SCAT Electronic News December 5 1999
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- Category: Archive 1999
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SCAT Electronic News December 5 1999
"SCAT - 40 Years of FAI Free Flight Competition"
Table of Contents
=================
Rubber Rules - Korsgard
Tie Dyed ? - O'Reilly
attached docs on Yagi stuff - Kowal
Pictorial Info - Gregorie
Rubber Rules
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Author : This email address is being protected from spambots. You need JavaScript enabled to view it.
Hello folks!
I love flying and struckling with F1B models. Some of the thrills
are the first few seconds of the climb and the height at the end of the
climb ....
I have six (self-built and expensive) models in the box and I would
hate to see some new rules making them to museum inventary!
What about the following:
1. 30 grammes of rubber as planned from 2001
2. Round 1 like now with 210 secs max.
Round 2-6 with 180 secs max. - as usual-
Round 7 and the fly-off rounds with 25 or 20 grammes of rubber plus
ballast to keep the universal 230 g total weight.
Advantage: The existing models could still be used, the amount of
rubber for most of the rounds would even not outclass newcomers and everyone
would still have the hope to qualify for the fly-off through most of the
contest. Ballasting for the 7th round and the fly-off could be done using a
kind of "bobbin" which also could compensate for shorter motors.
Well, I think this was a new idea!
Bets regards/keep F1B alive
Jorgen Korsgaard
Tie Dyed ?
==========
Author : This email address is being protected from spambots. You need JavaScript enabled to view it.
Aram,
I'm willing to bet that, if the colored batch of rubber business were
implemented, you would eventually find some individual who had dyed a few
motors.
Jim O'Reilly
[Jim , does RIT dye work ?]
attached docs on Yagi stuff
===========================
Author : This email address is being protected from spambots. You need JavaScript enabled to view it.
The files were created with:
MS-Paint
MS-WORD 97
Autocad LT 98
If people are having problems with the word file I can output it again
as straight text. Might as well do it now huh?
(See attached file: 2M Yagi Construction text only.txt)
The drawing does not show in this document but is in the paint file.
Hope this helps. ---Ken---
November 29, 1999
Ken Kowals 2 Meter tracking antenna
During my experiments with trackers I built a number of Yagi array type
antennas for my 2M-wavelength transmitter. I was able to attain a 3X gain
in range with the use of these antennas. Unfortunately I was trying
to use a scanner as my receiver which proved to provide an
inadequate range for serious use. The plus side of this for
all of you who are using transmitters of 2 Meter wavelength( 144-148 MHz)
is that for $20 or less you can build an antenna
that will triple your range and provide directionality.
At the Patterson Lee Hines and I tested My antenna against the "Nubbin
" antenna that came with his 2M handheld radio. We were able to pinpoint
the direction of the signal from over 500 Meters by using the signal
strength meter on his handheld and rotating the antenna until
the strongest signal was found. With the stock antenna we lost the
signal from the transmitter at approximately 250 Meters. We did not
go out to find the maximum distance that the signal could be
received from but my tests with a scanner showed at least a 3
times gain in distance.
Due to the results of this test I was asked to draw
up what I had and publish for all to use. So here it is:
My prototype was built using a piece of 3/4 inch PVC pipe for the
mast and 1/4 inch soft aluminum tubing for the elements (available
from hardware store). The lengths and spacing were all calculated using
the information out of a number of Ham books that I checked
out of our local library. I would credit them but it's
been a while and I did not collect this information.
I drilled holes in the PVC to accept the elements. Cut the elements
to size and installed them in the tubing. The main element is
called a bent Dipole I believe and is made up of a single
piece of tubing bent to shape. Note: The two ends of the
dipole must not touch!!!! The cable which is RG-58AU and is
available from the infamous Radio Shack comes with a BNC connector on each
end as I remember. Just cut off the end you don't need
peel back some insulation and tape one of the wires to each end
of the dipole.
That's all there is to it. I am sure
someone will come up with a folding/removable element version that will
pack down into a compact package. Just remember that all the dimensions
are important for optimum performance. Note: the theoretical performance of
this antenna is higher than what I have attained which says that with
more tuning the performance should be even better.
This antenna will only work on 2 Meter trackers.
So here it is, free for nuthin.
If anyone comes up with a way to tune this antenna for better performance
I sure would like to hear about it. Good luck and happy hunting
(for lost models that is).
Pictorial Info
==============
Author : This email address is being protected from spambots. You need JavaScript enabled to view it.
----------------------------------------------------------------------
> This email address is being protected from spambots. You need JavaScript enabled to view it. wrote:
>
> Could not open the three attachments to the nov 30 scat which
> was about yagi antenna.
>
The .BMP file will open with MS Paint, Paintshop Pro or L-View Pro to name
just a few PC programs. It may not be readable outside Windows because the
BMP format is a Microsoft proprietary format.
The DOC file opens OK in MS Word 95 and MS Word 97.
The DWG file is an AutoCAD file. I was also able to open it with TrueCAD 3.
As a side note, it's much better to publish pictures in GIF or JPG format
because these:
- can be viewed using any Web browser
- are not proprietary MS Windows file formats
- occupy much smaller files
If you use a PC to move pictures across the Internet you should really have
either Paintshop Pro or L-View Pro to prepare pictures for ending and to
view those you receive. Paintshop will handle a larger variety of file
formats but L-View is easier to use and cheaper. It's currently my
favourite. Both can be bought over the Internet.
Martin Gregorie
[ as an editorial comment to the readers - I do not have the time to change
the format of Graphical and other attachments - My policy
is to send them as is, unless I decide that they are altogther
to big and do not send them at all.]
.......................
Roger Morrell
