Telemetry - talking radios

DaveBright wrote:

JRI wrote: ..........set up my Tx to give me an alarm when my model is inside a programmable radius from the Tx.

I'm going to move the pilot's box 10 meters closer to the hedge

Bothered? I will use my pocket gps to plant my feet in exactly the right place then my laser distance meter to check the hedge is where it should be - and if you find a small spot on the back of your head getting warm, I might well have forgotten to turn it off

On a more serious note, until someone brings out true imminent stall sensors (e.g detectors that can measure airflow breakaway over wing leading edge) speed measurement is of limited value, other than speed freaks proving how fast their model went on the 'beat up'.

In a naive attempt to see if speed info could help inform me about how my model was flying I had set the Air Speed Indicator (e.g. pitot tube detected, not GPS detected, which is only ground speed) lower speed alarm on my Sebart Suhkoi 50e at 10mph (having started at 20mph) thinking this would give me some sort of warning for 'about to fall out of the sky' but it triggers regularly in the vertical maneuvers and still appears to fly quite happily below this speed in straight and level flight, dependent upon power setting/angle of attack etc. The other problem is that the way the Spektrum telemetry works is that the various sensors are scanned in a set order, so until the telemetry module gets to the info from the particular sensor it doesn't do anything, then seems to take a while to transmit info back to the Tx, look the info up in the alarm table I have set within the TX and then convert it to voice info for me to react to. Stall warnings in full size aircraft usually give you, at best, a second or two to react and are regularly sounding during the flare and touchdown, just watch/listen to any You Tube video of a light aircraft landing taken from within the cockpit.

Of course once one learns about the complexity of the stall, (angle of attack, C of G, G Force being pulled, bank angle, overall weight, air density etc. etc.) a reliable stall warning is just not possible from air speed alone. This is why we modelers become such good detectors of the imminent stall by how a model feels. Our models give good visual feedback (wing wobble, nose nod, looking mushy in a turn etc), which along with the increasing control inputs we are having to make to maintain control give us much more instant and reliable feedback in most cases. We just need to develop/improve our mental processing and reaction response to prevent the stall occurring.

JRI wrote:

DaveBright wrote:

JRI wrote: ..........set up my Tx to give me an alarm when my model is inside a programmable radius from the Tx.

I'm going to move the pilot's box 10 meters closer to the hedge

Bothered? I will use my pocket gps to plant my
feet in exactly the right place then my laser
distance meter to check the hedge is where it should be - and if you find a small spot on the back of your head getting warm, I might well have forgotten to turn it off

:woohoo: LOL

John, you asked about pros and cons of telemetry, I'm only dipping my toe into telemetry with my receivers sending back RX battery voltage and received signal strength, but I can't see there being any negative aspects to having a bit more info on what's going on in your plane.

The RX battery voltage is set to warn me if it drops below a value I've set. The signal strength is useful for piece of mind, and again the radio will warn me if it's low or critical. I've also chosen to have my radio log these and it also logs all stick inputs too, this has been quite interesting to look at, but I'm not sure there is any real valuable info that I can glean from it. Having said that, if (when) I loose a model I should be able to look at the logs and see if I lost contact or simple stalled the model.

I'm going to get a voltage sensor for my flight packs, and I know someone who is playing around with a GPS sensor, I'm interested to know how that copes with inverted and knife edge flying. I'd be interested to know how high and far I fly as I'm terrible as estimating distances.

As for the talking aspects, I've paired mine down to 'important warnings' which hopefully I won't hear, 30 sec timer to remind me to land and switch position confirmation, it is just reassuring to know that it was the retracts I put down and not the motor kill switch, otherwise landings happen a little quicker than expected!

I'm also using the telemetry to switch the timer on for my little slope soarer, so when I plug the battery in and the receiver connects my radio waits 15 secs then starts the timer (and data logging). That way I don't have to remember to flick a switch.

Anyway it strikes me that your sudden interest in this seems to coincide with Pete making excellent progress on the Mig.
Can you get a fuel flow sensor that will calculate your fuel reserves and convert that into flying time?

IMHO, telemetry is most useful when setting up a model. Is the receiver battery okay? What current is really going through that ESC? And so on. But after a few flights you know everything is fine and can ignore it all and just enjoy your flying. And because you can ignore all this telemetry info you need to reprogram the transmitter so it does not report back every 20 seconds which will lead to everyone else being annoyed by it.

When everyone is using telemetry with voice alerts it will get confusing on the flight line. Chris and I flew the other day with the same transmitter voice and it was strange to say the least. Maybe a set of headphones is needed?