Larry Taylor wrote:
What has been discussed here is the Antenna. If you look at different Receivers, you will find that they will have different length wire for a Antenna. Some receiver have coils on the board going into the matching stage of the receiver. This is where they match up the Antenna to the first stage of Amplification. Some just go into the matching input and there they are compensated for. So just looking at the wire and adding 1/2 or 1/4 the length to the wire onto it and thinking your doing things correctly, your wrong in that respect. But just the fact that you are adding wire, that is a good thing. The better the receiver can see the Tx Ant. the better it works. Just like what Gordy say's. "No signal no movey :-)" If your Fuselage is made up with carbon tube or a fuse that has carbon weaved in with Kevlar or Fiberglass its going to bock the receive signal by some degree. Just think of it as sliding your receive Ant. wire down a copper tube. It won't receive much, but if you have some that dangles out the end it will get more signal maybe enough to do the job. Its not at a certain wave length that has to be there to work. We are talking Receiver now. Transmitters is another story. The RF signal from a Transmitter travels at the speed of light. It is crossing the receiver wire Antenna and is creating a small AC voltage. The more wire you have the more voltage is being created on that wire.(SIGNAL!!!)
You will get to a point that the resisents will be to hi to be over come by the voltage created. We are now talking Long wire!! Transmitters on the other hand have a different type of problem with the length of the wire. If its not tuned correctly to the proper length there is a reflected signal going back to the electronics from where it came from. This reduces the over all output power to the Transmitting Ant. The bouncing back signal is out of phase with the one coming out of the electronics. It cancels it out by a small amount or and can damage the output of the transmitter if its a large amount. Most people remember about the Tuning of a Antenna and about the reflected part back when CB radios were the in thing " Good Buddy" A bad Ant, open or shorted coax would burn up the output circuit.
I just add wire to the receiver Antenna and just let it extended out the back. Longer is better. Problem solved with carbon fuselage Free info here no Lab expense required. Just my 45 years of experience working in Radios for a living with some EE Collage studies, Trade School Grad from Devry, and a FCC license to work on High Power radios,Military Ground and Aircraft schooling. I'm still working in it.
Larry Taylor KF6JBG
CD for the Visalia Fall Soaring Festival
2005 Oct 1st & 2nd
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----- Original Message ----- From: [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]> To: soaring@airage.com <mailto:soaring@airage.com> Sent: Friday, March 25, 2005 3:26 PM Subject: [RCSE] fuselages & radio range
They say that common sense is uncommon and I am as guilty as
everyone else in this department, so like everyone else..I went in
search of 'excaliber' the 'better' brand RX for use in my Pikes.
The Pikes have the Carbon Kevlar burlap weave fuse that has become
so popular and causes us to have to get our antenna's away from the
fuse, not just outside of it.
I was searching and trying all sorts of RX's... Some said, oh this
brand PCM has no problems....which of course means that the servos
don't move when the RX is not getting a signal....like non PCM
RXs...the condition is masked...and that works well enough to win
contests and keep the model safe for the most part...but it doesn't
'fix' the fuselage from blocking the signal.
I stopped searching when our number one radio guy said to
me....Gordy regardless of the components and how they are glued to
the board in a trick receiver....if they don't 'see' a signal they
don't have nuthin to work with.
The Fuselage blocks the signal, the fuse doesn't interfere with the
RX. No signal no movey :-)
The three choices which include 'hold' and programmable hold in the
Shadow are a BIG deal.
When I had 14mins left on my New Zealand LSF4 one hour task and my
Tranny started beeping, we attempted to do a quick charge, hoping
the model would just float around for 10 seconds or so...but no dice
as soon as I turned off it would go into a total death spiral. Hold
function would have been a nice feature there :-)
No receiver can think things up by itself, it just follows orders
and if no orders get to it...well you get the point. :-)
Gordy
-- Simon Van Leeuwen RADIUS SYSTEMS PnP SYSTEMS - The E-Harness of Choice Cogito Ergo Zooom
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