Questions tagged [nanovna]
The nanovna tag has no summary.
16 questions
0
votes
1
answer
139
views
Sleeve balun issue
Trying to make one of these for 434 MHz. The coax is RG-174 of some 3 mm diameter. I have calibrated the VNA (with 2 x 100 ohm resistors) right where the 47 ohm resistor can be seen, before sliding ...
- 327
0
votes
1
answer
164
views
Poor SWR on short coax line
I have build an antenna for 446mhz I have used 15mm copper tube for the dipoles and RG-58 for the coax. On the horizontal centre line I have created a coil 9 turns around a 25mm former. The feed line ...
-1
votes
2
answers
252
views
How to calibrate Nanovna for measuring simple wire without grounding?
I got lastly an antenna analyzer, Nanovna. I can calibrate it without problems for testing frequencies. The antenna for testing, is simply a wire for 20cm. I plug it into the middle space of the input ...
user24106
4
votes
3
answers
1k
views
What should a NanoVNA show for twisted pair impedance in TDR mode?
Thought I'd try doing some actual experiments with twisted pair feedlines and also just some general "non-coax" measurements and testing, but not until after I understood a bit more about ...
- 7,579
4
votes
1
answer
2k
views
Using NanoVNA to tune antenna
I'm extremely new to this, so I'm mostly asking for tutorials and so on.
I have tried configuring the device according to one tutorial I found. When I hook up the cheap antennas that came with a ...
- 155
2
votes
3
answers
4k
views
Why does SWR of a dipole decrease the closer it is to the ground?
I experimented with a 20m dipole made of a 1:1 balun connected to 2x ~5-meter lengths of copper wire, running parallel to the ground (by "ground" I mean "pavement", not quite the ...
- 25
3
votes
1
answer
255
views
How to determine if filter is well matched?
Hello i'm in process of creating band pass filters for my ham radio. I calculated the filter for 80m band basing on this website:
And recreated it in reality:
Then I started measuring it with ...
- 131
1
vote
0
answers
436
views
Is this amount of loss normal with LMR400?
I have a run of about 150 feet of LMR400 (specifically, it's this DX Engineering "400MAX" product). It connects to an Ed Fong antenna (2m, 1.25m, 70cm tri-band J-Pole) about 75 feet up a ...
- 448
7
votes
1
answer
1k
views
Why would a VNA not make a good Spectrum Analyzer? Or an SDR a good VNA?
Happy to be corrected where I'm wrong in any of this but in broad strokes my understanding is:
Spectrum Analyzer
measures input signal strength while sweeping across frequencies, measuring RF ...
- 7,579
4
votes
2
answers
2k
views
Measuring actual feedpoint impedance for a given frequency
Background
I'm attempting to tune an antenna with my NanoVNAv2.
I calibrated it using the included open/short/(50-ohm)load standards by screwing them directly onto the NanoVNA one by one and running ...
- 401
1
vote
2
answers
1k
views
How do I configure a NanoVNA v2Plus4 to check a 1:1 Balun?
Note that the menus are different than those I'm seeing on YouTube which aren't for the V2plus4. What's missing is "Isolation" and of course, there is an additional standard for that which ...
- 353
3
votes
1
answer
370
views
Can you think of any reason my NanoVNA says my antenna has 1.2 SWR while my radio says it has off the scale SWR?
My radio is an mcHF kit that I just finished soldering up. It receives fine, but when I went to transmit it's giving off the scale SWR. I rechecked my antenna with my NanoVNA, and it shows 1.2 SWR at ...
- 411
5
votes
1
answer
1k
views
Using a Return Loss Bridge and Nano VNA to measure amplifier characteristics
One of the difficulties of measuring active devices like LNA and IF amplifiers with the Nano VNA is the care needed to avoid over-driving the amplifier input and, more importantly perhaps, to avoid ...
- 989
5
votes
3
answers
2k
views
Measurement of antenna with VNA does not match its specs
I have a NanoVNA V2 Plus (50kHz - 3GHz) and decided to test my LoRa antennas:
an unknown antenna delivered with a LoRaWAN gateway (RAK831)
a 868Mhz antenna from Linx Technologies (ANT-868-OC-LG-RPS)
...
- 175
3
votes
2
answers
301
views
NanoVNA(v2)... what to capture for future reference when comparing past antennas?
I'm designing a HF antenna that uses a portion of a downspout (electrically isolated from the gutters above and lower portion) as a bottom-loaded shortened quarter-wave vertical.
I'm about to trim the ...
- 401