Hamish Posted July 6, 2009 Share Posted July 6, 2009 Having a couple of incidents, when I appear to have lost control and spiralled in, fortunately with minimal damage, I noticed that during my working on the model I had managed to coil the aerial back to the receiver. After feeding it back through this would have accounted for about 8". I both incidents the model was about 100m away from me and had been at least 300m before incidents. Could this be a factor? Quote Link to comment Share on other sites More sharing options...
Former Member Posted July 6, 2009 Share Posted July 6, 2009 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Olly P Posted July 6, 2009 Share Posted July 6, 2009 I'd say it was even probable that this was the cause. Hamish, what is the original antenna length, and what where you left with. I can probably work out what frequency it retuned itself too. On coiling at the end of an antenna, this is a trick that used to be used by radio operators to remove noise from some transmissions, by focusing the antenna on the correct frequency, it also had the advantage (for them, not us) of making the antenna more directional and increasing signal strength, from that direction strnger and unwanted interference from other sources weaker. Quote Link to comment Share on other sites More sharing options...
Hamish Posted July 6, 2009 Author Share Posted July 6, 2009 Thanks Phil and Olly The aerial had not been cut only pulled in and kind of coiled near the receiver. Model was my Boomer and the matter has been resolved for the moment. Had my Grandson up and we tried to park it beside a crows nest and although I could repair it, it has served its purpose. There had been no radio problems Live and learn that height is a saviour Quote Link to comment Share on other sites More sharing options...
Olly P Posted July 6, 2009 Share Posted July 6, 2009 Hamish, coiling effectivly shortens the antenna, in terms of RF transmission/absorbsion this means if becomes tuned to different frequencies. Coiling also has a directional effect on the remaining straight section of the antenna - there is a lot of mathmatics to understanding it all fully, I normally leave it to the FoS... Quote Link to comment Share on other sites More sharing options...
Hamish Posted July 6, 2009 Author Share Posted July 6, 2009 The coiling was not intentional and had just happened as I had been working repairing damage. There was not much theory involve when I made my xtal set ??? years ago Quote Link to comment Share on other sites More sharing options...
Olly P Posted July 6, 2009 Share Posted July 6, 2009 Hamish - understood ref coiling not being intentional. when you made a xtal set, was it a single crystal reciever? this would make the theory much more simple, as the crystal would have a range of frequencies it could be tuned to by the tuner dial, when you start looking at propogation and reception qualities antenna lengths get very interesting!! (or boring.....) Quote Link to comment Share on other sites More sharing options...
Hamish Posted July 6, 2009 Author Share Posted July 6, 2009 Olly From what I can recall it was a germanium diode in series with a coil, wound round an empty loo roll with a finned "condenser" in parallel, to enable the tuned circuit, connected to a pair of earphones It did work as I recall. I was at an age when I was hoping to speak to a green man from a planet in outer space. Quote Link to comment Share on other sites More sharing options...
Former Member Posted July 11, 2009 Share Posted July 11, 2009 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Brian Parker Posted July 12, 2009 Share Posted July 12, 2009 Also, Coiling will not turn an omni-directional antenna into a directional antenna. It will only detune/retune. Quote Link to comment Share on other sites More sharing options...
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