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-   -   Solo range test? (http://www.Wattflyer.com/forums/showthread.php?t=73600)

Brewerpaul 04-20-2014 12:31 PM

Solo range test?
 
I know that doing a range test before flying is a good idea, but I usually go to the field alone. How can I do this? One way I've thought of is to start the motor, leave the transmitter behind and walk away-- will the motor shut down when I get out of range? This is a stock Hawk Sky, btw. Downside is that I'd lose battery walking out and back.

solentlife 04-20-2014 02:38 PM

This has been a consideration for me and I came up with :

Pair of Walkie Talkies .. or Baby monitors.
Small Key cam or digital video.

Set up model on ground with one WT next to it ... and videocam looking at model.

Walk away from model while operating controls and counting of steps into other Walkie-Talkie as well as saying which control is being actioned.

The videocam will record what it sees on the model and also the sound of what you are doing.... along with how far from the model you are.

OR

You can reverse the WT part by locking the transmit button on the WT next to model ... walk away operating the Tx ... listening to the servos working .. when you hear chatter or the lack of servo movement - that is the loss of command. Video will confirm it.

Sounds a bit involved - but actually it's not. It's about the only way single-handed that I could think of doing it safely.

I wouldn't consider doing as you suggest ...

Nigel

Turner 04-20-2014 04:06 PM

Binoculars can be used as well. It can be helpful to put the plane on top of some non metal object to get it up a couple feet off the ground.

fhhuber 04-20-2014 04:06 PM

The range test can easily be done solo... tie the tail of the plane to something or use a tail trap. You can hear the motor respond.

you are testing at a reduced output power... so you aren't going t be walking a mile from the model.


A range test is checking radio communication. Any one control working correctly is proof of that. Checking for flaky connections between RX and servos you need to be at the model to carefully watch for jerky responses, but you don't have to check range at the same time.

pmullen503 04-20-2014 04:31 PM

Most Txs have a reduced power range check mode. That will detect most serious communication problems at 30 to 50 paces. You'll typically get better range aloft than you will at ground level.

solentlife 04-20-2014 04:33 PM

Its' one of those areas that people come up with solutions that suit them.

And I will say this : I believe that many people do NOT properly range check anyway ... they give a cursory check of a few paces stick this ... stick that ... and go fly.

In the old days of FM - it was much easier ... antenna left down on Tx .. walk away etc. Today some radios say they have Range Check - but some are doubted to actually have it ...
The range that control is lost is for many radios except parkfly RTf - considerable. My FrSky equipped gear will easily outdistance my estate grounds .. such that to find that distance (curiosity as to what distance it would be made me do it !) - I had to use the WT's ... I just could not see the model ..it was just a dot on the ground.
I read various that range check distance can be anywhere from 30 to 100 paces - depending on RTF Parkfly or full range gear. 30 paces is OK - you can still see / hear the model .. but 100 is a different ballgame.

The WT + cam suggestion I made - to me is about the only way I think I can be absolutely certain ... but it's my way and others have theirs. I have the gear at hand to do it ...
Maybe when I get home - I will do a video and upload to Youtube so others can see my idea ...

Nigel

solentlife 04-20-2014 04:36 PM

Quote:

Originally Posted by pmullen503 (Post 946035)
Most Txs have a reduced power range check mode. That will detect most serious communication problems at 30 to 50 paces. You'll typically get better range aloft than you will at ground level.

I have read other manuals and on-lines that talk about up to and over 100 paces for RC ... most I read say 30 paces for Parkfly gear ...

Nigel

fhhuber 04-20-2014 06:15 PM

Generally 300-350 ft for Spektrum range checks regardless of RX type.

The Spektrum "park flyer" RX isn't really range limited. its just got that single antenna that can easily be shadowed by the equipment installed in a model, especially if you use it in a larger model.
People have successfully used them in .60 class models and flown the plane to where its a speck in the sky. (I don't recommend that... because of the potential shadowing issue.)

I wouldn't be satisfied with a 30 ft range check on my Parkzone Vapor.

Other brands may give different results.

solentlife 04-20-2014 06:43 PM

Quote:

Originally Posted by fhhuber (Post 946048)
Generally 300-350 ft for Spektrum range checks regardless of RX type.

The Spektrum "park flyer" RX isn't really range limited. its just got that single antenna that can easily be shadowed by the equipment installed in a model, especially if you use it in a larger model.
People have successfully used them in .60 class models and flown the plane to where its a speck in the sky. (I don't recommend that... because of the potential shadowing issue.)

I wouldn't be satisfied with a 30 ft range check on my Parkzone Vapor.

Other brands may give different results.

I use the 4ch FrSky Rx in a number of my models as it's factory Spec'd at 1km ... unlike most others that quote 300m etc.

Lets be honest the real decider is the Tx in range with sensitivity of Rx secondary factor. So given sufficient power of signal - even a so-called limited range Rx should work far enough for our purposes.

As you say - the single antenna is a factor in shadowing.

I would not use a single antenna Rx in a larger model though and particularly my Wet-Fuel models .. I use the 'Full range' Dual antenna Rx's. I just feel more secure knowing its in there.
I'm sure the 4ch FrSky would work just as well - but nagging voice again !

Nigel

pizzano 04-20-2014 06:51 PM

The Spektrum "parkflyer" AR 400 RX has two antenna's.

Straight out of the manual:

"Range test......You should have total control of the model at 30 paces (90'/28m)......Voltage range 3.5v to 9.6v........TX should be charged at a min. voltage of 4.8v"......most newer Spektrum DX transmitters have a default low voltage cut-off setting (stock) set at 4.1v....obviously, higher voltage rates for both TX and RX is preferred!

All the experienced guys I've flown with never ground range test at less than 300' or football field length.....so that's what how I check range as well.

JetPlaneFlyer 04-20-2014 06:59 PM

Yep as per last reply, for Spektrum at least when using the reduced power range check mode you only need to go 30 paces away from the model, so you can easily see if the controls are responding correctly.

The guys who are walking hundreds of feet are probably old school pre-2.4GHz flyers. Back then Tx's didn't have low power range check mode so you had no option but to walk a long way.

solentlife 04-20-2014 07:00 PM

Quote:

Originally Posted by pizzano (Post 946050)
The Spektrum "parkflyer" AR 400 RX has two antenna's.

Straight out of the manual:

"Range test......You should have total control of the model at 30 paces (90'/28m)......Voltage range 3.5v to 9.6v........TX should be charged at a min. voltage of 4.8v"......most newer Spektrum DX transmitters have a default low voltage cut-off setting (stock) set at 4.1v....obviously, higher voltage rates for both TX and RX is preferred!

All the experienced guys I've flown with never ground range test at less than 300' or football field length.....so that's what how I check range as well.

OK - the 400m is dual antenna ... but no-one was detailing WHICH parkflyer Rx .. it was a general discussion ..

There you go - 30 paces ... yeh well - sorry I do not like 30 paces ... not enough in my book.

You also have to be careful because not all dual antenna's are true dual redundancy antenna's .. some are basically a single split to give dual ... Note I am NOT saying that Spektrum is guilty of that ...

As to who and when RC is done - I still maintain that most do not do it properly, in fact I reckon most don't even do it ... as I said - they walk a few paces ... stick this way, stick that way and fly. Like most things - there is correct and documented way to do things - and what actually happens.

Nigel

hayofstacks 04-20-2014 08:40 PM

If spectrum is supposed to range check at 300-350ft then all of mine have been at least 200ft short....

pmullen503 04-20-2014 08:57 PM

Quote:

Originally Posted by hayofstacks (Post 946063)
If spectrum is supposed to range check at 300-350ft then all of mine have been at least 200ft short....


My old DX6i said 30 paces (approx.100 ft) in range check mode. Supposedly that was 1/30 of full range. That same radio (in normal mode) would give at least 2400 ft on the ground which was the longest LOS I could get. It's probably more than that in air but I doubt I ever flew much farther away than that.

So if airborne range was at least 3000 ft., the 1/30th claim was probably pretty close.

BTW, Flysky V2 range check mode does nothing. The signal strength does NOT drop. That's why I was doing full power range checks with my DX6i as the control.

Wildflyer 04-20-2014 09:43 PM

We used to have a small flag on a stick or wire, that you could clip to a control surface, in such a way that you would see the flag waving back and forth, as you walked away doing a range check.

A bright little flag like they use to mark locations for sprinkler systems would work just fine, or something home made.

An 18" wire clipped to your elevator with a bright yellow or orange flag at the end, is easily seen from several 100 yards.

JetPlaneFlyer 04-20-2014 11:41 PM

Quote:

Originally Posted by solentlife (Post 946049)
Lets be honest the real decider is the Tx in range with sensitivity of Rx secondary factor.

That's not the way I understand it. Transmitter power is limited by local regulations. So basically per region all 'full range' transmitters have the same maximum signal output strength. The effective range therefore is mainly governed by the sensitivity of the Rx.

FWIW European regulations limit power to 100mW which is half of what the US is allowed. France has additional restrictions. Some brands allow switching between these power levels. For instance Spektrum allows switching between power levels except that European Tx's dont have the option for the higher power (illegal in Europe) US setting, they only have the 'EU' and 'France' option.

Other brands for simplicity just produce one power output for all regions, which of course has to be the lowest power to be legal in all regions. I think that (for instance) Futaba and FrSky take this option (owners of these systems please correct me if I'm wrong)

Panther 04-21-2014 05:28 AM

My FrSkys are 60 mW. I guess a techy guy could easily adjust it higher if need be. I haven't looked into it as the range is more than enough for my needs.

solentlife 04-21-2014 05:29 AM

JPF - I am aware of the max limits for different locations ... what I am referring to is the range is determined mainly by Tx capability ... without having to actually say the Parkfly RTF and the better Spekie / Futaba / 9x etc. etc that has full power related to location.

The matter of power is also subject to the format of the signal ... I cannot remember the exact description but I believe that Futaba chose the format that in fact is lower power than some others. It is not only Country related - but also how the signal format is that determines maximum legal power.

In the days before todays digitised computer based radios - it was common at Car racing to see an extra cell stuffed into a 2ch AM set of 27mHz ... whether it really did give an increase in power I'm not sure - but it was not an uncommon practice. A few race meetings I used to attend - I was an addicted electric race fanatic at one stage ! - the organisers banned that extra cell ...

Nigel

kyleservicetech 04-21-2014 05:37 AM

Quote:

Originally Posted by hayofstacks (Post 946063)
If spectrum is supposed to range check at 300-350ft then all of mine have been at least 200ft short....

My DX8 manual indicates the receiver should operate reliably at 30 paces or 90 feet with the range test enabled. If I point the DX8 antenna directly at the model, the range test for reliable model operation drops to about 60 feet.

kyleservicetech 04-21-2014 05:41 AM

Quote:

Originally Posted by solentlife (Post 946054)
There you go - 30 paces ... yeh well - sorry I do not like 30 paces ... not enough in my book.
l

For 2.4 Ghz, the actual distance your radio will work reliably during a "Range Test" of reduced transmitted power can easily be changed by altering the value of a resistor, or two. So, by a minor change in transmitter design of the range test circuitry, you could have a range test for 20 feet, 50 feet, or 500 feet, or what ever you want. For full power range, just about any decent 2.4 Ghz transmitter with a full range receiver will work reliably over a mile or three.

That's a lot different than the old 72 Mhz, (or 35 Mhz) radios. The range test on those transmitters simply involved collapsing the transmitter antenna. Since the antenna could only be made so small because of physical limits, the effective range was about 30 paces with the antenna down.

kyleservicetech 04-21-2014 05:49 AM

Quote:

Originally Posted by pmullen503 (Post 946065)

BTW, Flysky V2 range check mode does nothing. The signal strength does NOT drop. That's why I was doing full power range checks with my DX6i as the control.


Wow, that is interesting.

If true, this thing will quickly show exactly what is going on.

http://www.wattflyer.com/forums/showthread.php?t=72719

JetPlaneFlyer 04-21-2014 06:08 AM

Quote:

Originally Posted by Panther (Post 946112)
My FrSkys are 60 mW. I guess a techy guy could easily adjust it higher if need be. I haven't looked into it as the range is more than enough for my needs.

Yeah, i did hear that FrSky used lower power. this might be so they can be legal in France without change?

JetPlaneFlyer 04-21-2014 06:13 AM

Quote:

Originally Posted by solentlife (Post 946113)
The matter of power is also subject to the format of the signal ... I cannot remember the exact description but I believe that Futaba chose the format that in fact is lower power than some others. It is not only Country related - but also how the signal format is that determines maximum legal power.

100mW is the maximum total 2.4GHz transmitting power (in the EU), regardless of signal protocol used. It's simply a measure of the radiated power from the antenna, signal coding makes no difference. The USA has a 200mW limit but many manufacturers for consistency sake stick with a lower limit for all of their transmitters.
FWIW Spektrum claim quite clearly that their wide band DSM produces greater range (up to 3x greater) than their competitors narrow band FHSS systems. I tend to take these claims from any manufacturer with a pinch of salt to be honest, unless I see some evidence.

Quote:

The big reason wideband is so robust is coding gain. Essentially what this means is that the unique coding in a DSM2 or DSMX wideband signal allows it to be heard well above the noise of surrounding 2.4GHz signals without requiring any more power. In fact, a Spektrum wideband signal can achieve as much as 3X the range of its narrow-band competition using the same amount of power.
Source: https://www.spektrumrc.com/Technology/DSMX.aspx

solentlife 04-21-2014 06:42 AM

Quote:

Originally Posted by JetPlaneFlyer (Post 946125)
100mW is the maximum total 2.4GHz transmitting power (in the EU), regardless of signal protocol used. It's simply a measure of the radiated power from the antenna, signal coding makes no difference. The USA has a 200mW limit but many manufacturers for consistency sake stick with a lower limit for all of their transmitters.
FWIW Spektrum claim quite clearly that their wide band DSM produces greater range (up to 3x greater) than their competitors narrow band FHSS systems. I tend to take these claims from any manufacturer with a pinch of salt to be honest, unless I see some evidence.



Source: https://www.spektrumrc.com/Technology/DSMX.aspx

There actually is a different power limit based on format ... not only the overall total max you quote. I am trying to find the online review that quotes it ... it's our old 'friend' RC Model Reviews has it as well.. darned if I can find it now ... but it's there.


Nigel

solentlife 04-21-2014 06:47 AM

Quote:

Originally Posted by kyleservicetech (Post 946116)
For 2.4 Ghz, the actual distance your radio will work reliably during a "Range Test" of reduced transmitted power can easily be changed by altering the value of a resistor, or two. So, by a minor change in transmitter design of the range test circuitry, you could have a range test for 20 feet, 50 feet, or 500 feet, or what ever you want. For full power range, just about any decent 2.4 Ghz transmitter with a full range receiver will work reliably over a mile or three.

That's a lot different than the old 72 Mhz, (or 35 Mhz) radios. The range test on those transmitters simply involved collapsing the transmitter antenna. Since the antenna could only be made so small because of physical limits, the effective range was about 30 paces with the antenna down.

Yes ... yes .. yes ... ;)

Funny thing is that JR used to advise against collapsed antenna use of the Tx - as the RF section could fail.

As to FlySky Range Check - that has been a known issue for a long time that the Range Check function of the Bind button was never implemented. It is a hang over in the manuals and Module labels from the FM module days of the original 9x.

Nigel


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