Likely, the chains will not have such items.

We have an excellent "have everything" and then some hardware store in
Boulder. They are an independent.

Dave - W?LEV

On Mon, May 19, 2025 at 1:51?AM WB9YXA via groups.io <ahoffman1=
[email protected]> wrote:

Dave,

Where did you find the very large alligator clip shown in the photos in
the document? My usual sources aren't turning up anything big enough

to

bite a bnc connector.

Just curious.

Andy

--
This email has been checked for viruses by Avast antivirus software.
www.avast.com

Yes, when we can't find something at Ace, we head to Boulder. White Rock,
New Mexico also had something similar that "served" the lab at Los Alamos.

Good hardware stores are rare these days with all the chains.

Dave - W?LEV

On Mon, May 19, 2025 at 3:21?PM Dave Daniel via groups.io <kc0wjn=
[email protected]> wrote:

I severely miss McGuckins.

DaveD

On 5/19/2025 11:03 AM, W0LEV via groups.io wrote:

Any good hardware store may have them. Also a good electrical supply
house. Likely, the chains will not have such items.

We have an excellent "have everything" and then some hardware store in
Boulder. They are an independent.

Dave - W?LEV

On Mon, May 19, 2025 at 1:51?AM WB9YXA via groups.io <ahoffman1=
[email protected]> wrote:

Dave,

Where did you find the very large alligator clip shown in the photos in
the document? My usual sources aren't turning up anything big enough to
bite a bnc connector.

Just curious.

Andy

--
This email has been checked for viruses by Avast antivirus software.
www.avast.com

--

*Dave - W?LEV*


--
Dave - W?LEV

And Yardley Beers, W0JF, a Boulder legend along with McGukins.

Ed McCann
AG6CX

I severely miss McGuckins.

DaveD

--
This email has been checked for viruses by Avast antivirus software.
www.avast.com

Deepelec has not updated their firmware in several years and their architecture is not the same as your V3.

Why not open the case and disable the beeper? Put some tape across the output port or cut the PCB track.

Any good hardware store may have them. Also a good electrical supply
house. Likely, the chains will not have such items.

We have an excellent "have everything" and then some hardware store in
Boulder. They are an independent.

Dave - W?LEV

On Mon, May 19, 2025 at 1:51?AM WB9YXA via groups.io <ahoffman1=
[email protected]> wrote:

Dave,

Where did you find the very large alligator clip shown in the photos in
the document? My usual sources aren't turning up anything big enough to
bite a bnc connector.

Just curious.

Andy

--

*Dave - W?LEV*


--
Dave - W?LEV

Nizar,

Yes you need to use Enhanced response option for S21. It was created by DiSlord for these types of measurements.

On Sun, May 18, 2025 at 11:17 PM, Charles VK1CM wrote:

There is a lot of other goodies on his website, and I have found him very
easy to deal with.

Makis is a great guy, I have designed one of his products, a dual log detector board, , into a VSWR protection circuit, for my client, after he assured me of its continued availability. Tons of other great, useful products on his site, highly recommended.
73, Don N2VGU

This might help:

Hi Roger
I do not use enhanced response, indeed i dont use an unknownen function for me, i use SeeSi H4 SM NanoVNA + DiSlord 1.2.40 Firmware , Serial resistor with reasonnable 2cm legs only for 30Mhz maximum frequency use. Should i activate enhanced redponse??
73s Nizar

Hi folks,

I'm brand new here. I just got the NanoVNA-F V3 which is made by SysJoint.
Like with my other VNAs (a cheap small NanoVNA-H & a LiteVNA 64) the first thing I looked for was the (custom) firmware situation because the SysJoint NanoVNA-F V3 beeps every now and then and it's no possible to switch this off (I asked the SysJoint support).
So I was wondering ... I learned that there's another official manufacturer of the NanoVNA-F, Deepelec, and read that its firmware can be flashed onto a SysJoint NanoVNA-F, too?
But has the Deepelec firmware an option to switch any beeping off?
Are there other firmwares that can be flashed onto my SysJoint NanoVNA-F V3?

Thanks a lot & all the best,
Stefan.

I nearly fell out of my chair when I saw the HP fixture prices. May I
suggest using these:



There is a lot of other goodies on his website, and I have found him very
easy to deal with.

Regards,


Charles.
VK1CM

Dave,

Where did you find the very large alligator clip shown in the photos in the document? My usual sources aren't turning up anything big enough to bite a bnc connector.

Just curious.

Andy

On Sun, May 18, 2025 at 11:39 AM, Dan Pate - AI5OL wrote:

I fabricated a test lead that is a coax that terminates in a pair of alligator
clips. I clip the leads onto a panel mount SMA connector to attach the
Open/Short/Load calibration standards to calibrate to the reference plane at
the alligator clips. I can then clip the leads to the connections of the coil
to test.

Alligator clips are OK if you just want to get a rough idea of the impedance of the device you are measuring. The problem with them is you have an impedance discontinuity from the coax to the clips which can only be partially "calibrated out". Also when you calibrate the clip separation and lead spacing is different that when you are measuring the DUT. This all results in a poor reference plane.

Below is a measurement I did of a small inductor. It was tested at 100 kHz. on a DE-5000 LCR meter and then measured using alligator clips and a proper test jig. The results and comments are in the graphs.

Roger

On Sun, May 18, 2025 at 02:29 PM, Team-SIM SIM-Mode wrote:

Here my plots of S11 and S21 measurement of the 4.63Kohm leaded resistor at
same time , same graphe , same scale
they are dramatically differents , and I prefer the S21 obviosly . May be i am
missing some thing.

Something wrong with your S11 plot. It should be much better than that. Here is a re-post of my previous plot. S11 is flat but is off by 3 to 4%. Note that S21 is much better estimate at low frequencies but rolls off.

Questions
-----------

1. Do you have a photo you can post of your test jig(s) for S11 and S21 measurements?
2. Are you using the enhanced response option in the menu?
3. What version of firmware are you using?
4. Try a 10K and see what you get.

Hi Roger

Here my plots of S11 and S21 measurement of the 4.63Kohm leaded resistor at same time , same graphe , same scale
they are dramatically differents , and I prefer the S21 obviosly . May be i am missing some thing.

73's Nizar

On Sun, May 18, 2025 at 04:13 PM, Roger Need wrote:

You also need a good test jig because stray capacitance and inductance can
affect the results.

An ideal test fixture would maintain a 50Ω impedance right to the device body. The Keysight high-frequency SMD fixtures come close to this ideal, the device interface center conductor is a disk, coaxial to and coplanar with a grounded ring which is the outer conductor, with an insulated gap between.
The calibration standards and device under test are placed across this gap to make measurements; there is also a shielding cap which bayonets on during calibration and measurements, to stabilize the stray capacitance and add shielding from interference.
In the photo the brass thing is the outer ring and the inner electrode is indistinguishable as it is 1 or 2mm across.
It would not be to difficult with someone with a lathe, etc. to fabricate a pretty good one. Even a piece of .250" semirigid cable sanded flush would be pretty darned good for small SMD devices or it could be soldered into a ground plane plate flush with the shield for larger components.
Other Keysight accessory links, for inspiration:
Lower frequency:
I used this one a lot for UHF and below:

73, Don N2VGU

Those leads account for about +j5 at 28 MHz. I'm giving the leads about 28
nH of inductance. The +j5 ohms is about 10 % of your measurement system
impedance of 50 ± j 0 ohms.

Dave - W?LEV

On Sun, May 18, 2025 at 6:21?PM Team-SIM SIM-Mode via groups.io <sim31_team=
[email protected]> wrote:

Hi Dave

It's a leaded resistor with 2cm legs

73's Nizar

--

*Dave - W?LEV*


--
Dave - W?LEV