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Re: errors of "error" models
REF: 17 December 2019 - /g/nanovna-users/message/8335
- Dear Gary: this is obviously another experiment by itself - the objective is to investigate the possibility of an openly edited paper - at least one - and the paper by itself constitutes a concrete knowledge target - needless to say how much interesting we find this scientific procedure - best regards, gin&pez@arg - ps: let us know, please, if it is easy enough for you to get the basic paper by Hackborn from a nearby Library - |
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Re: Cases
Thanks Paul for your message, I will add you to the list and put a note on the group when I am ready in Jan. 2020.
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We can only but try. 73 ¨C All the best for the holidays to you and your family, talk in the new year. Les ¨C M0LPB Sent from Mail ( ) for Windows 10 *From:* Paul Sayer ( paulsayer123@... ) *Sent:* 18 December 2019 11:18 *To:* [email protected] *Subject:* Re: [nanovna-users] Cases I would be interested as well. Paul G0VKT On Wed, 18 Dec 2019, 10:12 Les Brown, <les.m0lpb@...> wrote:
Hi, As soon as we have a case for testing, I will put the information up on the group. Thanks for your reply, it is good to know that there is interest out there for the case. 73, all the best for the holidays, talk in the 2020 Les ¨C M0LPB Sent from Mail ( ) for Windows 10 *From:* davebb123456 via Groups.Io ( david.browne7@... ) *Sent:* 18 December 2019 07:06 *To:* [email protected] *Subject:* Re: [nanovna-users] Cases Hi Les I would like a case, let me know when you get some done, Thanks Dave Browne 2E0DMB On 18 Dec 2019 6:19 am, 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 Sent from Mail ( ) for Windows 10 *From:* Les Brown ( lesdbrown@... ) *Sent:* 18 December 2019 05:20 *To:* [email protected] *Subject:* Re: [nanovna-users] Cases Hi, All I have downloaded a basic design, this is eh1111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111llllllllllllllllllllllllllllllllllllllllllllllllllllllllsssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss Hi, All I have downloaded the basic design from this link:- This design looks OK, but I need to put it up on to the 3D printer to find out if any problems. Regards Price - this will be base of our case and if any mods needed, we can look at it from there. All cases made by me from home, will be at cost of material plus P&P were needed, and that is it to all Ham Radio Lic. holders. It might not be good business, but I am not in to making money from friends. Yours Les - M0LPB |
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Thermal effect?
Recently, I measured a 30 m loading coil for a short vertical antenna with my NanoVNA. I powered the VNA, calibrated for a span from 9 MHz zu 11 MHz with Nano VNA Saver 0.2.0 and started measuring (average 9/4) S11 (R+jX and Q). Repeating the scan, I found R slightly higher, but X beeing the same as before. So I measured again, with the same effect: R drifts higher, X stays the same.
Continually running scans, a pattern evolved. Checking the attached figure, it is clearly observable that R increased for about half an hour before the measured value stabilizes. X however is stable, right from the beginning. I stopped the scans after 37 minutes, when I had the feeling that it leveled out. After re-calibrating I measured again. It came as no surprise, that the NanoVNA continued to measure the same number for X. However, R was down (even a touch lower) to the value which I measured at the very beginning. But now it stayed at that number. My conclusion is, that there is a thermal effect during the warming up of the NanoVNA. Once the device has operating temperature this drift disappears. For whatever reason this seems to effect low |Z| (in my case around 1 Ohm for the real part of the impedance) to a much higher degree than higher values. I assume, this effect is lowest for |Z| around 50 Ohm. If you are aiming for high precision, especially at low |Z|, my advise is to let the NanoVNA warm up for about half an hour, and only than calibrate and start to measure. Has anybody encountered anything similar? Vy 73, Chris, OE1CGS |
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Re: Cases
Hi,
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As soon as we have a case for testing, I will put the information up on the group. Thanks for your reply, it is good to know that there is interest out there for the case. 73, all the best for the holidays, talk in the 2020 Les ¨C M0LPB Sent from Mail ( ) for Windows 10 *From:* davebb123456 via Groups.Io ( david.browne7@... ) *Sent:* 18 December 2019 07:06 *To:* [email protected] *Subject:* Re: [nanovna-users] Cases Hi Les I would like a case, let me know when you get some done, Thanks Dave Browne 2E0DMB On 18 Dec 2019 6:19 am, 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 Sent from Mail ( ) for Windows 10 *From:* Les Brown ( lesdbrown@... ) *Sent:* 18 December 2019 05:20 *To:* [email protected] *Subject:* Re: [nanovna-users] Cases Hi, All I have downloaded a basic design, this is eh1111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111llllllllllllllllllllllllllllllllllllllllllllllllllllllllsssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss Hi, All I have downloaded the basic design from this link:- This design looks OK, but I need to put it up on to the 3D printer to find out if any problems. Regards Price - this will be base of our case and if any mods needed, we can look at it from there. All cases made by me from home, will be at cost of material plus P&P were needed, and that is it to all Ham Radio Lic. holders. It might not be good business, but I am not in to making money from friends. Yours Les - M0LPB |
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Re: Cases
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 Sent from Mail ( ) for Windows 10 *From:* Les Brown ( lesdbrown@... ) *Sent:* 18 December 2019 05:20 *To:* [email protected] *Subject:* Re: [nanovna-users] Cases Hi, All I have downloaded a basic design, this is eh1111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111llllllllllllllllllllllllllllllllllllllllllllllllllllllllsssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss Hi, All I have downloaded the basic design from this link:- This design looks OK, but I need to put it up on to the 3D printer to find out if any problems. Regards Price - this will be base of our case and if any mods needed, we can look at it from there. All cases made by me from home, will be at cost of material plus P&P were needed, and that is it to all Ham Radio Lic. holders. It might not be good business, but I am not in to making money from friends. Yours Les - M0LPB |
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Re: Cases
Hi, All
I have downloaded a basic design, this is eh1111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111llllllllllllllllllllllllllllllllllllllllllllllllllllllllsssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss Hi, All I have downloaded the basic design from this link:- This design looks OK, but I need to put it up on to the 3D printer to find out if any problems. Regards Price - this will be base of our case and if any mods needed, we can look at it from there. All cases made by me from home, will be at cost of material plus P&P were needed, and that is it to all Ham Radio Lic. holders. It might not be good business, but I am not in to making money from friends. Yours Les - M0LPB |
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Re: Cases
I found the same case that Terry VK5TM did on eBay, item 174039026524. Looks like an interesting case for the -H. The listing also led to this:
73 -Jim NU0C On Tue, 17 Dec 2019 04:46:40 -0800 "Les Brown" <lesdbrown@...> wrote: OK, I see there is a problem that can be solved quite easily. |
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Re: SWR readings off scale
Hi Bing Wang
Reference position is the grid lines from lower Line = 0 to top line 0=8 Kind regards Kurt -----Oprindelig meddelelse----- Fra: [email protected] <[email protected]> P? vegne af bing-wang@... Sendt: 18. december 2019 01:43 Til: [email protected] Emne: Re: [nanovna-users] SWR readings off scale Anybody know how to set negative value for reference position. For example, -20dB. seems the num. keypad does not have "-" symbol. |
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Re: NanoVNA Saver software version 0.2.1 TDR operation
On Sat, Dec 7, 2019 at 09:06 PM, Clyde Spencer wrote:
In the TDR display there are two traces, One Red and one blue. I understand the red but not the blue. Would some please give me an explanation of the blue trace? =========================================================================== You can think of the red trace as equivalent to selecting <DISPLAY-TRANSFORM-LOW PASS IMPULSE> on the NanoVNA. Where the peaks are indicative of time and distance. The blue trace can be thought of as being equivalent to selecting <DISPLAY-TRANSFORM-LOW PASS STEP> on the NanoVNA. Where levels are indicative of impedance variations (see attachment). - Herb |
gin&pez@arg
Les Brown
Les Brown
Jim Shorney
Kurt Poulsen
