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PROCEDURES for MEASURING DM LOSS and CM ATTENUATION of CMCs


Siegfried Jackstien 2021/02/06 22:23

to compare chokes (when you have made a few and want to see what is best
for what appication) ... maybe put both values in one table?!?

you made one file to measure cm loss (common mode attenuation) and one
file to measure trough loss (differential mode attenuation) ... to see
what choke is best it would be good to see both values in a single file
(table)

but all overall ... GOOD WORK...WELL DONE

(i do know how to measure these things but it is a perfect write up for
a newcomer!!)

dg9bfc sigi

Am 06.02.2021 um 22:00 schrieb David Eckhardt:

David Eckhardt 2021/02/06 22:31

Both were aimed at the newcomers as step-by-step procedures to help get
used to using the NANOs and not be afraid of making a mistake. It's such a
useful instrument, I'll do about anything to encourage its use!
Personally, it belongs in every ham shack and as valuable as a DMM. It
should also find its place in every EE lab in the universities - just my
opinion.

I also have the data from a number of chokes I wound on various materials.
I've sent that out previously, but I've added to it for my own reference.
Siegfried, do you think that would be of any value to the group as well.
It presently is not in PDF format, but I could convert it if you believe it
would be of any aid to this group.

Dave - WØLEV

On Sat, Feb 6, 2021 at 10:23 PM Siegfried Jackstien <
siegfried.jackstien@freenet.de> wrote:

> to compare chokes (when you have made a few and want to see what is best
> for what appication) ... maybe put both values in one table?!?
>
> you made one file to measure cm loss (common mode attenuation) and one
> file to measure trough loss (differential mode attenuation) ... to see what
> choke is best it would be good to see both values in a single file (table)
>
> but all overall ... GOOD WORK...WELL DONE
>
> (i do know how to measure these things but it is a perfect write up for a
> newcomer!!)
>
> dg9bfc sigi
> Am 06.02.2021 um 22:00 schrieb David Eckhardt:
>
> It was requested by a number of responders that I convert to PDF. The
> attachments are in .PDF format which should be able to be read by
> everyone.
>
> There was also a request to place them in the files section of these
> NANOVNA sites. I am a member and will attempt that. However, if the
> moderators don't see them there, please place them there.
>
> Dave - WØLEV
>
>
>
>

--
*Dave - WØLEV*
*Just Let Darwin Work*

Siegfried Jackstien 2021/02/07 00:22

and you did that well ... a perfect step by step procedure for a newbie :-)

having a bunch of measured data sure is good ... so if you can make ONE
table from your tests that would be superb (cm and dm together) ... as a
third row maybe measure inductance?!? cause the series inductance is
what dampens the common mode current (as we all know a coil is an rf
resistor)

then you can have a rough idea what chokes do what ... have an idea how
many turns to use (depending what donut you find in your junk box) ...

at best an excel table ... cause that can then also brought to a
diagramm (a picture tells more then thousand numbers in a table)

when you measure a choke (dm or cm value) ... you can then see the sweep
from 160m to 10m with saver (or other soft) ... but when you have the
table with a dozen chokes ... and convert that in excel ... you have a
"sweep" for all chokes in a single view

just an idea from a dumb nut :-)

...........................

https://gm3sek.com/

http://www.ifwtech.co.uk/g3sek/in-prac/index.htm

https://www.nonstopsystems.com/radio/pdf-ant/article-cost-effective-chokes.pdf

https://gm3sek.files.wordpress.com/2019/01/G3TXQ-RC.pdf

a nice picture of "a few dozen" chokes on this page (scroll a bit down)
.... and on the bottom end ... a similar test jig like you used :-)

http://www.karinya.net/g3txq/chokes/

some more info?

http://k9yc.com/2018Cookbook.pdf




dg9bfc sigi

Am 06.02.2021 um 22:31 schrieb David Eckhardt:

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