Re: Latest version NanoVNA SAA-2N by Zeenko
Hi Greg,
I also have an SAA-2N which I purchased from R&L about 3-years ago. I’ve been updating it pretty much every time a new firmware version comes out, and have flashed new firmware into it at least a dozen or so times. I currently have DiSlord’s firmware version "V2 480x320v1.3.31.bin” in the unit and it works fine. He made that version available back on 16-Jun-2024 in the nanovna-beta-test discussion group. If you aren’t already a member of that group, I’d recommend joining the group.
I’ve had the best luck using NanoVNA-app to flash the firmware.
Good luck and good DXing. 73
Ken -- WBØOCV
From: Greg
Sent: Monday, July 22, 2024 11:50 PM
To: nanovna-users@groups.io
Subject: Re: [nanovna-users] Latest version NanoVNA SAA-2N by Zeenko
I purchased a SAA2N from R & L in 2023. The actual unit was mfgd by Zeenko. I have FW Version 1.3.07. Can anyone confirm that I can upgrade the firmware, what the new version is, and where I can obtain said firmware?
73, Greg N9GB
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Re: Latest version NanoVNA SAA-2N by Zeenko
I apologise for breaking into this topic. I wish to start a new topic but cannot find a link to do this. Both the tinySA and marconi instruments groups.io have this facility. Thankyou Phil G3SES On Tue, 23 Jul 2024 at 04:50, Greg via groups.io <gbconsulting54= gmail.com@groups.io> wrote: I purchased a SAA2N from R & L in 2023. The actual unit was mfgd by
Zeenko. I have FW Version 1.3.07. Can anyone confirm that I can upgrade
the firmware, what the new version is, and where I can obtain said firmware?
73, Greg N9GB
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Re: Latest version NanoVNA SAA-2N by Zeenko
I purchased a SAA2N from R & L in 2023. The actual unit was mfgd by Zeenko. I have FW Version 1.3.07. Can anyone confirm that I can upgrade the firmware, what the new version is, and where I can obtain said firmware?
73, Greg N9GB
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Re: How to Measure return loss ?
A couple tricks here:
1) if you've got an antenna hooked up that's moderately narrow band (match wise), do your return loss measurement well away from the design frequency.
2) TDR (computed from frequency swept data) is your friend, because it lets you see the loss up to the antenna (which you will almost certainly see)
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-----Original Message-----
From: <nanovna-users@groups.io>
Sent: Jul 22, 2024 10:16 AM
To: <nanovna-users@groups.io>
Subject: Re: [nanovna-users] How to Measure return loss ?
Hi Terry,
I have measured the performance hundreds of older coaxial cables.
I have found that return loss with the end of the coax is mismatched
into an open or shorted load detects deterioration only when it
has already reached an advanced state of deterioration. Apparently
the onset of coaxial calbe deterioriation is masked by the much
greater coaxial cable loss when using an extremely mispatched termination.
in my experience return loss is much more able to detect the onset of
coaxial cable deterioriation when the end of the cable terminated in
its charactersitic impedance.
Like new hardlines such as LDF4-50A or AVA4-50 have greater than 24 dB
return loss at frequencies up to well above 1 GHz. As the cable
deteriorates its 24 dB return loss drops to lower and lower frequencies
and the return loss measurements begin to show ripple vs. frequency.
Deterioration of solid dielectric flexible coaxial cables such as RG-213
is almost always caused degradation of the cable shield. The onset of
deterioriation can be reliably detected by simple shield resistance
measurements. Like new RG-213 has shield resistance of about 0.1
ohms per 100 feet. In my experience, return loss measurements
don't reliably detect RG-213 shield deterioriation until shield
resistance is about 0.5 ohms per 100 feet or more.
73
Frank
W3LPL
----- Original Message -----
From: "Terry N8JX"
To: nanovna-users@groups.io
Sent: Monday, July 22, 2024 3:47:57 AM
Subject: Re: [nanovna-users] How to Measure return loss ?
Thanks for the reply Don,
I am trying to determine if the buried hard line is bad, and what the rtl is at 50 mhz which I believe should give me a good indication if the hard line is in spec. do I divide the rtl in 1/2 since I only need to measure in one direction. Or is there a better way to check if it is bad?
Thanks Terry
|
Re: How to Measure return loss ?
Hi Terry,
I have measured the performance hundreds of older coaxial cables.
I have found that return loss with the end of the coax is mismatched
into an open or shorted load detects deterioration only when it
has already reached an advanced state of deterioration. Apparently
the onset of coaxial calbe deterioriation is masked by the much
greater coaxial cable loss when using an extremely mispatched termination.
in my experience return loss is much more able to detect the onset of
coaxial cable deterioriation when the end of the cable terminated in
its charactersitic impedance.
Like new hardlines such as LDF4-50A or AVA4-50 have greater than 24 dB
return loss at frequencies up to well above 1 GHz. As the cable
deteriorates its 24 dB return loss drops to lower and lower frequencies
and the return loss measurements begin to show ripple vs. frequency.
Deterioration of solid dielectric flexible coaxial cables such as RG-213
is almost always caused degradation of the cable shield. The onset of
deterioriation can be reliably detected by simple shield resistance
measurements. Like new RG-213 has shield resistance of about 0.1
ohms per 100 feet. In my experience, return loss measurements
don't reliably detect RG-213 shield deterioriation until shield
resistance is about 0.5 ohms per 100 feet or more.
73
Frank
W3LPL
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----- Original Message -----
From: "Terry N8JX" <n8jx100@...>
To: nanovna-users@groups.io
Sent: Monday, July 22, 2024 3:47:57 AM
Subject: Re: [nanovna-users] How to Measure return loss ?
Thanks for the reply Don,
I am trying to determine if the buried hard line is bad, and what the rtl is at 50 mhz which I believe should give me a good indication if the hard line is in spec. do I divide the rtl in 1/2 since I only need to measure in one direction. Or is there a better way to check if it is bad?
Thanks Terry
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Re: How to Measure return loss ?
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Re: How to Measure return loss ?
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Re: How to Measure return loss ?
A return loss bridge. I built my own, decades ago. It was for 75 Ohms and fixed frequency. I used it to troubleshoot some horrendous MATV systems in local school systems. They had let their electricians install the cheapest crap and treat it as electrical work, rather than as RF. A lot of coax was damaged during installation, and some was run in rain gutters on the roof. The taps weren't sealed, and the ice that formed crushed them. All you need is a signal source, the bridge and an RF voltmeter for basic tests, Do a search for "return loss bridge schematic" and you'll find plenty of information. Mine was built from a '60s ARRL handbook design. On Sun, Jul 21, 2024 at 11:17 AM Terry N8JX via groups.io <n8jx100= gmail.com@groups.io> wrote: Hello anyone have any suggestions on how to measure retun loss on 1 5/8
fxl-1873 50 ohm hardline when only 1 end accessible, velocity factor is
around 88% using a nano vna
Thanks Terry N8JX
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Re: How to Measure return loss ?
Hi Terry,
Some of the responses you are getting folks don't understand what you are trying to do.
It is correct Return Loss for looking at SWR or Impedance is two way loss, but you are trying to measure the insertion loss of the coax using the return loss function. For this measurement you DO divide the return loss measurement in half.
This technique only works if you have an open or a short at the other end of the cable. The open or short gives you total reflection which is required to measure the cable loss. So you need to be able to disconnect the other end of the hardline and leave it open.
Then measure the return loss. divide by 2 and compare that loss with what the spec sheet says the loss should be.
Good Luck 73 Greg WA1JXR
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Re: How to Measure return loss ?
Return loss is loss going both ways. Don't divide by two.
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On 2024-07-22 05:47, Terry N8JX wrote: Thanks for the reply Don,
I am trying to determine if the buried hard line is bad, and what the rtl is at 50 mhz which I believe should give me a good indication if the hard line is in spec. do I divide the rtl in 1/2 since I only need to measure in one direction. Or is there a better way to check if it is bad?
Thanks Terry
|
Re: How to Measure return loss ?
Thanks for the reply Don,
I am trying to determine if the buried hard line is bad, and what the rtl is at 50 mhz which I believe should give me a good indication if the hard line is in spec. do I divide the rtl in 1/2 since I only need to measure in one direction. Or is there a better way to check if it is bad?
Thanks Terry
|
Punch out the plastic and the pins to reduce the wear of the standards. On Mon, 22 Jul 2024 at 02:28, AA7US via groups.io <landrjoh@...> wrote:
I got tired of trying to keep track of all those little SMA calibration standards and adapters that I keep with my NanoVNA, so I made a thing!
It's a small pcb that uses common 1/4" wide edge mount SMA connectors to keep the calibration standards and adapters neatly organized.
A couple of pics are attached.
A PCB can be ordered directly from OshPark if you're interested:
https://oshpark.com/shared_projects/CAtOPKYg
73,
AA7US
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Re: How to Measure return loss ?
Are you asking about adapting the nanoVNA to the hardline connector?
Otherwise, since return loss is a one-port measurement, and you have one port accessible, I do not understand your question.
Since you mention velocity factor, are you trying to locate a discontinuity?
I am puzzled.
73, Don N2VGU
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Re: 140 ft end fed looks decent on 3 lower hf bands for digi
On Sun, Jul 21, 2024 at 08:01 AM, Barry K3EUI wrote:
I have no explanation for why the 140 ft "end-fed" with MyAntenna 49:1 UNUN
has a dip on the 160m band.
I've never operated on 160m, but I won't complain if the antenna works there.
Consider checking for an unexpected resonance in your balun or choke, which might overheat if operated in a resonant condition. This has happened to folks who tried running old non-WARC tube amplifiers on WARC bands, unaware of plate choke resonances in those bands they burnt out the chokes. You might want to try running at moderate power and see if anything gets hot. I have an 80/40 trapped/loaded dipole which shows a resonance in the 60 meter band. Nothing gets hot at the power levels I use on that band so it is not an issue. 73, Don N2VGU
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I got tired of trying to keep track of all those little SMA calibration standards and adapters that I keep with my NanoVNA, so I made a thing! It's a small pcb that uses common 1/4" wide edge mount SMA connectors to keep the calibration standards and adapters neatly organized. A couple of pics are attached. A PCB can be ordered directly from OshPark if you're interested: https://oshpark.com/shared_projects/CAtOPKYg73, AA7US
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Re: 140 ft end fed looks decent on 3 lower hf bands for digi
Not necessarily 130 feet.
Could be as little as 70 feet (20 meters or so) and present itself as a 1/8 wavelength, low radiation resistance, low impedance, and with sufficient CMC radiate from the coax as a top-loaded vertical.
73,
Ed McCann
AG6CX
Sausalito CA
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On Jul 21, 2024, at 12:47 PM, W0LEV via groups.io <davearea51a@...> wrote:
That would have to be a coax cable run of some 130-feet in itself. No
doubt just an UNUN / autotransformer at the feed (the 50-ohm side of the
49:1 UNUN) will not isolate the outer surface of the coax in participating
in radiation.
So, how long is the coax run from the 50-ohm port of the 49:1 UNUN /
autotransformer to the ham shack?
Dave - WØLEV
On Sun, Jul 21, 2024 at 7:02 PM Siegfried Jackstien via groups.io
<siegfried.jackstien@...> wrote:
just a guess the antenna "thinks" it is a quarterwave (and maybe uses
your coax as other half??)
dg9bfc sigi
Am 21.07.2024 um 14:01 schrieb Barry K3EUI:
I have no explanation for why the 140 ft "end-fed" with MyAntenna 49:1 UNUN has a dip on the 160m band.
I've never operated on 160m, but I won't complain if the antenna works there.
But I know it is 140 ft and not 270 ft long.
There is no way I can (easily) measure currents anywhere along the radiating wire!!
But if it works (well enough for me) on 80m and 40m for NVIS NBEMS regional (east coast) nets, that is acceptable.
I did not plan on using it on 20m, 15m, or 10m, but I won't complain if it works well there too.
Dave - TU once again for all of your wisdom and suggestions.
I'm trying it out today on two NBEMS 80m nets (Pa and NJ) on 3583 kHz
de k3eui barry
near Philly PA --
*Dave - WØLEV*
--
Dave - WØLEV
|
Re: 140 ft end fed looks decent on 3 lower hf bands for digi
Not necessarily 130 feet.
Could be as little as 70 feet (20 meters or so) and present itself as a 1/8 wavelength, low radiation resistance, low impedance, and with sufficient CMC radiate from the coax as a top-loaded vertical.
73,
Ed McCann
AG6CX
Sausalito CA
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On Jul 21, 2024, at 12:47 PM, W0LEV via groups.io <davearea51a@...> wrote:
That would have to be a coax cable run of some 130-feet in itself. No
doubt just an UNUN / autotransformer at the feed (the 50-ohm side of the
49:1 UNUN) will not isolate the outer surface of the coax in participating
in radiation.
So, how long is the coax run from the 50-ohm port of the 49:1 UNUN /
autotransformer to the ham shack?
Dave - WØLEV
On Sun, Jul 21, 2024 at 7:02 PM Siegfried Jackstien via groups.io
<siegfried.jackstien@...> wrote:
just a guess the antenna "thinks" it is a quarterwave (and maybe uses
your coax as other half??)
dg9bfc sigi
Am 21.07.2024 um 14:01 schrieb Barry K3EUI:
I have no explanation for why the 140 ft "end-fed" with MyAntenna 49:1 UNUN has a dip on the 160m band.
I've never operated on 160m, but I won't complain if the antenna works there.
But I know it is 140 ft and not 270 ft long.
There is no way I can (easily) measure currents anywhere along the radiating wire!!
But if it works (well enough for me) on 80m and 40m for NVIS NBEMS
regional (east coast) nets, that is acceptable.
I did not plan on using it on 20m, 15m, or 10m, but I won't complain if it works well there too.
Dave - TU once again for all of your wisdom and suggestions.
I'm trying it out today on two NBEMS 80m nets (Pa and NJ) on 3583 kHz
de k3eui barry
near Philly PA
--
*Dave - WØLEV*
--
Dave - WØLEV
|
Re: 140 ft end fed looks decent on 3 lower hf bands for digi
That would have to be a coax cable run of some 130-feet in itself. No doubt just an UNUN / autotransformer at the feed (the 50-ohm side of the 49:1 UNUN) will not isolate the outer surface of the coax in participating in radiation. So, how long is the coax run from the 50-ohm port of the 49:1 UNUN / autotransformer to the ham shack? Dave - WØLEV On Sun, Jul 21, 2024 at 7:02 PM Siegfried Jackstien via groups.io <siegfried.jackstien@...> wrote: just a guess the antenna "thinks" it is a quarterwave (and maybe uses
your coax as other half??)
dg9bfc sigi
Am 21.07.2024 um 14:01 schrieb Barry K3EUI:
I have no explanation for why the 140 ft "end-fed" with MyAntenna 49:1 UNUN has a dip on the 160m band.
I've never operated on 160m, but I won't complain if the antenna works there.
But I know it is 140 ft and not 270 ft long.
There is no way I can (easily) measure currents anywhere along the radiating wire!!
But if it works (well enough for me) on 80m and 40m for NVIS NBEMS
regional (east coast) nets, that is acceptable.
I did not plan on using it on 20m, 15m, or 10m, but I won't complain if it works well there too.
Dave - TU once again for all of your wisdom and suggestions.
I'm trying it out today on two NBEMS 80m nets (Pa and NJ) on 3583 kHz
de k3eui barry
near Philly PA
-- *Dave - WØLEV* -- Dave - WØLEV
|
Re: 140 ft end fed looks decent on 3 lower hf bands for digi
just a guess the antenna "thinks" it is a quarterwave (and maybe uses your coax as other half??)
dg9bfc sigi
Am 21.07.2024 um 14:01 schrieb Barry K3EUI:
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I have no explanation for why the 140 ft "end-fed" with MyAntenna 49:1 UNUN has a dip on the 160m band.
I've never operated on 160m, but I won't complain if the antenna works there.
But I know it is 140 ft and not 270 ft long.
There is no way I can (easily) measure currents anywhere along the radiating wire!!
But if it works (well enough for me) on 80m and 40m for NVIS NBEMS regional (east coast) nets, that is acceptable.
I did not plan on using it on 20m, 15m, or 10m, but I won't complain if it works well there too.
Dave - TU once again for all of your wisdom and suggestions.
I'm trying it out today on two NBEMS 80m nets (Pa and NJ) on 3583 kHz
de k3eui barry
near Philly PA
|
Terry W7AMI
Michael A. Terrell
Donald S Brant Jr
AA7US
