RC Groups

RC Groups
    Radios
        Discussion look Ma......no more Antenna on my DX-7......

#1 lazy-b Apr 07, 2012 09:16 AM

look Ma......no more Antenna on my DX-7......
 
4 Attachment(s)
Guys,

I hate those small 2.4 GHZ on top of my Transmitter, Specially all those Spektrum and JR Radio, cause the Spektrum and JR Transmitter have a very long Antenna, that I have difficulty storing on my Flight Box.

here is my solution, I just remove the Antenna and put it inside the Transmitter......you can easily convert it to its original looks, just incase you want to Sell it.

I hope I can do the same convertion for my other 2.4 Ghz transmitter.

#2 AndyKunz Apr 07, 2012 01:48 PM

That's not a very good idea. You just clobbered your range and created a very poor pattern.

They put them up like that for several reasons. It's not for aesthetics.

Andy

#3 WiseDuck Apr 07, 2012 03:23 PM

Maybe he's into parkflyers? :P Never thought anyone would say "gosh, what a bothersome thing, this ANTENNA on this TRANSMITTER, let's get it out of sight"..

#4 Telrin Apr 07, 2012 04:15 PM

Clearly someone who never flew with 35/72MHz :)

#5 SIRCOL Apr 07, 2012 04:17 PM

Quote:

Originally Posted by lazy-b (Post 21261912)
Guys,

I have difficulty storing on my Flight Box.

here is my solution, I just remove the Antenna and put it inside the Transmitter.

here is my solution put it back where it belongs
get a bigger flight box
or a transmitter case

#6 ivanc Apr 07, 2012 09:03 PM

I did a similar mod over a year ago and have not seen any range reduction.

Not a Spektrum radio but a Spektrum module and antenna ;) :

http://bulgaria21.net/modelairplane/...futspek012.jpg

http://bulgaria21.net/modelairplane/...futspek014.jpg

http://bulgaria21.net/modelairplane/...futspek015.jpg

http://bulgaria21.net/modelairplane/...futspek016.jpg

http://bulgaria21.net/modelairplane/...futspek017.jpg

http://bulgaria21.net/modelairplane/...futspek018.jpg

Ivan

#7 bossee Apr 08, 2012 04:17 AM

Hi lazy-b,

Did You make a full range test before and after the antenna modification?
So You know if the modification You did have any negative effect on the range.

/Bo

#8 lazy-b Apr 09, 2012 10:16 AM

I have not performed a Ranges Test, But I guess, it would have the same performace.......my next plan is to use an 2.4 GHZ Spektrum Analyzer to measure its Signal Strength, while the Transmitter is about 500 to 1Km away. and make a signal Strenght Reading on Each Position:
1. Few Inch away from Transmitter Base
2. at the Transmitter Base
3. inside the transmitter

any way, range is not an issue for me, cause I only use it to fly my MCPX helicopter.

#9 michaelpowell Aug 24, 2015 03:09 AM

Not a problem
 
These plastic cased transmitters won't attenuate the signal greatly, so the antenna can go inside easily enough, and I have a commercial transmitter built that way that gives remarkable range.

They put the antenna out in the open for old-times-sake, to avoid the old folk brought up on extended poles sticking out of the top from feeling lost. Besides, if they converted a transmitter, they needed something out there to balance the weight.

Have you noticed, cellphones had long antennas, but they have been incorporated into the case, either as a strip along the edge or, as with laptop computers, an internal antenna under the plastic case.

It's not a problem, really.

#10 mrcl Aug 24, 2015 04:11 AM

Quote:

Originally Posted by michaelpowell (Post 32504117)
These plastic cased transmitters won't attenuate the signal greatly, so the antenna can go inside easily enough, and I have a commercial transmitter built that way that gives remarkable range.

They put the antenna out in the open for old-times-sake, to avoid the old folk brought up on extended poles sticking out of the top from feeling lost. Besides, if they converted a transmitter, they needed something out there to balance the weight.

Have you noticed, cellphones had long antennas, but they have been incorporated into the case, either as a strip along the edge or, as with laptop computers, an internal antenna under the plastic case.

It's not a problem, really.

Uuuuh if you say so...

#11 srnet Aug 24, 2015 05:20 AM

Quote:

Originally Posted by michaelpowell (Post 32504117)
These plastic cased transmitters won't attenuate the signal greatly, so the antenna can go inside easily enough, and I have a commercial transmitter built that way that gives remarkable range.

Thats a diiferent radio, does not mean it applies to all radios of course.

Spektrum would have tested the radio and its range with the antenna in the expected position.

You would need to do before and after range tests to evaluate the actual range diffence, but you might expect that bringing the antenna closer to the metal parts in the TX would actually reduce range.

#12 freechip Aug 24, 2015 05:21 AM

way to bring back a 3 1/2 yrs old thread..

#13 AndyKunz Aug 24, 2015 10:50 AM

The plastic housing DOES affect the frequency and transmission characteristics.

Andy

#14 Dave H. Aug 24, 2015 11:55 AM

I think the design goals for laptops and cell phones are largely influenced by fashion and usability (ie: sliding into a pocket or purse) and you may recall that one recent phone had to be held in a certain way for its antenna to work well. RC TXs surely have some fashion influence but one would hope that performance wins. In the OP's case, it was probably fine since he probably never flies his MCPX more than a hundred feet away. Besides, if it crashes, it probably doesn't hurt anyone or itself.

Now (as noted: 3+ years later!) his most active topic is a totally different transmitter - which also has an antenna sticking out the top. I wonder if he made the same mod.

#15 ivanc Aug 24, 2015 01:34 PM

My 9C internal antenna installation did not show any noticeable degradation in range and I've flown larger planes (one of which has 110" WS) within visual range without issues. When doing range tests I never noticed reduced range before and after the antenna installation change.

I agree that the plastic housing affects the transmission characteristics, what I am saying is that in my case I did not notice it. I do not fly FPV/beyond visual range/behind obstacles so can not comment on whether external vs. internal antenna installation significantly changes range.

Now I no longer use the 9C for flying as I upgraded to a different transmitter with a very compact external antenna and without external wiring to it so the antenna location and size does not bother me.

Ivan


All times are GMT -5. The time now is 12:04 PM.