Foxeer pagoda pro 5.8G 2dBi RHCP FPV antenna LiteVNA Analysis

Foxeer pagoda pro 5.8G 2dBi RHCP FPV antenna LiteVNA Analysis
Full video is here : • 5.8GHz FVP Antenna Ana...
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Asanga Gunatilake

[@chrismofer]

I found my pagoda to be tuned to 5.6 or so as well. why? wouldn't 5.8 be the best as it's the center of most bands?

[@asangag]

yes 5.8 is the center frequency of that band and just because your antenna is not precisely tuned to that frequency it does not mean you are not getting a good range. there are lot of other factors affect the range. also with most VTX you can change the frequency to closely match the antenna resonant frequency.

[@chrismofer]

​@@asangag Thanks for the reply. I spent the day testing all my antennas, and of my 3 different brand Pagodas, my old Lumenier Pagoda 2 LHCP was centered exactly on 5.8, whereas my no-name RHCP in a plastic shell and a pair of brand new LHCP Pagoda 2 from Emax all were centered around 5.6GHz. Depending on which bands your VTX&RX have, the range of possible frequencies is 5.64 - 5.94 GHz. I've found with the VNA that while an antenna may have an SWR near 1.0 @ 5.6GHz, it could have a much poorer SWR up to like 3 at 5.9GHz. even if this means only 75% of the power gets transmitted, that's super important to me at 2.5 watts as one of my VTXs has, 25% reflected back could damage it. The Emax Nano antennas I tested seemed way off, like 5.5GHz center. this is actually outside the available bands for 5.8 FPV. for lower frequency antennas (5.6) the best band/channel is E4, if E isn't available R1 and R2 are close. Thankfully most of the antennas I tested like cloverleafs from spironet, AKK, etc and new small antennas from iflight were all centered close to 5.8 and had pretty wide bandwidth. for those antennas, the best possible channels are, in order, F4, A4, R5, B5, B4, A5. for your Pagoda centered @5690MHz, the closest would be R2 or E2. yours has great bandwidth.

[@asangag]

@@chrismofer good job in testing all those antennas. You should upload them to youtube if u can to help others. Man 2.5w vtx should give u a massive range...30km+ i guess

[@chrismofer]

@@asangag yes 2.5w blew my mind the first time i tried it, goes thru and around walls and trees for a surprising distance, and line of sight i only tested a few miles but it was very clear the whole way. it's the Foxeer Reaper specifically. it dissipates a lot of heat. for most general FPV flying 2.5w is excessive. I'm curious if an off-SWR antenna is as important to the receiver as it is to the transmitter. if it's equally important, then both antennas having an SWR of 2 at the operating frequency means it's only transmitting 90% of the energy it could be and the receiver is only receiving 90% of the energy that it could be, that means the energy is only 90% x 90% as good as it could be, or only 81%. in the worst case where both antennas are operating at SWR of 3, that's only 56.25% as much received power as you could be getting.

[@laklakan3380]

Hello. I would like to receive information about product. I produce antennas with a frequency of 5.8 GHz. Can I perform the SWR tests of the antenna I produced with this device?

[@asangag]

Yes this device can measure swr of 5.8g antenna

[@MrDehicka]

My advice, do not fixate on low SWR. Even 2.0 is only 10% loss and you will not notice a difference. Even a miniscule change in the radiation pattern diagram can overshadow this loss. 50 Ohm short has a perfect SWR, but totally sucks as antenna.

[@asangag]

yes its a valid point. 😀