FW 190 trouble

[hydrostatics]

Hey gang I was wondering I built my new GWS fw190 and sent it into the air this evening for a trim run I had it flying nice but I noticed on this flight that I was experincing a little freaky responce problem . almost like I was out of range So I landed and inspected it I noticed that the antenaa wire was still inside the fusalage but I didnt think this would be a big problem aperintly I might have been wrong .the second flight proved this, Flight went fine untill I decided to add some range and altitude to tmy flight plans , The plane lost total control I heard the servos do the funky chicken like signal lost and it plowed into the ground...(I almost cryed btw) My question to this forum is it more probable that my failure to dangle the reciver antena wire from the bottom of my airplane the cause of crash, Or is it more probably that the caslt reciver is to blame and be defective? I'm assuming its antena related and not reciver but I value the forums experence and would greatly apreciate your input.

[helihead]

Hey Hydro,

It could always be a bad receiver but I think it's likely the antenae. I had something similar happen a good while back. I don't think it was due to the fact that it was inside a foamy body so much as the fact that it was folded.

I have tried several thing to keep from dangling an antenae behind a small scale bird and it never works well if the antenae is shortened or folded or rolled up. If you want to get rid of the wire then you need something like a deans mini or a micro Z. Even then you will lose some range but it may not be an issue with smaller foamies that tend to fly cose anyway.

I also lost 2 models to the tin roof on a chicken house once. Flew too close and lost one. Thought it might be the chicken house but wasn't sure so I was dumb enough to try it again with another model. Same funky out of control thing happened. Now I stay away from big metal roofs.

[hydrostatics]

Wow, Im not the only person to try things twice lol, Thanks for the insite

[Leo L]

The rules regarding the antenna wires are quite simple:
1) NEVER shorten or lengthen the wire. Its length is set by the frequency band being used.
2) NEVER coil the antenna or cause it to be doubled up. You can reverse the antenna, such as going all the way to the tail and then back to the front, but do not go back to the tail again.
3) NEVER encase the antenna in anything metal. Plastic, wood, foam, etc. are all OK.

On most of my planes, I run the antenna through the fuselage to the tail, bring it out of the fuselage, then run it along the bottom of the fuselage toward the front, taping it to the fuselage with packing tape. It keeps the antenna neatly out of the way and there is absolutely no loss of signal. Before I tried this on my first plane I contacted the techs at Horizon Hobby. They told me that there would be no noticeable loss of signal and they were absolutely right.

[AirWarriorBelgy]

There are always two schools of thought on this issue

1st you "can" cut an antenna down or add to it ...but there is a caviat,
antennas are 1 meter long; Frequencies are measured in meters (full wave cycle antenna's are 6 meters I believe or is that 3 meters, anyway the key here is 1 meter)
a Meter equals approx 39 inches...you can cut an antenna in half, that's half a meter measured from the solder joint at the pc board, the east way is to fold the antenna in half and then cut at the halfway point.

Conversely your range will be cut in about half as well.

Some yrs Back GWS was selling RX's with the shorter antenna because of this proven radio theorum.

Base loaded antenna like the Deans and ...Litenna.. have capacitors at the base and a short antenna (again these are measured on the basis of a meter) the quantative amount of the base caps plus the length of the short wire equal 1 meter or 1/2 meter

so based on this proven theory you can "coil" an atenna around a non conductive media to create a simple base loaded system

This is the basis of Hitec's Electron 6 RX that comes with a carboard piece to wrap the antenna around and "Base Load" it. I have several Electron 6's and have wrapped the antenna around

many heli pilots wrap the antenna around the legs of the heli and have no issues with this...I have a blade CP that does this as well

going back and forth creates an antenna "Array" but again there is a reduction in range and the Coiling rules apply see the caviat below...but when was the last time you saw a Heli pilot going for the 1000 foot range. The other thing about this is that the skid legs are made of Carbon Fiber....not a good thing to wrap around, but I have never had a glitch in the Blade's RX quality (of course I fly only about 50 feet away at any given moment and never higher than about 50 feet)

Years ago we coiled the Antennas around a plastic tube, like a soda straw

The Caviat to base loading is even coils, with even spaces between the individual wraps and don't let the wire touch itself, although on the Electron 6 they tell you to do this and I did without experiencing glitches

There will be some range loss, but not as much as you would think, probably less than 10%; in real world figures that means you can fly 900 feet away as opposed to 1000 feet away (smaller parkflyers get really small fast at these distances)

Most glitch problems with Castle RX's is the Crystal seating, especially if you use a GWS single conversion crystal as I do. The trick here is to spread the legs of the crystal a skosh, then insert into the RX and then tape the crystal in (small piece of scotch tape over the top.

A wiggling crystal will cause more glitches than any other suspect item espedially during G-force exchange manuevers such as banked turning when the airframe may shudder a bit, although it is not noticable to the naked eye.

the next thing that will cause a glitch is two pieces of metal rubbing against each other, the sound created by this action is a freqency and can ghost or glitch your RX, how bout a servo wire laying on your antenna, or and esc wire...etc

an example of this I would to do as a kid with the family's older RF style remote control TV. I would take a steel Shiskabob skewer with a ring in the end and drop another skewer through the 1st ring, if i spun the skewer just at the right speed it would cause the channels to change on the TV, no more fighting for the remote.

Brushed motors that do not have capacitors soldered on can cause glitching too. Sometimes the factory installed solder joints come loose.

And yes Metal roofs, Baseball Backstops, Metal Bleachers, Soccer and Football goalposts can all cause a glitch by redirecting and altering a signal frequency, much like the antenna dishes used to send signals out into space, only in this case they act as a parobolic reflector of a sort, and your corrupted signal is broken and bounces back and holds just enough of the frquency to be read incorrectly by the RX.

Just to add, all of my planes now have Castle Berg 4l's in them ( that's about 25 berg 4l's in all ) as I went from Positive shift (JR Radios) to Negative shift (Futaba 9c) and not one of them has glitched on me, and I am flying at events all the time, as well as flying at a local school field.

I suspect something more than just an RX problem, but I would not necessarily rule it out either.

could be someone on the same frequency closer by than you think too

and one more interference issue....Ham radio operators are supposed to stay off the 72mhz band, and most of them do...but everynow and then:rolleyes:

A brushed motor going bad can cause glitches, guess whats in your servos....yup a tiny brushed motor.


Chuck

[mikee1159]

I'm new so if this is a silly question know why...lol
I have a spectrum radio. The antenna leads on the receivers’ are very short. Any problems because of this? I'm flying a Super Cub I traded over to the digital set up, as a result the receiver and antenna are inside the foam fuselage? Problem?:o

[AirWarriorBelgy]

no the spectrum systems..or 2.4 ghz systems do not need a long antenna lead due to
1) digital signal and signal binding
and
2) Fractal antenna arrays