And we are talking about folding back a *very* short length of wire compared to the total wavelength, not an extreme example of half the wavelength, so, as you yourself admit, for the application I specified, it works just fine with insulated wire. Thanks. On Mon, 12 Jun 2023, 23:00 Kenneth Hendrickson via groups.io, <dsp_stap= [email protected]> wrote:
It works fine for insulated wire too, you don't need it to short out. No, it doesn't.
Take the extreme case of having it folded back about half its length. This
is a technique used on 40 yagis, because the element length is so long. By
folding it back, you roughly cancel out the radiation from the outside ends
of the folded-back wire, but not from the center. This is because the
current near the folded portion of the element is roughly equal and
opposite, but the current at the very end of the element is very small,
while the current at the beginning of the element is very large, so they
don't cancel.
For very short lengths of insulated wire, it doesn't matter much, because
of the cancellation effect.
But when the lengths of the folded back element become very large, it
matters a great deal.
Just go with what I originally said, and use bare wire. Then you can fold
it back and wrap it on itself with absolutely no problem. I'm right about
this.
There is a reason I say everything I say, even if you don't perceive it at
first.
On Monday, June 12, 2023 at 04:42:19 PM EDT, Clint Sharp <
cjaysharp@...> wrote:
It works fine for insulated wire too, you don't need it to short out.
On Mon, 12 Jun 2023, 21:41 Kenneth Hendrickson via groups.io, <dsp_stap=
[email protected]> wrote:
--- Clint Sharp <cjaysharp@...> wrote:
You don't need to cut any, fold it and cable tie it
then you get a second chance if you go too far. This works well for bare wire, but not for insulated wire.
And if you follow my recommendation of only 12" on each end for 80m, and
only 6" on each end for 40m, you won't be going too far.
On Monday, June 12, 2023 at 04:27:58 PM EDT, Clint Sharp <
cjaysharp@...> wrote:
You don't need to cut any, fold it and cable tie it then you get a second
chance if you go too far.
If you really want to then you can cut later but 4 years on and my wire
antenna is still folded.
On Mon, 12 Jun 2023, 21:06 Doug, <jdkearney@...> wrote:
I'm not sure how to start a new thread here, but since there are a good
number of followers here, I'll try this.
Starting with a new inverted V for 40 M, I cut each side to about a foot
and a half longer. So now that I can see where my SWR of 1.43:1 plots
out as peaking/bottoming out at 6.800 MHz, how do I determine how much
I
should cut away on each side? Should I just cut 6" on each side and
recalculate, judging how much farther I have to cut?
Thanks.
Doug.
On 12/06/2023 15:38, Mike Anderson/KF?AWL via groups.io wrote:
Of all the stupid things.
NONE of the videos showed calibration on the end of the feed. They
all
did it right at the side of the vna! I finally happened on a video that did
it at the end of the coax n NOW its acting like it should ? FINALLY
getting a swr i can figure out after chasing how many different ghosts
?
--
*/If you forward this email, please delete the forwarding history which
also includes my email address. When sending emails, please BCC so as
to
hide all addresses. Thanks for helping to prevent Scammers and Spammers
from mining addresses and spreading viruses./
73
Doug Kearney, VA3DKA
*
*Ottawa, ON *
--
This email has been checked for viruses by Avast antivirus software.
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It works fine for insulated wire too, you don't need it to short out. No, it doesn't. Take the extreme case of having it folded back about half its length. This is a technique used on 40 yagis, because the element length is so long. By folding it back, you roughly cancel out the radiation from the outside ends of the folded-back wire, but not from the center. This is because the current near the folded portion of the element is roughly equal and opposite, but the current at the very end of the element is very small, while the current at the beginning of the element is very large, so they don't cancel. For very short lengths of insulated wire, it doesn't matter much, because of the cancellation effect. But when the lengths of the folded back element become very large, it matters a great deal. Just go with what I originally said, and use bare wire. Then you can fold it back and wrap it on itself with absolutely no problem. I'm right about this. There is a reason I say everything I say, even if you don't perceive it at first. On Monday, June 12, 2023 at 04:42:19 PM EDT, Clint Sharp <cjaysharp@...> wrote: It works fine for insulated wire too, you don't need it to short out. On Mon, 12 Jun 2023, 21:41 Kenneth Hendrickson via groups.io, <dsp_stap= [email protected]> wrote: ? --- Clint Sharp <cjaysharp@...> wrote:
You don't need to cut any, fold it and cable tie it
then you get a second chance if you go too far. This works well for bare wire, but not for insulated wire.
And if you follow my recommendation of only 12" on each end for 80m, and
only 6" on each end for 40m, you won't be going too far.
? ? ? On Monday, June 12, 2023 at 04:27:58 PM EDT, Clint Sharp <
cjaysharp@...> wrote:
? You don't need to cut any, fold it and cable tie it then you get a second
chance if you go too far.
If you really want to then you can cut later but 4 years on and my wire
antenna is still folded.
On Mon, 12 Jun 2023, 21:06 Doug, <jdkearney@...> wrote:
I'm not sure how to start a new thread here, but since there are a good
number of followers here, I'll try this.
Starting with a new inverted V for 40 M, I cut each side to about a foot
and a half longer. So now that I can see where my SWR of 1.43:1 plots
out as peaking/bottoming out at 6.800 MHz, how do I determine how much I
should cut away on each side? Should I just cut 6" on each side and
recalculate, judging how much farther I have to cut?
Thanks.
Doug.
On 12/06/2023 15:38, Mike Anderson/KF?AWL via groups.io wrote:
Of all the stupid things.
NONE of the videos showed calibration on the end of the feed. They all did it right at the side of the vna! I finally happened on a video that did
it at the end of the coax n NOW its acting like it should ? FINALLY
getting a swr i can figure out after chasing how many different ghosts ?
--
*/If you forward this email, please delete the forwarding history which
also includes my email address. When sending emails, please BCC so as to
hide all addresses. Thanks for helping to prevent Scammers and Spammers
from mining addresses and spreading viruses./
73
Doug Kearney, VA3DKA
*
*Ottawa, ON *
--
This email has been checked for viruses by Avast antivirus software.
www.avast.com
|
What is the sequence of menu selections to get to the display that talks
about version levels, and all the specifics of the nano. I have the
Nanovna-H4.
Thanks
Fred - N4CLA
|
|
|
It works fine for insulated wire too, you don't need it to short out. On Mon, 12 Jun 2023, 21:41 Kenneth Hendrickson via groups.io, <dsp_stap= [email protected]> wrote: --- Clint Sharp <cjaysharp@...> wrote:
You don't need to cut any, fold it and cable tie it
then you get a second chance if you go too far. This works well for bare wire, but not for insulated wire.
And if you follow my recommendation of only 12" on each end for 80m, and
only 6" on each end for 40m, you won't be going too far.
On Monday, June 12, 2023 at 04:27:58 PM EDT, Clint Sharp <
cjaysharp@...> wrote:
You don't need to cut any, fold it and cable tie it then you get a second
chance if you go too far.
If you really want to then you can cut later but 4 years on and my wire
antenna is still folded.
On Mon, 12 Jun 2023, 21:06 Doug, <jdkearney@...> wrote:
I'm not sure how to start a new thread here, but since there are a good
number of followers here, I'll try this.
Starting with a new inverted V for 40 M, I cut each side to about a foot
and a half longer. So now that I can see where my SWR of 1.43:1 plots
out as peaking/bottoming out at 6.800 MHz, how do I determine how much I
should cut away on each side? Should I just cut 6" on each side and
recalculate, judging how much farther I have to cut?
Thanks.
Doug.
On 12/06/2023 15:38, Mike Anderson/KF?AWL via groups.io wrote:
Of all the stupid things.
NONE of the videos showed calibration on the end of the feed. They all did it right at the side of the vna! I finally happened on a video that did
it at the end of the coax n NOW its acting like it should ? FINALLY
getting a swr i can figure out after chasing how many different ghosts ?
--
*/If you forward this email, please delete the forwarding history which
also includes my email address. When sending emails, please BCC so as to
hide all addresses. Thanks for helping to prevent Scammers and Spammers
from mining addresses and spreading viruses./
73
Doug Kearney, VA3DKA
*
*Ottawa, ON *
--
This email has been checked for viruses by Avast antivirus software.
www.avast.com
|
--- Clint Sharp <cjaysharp@...> wrote: You don't need to cut any, fold it and cable tie it
then you get a second chance if you go too far. This works well for bare wire, but not for insulated wire. And if you follow my recommendation of only 12" on each end for 80m, and only 6" on each end for 40m, you won't be going too far. On Monday, June 12, 2023 at 04:27:58 PM EDT, Clint Sharp <cjaysharp@...> wrote: You don't need to cut any, fold it and cable tie it then you get a second chance if you go too far. If you really want to then you can cut later but 4 years on and my wire antenna is still folded. On Mon, 12 Jun 2023, 21:06 Doug, <jdkearney@...> wrote: I'm not sure how to start a new thread here, but since there are a good
number of followers here, I'll try this.
Starting with a new inverted V for 40 M, I cut each side to about a foot
and a half longer. So now that I can see where my SWR of 1.43:1 plots
out as peaking/bottoming out at 6.800 MHz, how do I determine how much I
should cut away on each side? Should I just cut 6" on each side and
recalculate, judging how much farther I have to cut?
Thanks.
Doug.
On 12/06/2023 15:38, Mike Anderson/KF?AWL via groups.io wrote:
Of all the stupid things.
NONE of the videos showed calibration on the end of the feed. They all did it right at the side of the vna! I finally happened on a video that did
it at the end of the coax n NOW its acting like it should ? FINALLY
getting a swr i can figure out after chasing how many different ghosts ?
--
*/If you forward this email, please delete the forwarding history which
also includes my email address. When sending emails, please BCC so as to
hide all addresses. Thanks for helping to prevent Scammers and Spammers
from mining addresses and spreading viruses./
73
Doug Kearney, VA3DKA
*
*Ottawa, ON *
--
This email has been checked for viruses by Avast antivirus software.
www.avast.com
|
You don't need to cut any, fold it and cable tie it then you get a second
chance if you go too far.
If you really want to then you can cut later but 4 years on and my wire
antenna is still folded.
toggle quoted message
Show quoted text
On Mon, 12 Jun 2023, 21:06 Doug, <jdkearney@...> wrote: I'm not sure how to start a new thread here, but since there are a good
number of followers here, I'll try this.
Starting with a new inverted V for 40 M, I cut each side to about a foot
and a half longer. So now that I can see where my SWR of 1.43:1 plots
out as peaking/bottoming out at 6.800 MHz, how do I determine how much I
should cut away on each side? Should I just cut 6" on each side and
recalculate, judging how much farther I have to cut?
Thanks.
Doug.
On 12/06/2023 15:38, Mike Anderson/KF?AWL via groups.io wrote:
Of all the stupid things.
NONE of the videos showed calibration on the end of the feed. They all did it right at the side of the vna! I finally happened on a video that did
it at the end of the coax n NOW its acting like it should ? FINALLY
getting a swr i can figure out after chasing how many different ghosts ?
--
*/If you forward this email, please delete the forwarding history which
also includes my email address. When sending emails, please BCC so as to
hide all addresses. Thanks for helping to prevent Scammers and Spammers
from mining addresses and spreading viruses./
73
Doug Kearney, VA3DKA
*
*Ottawa, ON *
--
This email has been checked for viruses by Avast antivirus software.
www.avast.com
|
For 80m antennas, a foot on each side is a good small pruning adjustment.
For 40m antennas, 6" on each side is a good small pruning adjustment.
I know this from experience.
toggle quoted message
Show quoted text
On Monday, June 12, 2023 at 04:06:41 PM EDT, Doug <jdkearney@...> wrote: I'm not sure how to start a new thread here, but since there are a good number of followers here, I'll try this. Starting with a new inverted V for 40 M, I cut each side to about a foot and a half longer. So now that I can see where my SWR of 1.43:1 plots out as peaking/bottoming out at 6.800 MHz, how do I determine how much I should cut away on each side? Should I just cut 6" on each side and recalculate, judging how much farther I have to cut? Thanks. Doug. On 12/06/2023 15:38, Mike Anderson/KF?AWL via groups.io wrote: Of all the stupid things.
NONE of the videos showed calibration on the end of the feed. They all did it right at the side of the vna! I finally happened on a video that did it at the end of the coax n NOW its acting like it should ? FINALLY getting a swr i can figure out after chasing how many different ghosts ?
-- */If you forward this email, please delete the forwarding history which also includes my email address. When sending emails, please BCC so as to hide all addresses. Thanks for helping to prevent Scammers and Spammers from mining addresses and spreading viruses./ 73 Doug Kearney, VA3DKA * *Ottawa, ON * -- This email has been checked for viruses by Avast antivirus software. www.avast.com
|
I'm not sure how to start a new thread here, but since there are a good number of followers here, I'll try this.
Starting with a new inverted V for 40 M, I cut each side to about a foot and a half longer. So now that I can see where my SWR of 1.43:1 plots out as peaking/bottoming out at 6.800 MHz, how do I determine how much I should cut away on each side? Should I just cut 6" on each side and recalculate, judging how much farther I have to cut?
Thanks.
Doug.
toggle quoted message
Show quoted text
On 12/06/2023 15:38, Mike Anderson/KF?AWL via groups.io wrote: Of all the stupid things.
NONE of the videos showed calibration on the end of the feed. They all did it right at the side of the vna! I finally happened on a video that did it at the end of the coax n NOW its acting like it should ? FINALLY getting a swr i can figure out after chasing how many different ghosts ?
-- */If you forward this email, please delete the forwarding history which also includes my email address. When sending emails, please BCC so as to hide all addresses. Thanks for helping to prevent Scammers and Spammers from mining addresses and spreading viruses./ 73 Doug Kearney, VA3DKA * *Ottawa, ON *
--
This email has been checked for viruses by Avast antivirus software.
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Great Mike. Can you share that video source?
Doug, VA3DKA
toggle quoted message
Show quoted text
On 12/06/2023 15:38, Mike Anderson/KF?AWL via groups.io wrote: Of all the stupid things.
NONE of the videos showed calibration on the end of the feed. They all did it right at the side of the vna! I finally happened on a video that did it at the end of the coax n NOW its acting like it should ? FINALLY getting a swr i can figure out after chasing how many different ghosts ?
-- */If you forward this email, please delete the forwarding history which also includes my email address. When sending emails, please BCC so as to hide all addresses. Thanks for helping to prevent Scammers and Spammers from mining addresses and spreading viruses./ 73 Doug Kearney, VA3DKA * *Ottawa, ON *
--
This email has been checked for viruses by Avast antivirus software.
www.avast.com
|
Of all the stupid things.
NONE of the videos showed calibration on the end of the feed. They all did it right at the side of the vna! I finally happened on a video that did it at the end of the coax n NOW its acting like it should ? FINALLY getting a swr i can figure out after chasing how many different ghosts ?
|
I thought that when you do cal, you disconnect the antenna and do cal at the end of the feed line. Which way is correct? Chris Sent from Mail for Windows From: Doug Sent: Monday, June 12, 2023 2:14 PM To: [email protected]Subject: Re: [nanovna-users] I'm new to this and need some extra info #beginners1 #applications Hi Mike. I have been following your questions and can sympathize with your dilemma re calibrating and configuring your NanoVNA. I struggled with this aspect too, until I found this YouTube video, which explains it so clearly. The video is not perfect, but it got me to the right place in optimizing my 40 M Inverted V antenna. 73, Doug. On 12/06/2023 13:33, Mike Anderson/KF?AWL via groups.io wrote: Well I figured out part of my issue I think?
One of the videos I watched the guy was talking about meg. and it must have got stuck in my head and I kept setting meg instead of kHz on my freq ??¡á?
-- */If you forward this email, please delete the forwarding history which also includes my email address. When sending emails, please BCC so as to hide all addresses. Thanks for helping to prevent Scammers and Spammers from mining addresses and spreading viruses./ 73 Doug Kearney, VA3DKA * *Ottawa, ON * -- This email has been checked for viruses by Avast antivirus software. www.avast.com
|
Hi Mike. I have been following your questions and can sympathize with your dilemma re calibrating and configuring your NanoVNA.
I struggled with this aspect too, until I found this YouTube video, which explains it so clearly. The video is not perfect, but it got me to the right place in optimizing my 40 M Inverted V antenna.
73, Doug.
toggle quoted message
Show quoted text
On 12/06/2023 13:33, Mike Anderson/KF?AWL via groups.io wrote: Well I figured out part of my issue I think?
One of the videos I watched the guy was talking about meg. and it must have got stuck in my head and I kept setting meg instead of kHz on my freq ??¡á?
-- */If you forward this email, please delete the forwarding history which also includes my email address. When sending emails, please BCC so as to hide all addresses. Thanks for helping to prevent Scammers and Spammers from mining addresses and spreading viruses./ 73 Doug Kearney, VA3DKA * *Ottawa, ON *
--
This email has been checked for viruses by Avast antivirus software.
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Ok sorry to be such a pain.
I really want to get this up and rolling for field day and some demonstrations coming up and I feel like a idiot for not catching on.
Thanks for being so patient with me.
|
Mike,
Just set the start and stop frequencies to the widest approximate frequency range where you expect the antenna will be tuned to. For 10M try 25 to 32 MHz. The calibrate for this range. Set the yellow trace to read SWR and you should see a frequency where the SWR is at a minimum. Then use the rocker switch to move the marker to this point and you can read the frequency and SWR. Then slowly adjust your coil and you should see the SWR minimum move. You can "zoom in" by setting the start a bit higher and the stop a bit lower and the NanoVNA will interpolate the calibration.
Roger
|
Ok Roger, ? I watched the video but didn't glean a lot of learning from it. I'm not understanding were he is reading his freq from ? ?
At the moment I'm trying to set the coil in the center of the 10m band so I have a reference point of were I need to start for the rest of the bands but I'm not understanding something ?
In very simple terms, is there a way to set the vna look at what freq the antenna is matched at (ok its off so I need to make the coil shorter or longer to get to my freq) move the coil check the reading (ok that was the wrong direction, move THE PICKUP a few clicks the other way on the coil)
This is frustrating me because I'm sure its a simple process but I'm totally flubbing it up ?
|
Re: Firmware upgrade for original nanovna
|
Re: NanoVNA-H not seen by windows11 (no com port)
#nanovna-h
Dear Roger,
thank you very much for reply. In the meanwhile problem solved, it was the usb cable which was interrupted inspite of looking like brand new.
That is why I thought that might be a W11 driver problem. Thank you again, wish you all the best.
|
Firmware upgrade for original nanovna
Hi
I have a NanoVNA with version 0.8.0 firmware Dated June 2020. Is there a later version for this early NanoVna?
If so are ther some instructions somewhere. I did this in 2020 and it seemed straightforward but I seem to be struggling to find the right info at the moment.
regards
Don
|
Mike G8GYW. This VA5 sounds pretty good from the write up in their web page. Is it good enough to be the only 1 in your kit for a while?
Ed
|
Mike Anderson/KF?AWL
Roger Need