Surely the main point is that it will tell you when it's going out of range.....never had a problem with any of the receivers from 4-8 channel versions, except for one which was shielded by metallic covering(my fault!), which then gave me a "signal loss " warning at medium range but remained fully controllable.

Originally Posted by GordonTarling

All that those dbm figures tell you is that one receiver is a bit more sensitive than another. What it doesn't tell you is what the range IS under specific conditions. e.g. if the -98dbm gave 2km range, the the -106dbm could probably give 4km range (guess!), but the average modeller will never usually know the difference unless he's flying out of sight.

I agree with you. So many things affect effective range. All I was originally pointing out was that some receivers had more range than others.

I never fly far away though I have clubmates flying 250cc 3D models, 2.5m fast turbine models & half scale gliders: they might be more concerned to know some receivers are likely to have better range than others.

Guess it is all a question of symantics. If one receiver had half the range of another I wouldn't call it full range. On the other hand if they were both out of line of sight in even a large model I guess you could say they are both full range (the extra range of one being of no use).

Just use what works. I based my receiver selection (currently 13) on Jeti website. R7 for small model, R6 for small/middle & R8 for middle/large.

Dave

One of the really nice Jeti features is the output programming.

If receiver space is at a premium and you need the outputs just use 2 receivers: can take two five channel rx's and you have a 10 channel. Can locate them more easily as well.

When I wanted to test a second hand 50cc'er I put an R6 up front controlling throttle, choke & ignition. A second R6 put up near the wing tube controlling the 2 elevators, 2 ailerons & rudder. The output programming also let me dispense with the JR Matchbox on the elevator halves.

With Jeti there is no need for using Matchboxes or Powerboxes (other than power).

Dave

Originally Posted by wildpalms

I agree with you. So many things affect effective range. All I was originally pointing out was that some receivers had more range than others.

Dave

True indeed. One of my older Spektrum receivers certainly had only 'parkflyer' range. Literally, if you got more than 100 meters out, the receiver would loose the signal. My confusion came from the Esprit web site not being clear on the documentation. As my purposes for this radio are for sailplanes, range is an issue for me.

Esprit Models does show this 7 channel range as being Parkflyer/mid-range
http://www.espritmodel.com/jeti-dupl...telemetry.aspx

This 5 channel range as being indoor/parkflyer
http://www.espritmodel.com/jeti-dupl...telemetry.aspx

This 9 channel range as being full range
http://www.espritmodel.com/jeti-dupl...telemetry.aspx

Esprit really, really should correct their web site. It would not hurt to put the dBm levels in there either.

As ZB has stated that all receivers are full range and other users have stated they have no problems with ranging then I am comfortable with purchasing the DC-16.

One problem I have had in the past is the TX showing 0 and 0 on the 2 antenna at about 400 metres range and you then get an alarm.
The model glider in question had a carbon and kevlar fuselage, and carbon wings.
Even though the antenna were outside the fuselage, the carbon still masked the signal sometimes. Although I never lost control of the model, the warning messages were worrying.
The problem is that the TX power is 100mW, but the return TX power in the receiver is a lot less I suspect. When someone mentioned that the R7 power output is 6dbm and the R9 power output is 20dbm, that makes me think that the warning of low antenna and other telemetry will be lost sooner with the R7 than the R9 receiver. They probably still have out of sight range, but the telemetry fails sooner.
David

I'm not sure I'm buying the R9 output being 20dBm, as that is, by my calculations, 100mW. If this is true, then the receiver is outputting the same power level as the Tx. Maybe it is, but this seems suspect to me.

Also, Gordon in post #150 mentioned the Rx sensitivity numbers varying from -98 to -106dBm. Keep in mind that every 3dB is a loss of 1/2 of the power, so the power being rx'd at -98dBm is 267% Greater than that being received at -106dBm. So a Rx rated at -106 would definitely have greater range.

I do NOT, however, have any idea what the attenuation factors are over distance...so I couldn't say what the extra 8dB might mean in terms of increased range.

Hi, the receivers that aren't situated in a plastic box (like current R5 or R7) are meant to be shorter range and dedicated to parkflyers. All others are full range with sensitivity -106dB. The new receiver R5/satellite on one box is now being prepared and it will have also a full range. Parameters will be similar like this one:
http://www.jetimodel.com/index.php?page=product&id=189

And yes, it is possible to program all settings of receiver/Spin through a Jetibox emulator.

I sometimes think we fret too much about these RF power and sensitivity figures. Before converting to 2.4GHz, I found that any electric model on more than three cells or 500w, especially if a uBEC was used, was almost certainly to suffer from interference, often to the extent that it could be a real struggle to achieve a safe operating range even for normal sport aerobatic flying. Since switching to Jeti Duplex all my previously glitch-ridden models have been rock solid, even the 9 of them fitted with R4 and R5 receivers. These are not park flyers

Before going the Jeti route, I did read of people using the system in extreme range situationsoccasionally getting 'loss of signal' alarms. However, I was heartened to hear that even then there was no loss of control of the model, suggesting that the return link fails before the uplink. This is good design to my mind, and should be a source of reassurance rather than concern.

Equally, the fact that Jeti are prepared to publish sensitivity figures for their receivers rather than vague marketing hyperbole gives me confidence that someone has thought this system through pretty thoroughly.

Of course, this same engineering thoroughness is probably the reason I am still waiting for my DS-16. . . . .

+ 1 !

+2!

I occasionally receive a 'low signal' alarm when flying my electric Aghusky tug at great height/range, but I've never had even a hint of loss of telemetry or control - this is with an R10 receiver.

Originally Posted by MafRaf

Hi, the receivers that aren't situated in a plastic box (like current R5 or R7) are meant to be shorter range and dedicated to parkflyers. All others are full range with sensitivity -106dB. The new receiver R5/satellite on one box is now being prepared and it will have also a full range. Parameters will be similar like this one:
http://www.jetimodel.com/index.php?page=product&id=189

And yes, it is possible to program all settings of receiver/Spin through a Jetibox emulator.

This contradicts Jeti USA who are saying they are all full range and Jeti CZ who actually have different figures for a number of the hard cased receivers.

Originally Posted by GordonTarling

+2!

I occasionally receive a 'low signal' alarm when flying my electric Aghusky tug at great height/range, but I've never had even a hint of loss of telemetry or control - this is with an R10 receiver.

Same here. When I originally flew my 88" Extra on a pair of R6's it happened even more.

Since the official line is that they are full range none of this dbm stuff matters. In four years of flying Jeti Duplex I've not had any trouble and that is what really counts :-)

Dave

Now I am generally confused. I am unwilling to put a 5 channel 'parkflyer range/full range/unknown range' we are not sure what range receiver in a very expensive glider and have the glider fly away. Nor am I willing to stuff a 9 channel receiver into a RES glider.

Until JETI USA and JETI straighten out their published specs the JETI DC-16 and about $550 of JETI goodies are off my buy list.

Why in the world, JETI did not make a full range 4 or 5 channel receiver is beyond me.

Obake, don't lose sleep over it. The R5 will be fine. I have used several for a number of years in slope soarers (as well as park flyers) without ever receiving a warning about low signal strength, let alone complete signal loss. For bigger gliders I have used R6, R8 and R9's but ony because they have had more than 5 servos.

If you want the increased sensitivity of the larger receivers, get an R6 or R9, take the cover off and heatshrink it instead - the size then will be very similar to an R5 anyway. Fly it and have fun, enjoying the peace of mind that continuous signal strength and rx battery voltage telemetry gives you.

I think it is clear now. I messed things up by answering the question before Jeti USA. I'll steer clear of sticking my oar in in future :-)

Esprit has stated above that they are all full range. Should give you confidence to use whatever suits space/cost/cannel count.

Dave

Why there are two different prices for DC-16 ,$1295 $1090 ?