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coiling 72MHz antennas?

Old 05-23-2015, 10:02 PM
  #26  
solentlife
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The RTF packages are usually the cheap Radios that only give 100m or so .... nothing like the 27Mhz radios of yesteryear ....

I still have a Futaba M Series radio in 35Mhz ... which was a Factory modification from the original 27Mhz ..... that radio in stock form would match any stock 2.4Ghz radio today in range. In fact it would beat it if any chain-link fence / items in between Tx and Rx ..... as 2.4Ghz has a limitation in that arena.

Nigel
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Old 05-23-2015, 10:05 PM
  #27  
Panther
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All good comments. It is easy to get at the antenna connection on the board. Already soldered it back on once before. I might try a short (250 mm) wire and see what happens
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Old 05-23-2015, 10:49 PM
  #28  
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cut the antenna a bit long... solder on then measure and cut to exact (1/x wave) length. the shorter it is (quarter, eighth, 16th... wave) the more sensitive it is to not being exactly correct length.

Should put it on a scope and dial in the tuning also when changing antenna length... but that may be more trouble than its worth.
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Old 05-23-2015, 11:25 PM
  #29  
JetPlaneFlyer
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Originally Posted by Panther View Post
....36 mHz full range Rx and Tx.
Now, being 1 meter long, the antenna is going to look silly dragging behind the plane and also the possibility a prop tangle could ensue.
So... based on my limited knowledge from the old 27 mHz days and 1/4 wave antennas, is there a chance I can shorten it to 1/4 wave.
I'm guessing it's already only about 1/8 wave. The full wave length of a 36MHz signal is 8.33M

http://www.csgnetwork.com/freqwavelengthcalc.html

The best option would be to spiral wind it around a plastic tube or straw. Folding it back on itself is bad as the bit that's folded back effectively works directly against the signal received in the main run, cancelling it out.
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Old 05-24-2015, 06:03 AM
  #30  
Panther
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Originally Posted by JetPlaneFlyer View Post
I'm guessing it's already only about 1/8 wave. The full wave length of a 36MHz signal is 8.33M

http://www.csgnetwork.com/freqwavelengthcalc.html

The best option would be to spiral wind it around a plastic tube or straw. Folding it back on itself is bad as the bit that's folded back effectively works directly against the signal received in the main run, cancelling it out.
Good point. Probably chop 1/2 off and do a range check then a bit more......
I can always solder a new full length back on if I need to.
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Old 06-19-2015, 05:42 PM
  #31  
FlyWheel
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K, Is this acceptable?
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I ran the wire along the bottom edge of the Fuse. as far as the vertical stab, up it's LE and along the top of the fin and rudder (to prevent it from becoming entangled).

There's only a couple of inches hanging off the tip, so it's not as if I'm in danger of stepping on it.
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Old 06-19-2015, 09:26 PM
  #32  
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Originally Posted by FlyWheel View Post
K, Is this acceptable?
Attachment 181057Attachment 181058
I ran the wire along the bottom edge of the Fuse. as far as the vertical stab, up it's LE and along the top of the fin and rudder (to prevent it from becoming entangled).

There's only a couple of inches hanging off the tip, so it's not as if I'm in danger of stepping on it.
Yes, a very acceptable way to do it.
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Old 06-19-2015, 11:41 PM
  #33  
FlyWheel
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So there won't be any significant signal loss with this routing? Good.
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Old 06-20-2015, 05:09 AM
  #34  
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Can I ask, just out of curiosity; why OP isn't interested in 2.4GHz? Again, just curious.
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Old 06-20-2015, 05:36 AM
  #35  
FlyWheel
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Complexity. I actually have a 2.4GHz transmitter in my closet (Optic 6) and even though it is supposed to be one of the simpler transmitters I find it difficult understanding how to work it. I'm used to my Flash5X, it meets all my needs, I know how to set it up and it works fine.

"If it ain't broke..."
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Old 06-20-2015, 05:45 AM
  #36  
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Sure!

Just throwing it out there; but is the issue less about frequency and more about the difference between a complex computer radio and a simple 4/5/6 channel non-computer radio? Sometime you might have a gander at something like the DX5e, it's 2.4ghz but is a good ol' simple radio with a couple of switches, two sticks, trims, and switches for servo reverse. No programming or mixing or other complicated stuff.
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Old 06-20-2015, 08:22 AM
  #37  
Panther
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Originally Posted by FlyWheel View Post
Complexity. I actually have a 2.4GHz transmitter in my closet (Optic 6) and even though it is supposed to be one of the simpler transmitters I find it difficult understanding how to work it. I'm used to my Flash5X, it meets all my needs, I know how to set it up and it works fine.

"If it ain't broke..."
Ha, IF you can program an Optic 6 then you can program anything. Who told you they were one of the simpler ones?
They are great for basic stuff but I hated having to do more than that so I gave mine away. Taranis is easy compared to Optic 6.
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Old 06-20-2015, 08:24 PM
  #38  
FlyWheel
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OK, anybody have any recommendations that have an online manual i can read?

I will ever need more than six channels, and maybe not even that much. As I stated earlier, my Flash5X is sufficient for anything I plan on ever getting. Ironically, I read the manual for the 2.4 version of this TX and completely understood it even without having the box in my hand for reference, however it is so lacking (only one mix, compare that with the FIVE mixes I have on my 72MHZ version) that is was barely more than a toy. Sad, really.

Obviously I would like something that it least comparable to I got now. Here's the 5X manual for reference: http://hitecrcd.com/files/ManualFlash45SX.pdf
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