Range tested my Super Sportster today and lost signal at about 40 ft or so. What causes this? The batteries were fully charged. Cracked crystal maybe. The plane wasn't flown since jan 2 05

Could be the routing of your rx antenna, extraneous RF interferrence (not likely), or bad TX. Also, check and make sure your batteries are good--just because they're fully charged doesn't mean they aren't bad. There could be a bad cell that only shows up under a load...

Other things that can contribute to poor reception include nearby objects - like a car, building or other AC.

A range check is a great thing to do; but it is with a clear line of sight between the Tx & RX. After that then you can get into poor batteries, broken antennas, etc.

Remember "It's better to go home without flying, rather that going home with a bag full of broken Airplane." [&o]

(Cheaper too )

Even ground-water can affect your range check.

Is your Tx battery old or tired? A bad Tx battery is more likely to give you a bad range test than a weak Rx battery.

Having the receiver antenna wire very close to the ground can reduce range. Also, having the loose end of the wire laying on the ground can reduce range.

Tx antenna sections not makeing contact after setting for long time , remove any oil from tx ant

where was the plane and radio stored?moisture from condensation can cause all kinds of corrosion inside tx and rx,were the batteries in the plane and were they kept charged the past 8 months.there is also the possibility of black wire which is the negative leads off of both battery packs turning black instead of copper.sound like a check up by a service center would be the best thing to do if nothing has changed in your set up since the last time you flew.

thanks for the replys I'll probably check some things and maybe send it in. The line of sight was clear and the plane was on the ground. Plane was stored in a dry garage with all the rest of my stuff. Flew 2 others including maiden of pete n poke. They were fine. This is a fairly old setup should probably get a new set of batteries.

over here in the u.k. the fliers who want to fly at the nats have to have a new tx aerial and proof of sale, i think that is where your problem lies.

Although I still perform the simple 100ft range checks that are described in my radios' manuals, I no longer solely rely on them. With the aircraft at home, on the driveway, and a helper, I perform a peak test - walking as far as I can until the aircraft starts to 'glitch.' Most times, this distance is at least twice the 100ft distance that I use at the field.

If the 100ft test were the only test I performed, I could lose 50% of the possible range before the 100ft test would detect the deterioration. That's quite a bit to lose before detecting a problem!

I perform the peak test 3-4 times during the flying season, depending on how much flying I'm getting in.

Peak range will vary depending on all the factors noted by others here - battery condition, ant. position relative to servos, ant. condition - plus other things such as covering materials (metallic vs. non-metallic) - so find the peak for each aircraft, don't assume that all your aircraft will have the same peak range.

Also, as an instructor, I instruct my students to do their range checks the exact same way every time. Test method inconsistencies make it difficult to interpret/compare test results.