The
Prez Sez
Hi folks!
Can you believe that it is 2005 already? I'm having a bit of a rough
time believing that.
On to business; as you know, we have designated January as the month that
we do our financial audit (per corporation commission rules), so we plan
to accomplish that at this month's meeting.
Other actions we'll need to address are what field improvements we want
to do this year. Many of you have asked how the field lease plan
is going and we will address dusting that off and talking to the City about
that. Club re-certification, member dues, flying at Libby Field (or
not), and the Father's Day Fun Fly are additional issues to be discussed,
so this will be a full and busy next few months for the club members.
We will also need to recommend another Director to the Board of Directors.
As you know, Jerry Mingo is in Kosovo and has concerns about being on the
Board of Directors for the club from there. Your current Board consists
of the former Advisory Board (Meyer Gutman, Jerry West, Will Herman, Rich
Hotchkiss, and Jerry Mingo).
Please don't forget (like some of would really do that) the annual AMA
Convention in Ontario is the 7th, 8th and 9th of January. Even if
you don't have your tickets yet, you can get them at the door.
HAVE
A HAPPY NEW YEAR
Bill
And finally, our technical information this month comes from, Jean Sellers,
editor of Flightline of Yankee Hill, CA.
Radio
Equipment Care
Vibration
It is very
important to make certain that your receiver is not subjected to excess
vibration from the engine in your model. The common practice is to wrap
the receiver in soft foam and stuff it into the fuselage. However, the
new design of receivers have several, up to five, components that are very
easily damaged, or change values to affect a receiver's performance when
subjected to vibration. The best method is to make a box or tube of soft
foam plastic or rubber, and make it a size that allows a little movement
for the receiver. Then, wrap the bundle with masking tape, not rubber bands,
as these compress the foam, and reduce the insulation from vibration. Finally,
make absolutely certain that the servo and battery wires emerge from the
bundle at the opposite end from the antenna
Reversing
Switches
I have had
many transmitters with channels not working or with travel jammed at one
end. Many times this is due to a channel reversing switch not being set
correctly. Some transmitters have very light action reversing switches
that can change position very easily. Check to make certain that all the
switches are at their end positions, and toggle them several times to help
keep the contacts clean. If the channel is still bad, then it is usually
a problem with the respective stick assembly, usually the pot or its wires.
Transmitter
Battery Packs
I hate to
see the familiar method of installing transmitter NiCd packs using unreliable
snap fasteners rubbing on spring leaves. Too often I have seen these corroded
and lacking tension, with corrosion down inside the press studs parts.
It is my practice to change all of these battery connections with two heavy-duty
two-wired connectors which make a safe and easy to replace pack. I also
get to the isolation diode which will prevent cycling or load testing of
the internal battery. Here, I install a fuse across the diode, so that
it adds to the safety of the charge circuit, as the fuse will blow if a
short is made across the external wiring and then the standard diode backs
up the protection.
Servo Gears
After a severe
landing or crash the servos need to be checked for damage to their gear
trains. It is not necessary to open up the case, as a real test is to rotate
the servo output arm, without the servo being installed and driving the
gear train back thought its reduction to the motor. This very severe test
will show up any weak or damaged gears by a ratcheting or even a freewheeling
action. If you decide to replace the gears, make absolutely certain that
you find and remove all the broken teeth, as they are sometimes the same
color as the silicone grease used to quieting the gear action. Check for
teeth stuck into the good gears, and look where the motor pinion is located
for more hidden parts. When you install the output gear, be very careful
that you orient it in the correct direction to allow full circular travel
looking at the position of the end stop molding.
Transmitter
Antennas
The metal
whip antennas take a beating, so you need to look them over regularly.
Extend it fully and give it a shake, checking for slop in the sections
as this can be an intermittent connection. Clean it with tissue and alcohol
and use WD40 as a lubricant This will keep the internal connecting springs
clean. If any of the sections slide back, replace the antenna, and never
use metal gadgets to hold the flag in place. If you break the antenna,
simply solder the pieces together with brass tubing while you wait for
a replacement. Also check at the bottom as the threaded insert often breaks
loose.
Receiver
Antennas
The standard
length is one meter, while USA made receivers use three feet. However,
the actual length is not that important, so don't panic if you chop off
a few inches. You can safely splice back the broken end and cover the joint
with heatshrink sleeving. To replace the antenna at the circuit board requires
soldering skills, so it may be better to splice. Use a similar stranded
wire, the gauge and insulation is not very important. Never string an antenna
to the model using a metal clip at the end! Always try to route the antenna
at least two inches clear of any other internal wiring.
Editors Note:
Changing the receiver antenna length can and will adversely affect the
range of the receiver.
Transmitter
Dead?
You can check
the operation of a 72 or 75 Mhz transmitter by turning on a standard TV
set to channel 3 or 4 and noting the pattern on the screen when the transmitter
is close to it. You should hear a change in the buzzing sound as you move
the sticks on an AM or FM, but not the PCM! A common cause for a dead transmitter
is the internal fuse, which is sometimes well hidden. JR transmitters have
a problem with weak spring metal in their fuse holders, which can be an
annoying intermittent problem and needs retensioning when replacing the
fuse.
The Futaba
Attack and Conquest Transmitters often have intermittent on/off switches
and the only way to replace them is complete dismantling of the stick assemblies
and removing the front plate!
If you have
a battery box for loose cells, this is deadly! Replace with soldered in
cells, and in the Futaba 5 AU and 7 AU, these need their spring battery
contacts removed and the connection replaced with suitable matched connectors.
Don't run
you transmitter for longer than 15 minutes with the antenna collapsed,
as this will, in time, damage the RF transistor due to excess heat build
up. Use a servo driver to set up the servos, then use the transmitter to
fine tune the neutrals and travels. A low meter reading us usually a sign
of a bad battery pack!
from Flightline
Jean Sellers,
Editor
13136 Surcease
Mine Rd
Yankee Hill,
CA 95965
Club
Meeting
The next meeting of the MMRCC is scheduled for January 6, 2005 at 7:00
P.M. The meeting will be held at the Northrop Grumman facility. Personnel
are required to sign-in and sign out for security purposes. |
