I have upgraded to a 1 watt radio, but even with good dipole antennas I am only getting around 800 meters through trees and buildings (much more when up in the air of course). Better antennas may help, but I am considering using more power and 5 watt amplifiers appear to be possible to connect to the 3DR/Hope transmitter modules. I am concerned about transmitting and receiving with one module though. Has anyone done this before and know if the receiver circuit could be disconnected from the transmitter and bypass the 5 watt amplifier, so that it could transmit and receive half duplex with one antenna?

You need to be a member of diydrones to add comments!

Join diydrones

Email me when people reply –

Replies

  • I cant help but think that this would ACE my current project :P diydrones.com/forum/topics/hoperf...

    • Yes, that would be nice. You might have to overpower the other person's transmitter. A 5 watt linear amplifier would probably work for transmitting and you could use a second module for receiving (and two antennas), but it might be worth experimenting to see if you could connect the receiver to the transmitter and have one small module.

  • More power is generally not the best solution. It will add to your problems in most cases.
    Usually antenna placement and checking RF cables for loss will help. In most systems poor quality cable and connectors will have the greatest effect.
  • Developer

    You can connect a 5W linear amplifier and it will work. I assuming the 5W Liner amp has a built in 'RF switch' so the transmit power doesn't reflect directly onto the receiving stage. Unless you are building a home-brew solution?

    That said using more power may give you distance when line of sight, but trees and buildings are exceptionally good attenuators at these frequencies

  • Moderator

    FWIW, we're getting 30km comfortably with RFD 900's, with a 900MHz patch antenna on the vehicle and two OEM stick-on dipoles on the plane. I think their max power is 1W.

    5W seems overkill unless you want to go 60km+?

    21km on a bad day with RSSI's in the 90's:

    3702148448?profile=original

    • 30km is very good. I don't feel that I need 30km or 60km of range, but I am more concerned about poor reception when flying low near trees or around hills.

  • yes, it's possible to transmit at 100W too, that would be equally illegal in most countries, and equally bad for all those other devices you would interfere with.

    • True in most cases, but I have an amateur radio license and I plan on doing it legally like APRS data packets on 440mhz. Amateur handheld transceivers use 440mhz at 5 watts legally and don't interfere with anyone.

      • then you would know difference between mhz and Mhz ? 

        -sorry , but you asked for it :)

        • and between Mhz and MHz...

This reply was deleted.

Activity

DIY Robocars via Twitter
How to use the new @donkey_car graphical UI to edit driving data for better training https://www.youtube.com/watch?v=J5-zHNeNebQ
Monday
DIY Robocars via Twitter
RT @SmallpixelCar: Wrote a program to find the light positions at @circuitlaunch. Here is the hypothesis of the light locations updating ba…
Saturday
DIY Robocars via Twitter
RT @SmallpixelCar: Broke my @HokuyoUsa Lidar today. Luckily the non-cone localization, based on @a1k0n LightSLAM idea, works. It will help…
Thursday
DIY Robocars via Twitter
@gclue_akira CC @NVIDIAEmbedded
Nov 23
DIY Robocars via Twitter
RT @luxonis: OAK-D PoE Autonomous Vehicle (Courtesy of zonyl in our Discord: https://discord.gg/EPsZHkg9Nx) https://t.co/PNDewvJdrb
Nov 23
DIY Robocars via Twitter
RT @f1tenth: It is getting dark and rainy on the F1TENTH racetrack in the @LGSVLSimulator. Testing out the new flood lights for the racetra…
Nov 23
DIY Robocars via Twitter
RT @JoeSpeeds: Live Now! Alex of @IndyAChallenge winning @TU_Muenchen team talking about their racing strategy and open source @OpenRobotic…
Nov 20
DIY Robocars via Twitter
RT @DAVGtech: Live NOW! Alexander Wischnewski of Indy Autonomous Challenge winning TUM team talking racing @diyrobocars @Heavy02011 @Ottawa…
Nov 20
DIY Robocars via Twitter
Incredible training performance with Donkeycar https://www.youtube.com/watch?v=9yy7ASttw04
Nov 9
DIY Robocars via Twitter
RT @JoeSpeeds: Sat Nov 6 Virtual DonkeyCar (and other cars, too) Race. So bring any car? @diyrobocars @IndyAChallenge https://t.co/nZQTff5…
Oct 31
DIY Robocars via Twitter
RT @JoeSpeeds: @chr1sa awesomely scary to see in person as our $1M robot almost clipped the walls as it spun at 140mph. But it was also awe…
Oct 29
DIY Robocars via Twitter
RT @chr1sa: Hey, @a1k0n's amazing "localize by the ceiling lights" @diyrobocars made @hackaday! It's consistently been the fastest in our…
Oct 25
DIY Robocars via Twitter
RT @IMS: It’s only fitting that @BostonDynamics Spot is waving the green flag for today’s @IndyAChallenge! Watch LIVE 👉 https://t.co/NtKnO…
Oct 23
DIY Robocars via Twitter
RT @IndyAChallenge: Congratulations to @TU_Muenchen the winners of the historic @IndyAChallenge and $1M. The first autonomous racecar comp…
Oct 23
DIY Robocars via Twitter
RT @JoeSpeeds: 🏎@TU_Muenchen #ROS 2 @EclipseCyclone #DDS #Zenoh 137mph. Saturday 10am EDT @IndyAChallenge @Twitch http://indyautonomouschallenge.com/stream
Oct 23
DIY Robocars via Twitter
RT @DAVGtech: Another incident: https://t.co/G1pTxQug6B
Oct 23
More…