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[Paul R]

Hi all..

Just purchased new receiver as above.. With this model you get a BOBBIN, yes a bobbin, to wind up to 18" of the receiver antenna onto should you wish to do so. I thought you couldn't do this sort of thing with the receiver aerial ??? So if its too long this is what you do, and it says to wind it in a spiral fashion around the bobbin. The entire length of the rx antenna is over 1 Mtr in length. Thing is, if you can do this without compromising the performance of the receiver then I will because it will make things a lot tidier in the boat.. Advice please...

Regards

Paul R

[chingdevil]

I have a bobbin on both my standard Hitec rx and my micro rx, no problems at all with them. I like the idea, I would have wound the aerial up any way as it is so long.
I did try this trick on an Acoms unit, it did not like it at all servos constantly twitched.

Brian

[barry park]

A plain spiral will truncate the effective length as it is a block to radio frequency pickup.
Futaba says twist the subtracted length in a non-inductive fashion first........then wind round a card.
Replace that length with a vertical whip aerial of the same length.
Coil the twisted length round a card or bobbin.
Barry Park

[Paul R]

Hi Barry..

Futaba then seem to suggest differently from Hitec, who simply say wind in a spiral fashion (no more than 18" of antenna) around a small former or bobbin as they call it which is simply made of card which comes with the receiver. I'll try it and then do a range check and see what the results are. I mean you got to do something with the receiver antenna when its over 1 metre in length! In a small model thats long enough to hang out the washing!!

Paul R

[barry park]

Paul,
A bobbin coil is used to remotely sense motor slip in ac induction motors for rpm calculation...it is a good pickup for interference.
Twisting before bobbin winding will sort that.

It is good practice to wind long motor and battery leads in twisted pairs to cut emission.

I have never used a metre long vertical antenna and never had problems except when the solder joint to a socket broke leaving 4" ....so scratch the metre!
Half a metre is better than nothing.
Model submariners can run with their antenna entirely inside too.

Try a range test with a short antenna because you'll have a 10 minute walk with an extended antenna.......length does makes a difference.

Barry Park

[malcolmfrary]

The theory is probably that if the model needs the aerial concealed, it is of a size that concealing it in a tidy manner will compromise range, but you will still have all the practical range that you need.  When you can no longer see which way the boat is pointing, you are no longer controlling it, more a case of just offering suggestions.

[Paul R]

Right o.k.,

So it's o.k. to wind some of the receiver antenna onto a small flat bobbin, the only compromise being that the range might be affected somewhat , but I want to know if the antenna then becomes more likeley or should I say succeptable to RF interference. Hitec state that up to (46cm) of the total length of the antenna (105cm) can be wound onto the bobbin which is nearly half the length of the antenna surely thats going to have quite an affect on performance. The bottom line for me is this receiver is going into a £500 boat and I dont want the Tx to stop talking to the Rx in the middle of the lake or become more succeptable to interference. However it would be nice to have the antenna nice and tidy (excess wound onto a bobbin) in the boat.

Paul R   

[barry park]