Episode 932 another short duck. let's measure it buy female: www.banggood.com/custlink/vD3... buy male: www.banggood.com/custlink/vKv... Be a Patron: / imsaiguy
This is a reposted comment to ensure there is no confusion. At about 1:46 or so, it was said that the gain of a dipole was about 3 dBi. Actually, it is calculated at 2.15 dBi in free space. The presence of a nearby ground can change the measured dBI to a higher value. At no time am I implying that the reviewed antenna is a dipole.
In the second section, where you read from FCC Part 97 rules, be clear that the exceptions you quote apply to the Amateur Radio service, i.e. people licensed under Part 97, the Amateur Radio Service. They do not apply to just anyone who buys a Chinese radio from Amazon. Of course, when the zombie apocalypse comes there likely won't be any black vans driving around to issue citations....
0 dBd = 2.15 dBi Effective Isotropically Radiated Power (EIRP) is referenced to the Isotropic radiator you mentioned, whereas Effective Radiated Power (ERP) is referenced to the ideal half wave dipole. Of course not every half wave dipole is going to have 2.15 dB gain over an isotropic radiator, but that's the conversion factor everyone uses. If you file applications with the FCC (one of my day jobs), depending on which radio service you're seeking authority for or certifying a device to, the FCC may request the ERP or EIRP and gain relative to a dipole or an isotropic source and you have to be able to convert between the two depending on which reference you used in your design/specifications.
A simple long-wire antenna is very often the best multi-band antenna that you can afford or have room for once you match them to the Transceiver. Best SW antenna I ever had was a length of #30 wire that I shot up over the tall oak-trees in my backyard with a Bow&Arrrow - it prododuced over 7 volts of RF/noise as measured by a 5 Mhz O-scope! Europe SW was crystal clear in Atlanta, Ga.! (then we moved, House probably burned to the ground from lightning later...)
This is a reposted comment to ensure there is no confusion. At about 1:46 or so, it was said that the gain of a dipole was about 3 dBi. Actually, it is calculated at 2.15 dBi in free space. The presence of a nearby ground can change the measured dBI to a higher value. At no time am I implying that the reviewed antenna is a dipole.
In the second section, where you read from FCC Part 97 rules, be clear that the exceptions you quote apply to the Amateur Radio service, i.e. people licensed under Part 97, the Amateur Radio Service. They do not apply to just anyone who buys a Chinese radio from Amazon. Of course, when the zombie apocalypse comes there likely won't be any black vans driving around to issue citations....
Thank u
0 dBd = 2.15 dBi Effective Isotropically Radiated Power (EIRP) is referenced to the Isotropic radiator you mentioned, whereas Effective Radiated Power (ERP) is referenced to the ideal half wave dipole. Of course not every half wave dipole is going to have 2.15 dB gain over an isotropic radiator, but that's the conversion factor everyone uses.
If you file applications with the FCC (one of my day jobs), depending on which radio service you're seeking authority for or certifying a device to, the FCC may request the ERP or EIRP and gain relative to a dipole or an isotropic source and you have to be able to convert between the two depending on which reference you used in your design/specifications.
nano vana what great bang for your buck is that fantastic !
I was looking, I saw about 320.
That's too bad :-) I couldn't see the scale on my phone but it did look a bit too far up...
-2 db is more likely
Where was that other small dip at? 1.25m?
how about swr that antenna? it is ok in vhf and uhf?
Another great demo. Have you any experience using the LibreVNA USB system. I am torn as to which way to go. Karl
I would like to get a Libre. Want to donate one 😀
I just picked up an old Wilson DL 1000 3.7-4.2 GHz Downconverter. Was used on a 10 foot satellite dish.
Can I send it to you for a tear down?
I've already done two teardowns like that
czcams.com/video/ejF1PtiP7MU/video.html
czcams.com/video/AI_jqVyC7CI/video.html
I dont know much about RF but I have a long wire I stuck in my phone and I went from -133 db to -107 ; -99 on a good day.....
A simple long-wire antenna is very often the best multi-band antenna that you can afford or have room for once you match them to the Transceiver. Best SW antenna I ever had was a length of #30 wire that I shot up over the tall oak-trees in my backyard with a Bow&Arrrow - it prododuced over 7 volts of RF/noise as measured by a 5 Mhz O-scope! Europe SW was crystal clear in Atlanta, Ga.!
(then we moved, House probably burned to the ground from lightning later...)
Hello.
I like very mutch your´s videos.
My comment: how can they say that the antenna has 50 ohms if the value of vswr is 1.5:1.Don't realize
73´s
Label: Imdepdance [sic] I smell fake.