Re: If only Duct Tape were conductive.........?
Yes, indeed. Setting the stained glass in Pb ribbon. Not the best
conductor, but we still use it in solder (oooops, not since the RoHS
initiative ).
So, should all those beautiful stained glass windows be responsible for
proclaiming all the cathedrals and churches dangerous? That was an issue
when NotreDame burned.
OK, so much for relating to complex impedances and the NANOs.......
Dave - W?LEV
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On Tue, Dec 21, 2021 at 11:07 PM G8DQX list <list@...> wrote: So, all those lovely East Anglian country churches with their stained
glass windows were so glazed not so much to the Greater Glory of God,
but rather to deliver wideband stealth aerial (antenna) structures to
assure reception of the latest farming prices (and weather) on the radio!
Interesting! (And very daft)
73, Stay Safe,
Robin, G8DQX
On 21/12/2021 15:07, KENT BRITAIN wrote:
You can also get Aluminium Tape at Home Depot and Lowe's.Back with the Air conditioning duct work.
At Hobby Lobby you can get Copper tape. Back in the Stain Glass section.They wrap the edges of the glass with Copper tape then solder the
pieces
--
*Dave - W?LEV*
*Just Let Darwin Work*
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Re: If only Duct Tape were conductive.........?
So, all those lovely East Anglian country churches with their stained glass windows were so glazed not so much to the Greater Glory of God, but rather to deliver wideband stealth aerial (antenna) structures to assure reception of the latest farming prices (and weather) on the radio!
Interesting! (And very daft)
73, Stay Safe,
Robin, G8DQX
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On 21/12/2021 15:07, KENT BRITAIN wrote: You can also get Aluminium Tape at Home Depot and Lowe's.Back with the Air conditioning duct work.
At Hobby Lobby you can get Copper tape.? Back in the Stain Glass section.They wrap the edges of the glass with Copper tape then solder the pieces
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THANKS BUT MY VERSION IS H WHICH I HAVE TO REVISE IS NOT H4, DO YOU KNOW
HOW TO DO IT?
73 IZ0UIN FABRIZIO
Il giorno mar 21 dic 2021 alle ore 22:22 Larry Rothman <nlroth@...>
ha scritto:
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Place the nano H4 into dfu mode manually by holding in the jog sw and
turning on - there will be no display.
Attach to PC and flash H4 firmware.
Done.
On Tuesday, December 21, 2021, 03:25:20 p.m. EST, fabrizio licchelli <
fabriziolicchelli1@...> wrote:
hello everyone, because of my mistake I loaded the wrong firmware of
nanavna h4, do you know how to restore to h version?
73 iz0uin fabrizio
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Yes.....I shall cease ??
Dave - W?LEV
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On Tue, Dec 21, 2021 at 9:00 PM joe bell <joe.g4pmy@...> wrote: Hi Dave
I will correct my statement. Optimising the wire length such that the
maximum wire length for the frequency in operation, rather than have
greater loss in the matching unit.
A whole new topic could arise !
Joe
--
*Dave - W?LEV*
*Just Let Darwin Work*
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Place the nano H4 into dfu mode manually by holding in the jog sw and turning on - there will be no display.
Attach to PC and flash H4 firmware.
Done.
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Show quoted text
On Tuesday, December 21, 2021, 03:25:20 p.m. EST, fabrizio licchelli <fabriziolicchelli1@...> wrote:
hello everyone, because of my mistake I loaded the wrong firmware of
nanavna h4, do you know how to restore to h version?
73 iz0uin fabrizio
|
Hi Dave
I will correct my statement. Optimising the wire length such that the maximum wire length for the frequency in operation, rather than have greater loss in the matching unit.
A whole new topic could arise !
Joe
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The more wire, the more times around the Smith Chart. Open to short to
open to short to............
Dave - W?LEV
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On Tue, Dec 21, 2021 at 8:10 PM joe bell <joe.g4pmy@...> wrote: Way back in the thread it was mentioned that low SWR did not necessarily
mean a great aerial had been made, and gave a dummy load of 50 ohms as
an example. Quite true, but another rule of thumb would be that in
principle the more wire you get in the sky, the better the signal RX and
TX providing it is matched to the equipment impedance. The more wire the
greater the impedance which is why you will see figures quoted between
2K ohms and 4Kohms for end fed long wires.
It is also handy to make termination resistances of 25ohm (non
inductive) which should show up on the vna as 2:1 ratio, and provide
that extra confidence that the measurement system is working.
When you wind your unun, you can terminate the wire output with a
variable resistance non inductive, back to the input common. When
adjusting the pot, you will see at some point you will hit the magic low
swr at the frequency of interest, then remove the pot from circuit and
measure its resistance, which will allow you to confirm the Z transform
ratio of your unun at that frequency.
I attach a photo of a test unun I made which is a 64:1 TAPPED AT 49:1
with a primary is 2 turns, and 120pf input to ground. I once wound an
unun from flat tape copper and that allowed easy tapping to provide an
input from the cold end, and also output taps, but sadly not seen the
right tape for a while.
The VNA is a great tool and at a cost of <$100 as well and much thanks
to the people who develop both hardware and software easing its use in
the ham shack.
joe
--
*Dave - W?LEV*
*Just Let Darwin Work*
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hello everyone, because of my mistake I loaded the wrong firmware of
nanavna h4, do you know how to restore to h version?
73 iz0uin fabrizio
|
hello everyone, because of my mistake I loaded the wrong firmware of nanavna h4, do you know how to restore to h version?
73 iz0uin fabrizio
|
Way back in the thread it was mentioned that low SWR did not necessarily mean a great aerial had been made, and gave a dummy load of 50 ohms as an example. Quite true, but another rule of thumb would be that in principle the more wire you get in the sky, the better the signal RX and TX providing it is matched to the equipment impedance. The more wire the greater the impedance which is why you will see figures quoted between 2K ohms and 4Kohms for end fed long wires.
It is also handy to make termination resistances of 25ohm (non inductive) which should show up on the vna as 2:1 ratio, and provide that extra confidence that the measurement system is working.
When you wind your unun, you can terminate the wire output with a variable resistance? non inductive, back to the input common. When adjusting the pot, you will see at some point you will hit the magic low swr at the frequency of interest, then remove the pot from circuit and measure its resistance, which will allow you to confirm the Z transform ratio of your unun at that frequency.
I attach a photo of a test unun I made which is a 64:1 TAPPED AT 49:1 with a primary is 2 turns, and 120pf input to ground. I once wound an unun from flat tape copper and that allowed easy tapping to provide an input from the cold end, and also output taps, but sadly not seen the right tape for a while.
The VNA is a great tool and at a cost of <$100 as well and much thanks to the people who develop both hardware and software easing its use in the ham shack.
joe
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Assuming the transformer losses were low I would expect low swr on multiples of the lowest frequency, such as 80, 40 20 and 10 meters.Can you check the core temperatre at other frequencies to see if the power is being dissipated in heat.
Mike N2MS
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From: Bo W4GHV
Sent: Monday, December 20, 2021 04:23 PM
To: [email protected]
Subject: Re: [nanovna-users] SWR measurement
Will do. I just did a 80--10 meter sweep of my 80-10 EFHW with 12801 data
points on the PC app. Wow!
The Smith Chart and SWR show why the EFHW is so popular. SWR <= 2:1 over
the whole range!
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Re: If only Duct Tape were conductive.........?
Or better yet, COPPER tape: 66' x 1" wide for $13
I just finished making a "Barber Pole" style Yagi antenna with this stuff, and some 1.5" PVC pipe. Wrap the tape around the pvc like an old swirling barber pole out side a barber shop, and you can reduce the size/length of the elements by about 60 or 70%.
--
Regards,
Chris K2STP
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Fantastic, thanks for this. ?I hadn't updated the versions in recent months as I've been distracted from radio by work... very frustrating! The plus side is that this means the latest 1.1 version was big leap! Very nice, thank you Dislord, and Larry for literature.
Hal M0TUI
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Ken: Instead of adding and removing turns you could just tap the secondary and pick the one you want/which gives the best match.
73, Don N2VGU.
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Re: If only Duct Tape were conductive.........?
You can also get Aluminium Tape at Home Depot and Lowe's.Back with the Air conditioning duct work.
toggle quoted message
Show quoted text
At Hobby Lobby you can get Copper tape.? Back in the Stain Glass section.They wrap the edges of the glass with Copper tape then solder the pieces togther..Kent WA5VJB
On Tuesday, December 21, 2021, 08:07:16 AM CST, Donald S Brant Jr <dsbrantjr@...> wrote:
When I lived in an apartment I made a 6 meter dipole out of 3M #425 aluminum tape and stuck it under the eaves.? It stayed up for 3 years until I moved out.? I love that tape, it has a dead-soft aluminum base with an aggressive yet cleanly removable adhesive.? One of those things that you keep finding uses for once you have some.?
73, Don N2VGU
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Re: If only Duct Tape were conductive.........?
When I lived in an apartment I made a 6 meter dipole out of 3M #425 aluminum tape and stuck it under the eaves. It stayed up for 3 years until I moved out. I love that tape, it has a dead-soft aluminum base with an aggressive yet cleanly removable adhesive. One of those things that you keep finding uses for once you have some.
73, Don N2VGU
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Re: Transimission mesurements
I had no idea what he was talking about, but now that you mention Guys and Dolls, it makes perfect sense. :-) 73, Zack W9SZ <> Virus-free. www.avast.com <> <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2> On Tue, Dec 21, 2021 at 1:35 AM Garry Champion via groups.io <m3ngc= [email protected]> wrote: Wow, just to avoid confusion, I read Robins comment to be a referrence to
"Guy and Dolls the musical" and the inferrence that there are many more men
than women in our great hobby is very true.
How it could be insensitive is beyond me so I'm sorry if my reading of the
situation offends.
Time to let this pass.
--
It is better to help than hinder and judge.
Garry
M0MGP....GB6WLB (SES).....GB6NT (SES)
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Bo W4GVH mentioned great results with their matching transformer and EFHW antenna. What turns/impedance ration was your transformer, Bo? Henry started this discussion thread describing a 6:1 turns ratio, which would correspond to a 36:1 impedance ratio. I have always seen that a 49:1 impedance ratio was the ¡°ideal¡± for feeding the EFHW. That made me ponder what the actual best impedance ratio for an EFHW would be. Assuming 3 primary turns, a 49:1 would correspond to 21 secondary turns. If one goes 4-turns either side of the ¡°magic¡± 21-turns, here would be the theoretical impedance ratios: Secondary turns Impedance Ratio 17 32:1 18 36:1 19 40:1 20 44:1 21 49:1 22 54:1 23 59:1 24 64:1 Granted, in true ham-radio fashion of experimentation, I could wind such a transformer by adding or removing the appropriate number of turns and feed the various configurations into an EFHW and nanoVNA, but I was wondering if someone has already performed such an experiment and what the results might be. Thanks in advance for everyone¡¯s insights. 73 and Merry Christmas to all. Ken -- WB?OCV From: Bo W4GHV Sent: Monday, December 20, 2021 04:23 PM To: [email protected]Subject: Re: [nanovna-users] SWR measurement Will do. I just did a 80--10 meter sweep of my 80-10 EFHW with 12801 data points on the PC app. Wow! The Smith Chart and SWR show why the EFHW is so popular. SWR <= 2:1 over the whole range!
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Re: NanoVNA v1.1.00 fw pack for all H / H4 / LiteVNA / V2 / V2Plus / V2Plus4
#firmware
Hi DisLord, thank you very much for your work! You write:
V2Plus4 firmware work only on old V2Plus4 devices, new V2Plus4 devices have
different LCD module not supported by this fw.
How do I determine, which version of the device is the old one and which ist the new one? Best regards Chris
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Roger Need
Chris K2STP
Donald S Brant Jr