Hi Jo,
I should have been more succinct. No dispute about longer is better as I mentioned a couple of emails ago. But "only" if if the fuselage is produced from carbon, and is demonstrating poor/directive range issues.
I wanted to stay away from refering to the portion within the fuselage as actually being referenced to GND, similar to COAX cable. But the physical spacing to create this is way off. As the internal portion is being detuned, whatever is required externally moves back toward resonance.
The "Y" portion, where you have two arms, serves no purpose. I would bet a single leg running up just one V-tail will dmeonstrate equal sensitivity if not better. The extra feedpoint created by the second leg of the "Y" dissipates energy, resulting in a net-loss as seen by the RX front-end. What happens during flight is that either leg while act as part of the receiving antenna depending on orientation to the TX...while it's counterpart robs it of energy :^)
regards from Canuck land, say hi to Ariel for me!
Jo Grini wrote:
I have to answer this... Atleast since it is me that wrote the Samba article...
Longer antenna in a Pike IS better. This because the fact that the antenna
inside a carbon fuse is shielded just like you car antenna is untill it
exits the car to the antenna. So if 30cm is outside the fuse you HAVE only
30cm antenna...
But the things get complicated since some of the antenna inside also
receives SOME of it. SO what is the real length? No one knows...
The same problem comes when you tape the antenna along the fuse. It is being
shielded since it is VERY close to the fuse. Just like laying your car
antenna down on the roof. The reception goes down and that fancy music gets
corrupted..
Y-antenna IS better. On a V-tail running two antennas you get a good angle
to the Tx (you) whatever angle the plane is flying. Therefore the tests show
it is better. The Swedish F3B team (some of them) even ran the antenna out
the elevator and then back again to exit the top of the rudder fin...
Oh BTW I have been testing a lot now on 72mhz also. Very little difference to 35mhz.... The stock antenna (both Rx/Tx) are also supplied in the same lengths.
BTW Simon say hi to all I know up there! Hope to see you again sometime!
Regards Jojo in Norway (that hope to receive a 9303 from Horizon very soon :-) www.grini.no
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Date: Fri, 25 Mar 2005 23:13:16 -0800 From: Simon Van Leeuwen <[EMAIL PROTECTED]> To: Larry Taylor <[EMAIL PROTECTED]> Cc: soaring@airage.com Subject: Re: [RCSE] fuselages & radio range, Antenna Stuff Message-ID: <[EMAIL PROTECTED]>
This is incorrect and misleading...adding wire to an antenna for the sake of it does not result in better gain! Longer is NOT better! More wire does not equate to more voltage at the antenna element no matter what the condition...
Date: Fri, 25 Mar 2005 23:14:27 -0800 From: Simon Van Leeuwen <[EMAIL PROTECTED]>
Subject: Re: [RCSE] Check out Samba Model, Antenna Message-ID: <[EMAIL PROTECTED]>
keep in mind these recomendations are squarely based on 35-40MHz experiences...the "Y" thing is an absolutely useless feature.
[EMAIL PROTECTED] wrote:
Click here: Samba Model, Antenna <http://www.modely.cz/samba/antenna.htm>
All,
Samba Model is a very good supplier to report and recommend solutions to the use of antennas with carbon fuselage sailplanes.
With my sub-rudder type sailplanes, I have had very good results with the antenna directed down from the pod fuselage below the carbon boom to the sub-rudder with a rubber band tensioner.
Dale Nutter [EMAIL PROTECTED]
-- Simon Van Leeuwen RADIUS SYSTEMS PnP SYSTEMS - The E-Harness of Choice Cogito Ergo Zooom
RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to [EMAIL PROTECTED] Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off. Email sent from web based email such as Hotmail and AOL are generally NOT in text format
-- Simon Van Leeuwen RADIUS SYSTEMS PnP SYSTEMS - The E-Harness of Choice Cogito Ergo Zooom
RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to [EMAIL PROTECTED] Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off. Email sent from web based email such as Hotmail and AOL are generally NOT in text format
