Nf-ID: #R:hpspdla.spd.HP.COM:15680022:trsvax:1195667298:000:4780
Nf-From: trsvax.tandy.com!earl    Aug 19 08:22:00 1992



/* ---------- "AM vs FM AGAIN? - Have Mercy" ---------- */
I know there have been lots of discussions lately on the net concerning
AM versus FM, but the topic has been of no interest to me until now so I
haven't been reading up on it.  Please bear with me when reading this
question for the umpteenth time.
Basically, I've had an Airtronics FM radio system on backorder for about
a month now.  I called Airtronics yesterday and they informed me that
some parts are on backorder and they should get them in another 1 to 1.5
months.  I figure that by the time they get the parts, build the radios,
ship them to Tower, and Tower ships it to me, it will be at least 2 more
months.
Well, Futaba also sells a micro system, but it is AM.  So now the big
question.....
IS AM SO MUCH WORSE THAN FM THAT I SHOULD WAIT TWO AT LEAST TWO MONTHS
FOR THE FM SYSTEM?
I know AM has more of a problem with noise, etc, but has anybody read,
heard, seen anything that would convince me to wait for FM or go with
the AM?
Thanks in advance!!
- Bill G
************************************************

   There are advantages and disadvantages to everything. Basically, it
   mainly boils down to what kind of noise and interference exists where
   you will be doing most of your flying. I have three Futaba 4nBL-E's
   for small electric planes, these are AM based radios. All three have
   performed flawlessly, and glitchless here in my area. The electric
   motors have capacitors across their power lines, but there is still
   lots of arc'ing and sparking coming off of the brushes. If possible
   check and find out what frequencies tend to have the most problems in your
   locality, and don't order a radio on those frequencies, but get a frequency
   that noone is complaining about.

   IMHA, in my long experiences at RC modeling and flying, most radio problems
   can be based on the modeler trying to save a buck. Recycling old servos
   into a new plane, replacing a single cell in a old nicad pack, reusing a
   old switch harness, reusing the old battery pack pigtail on a new pack,
   et cetera.  Then when something goes wrong, the modeler immediately blames
   radio interference. Basically, the cost of the RC equipment has dropped
   way down from the old days, when you had to take out a second mortgage on
   your house to buy a RC system. If you build a new airplane, put in a new
   pack and switch harness too. Older servos?, unless your really positive that
   the servos are good, then at the very least put good (new) servos on the
   ailerons and elevator controls. If your using the low cost, inexpensive
   servos, it is far better to just put in a new set, as they are pretty low
   in cost. To me it is cheaper than having a whole plane die in a pile of
   rubble after a crash. If you've crashed, the entire radio system is now
   unreliable, until it has been carefully checked out (eg. high G-forces, and
   the shock breaks loose solder joints, weakens wires and connectors, and
   cracks the receiver's frequency crystal.)

   Before you fly, check out the model carefully. Are the control surfaces'
   hinges loose? Is the motor loose? Are the adjustable clevis's pins worn
   or loose? Are the clevis's staying snapped on the control horns properly?
   Are the wing hold downs and their respective mounting places OK?, Are the
   servos loose in their trays? (I have had servos come loose after numerous
   flights, luckily I caught it on the ground). Have you lost any screws
   that are holding anything in place? Is the receiver's antenna frayed, worn
   or cut, especially where is goes through the fuselage or attaches to the
   model anyplace. Having a antenna break off in flight can be a big problem.
  
   If everything checks out OK, and then you have glitches and funny things
   in the air, you can blame radio interference. I have seen RCer's crash a
   plane saying "I don't have it, I lost it!!", and afterwards during the 
   examination, I find that the battery pack is low or dead, and when I tell the
   modeler my discovery, he shrugs it off as impossible, I've used that same
   pack for three years without trouble, and it was just charged last night.
   "You can lead a horse to water, but you can't make 'em drink it."


***********************************************************************


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 construed  as  being  provided  by  Radio  Shack or Tandy Corp.  Radio
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						Earl W. Bollinger
						@ <trsvax!earl>


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