Thread: New Product RangeLink UHF Long Range system
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Old Jul 11, 2012, 12:09 PM
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United States, CA, Los Angeles
Joined Nov 2010
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Originally Posted by ecworks View Post
Couldn't concentrate on work so I kept working on this problem and finally decided to rearrange the entire layout. I moved the 1w 1280 vid transmitter out to the very end of the left wing and attached the stock antenna which tilts up or down. Temporarily laid the wiring from the transmitter on top of the wing back to the fuselage. Then I moved the Rangelink stock antenna out to the far end of the right wing and used an 18" antenna extension. Wired the Rangelink receiver to my FY-30 gyro and wired the 1280 vid transmitter to a small battery and the vid servo wire to the Eagletree and powered the whole thing up. Results: In micromode for the rangetest I now get 42 meters roughly. In normal low power mode the rangelink is holding at 98% for as far as I can walk away. (couple hundred yards on my street) A few days ago the 1280 1w vid transmitter knocked down my range test to 15 meters or less. The only question I now have is whether the 18" antenna extension will reduce my Rangelink reception very much.
I'll do a long range ground test soon so see if I can go a few miles downrange and see how the Rangelink and 1280 vid perform together.

So it seems to have been the distance between the rangelink and the 1280 1w transmitter. Originally it was a foot apart. Now close to 3 feet.
From your description, it sounds like you also changed your power sub-system. In other words, you isoloated the VTx from the rest of the system. Keep in mind EMI comes in two basic flavors, radiated and conducted. With all the clocks, microprocessors and amplifiers in our systems, you would be surprised how many different frequencies you can end up with. Most are low enough amplitude as to not cause a problem but sometimes they can bite. If my assumption is correct you can use a common mode filter such as this one. If my assumption is not right, then, as you discovered, distance is your friend. On the 18"...I believe Sid uses RG316 for his Ant leads. 18" would attenuate about .3dB @ 1.3GHz. Range effect would be minimal.
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