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No, I am not member of the NanoVNA-F group

73, Gyula

I've found for higher load resistance greater than 1000 ohms
the bridge with a reference leg closer to the target made for far
better accuracy.

These US$10 bridges can be fairly easily hacked to increase R of all 3 fixed legs.

good 'ol days

For retired boomer geeks, these ARE the good days,
given what would then have been literally incredible capabilities
now available for the cost of a dinner and drinks.

How long before Arduino supports FPGAs?

How about those old IBM Selectric terminals for APL?
There is a push on right now to bring back APL due to it's algorithmic nature and you can write an entire program in maybe 4 symbols.??

The only issue today is how to overtype chars - but those Selectrics - what an invention.

On Monday, December 2, 2019, 3:50:52 p.m. GMT-5, Oristo <ormpoa@...> wrote:

> ever make a punch card doily

I accidentally overpunched a job card, crashing the 1620
and was invited to use only the HP thereafter.

I've found for higher load resistance greater than 1000 ohms
the bridge with a reference leg closer to the target made for far
better accuracy. Ran into that measuring loops at 10mhz
and up.

50 ohms is standard as most of the world is 50 ohms, or maybe 75.

However I have a set of references built up over the years of suitable
high stability resistors and capacitors for years back when a VNA
was a nice idea, for the rich.

I'd have to dig but HP/Agilent had a seris of notes for making
measurements that would be at the limits for the big box VNA/PNAs.

Allison
-----------------
I do not accept private email due to forum scraping groups.io

ever make a punch card doily

I accidentally overpunched a job card, crashing the 1620
and was invited to use only the HP thereafter.

the feeling of a dropped card deck

The first time I saw a magic marker line diagonally down the long side of a stack,
I wondered, but then it soon became clear...

Very good Oristo. Makes sense. I built a tandem coupler prior to getting the vna. Same idea as you outlined. This coupler is very interesting unit as it shows a directivity at HF of nearly 60 dB. Using a signal generator and a portable Oscope it was quite good at capturing mag and phase of the reflection coefficient. Its design is flexible and hence may be a good candidate for a Zo other than 50 ohm.

Alan

I know the feeling of a dropped card deck well spent 2 days putting a 6000
line is IBM system 360 assembly code deck back in order from an earlier
list file.

Yeah we've all been there, but did you ever make a punch card doily and hide it in someone's deck??

I started on an IBM 1101 in high school.??

It put out so much RFI that one student coded loops (in Fortran 66) and it played the morning anthem one day.??

The good 'ol days, eh?

Spoken like someone who has dropped a card deck. :-)

(I actually owned a tool with the correct size hole (and reach) that enabled you to "repair" mis-punched tapes.)

--
Cheers, Ed Humphries, KT4ED

Hi Herb -

how both of you manage

Thanks, I do not speak for Larry, but my father used to say
"I've been lost here before!"
Wiki whacking is similar to code refactoring
and some user feedback reminds me of code reviews.

still have a livelihood

Here are hints:
some of my first programming was Fortran on this

.. and assembler on HP’s 2116A..
punch tape and teletype was much nicer
than punch cards and JCL.

On Mon, Dec 2, 2019 at 09:56 AM, <erik@...> wrote:

"How accurate did you find this test method using references other than 50 ohms (75, 1000, etc) ?

Did not test other references"

===============================================================================

Got that Erik. For 50 ohms did you get more accurate measurement results with the external bridge, or just a more accurate results over a wider range?

- Herb

On Mon, Dec 2, 2019 at 10:29 AM, Gyula Molnar wrote:

It's nice content but need pdf optimize so reduce 86%
now 13.834KB and reduced is 1.936KB
It is worth optimizing, I have not experienced any loss of content or color
and it has become much smaller.

============================================================
Gyula

Great size for reducing bandwidth and sharing on the web. Are you a member of the NanoVNA-F group? I'm sure the members there would appreciate the pdf optimized document.

- Herb

Oh, I love your program Rune!

It is terrific!

Mike WY6K

Hi Herb,

It's nice content but need pdf optimize so reduce 86%
now 13.834KB and reduced is 1.936KB
It is worth optimizing, I have not experienced any loss of content or color and it has become much smaller.

73, Gyula HA3HZ

It's nice content but need pdf optimize so reduce 86%
now 13.834KB and reduced is 1.936KB

73, Gyula

If the owner/admin goes to SETTINGS and scrolls down to the WIKI section there is something called a STICKY WIKI PAGE.

This can be whatever WIKIPage you want a (previously created WIKI pages is selected in a pulldown) and it shows up in the space above the Messages when you click on the MESSAGES
link on the sidebar. It is always shown above the Messages. This could be used to display a short page that says "Newbies should click on the WIKI link in the sidebar to get started".
or something like that.

Michael VE3WMB

On Mon, Dec 2, 2019 at 09:50 AM, Larry Rothman wrote:

Something like the attached image?

=============================================================
Believe me Larry,
Even with a sign post like that you will get the occasional message asking how to locate the Wiki and File pages : )

Pretty much for the same reason so many bikes get assembled incorrectly on Xmas eve.

- Herb

On Mon, Dec 2, 2019 at 09:47 AM, hwalker wrote:

but it would be an interesting project to translate your Octave code to Python

The octave code is a direct translation of the python code in nanoVNA-saver.
If you need python than go look at nanoVNA-saver or ask Rune to enable the measurement of calibration input from CH1 instead of CH0, should be rather simple to implement.

--
NanoVNA Wiki: /g/nanovna-users/wiki/home
NanoVNA Files: /g/nanovna-users/files
Erik, PD0EK