Episode 1473 I found this on Aliexpress, claimed to be 800MHz to 6000MHz Be a Patron: / imsaiguy
Жүктеу.....
Пікірлер: 62
@IMSAIGuy Жыл бұрын
I'm doing another video where I solder down the coax.
@marcino8318 Жыл бұрын
those holes are for mounting handle to carry antenna for wideband sniffing.
@milesprower6641 Жыл бұрын
Try connecting the NanoVNA to a computer via VNA Saver. You can do higher resolution scans and save the graphs as images and insert them into the video directly. Even annotate them.
@KG4JYS Жыл бұрын
Pretty sure the holes are where you can strap the cable down with a zip tie. I've got a similar antenna that came inside a housing and was attached that way.
@fannyjim60943 ай бұрын
Incredibly work!
@khimbittle7705 Жыл бұрын
antennas! not getting bored
@Electrotech1980 Жыл бұрын
Keep at it, love your videos. Keep in mind that the Nano VNA is feeding square waves into the antenna and wasn't able to replicate the readings common to your expensive machine.
@espenlyngaas9502 Жыл бұрын
We're not getting bored!
@diemaschinedieviereckigeei2941 Жыл бұрын
It would be interesting to see, how efficiently this antenna really performs at the high end of the specified band. The PCB material seems to be standard FR4, which gets increasingly lossy above 1-2 GHz.
@KossuJahvetti2 ай бұрын
Great video! Is it possible to design "log periodic antenna" for two bands, example 800-900Mhz and 1700-1800Mhz if frequencies between is not in your interest? Aiming of course keep the boom length reasonable with most gain on those two bands.
@PlaceholderforBjorn Жыл бұрын
I've seen on some trading sites that those holes doesn't have any function on the antenna design. But is intended for a mount, like a pistol grip.
@IMSAIGuy
Жыл бұрын
ray gun
@silverXnoise
Жыл бұрын
I assumed it was to zip-tie the cable, although they're spaced a little too wide for that. +1 for ray gun.
@zerobow9413 Жыл бұрын
FYI the nano VNA has software might look better
@byronwatkins2565 Жыл бұрын
I think the holes are for mounting and zip-tying the cable.
@1shARyn3 Жыл бұрын
holes as passthru for zipties to hold the transmission line?
@TheElectronicDilettante Жыл бұрын
How about opening the insulation and soldering the coax only where it intersects each element? What would be a good functional test? I’ve tried using Vistumbler with various 2.4ghz/5ghz antennae to see the number of access points I can reach with one antenna versus another. Quick note… I vote for the return of story time and IMSAI Dog. Have a good day!
@cowshittt Жыл бұрын
Soldering down a coax to the boars should improve the performance. Soldering the cable to the antenna is the missing BALUN .
@IMSAIGuy
Жыл бұрын
probably, it stumped me why it had the big ugly connector. what's the point if you are going to solder it
@cowshittt
Жыл бұрын
@@IMSAIGuy That connector makes no sense.
@pbaemedan Жыл бұрын
I have 4 of this type and that I use for EMI pre-compiance testing.
@__--JY-Moe--__ Жыл бұрын
gramps has got to tell us how everything works! he's the only 1 that can calibrate the machine! *the oppositional reluctance dipole antenna* ! never heard of one! I'm sure it works 4 the Union ! good luck Pat.
@uni-byte Жыл бұрын
The only way the soldered down coax could work is if that buss was connected to the shield. If it was connected to the center conductor that operation would leave you with .. not much.
@IMSAIGuy
Жыл бұрын
of course is the ground side design: fenix.tecnico.ulisboa.pt/downloadFile/844820067125562/Extended_Abstract.pdf
@ivolol Жыл бұрын
One IMSAI Guy's journey through aliexpress to find the best antennas in the land! Does your NanoVNA have an ability to screen capture into a computer or USB stick or similar? I'm not sure if you have a video on it already, but I'd be interested to know why your HP thinks it can get to 15-20 -dB whereas the nano was only reporting around 10.
@IMSAIGuy
Жыл бұрын
I guess you get better numbers when you pay $30,000. Or it might be due to the HP connector attached to ground and helping out
@MrMersh-ts7jl Жыл бұрын
freshly calibrated machine. I see what you did there. 😂
@IMSAIGuy
Жыл бұрын
thanks for reading the fine print! 😎
@Stevef-sk3jcАй бұрын
hows it perform, i bet its gain is bad due to the circuit board blockage
@nickcaruso Жыл бұрын
What are you doing with these antennas? Inquiring minds want to know!
@robinbrowne5419 Жыл бұрын
More antenna voodoo :-)
@____________________________.x Жыл бұрын
Why is the feed element on the opposite side from say a Yagi?
@IMSAIGuy
Жыл бұрын
the shorter wavelength will choose the short dipoles if fed correctly, if fed from the other end then the short wavelengths will find long dipoles and odd things will occur.
@none_of_your_business Жыл бұрын
what's the smallest HF antenna that you could have? could you possibly hang one out the window of an apartment?
@IMSAIGuy
Жыл бұрын
you can use antennas designed for cars, or put a wire antenna under the eves of the roof, or in the attic. search around, there are thousands of people who have tackled that problem.
@jeffreyyoung4104 Жыл бұрын
What happens if the antenna is fed from the aft end? Does it have to be fed from the front, just because the TV antennas were?
@IMSAIGuy
Жыл бұрын
it won't work right. the shorter wavelength will choose the short dipoles if fed correctly, if fed from the other end then the short wavelengths will find long dipoles and odd things will occur.
@jeffreyyoung4104
Жыл бұрын
@@IMSAIGuy I never looked at it that way, and that makes a lot of sense now!
@darkobul1 Жыл бұрын
Can you use vna to analyze transformers ?
@IMSAIGuy
Жыл бұрын
sure
@chrisscott1547 Жыл бұрын
I'm not sure why Yagi is in the title - it is certainly not a Yagi - just adds more confusion. It looks a bit like a log periodic, but until we see directivity and front-to-back ratio, perhaps we should categorize it as Just-a-Bunch-of-Dipoles. It would not surprise me if directional performance is very poor and it's a complete fraud. EDIT: (Mark subsequently corrected the title, removing Yagi)
@K1ZEK Жыл бұрын
Boy you have a tough audience. LOL It would be fun putting it in front of a parabloc reflector and using it as a feed! Scanning the sky😮. 73. Leo
@IMSAIGuy
Жыл бұрын
It's a tough crowd and occasional heckler. I will not be scanning the sky as I don't speak Martian. 😎
@K1ZEK
Жыл бұрын
@@IMSAIGuy I have about 8 satellite dishes installed that I poke around the sky with. Hoping to get back to it soon. It's like SWL but higher frequencies. 73 Leo
@knglaser Жыл бұрын
I would call that a "logperiodic looking object" which does not do what it's supposed to. the elements are on top of each other, no interleaving, not a logperiodic.
@IMSAIGuy
Жыл бұрын
did you actually watch the video??
@knglaser
Жыл бұрын
@@IMSAIGuy yes, the whole one. perhaps missed some language hints (:
@IMSAIGuy
Жыл бұрын
@@knglaser they are not on top of each other, they are staggered and out of phase.
@knglaser
Жыл бұрын
@@IMSAIGuy wow, I stared at the end where there was closeups and thought there was copper under each of the silkscreen legs, quite hard to spot that detail
@Unpopular_0pinion Жыл бұрын
Is that an antenna built into a pcb?
@IMSAIGuy
Жыл бұрын
yes, it just traces on a PC board
@Unpopular_0pinion
Жыл бұрын
@@IMSAIGuy That's lit!
@paulsherman51
9 ай бұрын
Wonder if you could put two PC boards together, at 90-degrees to each other, receiving both H and V polarizations? Would they be phased at 0 or 90 or 180?
@Yuehanlad Жыл бұрын
Log antennas are not 50 ohms, so you need a balun.
@IMSAIGuy
Жыл бұрын
actually the PCB designs are made to operate at 50 ohm and get better than 10dB across the range. There are several papers on line. They are supposed to have a soldered down coax. I will need to take off this silly connector and give it a try
@willthecat3861
Жыл бұрын
@@IMSAIGuy The balun (and matching) network are etched on the pcb The holes, in the pcb, are part of the matching network... and a possibly for implementing 'opens.' There a similar Chinese design... to the one you show... that uses a conductor backed coplanar waveguide to match.
@@willthecat3861 How can the holes have an effect when they are outside the copper plated parts? Or has this PCB really more than 2 layers? (Shining light through most cheap PCB antennas shows that they don't.)
Пікірлер: 62
I'm doing another video where I solder down the coax.
those holes are for mounting handle to carry antenna for wideband sniffing.
Try connecting the NanoVNA to a computer via VNA Saver. You can do higher resolution scans and save the graphs as images and insert them into the video directly. Even annotate them.
Pretty sure the holes are where you can strap the cable down with a zip tie. I've got a similar antenna that came inside a housing and was attached that way.
Incredibly work!
antennas! not getting bored
Keep at it, love your videos. Keep in mind that the Nano VNA is feeding square waves into the antenna and wasn't able to replicate the readings common to your expensive machine.
We're not getting bored!
It would be interesting to see, how efficiently this antenna really performs at the high end of the specified band. The PCB material seems to be standard FR4, which gets increasingly lossy above 1-2 GHz.
Great video! Is it possible to design "log periodic antenna" for two bands, example 800-900Mhz and 1700-1800Mhz if frequencies between is not in your interest? Aiming of course keep the boom length reasonable with most gain on those two bands.
I've seen on some trading sites that those holes doesn't have any function on the antenna design. But is intended for a mount, like a pistol grip.
@IMSAIGuy
Жыл бұрын
ray gun
@silverXnoise
Жыл бұрын
I assumed it was to zip-tie the cable, although they're spaced a little too wide for that. +1 for ray gun.
FYI the nano VNA has software might look better
I think the holes are for mounting and zip-tying the cable.
holes as passthru for zipties to hold the transmission line?
How about opening the insulation and soldering the coax only where it intersects each element? What would be a good functional test? I’ve tried using Vistumbler with various 2.4ghz/5ghz antennae to see the number of access points I can reach with one antenna versus another. Quick note… I vote for the return of story time and IMSAI Dog. Have a good day!
Soldering down a coax to the boars should improve the performance. Soldering the cable to the antenna is the missing BALUN .
@IMSAIGuy
Жыл бұрын
probably, it stumped me why it had the big ugly connector. what's the point if you are going to solder it
@cowshittt
Жыл бұрын
@@IMSAIGuy That connector makes no sense.
I have 4 of this type and that I use for EMI pre-compiance testing.
gramps has got to tell us how everything works! he's the only 1 that can calibrate the machine! *the oppositional reluctance dipole antenna* ! never heard of one! I'm sure it works 4 the Union ! good luck Pat.
The only way the soldered down coax could work is if that buss was connected to the shield. If it was connected to the center conductor that operation would leave you with .. not much.
@IMSAIGuy
Жыл бұрын
of course is the ground side design: fenix.tecnico.ulisboa.pt/downloadFile/844820067125562/Extended_Abstract.pdf
One IMSAI Guy's journey through aliexpress to find the best antennas in the land! Does your NanoVNA have an ability to screen capture into a computer or USB stick or similar? I'm not sure if you have a video on it already, but I'd be interested to know why your HP thinks it can get to 15-20 -dB whereas the nano was only reporting around 10.
@IMSAIGuy
Жыл бұрын
I guess you get better numbers when you pay $30,000. Or it might be due to the HP connector attached to ground and helping out
freshly calibrated machine. I see what you did there. 😂
@IMSAIGuy
Жыл бұрын
thanks for reading the fine print! 😎
hows it perform, i bet its gain is bad due to the circuit board blockage
What are you doing with these antennas? Inquiring minds want to know!
More antenna voodoo :-)
Why is the feed element on the opposite side from say a Yagi?
@IMSAIGuy
Жыл бұрын
the shorter wavelength will choose the short dipoles if fed correctly, if fed from the other end then the short wavelengths will find long dipoles and odd things will occur.
what's the smallest HF antenna that you could have? could you possibly hang one out the window of an apartment?
@IMSAIGuy
Жыл бұрын
you can use antennas designed for cars, or put a wire antenna under the eves of the roof, or in the attic. search around, there are thousands of people who have tackled that problem.
What happens if the antenna is fed from the aft end? Does it have to be fed from the front, just because the TV antennas were?
@IMSAIGuy
Жыл бұрын
it won't work right. the shorter wavelength will choose the short dipoles if fed correctly, if fed from the other end then the short wavelengths will find long dipoles and odd things will occur.
@jeffreyyoung4104
Жыл бұрын
@@IMSAIGuy I never looked at it that way, and that makes a lot of sense now!
Can you use vna to analyze transformers ?
@IMSAIGuy
Жыл бұрын
sure
I'm not sure why Yagi is in the title - it is certainly not a Yagi - just adds more confusion. It looks a bit like a log periodic, but until we see directivity and front-to-back ratio, perhaps we should categorize it as Just-a-Bunch-of-Dipoles. It would not surprise me if directional performance is very poor and it's a complete fraud. EDIT: (Mark subsequently corrected the title, removing Yagi)
Boy you have a tough audience. LOL It would be fun putting it in front of a parabloc reflector and using it as a feed! Scanning the sky😮. 73. Leo
@IMSAIGuy
Жыл бұрын
It's a tough crowd and occasional heckler. I will not be scanning the sky as I don't speak Martian. 😎
@K1ZEK
Жыл бұрын
@@IMSAIGuy I have about 8 satellite dishes installed that I poke around the sky with. Hoping to get back to it soon. It's like SWL but higher frequencies. 73 Leo
I would call that a "logperiodic looking object" which does not do what it's supposed to. the elements are on top of each other, no interleaving, not a logperiodic.
@IMSAIGuy
Жыл бұрын
did you actually watch the video??
@knglaser
Жыл бұрын
@@IMSAIGuy yes, the whole one. perhaps missed some language hints (:
@IMSAIGuy
Жыл бұрын
@@knglaser they are not on top of each other, they are staggered and out of phase.
@knglaser
Жыл бұрын
@@IMSAIGuy wow, I stared at the end where there was closeups and thought there was copper under each of the silkscreen legs, quite hard to spot that detail
Is that an antenna built into a pcb?
@IMSAIGuy
Жыл бұрын
yes, it just traces on a PC board
@Unpopular_0pinion
Жыл бұрын
@@IMSAIGuy That's lit!
@paulsherman51
9 ай бұрын
Wonder if you could put two PC boards together, at 90-degrees to each other, receiving both H and V polarizations? Would they be phased at 0 or 90 or 180?
Log antennas are not 50 ohms, so you need a balun.
@IMSAIGuy
Жыл бұрын
actually the PCB designs are made to operate at 50 ohm and get better than 10dB across the range. There are several papers on line. They are supposed to have a soldered down coax. I will need to take off this silly connector and give it a try
@willthecat3861
Жыл бұрын
@@IMSAIGuy The balun (and matching) network are etched on the pcb The holes, in the pcb, are part of the matching network... and a possibly for implementing 'opens.' There a similar Chinese design... to the one you show... that uses a conductor backed coplanar waveguide to match.
@IMSAIGuy
Жыл бұрын
fenix.tecnico.ulisboa.pt/downloadFile/844820067125562/Extended_Abstract.pdf
@Yuehanlad
Жыл бұрын
@@IMSAIGuy cheers thanks for the link.
@cyberyogicowindler2448
2 ай бұрын
@@willthecat3861 How can the holes have an effect when they are outside the copper plated parts? Or has this PCB really more than 2 layers? (Shining light through most cheap PCB antennas shows that they don't.)