In case it is helpful, here are all my HAM radio videos in a single playlist kzread.info/head/PLxdnSsBqCrrEUHbKHxcHHhPaBrHg_qKE4. All my high altitude balloon videos are located at kzread.info/head/PLxdnSsBqCrrH_mfqhVgLsPnxVjIlHWeLq. You can support this channel by clicking on the 'Thanks' button underneath the video or via Patreon at www.patreon.com/christopherwlum. Please let me know what you think in the comments. Thanks for watching!

I just ordered cmy VNA, so looking forward to checking my J-Pole I made to see where it sits for 2M, the digital SWR meter I also have says its currently at a 1:1 so we shall see soon. Great video, thanks

@ChristopherLum

Жыл бұрын

Sounds like fun, thanks for watching!

Thanks for sharing. Would be good to do some simulation to see what the optimum antenna length is, and whether it matches what you got.

You have to calibrate the NanoVNA every time you change frequency range, and to do measurement of the antenna, and not the the antenna + the coax cable, the calibration have to be done on same reference (end of coax) as the antenna.

@dokatecdev5858

Жыл бұрын

ok, here I have a question now! Shouldn't you include the cable in the measurement/tuning? Background: I made some 2.4GHz antennas for WIFI, I took some 433 MHz helix, pulled it a little and cut it down while looking at the reflection chart. This worked kinda great (except that the down peak was kinda tight which influences the bandwidth). But after attaching the tuned antennas to a SMA cable and connecting this to the WIFI µFL connector, the result wasn't that good anymore. I think I should have measured including the SMA cable because of its influence. Or am I wrong? Beside that, I think it would be best to measure/tune everything when it is connected to the WIFI module, but I still have to find out how to achive this. Soldering a simple cable to the µFL connector and attach the VNA to it probably is no real solution. But this is what I try to find out currently.

@MrRealisticMan

Жыл бұрын

@@dokatecdev5858 To my knowledge Is the reference point (plane), where the measurement will be done. If the goal is to measure an antenna (DUT device under test), the calibration have to be done on the same plug/cable where the antenna (dut) will be connected to be measured. Same apply to all measurements with a VNA, to what ever one want to measure. Calibration have to be done on same plane as the DUT will be measured. If the VNA is calibrated at the connector and then connected to a long lossy coax and an antenna, the VNA is not able to tell the coax and antenna appart, and the coax+ antenna are the DUT. At times the interest is how an antenna system included cables is behaving, then all the system is DUT. If there is need for adapters, there will influence, but as long the wavelength is less than 1/10 of a 1/4 wavelength at frequency of interest, it don't influence in layman's term. Hope it clarifies your question.

@wes11bravo

Жыл бұрын

I understand that if the feedline radiates RF, you're going to have problems but what is the issue with calibrating the NanoVNA using your feedline, then tuning the antenna with the feedline connected to the antenna? Since your radio is going to use the feedline, shouldn't it be taken into account while adjusting the antenna?

@KA9DSL

8 ай бұрын

Save your settings in memory, works for me. Exam: 10m, 6m, 2m, 440

@IBasilisvirus

7 ай бұрын

Agreed. He needs to calibrate with the coax cable on the VNA, and hook up the short/Open/50Ohms to the end of the coax for calibration.

Always log mag. Forget SWR - it is much less useful and readable than return loss. And you should have done the cal at the far end of the connection cable. Always calibrate as close to the item yuou are checking as possible

QUESTION. How do use a nano outdoors? Next to impossible to read I have found.

Thanks!

@ChristopherLum

2 жыл бұрын

Ali, thanks for the support! I really appreciate it. I'll actually be using all the funds from Super Thanks to fund science projects for K-12 students. Do you have any particular interests in terms of videos or topics? I try to prioritize request made by supports as I plan future videos. In any event, I want to again say thank you for your contribution and for supporting the channel. I hope to hear from you at a future KZread video!

@NFL_31258

2 жыл бұрын

I am interested in EE related content (antenna, control, DSP) but that is just me.

@ChristopherLum

2 жыл бұрын

@@NFL_31258 That is perfect, I've actually got several videos planned in the future that cover some of these topics (mostly control and some RF discussions in the context of HAM radio). Hopefully I'll see you around at a future video!

@nats50

11 ай бұрын

19.4 inches or 19 inches, 11 mm at 144.39 MhZ without using the Nano?

Did you cut from each radial or just from active element?

great work mister thank you please mister can you share us the video of (Introduction to Linear State Estimation) please mister in need it

@ChristopherLum

2 жыл бұрын

Hi, Thanks for reaching out. If you have questions or would like to request a video, I hope you'll consider supporting the channel via Patreon at www.patreon.com/christopherwlum. I'd love to have you as a Patron as I'm able to talk/interact personally with Patrons. Thanks for watching! -Chris

you did not calibrate it.

Any attack missiles come your way lol