"Splitting" TX Antennas and/or RX antennas with T Splitter???

[SMP]

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Anyone ever tried "Splitting" TX Antennas and/or RX antennas with T type sma splitters??? Can see the benefit of doing this on the RX side to get multiple antennas in play but wondered if it actually works AND if you could do the same to TX antennas...

 

[RTRyder]

View attachment 13964
Anyone ever tried "Splitting" TX Antennas and/or RX antennas with T type sma splitters??? Can see the benefit of doing this on the RX side to get multiple antennas in play but wondered if it actually works AND if you could do the same to TX antennas...

I'm not an RF engineer but from tinkering with FPV gear for a while I've learned a few things. Main point is most TX see the antenna as a 50 ohm load, adding a splitter and another antenna will change that. Result can be poor performance and decreased range up to blowing the final output on the TX side depending on which way the resistance goes. The RX can utilize multiple antenna provided they are setup as a phased array, again with the proper resistance value as seen at the RX. The other method is to utilize a switching or 'diversity' receiver that will swap between the antenna with the stronger signal.

Ultimately it could probably be done on the TX side but would require a bit of engineering to make it work with an understanding of what it is you're trying to achieve. On the RX side changing to a different style antenna like a circular polarized crosshair or mini patch will give you greater range between the TX and RX. I use the TBS 5 DBI patch on my Fatshark goggles and get crystal clear reception over a much longer range than is possible with a standard whip antenna... http://team-blacksheep.com/products/product:111

Ken

 

[SMP]

Drat... Ok I concede I concede!! I will stop trying to blow up my Transmitters!! :dejection: (Thanks Ken!!) PS thx for the link on the Patch, that looks about right! I tried using a helical and people laugh and point (ok just my wife...)

Incidentally - Running 600mw Immersion TX - Tried it with two different sets of CPs TX/RX and the Immersion Ducks outperformed both sets... Strange! The helical looked funny and was no better either... Dunno Immersion Super Sticks???

Anyways thanks will try out that Patch once TBS starts taking money again (deepsigh)

 

[Electro 2]

I know RF, did it prefessionally for 40 years. You need a power divider. A "T" is not OK, impedance mismatch, as stated. If used in the receive side these devices are sometimes called a "multicoupler". Can be active or passive. If used in the transmit side, called a "power combiner". Mind you you cannot combine two transmitters randomly as they are not cophasic. If the transmitters are on different frequencies, and both frequencies are within the bandwidth of the antenna system, yes again, but not on the same frequency. Basically, one antenna can feed multiple receivers with a divider, transmitters, no. That said, I'm not aware of any inexpensive, lightweight, combiners that would work at microwave frequencies, so the aircraft side is out. Two receive antennas may not yield any results as they are located at different points in space, so they will yield different phases as well. The combined node will exhibit the algebretic sum or difference of the two signals. Might be a plus, might be minus. One recieve antenna feeding multiple radios, heck yes. My base VHF-UHF monitoring station of 9 radios is fed from single antenna.

 

[SMP]

Chuckling here... Well YUP! That about sums THAT up Thx Electro!