It is not that critical for a receiver.
Do a range check when you can something before and after. That will give you peace of mind.
If you just can't see yourself adding on to the Receiver wire than run it in the wing.
Just don't fold it up,coil it up,shorten it up,or run it along other wires. Its so easy to just add on and use alittle shrink tubing to cover up the solder joint. You don't need to have 4 feet hanging out. Rang Check, Rang Check Range Check. You will be happy than.
Wire: Use a highly stranded wire. The more strands it has the more it can flex, like servo wire. You can cut the Antenna wire closer to the receiver and add and extend it there. So that the factory wire can dangle out the fuse.
Larry Taylor KF6JBG CD for the Visalia Fall Soaring Festival 2005 Oct 1st & 2nd Home: [EMAIL PROTECTED]
----- Original Message ----- From: "Paul Emerson" <[EMAIL PROTECTED]>
To: <soaring@airage.com>
Sent: Friday, March 25, 2005 10:10 PM
Subject: Re: [RCSE] fuselages & radio range, Antenna Stuff
<friendly curiosity>
I thought RX antennas were "tuned" to a frequency by being a specific length. So wouldn't adding wire put it out of tune? Or is more wire always better because it has more surface area to receive?
Not even remotely an engineer, Paul
On Fri, 25 Mar 2005 17:22:35 -0800, Larry Taylor <[EMAIL PROTECTED]> wrote: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
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
Home: [EMAIL PROTECTED]
----- Original Message ----- From: [EMAIL PROTECTED]
To: 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
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