Re: conecting to a homebrew hf verticle antenna
Bigger question is why a balanced 600 ohm line to an unbalanced vertical which
typically is low impedance?
Short form is the 19" of wide at most will skew the data as your moving the VNA 18 inches
above your ground reference ( the counterpoise for the antenna) and will likely see variations
between holding it and laying it on the ground.
IF you use a balun the only one is a 1:1 isolation as you have no idea what the antenna
impedance is but its likely lo. If you use a lot to high your likely going to see greater mismatch.
Suggested hookup is short as possible leads from connector to the antenna connection
points as then you get the actual antenna feed impedance (R,jX).
Allison
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I do not accept private email due to forum scraping groups.io
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conecting to a homebrew hf verticle antenna
Hi all,ive a nanovna with bnc conectors,i want to connect it to my homebrew vertical to play with the base loading coil,currently i have 600 ohm ladderline with one leg going to the loading coil and the other to ground,if i conect the center of my bnc coax to the coil and screen to ground,will it work,the coax with the bnc on the end to go on the nano is about 18 inches long,will that work or do i need a balun?,at the moment the ladderline goes to a 9-1 balun in the shack.73
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Re: errors of "error" models
GIN&PEZ;
Indeed an interesting experiment, and one of which my contribution may be quite small and insignificant. :-)
I am certain I can (with some effort) locate the reference Hackborn article, but with limited effort on the web, I also have not met with success.
I have however found references to his work, and also the works of others pursuing goals quite similar to yours. Acknowledging that your work, as well as there¡¯s spans decades, and that Hackborn¡¯s paper serves as a reference standard for comparison, it is unlikely I will be the investigator most capable of finding noteworthy feature differences, flaws, or revelations. At best I would expect to gain understanding and confidence in the results I am able to achieve.
Having said that; I would remiss to make assumptions that you are (in deference to my judgement), intimately aware of ¡°all¡± similar efforts past and present. To that end I will alert you to information that you may wish to review and comment on for relevance before I confuse myself with Information overload.
The following by example:
Also a possible item of interest is a Patented scheme (US6,300,775B1) with similar stated goals, by far exceeding my current math skills.
--
73
Gary, N3GO
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Re: First PCB pictures of the V2
any plans on selling the boards without the screen?
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Re: Simple example of interfacing Octave with nanoVNA
#octave
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Re: First PCB pictures of the V2
On Wed, Dec 18, 2019 at 09:54 AM, Gabriel Tenma White wrote:
On this particular unit the nastiness starts at 3.4GHz.
Exceptional performance, especially taking the target price point into account. You all did a very good job. I wish my home build 3GHz VNA would be that good -- NanoVNA Wiki: /g/nanovna-users/wiki/homeNanoVNA Files: /g/nanovna-users/filesErik, PD0EK
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Re: NanoVNA Saver software version 0.2.1 TDR operation
Rune,
Yes something is not quite right.
I used the TDR function on the NanoVNA in stand-alone mode and got impedance measurements that made sense to me. I cascaded some 50 ohm (RG58), 75 ohm (RG59) and 93 ohm (RG62) coax and could see the impedance steps.
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Herb,
Thanks for the info. Nice to know the source of the cable. Hope the connectors are properly installed.
Roger
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Re: First PCB pictures of the V2
Is Hugen involved with this V2 product or is he doing a separate development?
BTW - Hugen's supplier Maggie King emailed me today stating that revision 3.4 of the NanoVNA-H is now available at her site.
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Re: First PCB pictures of the V2
Any reason you could not give it an SPI interface? then you would only need to break out 1 pin for CS which may be easier? IF you even need to you could just make it so we pick "screen OR serial" that way with a jumper or something. Since i feel like most serial/non usb applications would be remote anyway Tim Keller On Wed, Dec 18, 2019 at 1:21 PM Gabriel Tenma White < OwOwOwOwO123@...> wrote: Would have done that but there are only two free GPIOs and looking at the
layout they are pretty much impossible to route out. I'll try to think of
something maybe involving the USB connector.
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Re: First PCB pictures of the V2
On Wed, Dec 18, 2019 at 09:54 AM, Gabriel Tenma White wrote:
¡. price: most likely similar to the -H, so around $60. I don't know where the $100 BOM cost rumor comes from but it's false, the BOM cost can't be anywhere
near $100 if this is to retail for $60 ;) There aren't much development costs because OwOComm sponsored the initial R&D on condition that all designs be
open sourced. ¡.
============================================================================
Gabriel,
I keep forgetting that your OwOComm sponsored V2 design effort is a different branch than Hugen's , and he also wants to keep the BOM of his V2 build below US $100. Your target price of $60 for a 3 GHz VNA with performance specifications exceeding the NanoVNA-H is very aggressive. What kind of case packing are you considering that would accommodate using different size displays? The success of the NanoVNA-F indicates that packaging and display size are a primary motivator for a lot of buyers. Wish you much success.
- Herb
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Re: First PCB pictures of the V2
OK, thanks.
Many devices use pin 4 of the microUSB connector as a switching line (ex: cellphones use it to switch to OTG when pin 4 is grounded).
Maybe you could use that to route serial to the connector if pin 4 is pulled hi or low?? Just a thought.
Thanks
Larry
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On Wednesday, December 18, 2019, 1:21:58 p.m. GMT-5, Gabriel Tenma White <owowowowo123@...> wrote:
Would have done that but there are only two free GPIOs and looking at the layout they are pretty much impossible to route out. I'll try to think of something maybe involving the USB connector.
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Re: First PCB pictures of the V2
Great news, Gabriel.
Would it be possible to have a serial interface option that you can select via an on-screen config command?
That way, end users could opt to use their own add-on serial to BT or serial to WiFi or serial to ?? interfaces.
Thanks,Larry
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On Wednesday, December 18, 2019, 12:54:43 p.m. GMT-5, Gabriel Tenma White <owowowowo123@...> wrote:
option to rotate screen 180 degrees: should be doable; I think the ILI9341 has a command to do that without flipping the data.
bluetooth: not yet, maybe V3 ;)
display size: base version will have a 2.8'' display. User can swap in a 3.2'' ILI9341 display (drop in replacement) or a 4'' ST7796S display (pending firmware support). We are likely going to offer a version with 4'' display, maybe a month or so after the release of the base version.
jog switch: it's already the same part number as the one used in the -F, just without the nipple installed. Using the jog switch is optional as all features can be accessed from the touch screen.
price: most likely similar to the -H, so around $60. I don't know where the $100 BOM cost rumor comes from but it's false, the BOM cost can't be anywhere near $100 if this is to retail for $60 ;) There aren't much development costs because OwOComm sponsored the initial R&D on condition that all designs be open sourced.
I've attached the uncalibrated load plot. The performance of the baluns deteriorate rapidly above 3GHz so this is going to be marketed as a 3GHz instrument rather than a 3.5GHz one. On this particular unit the nastiness starts at 3.4GHz.
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Re: First PCB pictures of the V2
option to rotate screen 180 degrees: should be doable; I think the ILI9341 has a command to do that without flipping the data.
bluetooth: not yet, maybe V3 ;)
display size: base version will have a 2.8'' display. User can swap in a 3.2'' ILI9341 display (drop in replacement) or a 4'' ST7796S display (pending firmware support). We are likely going to offer a version with 4'' display, maybe a month or so after the release of the base version.
jog switch: it's already the same part number as the one used in the -F, just without the nipple installed. Using the jog switch is optional as all features can be accessed from the touch screen.
price: most likely similar to the -H, so around $60. I don't know where the $100 BOM cost rumor comes from but it's false, the BOM cost can't be anywhere near $100 if this is to retail for $60 ;) There aren't much development costs because OwOComm sponsored the initial R&D on condition that all designs be open sourced.
I've attached the uncalibrated load plot. The performance of the baluns deteriorate rapidly above 3GHz so this is going to be marketed as a 3GHz instrument rather than a 3.5GHz one. On this particular unit the nastiness starts at 3.4GHz.
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Re: First PCB pictures of the V2
On Tue, Dec 17, 2019 at 06:32 AM, Gabriel Tenma White wrote:
Here are the final pre-production prototypes, and plots showing uncalibrated
and calibrated S21 floor
Gabriel, Seeing the uncalibrated phase performance till 3GHz and the S21 isolation level I have to congratulate you with this result. The phase performance is MUCH better then the 3GHz bridge you can buy on eBay. Is it possible to also show the uncalibrated s11 with a load connected to port 1 (CH0)? Any reason why you stop the scan at 3GHz? -- NanoVNA Wiki: /g/nanovna-users/wiki/homeNanoVNA Files: /g/nanovna-users/filesErik, PD0EK
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Re: First PCB pictures of the V2
On Wed, Dec 18, 2019 at 06:14 AM, Pierre Martel wrote:
got a price range for the unit?
====================================================================
Hugen or Gabriel posted previously that the design objectives included keeping BOM costs below $100 and compatibility with current software base. That would probably bring the initial retail price to about the same as the current 4.3" NanoVNA-F in order to re-coup developmental costs. You can expect the cost to drop after the inevitable wave of clones start to appear.
- Herb
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Hope the keyboard lived through the experience ;) I'm interested in a case as well. Cheers, Lyle NM6Y On Wed, 18 Dec 2019 06:19:40 +0000 "Les Brown" <les.m0lpb@...> wrote: Sorry, had to run and the keyboard hit the floor.
I have downloaded a basic design, and we can mod it as we like.
But as I keep saying, the cost will be min. For all Ham radio Lic. Holders.
73
Les M0LPB -- 73 NM6Y Bickley Consulting West Inc. "Black holes are where God is dividing by zero" -- 73? ?NM6Y Bickley Consulting West Inc. "Black holes are where God is dividing by zero"
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Any expensive proffesional instrument needs 30 warmup minutes. It is really ussual. Calibration has to be done after warmup too.
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Re: First PCB pictures of the V2
got a price range for the unit?
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Le mar. 17 d¨¦c. 2019 ¨¤ 20:20, n2msqrp <mstangelo@...> a ¨¦crit :
Thanks for the update.
Could you use a more robust switch like that on the NanoVNA-F?
Looking forward to getting a unit.
Mike N2MS
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Yes, I measured with NanoVNA Saver 0.2.0, so having the USB connected is a must. The battery actually was already fully charged at the beginning, so shouldn't be too much of a problem unless the charging process is not optimal.
I don't see any possibility to suppress charging when using NanoVNA Saver anyway, besides removing the LiPo if this is the problem. Is there any?
Thx,
Chris, OE1CGS
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Roger Need
OwO
Lyle Bickley
Juan Pablo EA4CIV