Range tests

[SIMON CRAGG]

Range checked a T6EX the other day.

 

Bound ok, power  down range check ok.

 

Took off and at about 60yds, model completely uncontrollable and turned an 80" wingspan airframe into matchwood. 

 

Totalled motor, Lipo and ESC.

 

Fault?...........antennae wire disconnected from board in back of TX..

[Cuban8]

I would have thought that one has to be 100%  sure that the single essential function  of our radio control link is working to 100%.

By that I mean that the transmitter is radiating a signal strength exactly as the manufacturer intended. If that is not the case then the value of what we do in terms of correct installation at the rx will not have the full  effect that one would expect. 

A tranny operating with unnoticed  reduced power caused by any manner of issues might pass a normal reduced power range check, and may well appear to give adequate control........until the link is put under stress and the reduced tx power causes a problem, for instance, the model being inadvertently flown somewhat further away than is normal for whatever reason. 

 

 

[leccyflyer]

14 minutes ago, Cuban8 said:

I would have thought that one has to be 100%  sure that the single essential function  of our radio control link is working to 100%.

By that I mean that the transmitter is radiating a signal strength exactly as the manufacturer intended. If that is not the case then the value of what we do in terms of correct installation at the rx will not have the full  effect that one would expect. 

A tranny operating with unnoticed  reduced power caused by any manner of issues might pass a normal reduced power range check, and may well appear to give adequate control........until the link is put under stress and the reduced tx power causes a problem, for instance, the model being inadvertently flown somewhat further away than is normal for whatever reason. 

 

 

There isn't a single essential function in our radio control link though - the transmitter and receiver both have to work and the servos have to move the control surfaces appropriately or the model isn't going anywhere under full control.

 

[Don Fry]

Might I suggest. (Note I am well fed, and benignly happy) that this is a range test, to check functionality of the link in a toy aircraft. 
Read the instructions from the maker of the kit, do them. All you can do.
Please note, the US Air Force were looking for a lost, very expensive, very heavy and fast, low dropping object yesterday. Luckily without pilot.

[john stones 1 - Moderator]

21 minutes ago, Don Fry said:

Might I suggest. (Note I am well fed, and benignly happy) that this is a range test, to check functionality of the link in a toy aircraft. 
Read the instructions from the maker of the kit, do them. All you can do.
Please note, the US Air Force were looking for a lost, very expensive, very heavy and fast, low dropping object yesterday. Luckily without pilot.

 

Maybe next time they'll do a range check before flying.

[Cuban8]

19 hours ago, leccyflyer said:

There isn't a single essential function in our radio control link though - the transmitter and receiver both have to work and the servos have to move the control surfaces appropriately or the model isn't going anywhere under full 

One has to start somewhere, and I'd be concerned that before anything else, the tranny was functioning correctly. All else is then built on that. 

Analogous to the brakes on one's car, perhaps?

 

 

[RottenRow]

Also the tranny is probably used for more than one model, so has the capability to cause multiple carnage…

 

Brian.

[Rich Griff]

Hi Simon cragg,

 

So sorry to hear of your radio failure and resulting crash.

 

It's a worry to find out it's a futaba set and it's  disconnected aerial lead !

 

May I ask please what futaba tx is it, and, is the connection a "push on spade female" type please ?

 

Thanks in advance.....

 

 

[MattyB]

2 minutes ago, Rich Griff said:

May I ask please what futaba tx is it, and, is the connection a "push on spade female" type please ?

 

Thanks in advance.....

 

Go crazy - try reading his post....! 😉

 

 

Edited September 22, 2023 by MattyB

[Martin Harris - Moderator]

Interesting failure.  These are “industry standard” connectors if I’m not mistaken - was there any possibility that it could have been disturbed prior to the flight?

 

On the related subject, I’ve always felt pretty secure with my telemetry reporting both signal strength received at the model and packet loss statistics. Do any of the RF experts see any potential problems in using these as real world monitoring to back up the possible shortfalls of artificial software controlled range testing?

[MattyB]

27 minutes ago, Martin Harris - Moderator said:

…On the related subject, I’ve always felt pretty secure with my telemetry reporting both signal strength received at the model and packet loss statistics. Do any of the RF experts see any potential problems in using these as real world monitoring to back up the possible shortfalls of artificial software controlled range testing?

RSSI telemetry has saved at least ltwo of my models from a poor initial setup back before I really knew how to  install 2.4 in a composure gliders. It also notified me when my Ultraguard had been triggered in the Sebart Miss Wind after the UBEC failed on an early flight, meaning I could land immediately and troubleshoot the issue. In total I calculated those three instances saved me £1700 at least, so telemetry is 100% worthwhile IMO, though IMO  it doesn’t completely replace the need to do a range test every now and then.

Edited September 22, 2023 by MattyB

[Geoff S]

I always use the internal antennae on my FrSky Horus 10.  I took my Liddle Stik down to a local field I use occasionally (it's 5 minutes walk) and was surprised to get an RSSI warning even though, as it's quite a small model, I fly fairly close in.  I eventually found that for some reason the option had shifted to external antenna (which wasn't fitted!) so I was flying with no antennae at all!  I was quite impressed.  I#ve since fitted a dummy load to the external antenna connection and changed the set up to ask which antenna option to use every time I switch on.  So I guess RSSI saved my model - though it's a pretty low cost, scratch built one, I'd be sorry to lose it.

 

Needless to say, I hadn't done a range check since I maidened it, though I always do a thorough one with a new model - especially one I've built.

[leccyflyer]

1 hour ago, Martin Harris - Moderator said:

Interesting failure.  These are “industry standard” connectors if I’m not mistaken - was there any possibility that it could have been disturbed prior to the flight?

 

On the related subject, I’ve always felt pretty secure with my telemetry reporting both signal strength received at the model and packet loss statistics. Do any of the RF experts see any potential problems in using these as real world monitoring to back up the possible shortfalls of artificial software controlled range testing?

Either Simon has just used a picture from the interwebs for illustration of the connector type, or he's modified his transmitter, relocating the 2.4ghz antenna to an internal position, rather than the unoccupied slot in the top of the TX.  I've never had a T6EX but would be surprised if Futaba used a small piece of balsa inside their transmitters straight from the factory. I think it's a picture from the 'net of a modified transmitter.

Edited September 22, 2023 by leccyflyer

[Cuban8]

I replaced a broken aerial on a mate's Spektrum DX7 some time ago and the RF PCB to aerial lead connector was indeed one of the industry standard snap connectors that were mentioned. I also recall it being a very tight snap fit that needed care when removing/replacing.

[Phil Green]

Its called a U.FL connector 🙂