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Poor scan quality


Klaus Wörner 2021/01/26 11:37

I scanned an attenuator of 30dB with my V2. Normally I would like to say that I haven't a plus-version. But the scan quality of the newest V2_2 is very poor.
Then I changed to the V2plus and the quality is quiet better (both from https://github.com/nanovna/NanoVNA-V2-firmware).
If I use the nanovna-v2-20200926-v2_2 it's very good (see screenshots).
Why the quality is quiet better on the old version?

Klaus
DL5KV

Siegfried Jackstien 2021/01/26 22:55

hello klaus

your first scan does not look bad (with a bit of avg added it would look
perfect)

the second scan is WORTHLESS ...

you can NOT just change the fw to make a normal v2 to a v2plus

it needs THREE steps to convert a v2 to a plus

1.change BOOTLOADER (it does not work with the normal bootloader it MUST
be changed)

2. change 3 smd parts

3. upload the plus firmware

only if you have done all three steps it works correct ...

only change fw is NOT the right way to convert to a plus ... main thing
is to change also the bootloader!!!

greetz sigi dg9bfc

Am 26.01.2021 um 19:37 schrieb Klaus Wörner:

Klaus Wörner 2021/01/26 22:57

Hello Siegdried,

you missunderstood me. I NOT want to convert it to plus. I wondered that the wold firmware has a good curve and the new not. The second thing I wonder is, that the plus firmware shows a better curve than the normal firmware, but I'm not sure if I have a normal or plus version. But both firmwares shows worse curves as the sold one.


--
Klaus, DL5KV

Siegfried Jackstien 2021/01/27 15:36

You can not compare curves with just change fw!!!!!! Trying the plus fw in a nonplus hw is useless...
And... You should know what hw you have..looking in the version screen is of no help.. If you accidently uploaded a plus fw.. On a nonplus hw... It will show you a wrong hw revision in the versions screen...
So.. Find out what you bought... Then upload the correct fw...
Greetz sigi dg9bfc

Am 27.01.2021 07:57 schrieb Klaus Wörner <dl5kv@darc.de>:

Klaus Wörner 2021/01/30 08:49

You missunderstood me repeated.
In the past there was no plus-firmware, I had no chance to get a plus version, and the measurements were very good. With the firmware from september this is too. But the firmware from october has very swoosh. It's a problem of the changings in the firmware from september to october.
I attached two measurements with NO plus-firmware. You can see that the old firmware makes a smooth curve, the curve of the new firmware is swoosh.

--
Klaus, DL5KV

Siegfried Jackstien 2021/01/30 18:25

try novembre version (24.11. experimental) ... its the last "official"
from owo

greetz sigi dg9bfc

ps added both versions ... for small and big lcd

Am 30.01.2021 um 16:49 schrieb Klaus Wörner:

Ted Chesley 2021/01/30 10:54

Hi Sigi, A quick question: I have FW ver 1013 on my SAA-2N, Is the 11-24 ver 20201124-v2.74 compatible with these units? It tends to be confusing between SAA-2N , SAA-V2, V2+, V3 .

THX....Ted (KD7AQO)

Siegfried Jackstien 2021/01/30 19:07

yes ... you can use the 2.74 fw on the saa2n

there are in fact now

normal v2 (small lcd) genuine owo design ... that also is same as saa2
(huygen clone) ... normal v2 fw used

v2plus (small lcd but changed smd parts, new bootloader and the plus fw)
... better unit with increased speed but in fact same thingy

saa2n (huygen design) ... a v2 with 4 inch lcd and n connectors ...
normal fw but for bigger lcd ... the 2.74 fw is fine

v2plus4 ... different bridge and fw ... goes up to 4 gig and needs a
different fw (v2plus4 fw)

so we have

v2 with small and big lcd

v2plus with small and big lcd

v2plus4 (only with big lcd available)

yes 5 different versions are on the market .. and so also 5 different fw
to be used ... and for most of them there are official fw available PLUS
fw from users (dislord is good in writing new ones)

no wonder some users are a bit puzzelt about what to use :-)

greetz sigi dg9bfc

ps i converterd my saa2n to a "plus" ... and use the 511 points fw from
dislord

Am 30.01.2021 um 18:54 schrieb Ted Chesley:

Siegfried Jackstien 2021/01/30 19:13

ted you got mail :-)

dg9bfc

Am 30.01.2021 um 18:54 schrieb Ted Chesley:

Ted Chesley 2021/01/30 23:40

Hey Sigi, THX Much for the reply as to FW versions. Nice to have a
list in one place. I'll give the 1124.2.74 version a go.
Regards....Ted (KD7AQO)

Siegfried Jackstien 2021/01/31 00:10

if you want more scan points (finer resiólution) then use the 511 pt fw
from dislord

works fine here

dg9bfc sigi

Am 30.01.2021 um 23:40 schrieb Ted Chesley:

Ted Chesley 2021/01/31 02:36

Hi Sigi, THX for the further suggestion. I will try it after
1124.ver24. Would improve resolution for filters and TDR measuring
cable length. I use the PC programs (with higher scan numbers) for
that now, but it would be useful for the portable unit in the field.
By the way, if I had a suggestion as to a low cost dream instrument it
would be a combo of a NanoVNA and TinySA in an integrated instrument
with metal case, solid connections and 4" screen. Bet they'd sell a
bunch of those, if available.
THX Again.....Ted (KD7AQO)

Siegfried Jackstien 2021/01/31 07:15

do you sit well??

if you have a bit more money for the hobby look for the kc901 series ...
yes its much more expensive ... but depending on model goes up to 4,
6.8, 9.8 or the big model up to 20 gig!!!... and has a much higher
dynamic range (so testing duplex filters is easy)

KC901S+ 1300 dollar

KC901V 1800 dollar

KC901M 2300 dollar

KC901Q 3000 dollar

ok ok i see it is MUCH more expensive ... grin but the performance is
MUCH better also

they also sell a real time spectrum analyzer (kc908) with demodulation
(speaker inside!)

greetz sigi dg9bfc


Am 31.01.2021 um 02:36 schrieb Ted Chesley:

Ted Chesley 2021/02/01 17:16

Hi Sigi, THX again for the reply and suggestions. Being retired, I
still do a bit of consulting in terrestrial cable, Microwave, fiber
optics etc. Work mostly in transmission of 256QAM 6MHz BW video and
data. I have several portable pieces of test equipment up to 12GHz, as
well as bench units. Also I use a couple of the USB instruments,
capable to 6GH, i.e. RF Explorer, Telemakus, etc. In the distant past
I was trained as an USAF PMEL (Precision Measuring Equipmen Lab)
technician so I tend to be intrigued with these small portable useful
instruments, and CHEAP! I follow the conversations on this site, from
both hams and lab guys (and gals) and have picked up a lot.
Disciplines may be different but the fundamentals are always the same.
Regards......Ted (KD7AQO)

Siegfried Jackstien 2021/02/01 20:13

compared to real professional gear (r+s, hp, etc) the kc901 series is
still cheap ;-)

greetz sigi dg9bfc

Am 01.02.2021 um 17:16 schrieb Ted Chesley:

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