SMALL - Telemetry SMALL - Radio
Thread Tools
Old May 18, 2015, 09:33 AM
benzy2 is online now
Find More Posts by benzy2
Registered User
Joined Jan 2009
4 Posts
Discussion
Why diversity and not a T connector?

I'm new to FPV and have been reading/watching videos on setup as much as possible. I've learned all about antennas, bands, ground stations, etc. After picking up a FPV Nano QX I'm absolutely hooked on FPV.

One thing I see a lot is people talk about diversity receivers that switch from one antenna to another. Makes sense and seems valuable in multiple situations. What I don't know and haven't seen answered is why we simply don't use a T connector and hook two antenna into a single receiver. Mostly this came about by wanting to add a directional antenna as well as a mushroom style onto my Fatsharks without extra wires. It doesn't seem to be done at all so I'm assuming there is a significant reason not to do so but I don't see it listed in most of the educational posts/videos. Any help on why this isn't acceptable?
benzy2 is online now Find More Posts by benzy2
Reply With Quote
Sign up now
to remove ads between posts
Old May 18, 2015, 11:30 AM
DanT is offline
Find More Posts by DanT
Registered User
DanT's Avatar
United States, TX
Joined Feb 2006
1,618 Posts
Simple,, but I don't have the right words .
Two antennas will not work together ...!
Done .. LOL
DanT is offline Find More Posts by DanT
Reply With Quote
Old May 18, 2015, 11:51 AM
waltr is offline
Find More Posts by waltr
Team WarpSquad
United States, PA, Doylestown
Joined Jan 2014
6,021 Posts
If the signal arrives at the second antenna 180° of of phase from the signal on the first antenna then the signals will cancel and the RX will see NO Signal.
waltr is offline Find More Posts by waltr
Reply With Quote
Old May 18, 2015, 02:30 PM
CyberJay is offline
Find More Posts by CyberJay
Rsetiegerd Uesr
CyberJay's Avatar
USA, AR, Cave Springs
Joined Apr 2005
3,211 Posts
Quote:
Originally Posted by waltr View Post
If the signal arrives at the second antenna 180° of of phase from the signal on the first antenna then the signals will cancel and the RX will see NO Signal.
This...

People do build antenna networks where multiple antennas are carefully built into an array. This can boost the signal if it's done correctly. But if it's not done correctly it can reduce the signal.

You cannot just randomly connect antennas together. Phased arrays are fairly advanced antenna building, each component of the antenna matters, the placement of each antenna matters, the length of coax feeding each antenna matters. It's not an easy thing.

-J
CyberJay is offline Find More Posts by CyberJay
Reply With Quote
Old May 20, 2015, 08:28 PM
IBCrazy is offline
Find More Posts by IBCrazy
Engineer for Christ
IBCrazy's Avatar
Amherst, VA
Joined Jun 2006
10,971 Posts
Quote:
Originally Posted by CyberJay View Post
This...

People do build antenna networks where multiple antennas are carefully built into an array. This can boost the signal if it's done correctly. But if it's not done correctly it can reduce the signal.

You cannot just randomly connect antennas together. Phased arrays are fairly advanced antenna building, each component of the antenna matters, the placement of each antenna matters, the length of coax feeding each antenna matters. It's not an easy thing.

-J
Nailed it! Well put!
IBCrazy is offline Find More Posts by IBCrazy
Reply With Quote


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion If it wasn't Torture, Why not let the Police and Prisons use it? FlyCush Life, The Universe, and Politics 83 Dec 17, 2014 11:15 PM
Discussion E-flite UMX Spitfire Mk.IX, why why why not? Jerka Micro Ready-to-Fly 3 Oct 03, 2014 04:38 AM
Discussion Why do the HiTec chargers not allow balance connector charge ONLY ror1 Batteries and Chargers 33 Oct 31, 2012 01:59 PM
Why not use RJ45 connectors for servos? Riserflier The Builders Workshop 11 Sep 30, 2005 10:12 AM
Building Larger LiPo Packs, Why Not Use Connectors More Than Pre-Built Packs? DavidJ Batteries and Chargers 11 Jul 28, 2004 05:15 PM