Old Antenna and new

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Old Antenna and new

Postby Gadgets » Mon Sep 06, 2010 8:35 am

Hi.

I just installed and tested my FRSky in my JR-9X.
All is fine.

I know that that FM/PCM output is dead, but would the old antenna cause any problems if I leave it in?

I normally use it as a wind sock (Tie a ribbon at the end).

Also, I remember reading that FM/PCM singal is weakest from the tip. If you can picture a cone growing out of it towards the sky. Hence we would never point the anntena at the plane/heli. Does this hold for the 2.4GHz?


thanks
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Re: Old Antenna and new

Postby RCModelReviews » Mon Sep 06, 2010 9:27 am

You can leave your old antenna in place, it won't hurt anything -- although it would pay to keep it retracted.

Yes, 2.4GHz is just like the old long-wire frequencies insomuch as there is a lower intensity of signal emitted from the end of the antenna. However, in my flight-testing of the FrSky system I flew a 1.6m model to the limits of visibility and pointed the transmitter antenna directly at it without any effect on control so it's fair to say that there's a lot of headroom available and you won't have to worry too much. I never even think twice about whether I'm pointing my antenna at the model and have never had any issues.
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Re: Old Antenna and new

Postby Gadgets » Tue Sep 07, 2010 11:47 am

Thanks for the Info.

BUT the windsock is less effective is retracted. Any reason you recommend that?

thanks again
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Re: Old Antenna and new

Postby RCModelReviews » Wed Sep 08, 2010 12:53 am

Any conductor in the vicinity of a 2.4GHz antenna will change the radiation pattern of the 2.4GHz antenna somewhat. Depending on exact spacings, lengths etc, that change could be dramatic -- but chances are it won't be.

I would simply do some range-tests to see if the effects are detectable or significant in your case.
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Re: Old Antenna and new

Postby Gadgets » Wed Sep 08, 2010 10:45 am

thanks, i had similar thoughts, but rather hear it from an expect
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