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Re: RF output from nanoVNA-H and H4
On Auto, if the LNA maintained linearity, it would deliver 3 watts back into the NanoVNA.
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NOT RECOMMENDED! Safe guess the LNA will limit, but could still be enough power to damage the Nano. You really need a supply of attenuators when testing amps on VNAs.? To limit input power levels to the amp to keep it linear, and on the output to protect the VNA.? ? ? Personally I like to use a signal generator and a Power Meter when testing an amp. On Thursday, February 29, 2024 at 07:45:37 AM CST, montanaaardvark <boblombardi@...> wrote:
On Wed, Feb 28, 2024 at 10:07 AM, Bruce KX4AZ wrote: A related question is what power is acceptable on port 2 (of an H4)?? I have an LNA I wanted to measure the gain of but not having a large selection of attenuators I was afraid to do that.? It has 24 dB gain and I'm pretty sure any of those increased by 24 dB (if the amp could put that out without compressing) could be an issue. I'm sure I should know this, but I don't. Bob ___________ W4ATM - 35 miles south of the Kennedy Space Center Retired RF Design Engineer, mostly PLL synthesizers & receivers, DC - 10GHz Now retired and able to play with all those hobbies I hardly had time for. |
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Re: RF output from nanoVNA-H and H4
On Wed, Feb 28, 2024 at 10:07 AM, Bruce KX4AZ wrote:
A related question is what power is acceptable on port 2 (of an H4)? I have an LNA I wanted to measure the gain of but not having a large selection of attenuators I was afraid to do that. It has 24 dB gain and I'm pretty sure any of those increased by 24 dB (if the amp could put that out without compressing) could be an issue. I'm sure I should know this, but I don't. Bob ___________ W4ATM - 35 miles south of the Kennedy Space Center Retired RF Design Engineer, mostly PLL synthesizers & receivers, DC - 10GHz Now retired and able to play with all those hobbies I hardly had time for. |
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Re: firmwares
2023? - No, in DiSlord's repo you'll get the latest and greatest version from 25.Feb.2024 - just build it and load it into your NanoVNA-H.
If you do not want to build the binaries on your own you can download them in my repo - just created them based on DiSlord's last commit acbe9f1 from 25.Feb. HTH Martin |
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Flat line H4
Good day hive mind, suggestions please.
NanoVNA-H4, latest software installed, not connected to pc, SOLT cal done antenna shorted out prior to connecting to VNA However when I connect the antenna all I get is a perfectly flat line across tge bottom of the screen, so either the front end popped between uses (is it worth repairing?) or Ive set something somewhere that my aging brain has forgotten to u set. BTW my original NanoVNA2.8 inch works fine so Im still able to test my Ae. Thanks in advance -- It is better to help than hinder and judge. Garry M0MGP....GB6WLB (SES).....GB6NT? (SES) M5C Contest Group |
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Re: firmwares
That's him, although if you are looking for firmware, that's not the correct repo - that's the app.
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Firmware for the most common units is in - Tim On 2/28/24 15:49, Nick wrote:
DiSlord, --
Tim Dawson 972-567-9360 |
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Re: firmwares
yes
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Am 28.02.2024 um 21:49 schrieb Nick: DiSlord, |
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firmwares
Hi DisLord,
I want to update a nanovna-h device and a litevna64. I cannot find the firmware because the messages are not created with a correct subject. The messages are completely spammed with lots of replies. Is there a simple method of finding them? In addition, where can I find the newest nanovna app? Thanks |
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Re: where is the end fed natural resonance
There a nice picture of a Zeppelin with such an antenna deployed at
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Half-wave radiator with quarter-wave matching transmission line. 73, Maynard W6PAP On 2/28/24 09:22, Peter Voelpel wrote:
That is correct. |
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Re: where is the end fed natural resonance
The zeppelin patent with a diagram is attached. ?The priority was to avoid sparks as the hydrogen in the envelope might explode. There was no transmission line as the antenna was linked coupled to the transmitter. My first transmitter, 2 tube 30 watts used link coupling. The Zeppelin ant did not have a counterpoise. As can be seen from my post from ARRL handbook a single wire is not a counterpoise.
Notable Patents on Antenna Design ( ) aktuellum.com ( ) favicon1.ico ( ) ( ) Ray W8LYK |
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Re: RF output from nanoVNA-H and H4
Are the figures for total power including harmonics or just the fundamental?The dBm values I posted are for the fundamental frequency. The screen caps in my original post display the dB of the harmonics relative to the fundamental. Being a square wave, the harmonics are quite strong, of course, which the nanoVNA also takes advantage of for frequencies beyond 300 MHz. |
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Re: where is the end fed natural resonance
Te Zeppelin story is real. PBS had the lowdown on the errors made which
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caused the explosion. My folks witnessed the "story" realtime when they were living. BTW: the feed impedance of a 1/4-wavelength radiator against a good image plane (the Zeppelin conducting framework) is nominally 36-ohms real. It is NOT a high-Z! Here is an excellent write-up of the "real" Zepp antenna by Owen Duffy. In reality, it's an inverted-L. The vertical section acts as a transformer to feed the high-Z of the horizontal (traditional) 1/2-wavelength conductor. It is NOT just a 1/2-wavelength hunk of wire! Dave - W?LEV On Wed, Feb 28, 2024 at 3:29?PM N2MS <mstangelo@...> wrote:
The Zepplin was a rigid metal frame dirigible which was used as a-- *Dave - W?LEV* --
Dave - W?LEV |
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Re: where is the end fed natural resonance
That is correct.
The part of the open-wire quarterwave feedline closest to the Zeppelin is a voltage node. 73 Peter Patent DE225204 from 1909:: -----Original-Nachricht----- Betreff: Re: [nanovna-users] where is the end fed natural resonance Datum: 2024-02-28T17:57:19+0100 Von: "Siegfried Jackstien" <siegfried.jackstien@...> An: "[email protected]" <[email protected]> As far as I know the zepp is a halfwave wire fed over a quarter wave transformer and NOT a quarterwave against the zeppelin frame dg9bfc sigi Am 28.02.2024 16:28 schrieb N2MS <mstangelo@...>:
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Re: where is the end fed natural resonance
As far as I know the zepp is a halfwave wire fed over a quarter wave transformer and NOT a quarterwave against the zeppelin frame
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dg9bfc sigi Am 28.02.2024 16:28 schrieb N2MS <mstangelo@...>:
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Re: Question on remote use of NanoVNA
Hi Andy,
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Ward, AE6TY, did this and offered to help with the software he used. You can google AE6TY and SimSmith to find his web pages. John, WoGN On 2024-02-28 07:04, Andrew Harman wrote:
I'm curious if it is possible or if anyone has attempted (with any luck) to attach a wifi dongle to their NanoVNA. I'm not sure but think an OTG adapter may be necessary. A question of the power at the port comes into question. I'm thinking this would be useful during those "as installed" antenna tests -vs- taking imprecise measurements on the ground. |
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Re: where is the end fed natural resonance
Barry,
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This discussion is nothing new. Hams were and are always looking for an antenna that will do it all and require minimal installation. The EFHW is just the 21st century version of Gotham Antennas. Old timers will remember them: <> I got my first radios from a Lafayette Radio store in New York in the late 1960's. They had a small Amateur Radio section in the front. I still remember the spiel. After making a sale he would ask "You bought the radio. Now what are you going to do with it?" Hams rarely consider the environment that they intend to use the radio or antenna installation. Since many Hams in the city lived in apartments or has postage stamp lots he sold them an antenna that at least would get them started. A popular one was Hustler whips, I forgot the others. What's old is new again. Mike N2MS On 02/28/2024 7:19 AM EST Barry K3EUI <k3euibarry@...> wrote: |
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Re: where is the end fed natural resonance
The Zepplin was a rigid metal frame dirigible which was used as a counterpoise against a quarter wavelength antenna from the transmitter. Why would one feed a high voltage source when the gas bags were filled with explosive hydrogen?
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I don't know where this Zepplin story originated. Can anyone enlighten me? Mie N2MS On 02/27/2024 7:28 PM EST John <radio@...> wrote: |
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Re: RF output from nanoVNA-H and H4
OK, I located the level setting that Roger mentioned, so these are the full measurement sets at all of the levels, in CW mode at 14.0956 MHz...
NanoVNA-H classic Level setting dBm Auto -13.0 2 mA -13.0 4 mA -9.7 6 mA -8.7 8 mA -8.2 NanoVNA-H4 Level setting dBm Auto -9.1 2 mA -9.1 4 mA -3.2 6 mA 0.2 8 mA 2.3 |
Ho-Ro
Garry Champion