RE: SYSTEM3000 Beginner's question
 

Tiger I had the same problem with my futaba 7c when I turned it on in my basement. once I went to the field it was fine.
Maybe the seniorita is telling you it is itching to get some air time. :D LOL

RE: SYSTEM3000 Beginner's question
 

Why?? Because when you lower the antenna the transmitter is not longer sending out a signal, and the receiver no longer has instructions to follow so it just twitches like that.

You want to avoid extended periods with the antenna collapsed. The transmitter circuit in your radio is putting out energy that is intended to be sent out of the antenna. When you collapse the antenna that energy has to go somewhere, and that somewhere turns out to being released as heat. That heat can and will burn out the transmitter portion of the radio.

Ken

RE: SYSTEM3000 Beginner's question
 

Just so you know I'm not blowing smoke your way, I am a Ham radio operator. Callsign KC0MDA.
When you collapse your antenna you are mismatching the impedence of your transmitter and antenna. This mismatch effects signal power output and allows your receiver to try to find some other source of information. If there is something in the house or in the vicinity of your receiver that is transmitting some kind of RF encoded information, then your receiver is trying to decode what it is receiving. This is translated visually by your servos jumping around.

What concerns me is how far from your model is this radio when the antenna is collapsed?

RE: SYSTEM3000 Beginner's question
 

Ken, how long is a long period? I usually start my engine, tune it, do a close range control check and walk out to the flightline before extending my antenna. Will this hurt my radio?

RE: SYSTEM3000 Beginner's question
 

I have to agree with RCKen and disagree at the same time. The transmitter continues to output a signal, but due to the reduction in antenna length the transmitter circuitry is mismatched. The mismatch is impedence is what creates heat becuase the radiation cannot flow easily from the antenna.

Overboard, no, that period of time should not be long enough to hurt anything. Unlicensed RC transmitters only output around 500 to 650 mW (milliwatts) of power. Max power allowed by the FCC for Ham transmitter is 1 watt, which is still a very low amount of power. The only way I could see heating up the final amplifier transistor in a RC transmitter would be to leave it on with the antenna collpsed or removed for a very long period of time, perhaps overnight.

Also 72 mHz transmissions are generall low enery radio waves anyway. They don't require a lot of power to carry information anyhow.

RE: SYSTEM3000 Beginner's question
 

It happens both away about ten feet and right in front of it. I understand what you say ken and vertigo. But all manuals state that you should do a radio check both WITH THE ANTENNA COLLAPSED and with it EXTENDED. Why have such a test when all the servos are going to do is jump around. From what I have read in manuals the servos are supposed to run smoothly both with extended and collapsed antenna.

RE: SYSTEM3000 Beginner's question
 

Isn't that what they call a range check. You are supposed to do it first with collapsed antenna then with extended?

RE: SYSTEM3000 Beginner's question
 

PRE-FLIGHT CHECK LIST:
As stated in my Sig "The basics of radio control"

Radio range check:
(in part) . . . (quote) With the radio antenna totally collapsed, start walking away from the model while constantly working one of the controls, like the rudder, as you go. Keep walking and moving the sticks until control is lost. You should be at least 30 or 40 feet away from the model (sometimes it's much more) when you lose control . . . (unquote)

I can't even do that because as soon as I turn the radio on with collapsed antenna the servos go crazy. So I can't even get to a range check.

RE: SYSTEM3000 Beginner's question
 

Yeah, range check. What you're telling me is that at 10 feet, you servos are jittery. Worrisome. Several things can contribute to jittery servos at a close range. Ideally you shold be able to get 50 feet or more out of a collapsed antenna range check.

Some things to check for.
- Is your receiver antenna touching metal of any sort?
- Is you receiver battery fully charged? Low charge on a receiver battery leads to decreased sensitivity in the receiver. Had this one come up for me recently. Drove me nuts.
- Is your receiver battery supplying the full amount of voltage it is rated for? (i.e. bad cell in the pack)
- Is you transmitter battery fully charged?
- Long shot, but they do make RF noise. Is there a flourescent light nearby?
- Is there a computer nearby? The power supplies in older computers were notorious for being RF noisy. A lot of reasons why Hams would wrap their computer in tin foil years ago. :)

RE: SYSTEM3000 Beginner's question
 

What bothers me, is that you're not getting any range with the antenna down. My radio can sit on the bench with the antenna down and the plane can be in the other room and I don't get any noise/jitters in my servos. Even with my single conversion GWS receivers I don't have any problems. I wonder about your receiver now.

RE: SYSTEM3000 Beginner's question
 

Tigerdude,
Yes that is what a range test is. But looking at your pictures from your build thread you show the receiver antenna coiled up, if that's the case then 10' will be just about as far away that you can get. When you do a range test you should have the receiver antenna FULLY EXTENDED. With the receiver antenna fully extended then you should be able to get ~100' away from the plane and still control it with the transmitter antenna collapsed.

Ken

RE: SYSTEM3000 Beginner's question
 

Turning on two receivers at the same time will not cause any problems. They will both do whatever the transmitter tells them to. You should definitely be able to control the Seniorita flight pack with the antenna down.

Check these things in order:
Is the battery fully charged? A weak battery can cause poor reception.
Even if it is charged, check it with a battery tester to be sure it's working.
If you don't have a battery tester, try the battery from the LT-40.
Do you have the receiver antenna wire fully extended? If it's still coiled up, it won't receive well.
Did you route the wire parallel to metal pushrods? This can cause interference. Try pulling the antenna out of the plane to see if it improves.
Is one of the servos stalled? This can drain extra power, possibly causing poor reception.

If none of these help, it's time to start eliminating possible bad components.
Unplug all but one servo. Does it still jitter?
If yes, try a different servo to see if that jitters too.
If both jitter, you might have a bad receiver. However, before you decide this, try plugging the battery directly into the receiver to confirm that the switch isn't bad.
Next, try swapping the LT-40 and Seniorita receivers.

RE: SYSTEM3000 Beginner's question
 

1. Has it always done this?
2. Are the batteries fully charged? TX & RX?
3. Check RX antenna routing
4. Don't have TX too close to the Plane. Signal may actually be too strong. Step back a few (5) feet and try again.

RE: SYSTEM3000 Beginner's question
 

After seeing the picture above, my thoughts move to the coiled antenna.

RE: SYSTEM3000 Beginner's question
 

Ken, wrong plane. Picture is of the Tower trainer. Problem is the LT-40.:D Good point though.

RE: SYSTEM3000 Beginner's question
 

Point I was going to make to him bruce. I thought it was the LT-40 that the problem was with but I was wrong, it is perfect. The problem as it turns out was the Senioritta. I looked at the setup there and found out that the servos were linked up wrong and THAT was the airplane that the elevator and rudder were on the right stick (I knew there was a plane that was set up that way). I have since corrected the linkup and it is now correct. I have still got some jerking in the servos as mentioned earlier and I am still working on it. Will get back to you if I can not figure it out. Thank you.


I understand that the antenna has to be uncoiled but I only plugged the servos into the receiver of the Tower Trainer to install the servos.
I assure you that is not the reason for the servo frenzy. The antenna is attached at the fin.