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I love my Spektrum Dx7 and my 2.4Ghz JR XPS9303 and i refused to trade its solid rock performance by a 72mhz radio just to increase range of my FPV/UAV. So in collaboration with my friend JB we find out the cheapest and secure way to amplify the signal, it even works in some Futabas and virtually with any 2.4Ghz radio, but some modifications are required. Lets see some options:-Spektrum Dx7 this is the cheapest solution for a very reliable 2.4Ghz radio, i used it for about a year and i never had any signal glitch (unless i fly beyond 2000 feet). The problem with this one is that you have to modify it, you need a SMD to U.FL adapter, drill a hole in the side of your radio and just connect and screw the adapter, no soldering required. If you have more than 5 hours of experience with Legos your qualified to do this job. Then you just need to connect the booster. The one in the picture (middle) is already modified.-If you have the awesome JR radio but is 72Mhz you can buy the Spektrum 2.4Ghz module and just insert it in the back of your TX, personally this is my favorite setup. It's a good deal because includes a $99 dlls receiver for free! Note that JR TX alone cost around $600 dlls, but you can get it for less, i got mine for 300 bucks with Spektrum Module included on R/C Groups =P. Remember you are looking for the JR XPS9303.If you have one of the fallowing Futaba radios:7U Series Radios8U Series Radios8J Series Radios9C Series Radios9Z Series RadiosFN Series RadiosYou can just go and buy the Spektrum 2.4Ghz module, easy and with no hassles. It's also a good deal because includes a $99 dlls receiver for free!

One of the advantages of the Spektrum receivers is the build in diversity system, you can even buy one with 4 satellites like this one, or buy a super tiny, tiny setup like this one, or the traditional one.The diversity is crucial to have a reliable link when you are flying far away, also Spektrum has a receiver for Carbon Fiber airplanes (Carbon Fiber blocks RF signals).The idea is to have the best reliable hardware with an SMA connector and the SMA extension cable, after that you are ready for the final step: Get an amplifier. But we are talking about a few hundred dollars here, if you get the weakest one of 100mW it will cost you around $150 dlls. This is not pocket friendly in my point of view. So again our Asians friends come to the rescue, after making some research around the net I've found on eBay and a home Wireless Amplifier, so i decided to give it a chance and i bought it for 60 bucks including shipping! Wow that's a good deal! The one i got is this one.Note that the amplifier needs 6Volts to work, you can get a cheap 6V power regulator from here and just make the adapter. A 3 Cell LIPO is enough to supply it for a long time.

After receiving the AMP i did some tests, here are my results:Before using the amplifier, i was able to fly around 3000 feet away (~1 km) using a 900Mhz@500mW Video transmitter. I never lost the video signal, only the radio link...Using a 1.3Ghz@1Watt Video transmitter i was unable to fly more than 2000 feet away (~600meters). So the 1.3Ghz Video transmitter reduces my 2.4Ghz Spektrum range...Then i got my cheap Asian amplifier and using a 2.4Ghz Patch Antenna i was able to fly around 2.6 miles (4.18Km) away without a single glitch, but i was unable to continue because now my video was causing me problems, hehe!Not bad at all! Honestly i don't need more than 2 miles of coverage, is really a long way for an EasyStar. In conclusion the maximum range for my setup still unknown, but the range achieved is more that 2.6 miles and the +2 extra miles of coverage gained for less than $100 dlls is really a good deal for me!

Now just remember this:-The range will be different in other setups.-Never turn on your radio without antenna.-Never turn on the Amplifier without antenna.-Note that in some country's this amplifier may be illegal.Thanks for watching!
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Comments

  • Is this a good Attenuator?  4dB Attenuator, SMA Connectors- DC-1500 Mhz 

     

    Roy

  • Frank,

    I have the same question and no buddy really answered it for me.
    but I think it can. I think you or I would have to wire it between the antenna and the module. But not sure how.

  • Jordi will this system work on a Hitec Aurora 9

  • Polonius,

    Circuits "pull" amperage, the power supply they make can supply up to 2A (and I don't think the booster even requires anywhere near that).  Having a BEC that can provide up to 3A is just fine.  I power my BEC with a 3S lipo.

  • Good question.

    Do you think they sent you the wrong booster? Or were you expecting it to be 12V?

  •  The 6V power regulator linked in the specs above outputs 6V at 3A.  The adapter that came with the Argtek booster is rated @ 6V / 2A.  Feeding the Argtek booster using a 3S lipo, via the exact 6V regulator linked in the specs above, will that be OK for the booster?  Or would this regulator actually fry the booster?  Do I need to find a regulator with 2A output?  Or will the regulator feed the Argtek only the amperage it demands (2 amps?).

    I don't want to fry my equipment on day one!

    Thank You...!

  • I just added the 1 watt booster to my Dx6i, connects to Ar6115 in my EasyStar II. 

    I originally planned to run both the Dx6i and the booster from a 2200mah 3S lipo through a 6V BEC. I was looking for a 1000 mah 2S lipo to fit in the battery case of the Dx6i (2200mah 3S was too bulky velcroed to the outside). Then I figured out that for 2500mah AAs hold more energy (7.4 watt-hours) than a 1000mah 2S lipo (7.4 watt hours). For comparison, the 2200mah 3S lipo is still better, 24 watt-hours. I'd already tapped the leads from the battery case. Instead of connecting the lipo to the Dx6i, I connected the four AAs to the booster. Now I turn on the Dx6i and both the Dx6i and the booster come on. The Ni-MH AAs only produce about 5.2volts in series, but the booster seems to work just fine. I did actually connect the lipo and BEC, which produced 6.2volts and also powered the booster and radio, no problem. That's with a volt meter - the Dx6i display appears to read .5 volts high! 

    I did a ground test with the AA setup, leaving the FPV camera aimed at the tail to check the Dx6i. The test was on a hill where I could get above the trees. I left the airplane on a tripod at elevation 2284' and drove uphill with the Dx6i and Fatshark Predator video glasses (plane has AR6115 rx and Immersion 5.8ghz Vtx. I'm using Spironet antennas.

    Ground test results:

    5500' feet away and 190' higher - I had a strong video and control signals. I could even put my car between the Dx6i and the plane and still turn the rudder and propeller. 


    8300' away and 660' higher - I had a good video signal as long as the Spironet antenna was vertical. The 5dbi booster antenna worked only when vertical and reached the plane only if I didn't stand between the antenna and the plane. The 3dbi antenna worked both vertical and horizontal, and didn't lose contact as quickly when I stood between the Dx6i and the plane. The 3dbi antenna, also made the video signal fuzzy.

    Added note - I recently moved the Vtx from a spot behind the cockpit to the rear of the tail boom, ran coaxial cables for video signals and put ferrites on the feeds to the Vtx and video camera. The video signal was MUCH stronger than before!

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  • Hey Jordi, this upgrade looks easy and cheap! I got lots of useful info here, but can I use my original spektrum AR6200 Rx? will it work? Also the patch antenna.. is it omni-directional meaning that i have to point it towards the aircraft at all times?

    thanks! :D

  • Are there any diagrams on how to wire this into a Hitech module?

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