leroifort

I plan to buy a short soft graupner antena for my TX mc24
I transmit in 35Mhz (belgium here)
catalog says that those antenas have the same performance than a "normal" one, and they are not very expensive.

In that condition I ask myself why I don't see more of those antenas on the flying fields ?????

what's the trouble with those stufs?

visioneer_one

My Feedback: (506)

I now use 'Ducks on all my transmitters. They work just fine; I've had no range problems with them.

I've replaced broken telescoping ones a couple of times, stepped on them by accident, poked myself in the eye, whacked other flyers, etc.

The final straw? I got the antenna caught in the hi-start line. Launched the sailplane, then the TX. Broke everything. Ohhhh the pain.

Thank God I wasn't using a neckstrap!

leroifort

I assume that "ducks" is the correct word for "short soft antenas" in your language

aksmithrc

My Feedback: (2)

"rubber duck" or "rubber ducky" is the term used

Rodney

Note that the propgation pattern on the rubber duckies is not the same as with the conventional whip antenna. On a whip, if you point the antenna at the plane, you are sending it the minimum signal. On the rubber duckie, the stronger signal is off the end of the antenna. I can not remember where I read the information but I re call seeing that the whip will radiate a higher power density in some direction than the rubber duckie will, i.e. you will have more range in some directions with the whip than you will with the rubber duck.

leroifort

dear friends, I experimented my ducks antenna, I ordered it from graupner and it was designed to perfectly fit my graupner TX.
in the package was writte a big warning about the reduce efficiency of those kind of antenas. I went confident to the field after what I readed on this thread
During flight, my plane entered the fail safe mode several time for a short time.
It looks like with the USA TX band 72 Mhz you don't experiment troubles, but here in 35Mhz it's something else.
It seems logic because the lenght of your waves are shorter than our and you don't suffer a lot of the diference in lenght in antena regarding the theorical optimum lenght (half of the lenght of the wave)
So I warn here the european modelers who readed this thread.
ducks antennas are not a must under our latitude (oups I should say longitudes ))

Ladyflyer

My Feedback: (2)

Short and soft will work . Long hard ones are more effective in my experience.

Mr L is right the problem is worse at the longer wave,lower frequencies.

Forgues Research

My Feedback: (7)

It depends on how you interpret what you just said

JOHNBONE

I was always wondering if I could get a rubber duckie for my Futaba 9C, anybody know?

leroifort

John, I mail you free my 35Mhz ducks for graupner if you want.
too dangerous to me, I nearly losted a plane this morning when trying that stupid stuff (see my previous post)

Ladyflyer

My Feedback: (2)

I will try to find the Smiley Antenna website. They ptobably will make one for you.
In the meantime someone else may know the whereabouts of Smiley antenna Co.

JOHNBONE

leroifort, thanks but I use 72 mHz. Seems as if not many people I know here in Germany use 72, kind of puts me at an advantage I guess. But I really come close to breaking the stock antenna off all the time when I keep turning around and my son is standing there.

skypupmut

http://www.htantennas.com/rcduck.htm
I got one for my ECLIPSE from them
fast friendly business, and their antennas are realy tuned for our frequency range
they are the manufacturer for most public and other radio eq.

leroifort

I wish I could find a duck antena with integrated signal amplifier in order to have reliable perfos in the 35Mhz band

leroifort

leroifort, thanks but I use 72 mHz. Seems as if not many people I know here in Germany use 72

is 72 Mhz allowed for RC in germany?

JOHNBONE

Nobody has told me it wasnt. The folks at the club dont say anything. I know there is a surface radio frequency that cannot be used because it is used by the post office.

HarryC

My Feedback: (1)

I, and one other member of my club, use the rubber ducks on our Multiplex Tx on 35 Mhz with no problems. This is for flying standard sports models at typical distances. I would not use it if I was flying at extended range such as with a large sailplane. Mpx warns that range is about 70% ish with a rubber duck depending upon conditions, but normal range seems to be so far to start with that in most cases the reduction is not a problem.

Harry

JOHNBONE

Wow, 70%ish, I was hoping to get around 95 to 100 %. Guess I will stick with my stock stick :stupid:

EMU-187

antenas should be tuned to the freq. The length of the element should be the length of the wave, or 1/2, 1/4 etc. the closer you get to the length the more gain/efficency of radiation you get. The rubber duck is just some insulated wire wrapped a dielectric core, 35MHz would be approx 7 to 8 meter wave length, 72MHz would be approx 4 or 5 meters. I didn't calculate, I know 6 meter band is is 50-54 MHz. If you use a Rubber duck you lose power, so noise or other signals could make life interesting. Hope this helps, I know radio theory, just getting into Helis, John

leroifort

I also used it in a very normal range....... You make me feel anxious about the healt of my TX
I was flying a Wonder, very small model, so I was evoluting very close to myself.......

JOHNBONE

leroifort, man you got me scared over here about the frequency I use , think there is a way to find out for sure?

leroifort

leroifort, man you got me scared over here about the frequency I use , think there is a way to find out for sure?

I will check that in my books tomorrow morning and post the answer on this thread.
But be sure I am not going to give your adress to the police

leroifort

John, I send you a PM

HarryC

My Feedback: (1)

Leroifort, I have used the rubber duck on a .90 size aerobatic model doing the old fashioned turnaround style schedules which take the model some distance away, and had no problems. Any very short time losses would have been masked by the failsafe but anything over 1/2 second would have closed the throttle and that never happened. I have also used it on a Twinjet electric model with a cheapie Rx, and had no problems.

Harry

leroifort

I have to present my humble excuses to the duck antena manufacturers and rcu members using ducks . In fact today afternoon my sig four star 120 entered the fail safe mode and never went out . I was using my telescopic antena. RX system can not be involve because my first problems started with a other plane. My adverses coment about ducks antena were wrong.

my 120 is a total loss

my graupner mc24 is on auverhall

RIP......