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[ian-mccaffrey]

hi guys i got an old handset and receiver ... not 2.4 ... but not sure what frequency its just for my 7 yr old daughter to plod around the pond with ... ... any way ...  the ariel is about a meter long .... is it ok if i trim it down to size ?

[Tug-Kenny RIP]

The word you are looking for is  no..   It will affect the abilities of the radio in range and power.

Cheers

Ken

[ian-mccaffrey]

ok so the boat is about a foot long ... what am i ment to do with the 2 and a half ft left over from the ariel . do i stuff it inside and leav some hanging out or do i take it all out

[sailorboy61]

I (think) its all to do with wavelength, and the whole length of the aerial is matched to the Tx/Rx so its all needed. You might get away with it partially retracted, but it will certainly limit range, so keep the boat in an enclosed pond. Alternative is to swap out the rx in the boat and get a new 2.4 Tx/rx combo.

[Netleyned]

Not a good idea to retract the txt aerial.
Run the ex aerial up and down the boat a couple of times and rules the end up a mast or deck house

Not a good idea to run an unknown frequency at a pond with other users.
If you have no idea of the frequency band it could be 35 MHz
which is a no no for boats.
If it is 27 or 40 it could interfere with other users of the same spot frequency.
2.4 GHz with its short tx aerial will be much safer in the hands of a 7 year old
at the pond side.

Ned

[ian-mccaffrey]

i dont want to use 2.4 as im trying to keep it cheap and cheerfull . i had this given to me .


and netleyned . its for a boat .... i do know that much ... and i just cant remember what it is off the top of my head !! as i havnt got it in my hand infront of me .

[barriew]

Wind the excess aerial round a former of some sort - a tube is best and space out the windings. Keep the whole lot above th water line and you will be OK.


Take a look at the third photo down in this post http://www.modelboatmayhem.co.uk/forum/index.php?topic=41638.0


Barrie

[john44]

As above
Have the crystals got a frequency stamped on them?

john

[ian-mccaffrey]

As above
Have the crystals got a frequency stamped on them?

john

probably !!!

[malcolmfrary]

Retracting the TX antenna can overload the output transistors, which kills them, sometimes quickly, sometimes less so.
A while ago, it was possible to buy "stubby" transmitter aerials, these were rubber items with the proper length wound in.  Some loss of range, but usually within acceptable limits, and avoids overloading the output stage.  The cost might be comparable to a new 2.4GHz setup, without the convenience.
Shortening the RX aerial will impact range.  Winding it on a former, preferably in an untidy manner to stop it becoming a tuned coil (probably tuned to the wrong frequency) and hiding it inside the superstructure is best.  This still cuts range, but not as badly. 

[ian-mccaffrey]

Retracting the TX antenna can overload the output transistors, which kills them, sometimes quickly, sometimes less so.
A while ago, it was possible to buy "stubby" transmitter aerials, these were rubber items with the proper length wound in.  Some loss of range, but usually within acceptable limits, and avoids overloading the output stage.  The cost might be comparable to a new 2.4GHz setup, without the convenience.
Shortening the RX aerial will impact range.  Winding it on a former, preferably in an untidy manner to stop it becoming a tuned coil (probably tuned to the wrong frequency) and hiding it inside the superstructure is best.  This still cuts range, but not as badly.

 ok so basically wrap it loosely and messily around a bit of wood or something .  and it should be ok . but not too much range ...? am i rite .... teh area of pond that she will be using is less than 20 meters . . would this be ok

[malcolmfrary]

With a straight vertical aerial, 400 yards should be no problem.  Scrunched up, about 100 yards.  20 yards/metres should not be a problem depending on how well the motor is suppressed, as the local transmitter that the motor and its wiring provides can easily swamp out the real TX signal.

[ian-mccaffrey]

With a straight vertical aerial, 400 yards should be no problem.  Scrunched up, about 100 yards.  20 yards/metres should not be a problem depending on how well the motor is suppressed, as the local transmitter that the motor and its wiring provides can easily swamp out the real TX signal.

well thanx for all the help guys ... ill try it . but got a feeling im heading towards 2.4 !!!!