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Airworthy Radios and Installations (a few thoughts)!

Hai-Lee

Old and Bold RC PILOT
#41
Really Nice work. I would like to see your LOS plots just for my education. I bet the graph has colors and patterns ad nauseum.. (joke follows) probably a null area just above the only big rock in the entire field, too, or just before the trees. Based on the complaints I have heard form others, probably right at the end of the runway also.

I see you have justified your 3 antenna as having no LOS.

Any defination in the data regarding high end named equipment? Futaba, Graupner, expensive Spectrum, or do they all perform similair? I only ask since, to my awareness, I haven't had an issue with my 6ex Fasst system, however that might only be due to my knowledge of antenna systems.
Even though I have been accused of Spektrum bashing I must inform you that a DUAL ANTENNA DX6 or DX8, (latest models), with receivers that have satellite receivers are the best current setup but sadly the cost is way beyond most newbies!

As you can see IF you have a single antenna Tx then you MUST look into good quality Rxs. So the T16 and the like modular Tx systems can be used safely IF the Rx is adequate. Now there is a proviso on the use of a single antenna Tx and that is that the Tx antenna must be able to be used vertically or even leaning back towards the Tx operator about 20 degrees. A fixed position antenna sticking out of the top of the Tx at right angles to the top of the Tx actually leans the Tx antenna NULL into the flying area directly in front of the operator and so maintaining control in front of you ate any height and distance could be impossible!

I have been touch with FlySky seeking 3 antenna Rxs and only time will tell if that was a waste of time! The "Paladin" has exceptional transmit antenna positions but the Rxs are still a problem.

As for a entry level recommendation I will still maintain that the FlySky iA6 2A is very hard to beat on price and it has range issues in a few areas which you can avoid easily as long as you are aware they exist! It was a close run thing in fact BUT the length of the Rx antenna leads and the total cost to get in the air with a real degree of confidence just pushed it ahead of the pack!

Have fun!
 

Bricks

Well-known member
#42
The new Spektrum receivers have no external antennas it looks to me they are copying the type of antenna that cell phones use with built in boosters. It will be interesting to see how these receivers compare to the external antenna receivers.
 

Hai-Lee

Old and Bold RC PILOT
#43
The new Spektrum receivers have no external antennas it looks to me they are copying the type of antenna that cell phones use with built in boosters. It will be interesting to see how these receivers compare to the external antenna receivers.
They are labelled as "Sport" receivers though there is no explanation as to what that is supposed to mean! Whilst I do not know for sure, I suspect it is a special range or lightweight receivers for Quads which are forever ripping antennas off in crashes especially those who participate in FPV racing! Ripping an antenna off of a Rx in a crash with a fixed wing is somewhat uncommon to rare!

Have fun!
 

Hai-Lee

Old and Bold RC PILOT
#45
The receiver is desighned with planes in mind.
Interesting! What planes?

If "all planes" is their claim then it seems that they are ignoring their own setup advice given for RC model aircraft antenna placements!

https://www.spektrumrc.com/Experience/InstallationBestPractices.aspx

It is impossible to fit your plane's antenna away from all other noise sources and metal structures, (like wires, battery, motor, and the like), if the antenna is internal in the Rx and all of the Servo and ESC wires must connect into the other end. As the Rx is normally in the approx middle of the servos and ESC, wires would seem to be coming in from all directions.

It is also interesting to note that the sport Rx AR620 is listed as being suitable for indoor and lightweight parkfliers AND it does not say ALL aircraft but rather just MOST! When you see the specs of the AR636 Sports Rx you may find that apart from AS3X they have also retained the use of satellite Receivers and claim suitability for parkfliers up to giant scale aircraft.

What is their understanding of a lightweight parkflier? Their full range claims pertain to their idea of a Lightweight parkflier! My idea of a general parkflier has a range of over a kilometer. Most lightweight parkflier retail offerings are quite small and almost impossible to see at a kilometer! In other words, Lightweight Parkfliers are the TOYS.

This actually brings up the question of manufacturers definitions! What is full range for a lightweight parkflier? The term "Full Range" is not actually quantified and therefore is a subjective figure! To me a range statement has a physical measure and it should NOT be qualified with an "UP TO".

The radio system I am seeking to replace has a range figure given as 1 kilometer and I know that my current radio system exceeds that range without issue as long as I follow the best antenna setup procedure I can. I have observed "Lightweight" parkfliers, (retail offerings) fail to fly beyond 200 metres without losing signal, (factory setup)! This is actually typical of the misleading generalizations that abound in the information provided by RC equipment manufacturers! Most does not mean ALL!

Currently Fixed wing RC model aircraft, and drones, fall under the legislative jurisdiction of the appropriate civil aviation authorities and maintaining radio control is important for aviation safety. Would you or anyone like to follow manufacturer recommendations, (even when they are not well explained or even clarified), and then find out that you are legally liable for an aviation incident with possible loss of life and millions of dollars in damages?

Perhaps, as a concerned citizen, I should raise the short comings of radio control systems with those who have the power to restrict, control, prohibit, punish, and even seize items that are unsafe to general aviation. Then I could discuss the issues I have raised herein with other persons who are trained in radio and communications, and have them assess any weaknesses in the current radio products that are marketed as suitable for general fixed wing RC model aircraft, (Aviation), usage. Mind you IF one national Aviation authority makes a ruling, imposes usage conditions, or causes legislation to be raised controlling an aspect of Aviation other national authorities will generally follow in rapid time!

The acceptance of what radio manufacturers state about their products without reading between the lines or even seeking clarifications on any odd usage of wording, (like most aircraft), is rife with users and it does cause a lot of problems and great expense.

Generally if it does not state ALL aircraft then there is a limitation! Do your research as it is your money and safety at stake!

Have fun!
 

Bricks

Well-known member
#46
The manufactures are covering there bases as they have know knowledge of where or how some one might use there product. As a friend of mine tried to fly his quad copter around a cell tower and lost his FPV quad so he blamed the radio system he was close enough that the quad ended up on the tower when LOS happened. So now all he does is bad mouth the system he was using ( not the smartest or brightest thing to do ). This is just a small sample of what someone might do so if the manufacturer said this receiver is this distance then that opens them up for a libel suit if some out side factor causes a problem..

The glider guys are complaining as they thought this new receiver would work in there gliders but it is too big to fit in the fuselage.
 

Bricks

Well-known member
#47
Perhaps, as a concerned citizen, I should raise the short comings of radio control systems with those who have the power to restrict, control, prohibit, punish, and even seize items that are unsafe to general aviation. Then I could discuss the issues I have raised herein with other persons who are trained in radio and communications, and have them assess any weaknesses in the current radio products that are marketed as suitable for general fixed wing RC model aircraft, (Aviation), usage. Mind you IF one national Aviation authority makes a ruling, imposes usage conditions, or causes legislation to be raised controlling an aspect of Aviation other national authorities will generally follow in rapid time!

The acceptance of what radio manufacturers state about their products without reading between the lines or even seeking clarifications on any odd usage of wording, (like most aircraft), is rife with users and it does cause a lot of problems and great expense.

Generally if it does not state ALL aircraft then there is a limitation! Do your research as it is your money and safety at stake!

Have fun!
Talk about opening one heck of a can of worms getting more government involved to me is NOT the answer. Free market decides what companies survive if there product does not do the job then people will quit buying it. As you have said yourself most LOS`s are from a poor setup, and this usually comes from beginners not knowing the difference. At our club we have not lost a plane to LOS that I know of, most losses are from pilot error or some mechanical problem. The last plane I lost was a Nitro the on-off switch failed in midair so do we need the manufacturer to go thru government qualifications to guarantee the switch would never fail?
 

Hai-Lee

Old and Bold RC PILOT
#48
The manufactures are covering there bases as they have know knowledge of where or how some one might use there product. As a friend of mine tried to fly his quad copter around a cell tower and lost his FPV quad so he blamed the radio system he was close enough that the quad ended up on the tower when LOS happened. So now all he does is bad mouth the system he was using ( not the smartest or brightest thing to do ). This is just a small sample of what someone might do so if the manufacturer said this receiver is this distance then that opens them up for a libel suit if some out side factor causes a problem..

The glider guys are complaining as they thought this new receiver would work in there gliders but it is too big to fit in the fuselage.
I know what you are saying and as for your friends Cell Tower experience you should ask him to look up signal blocking, and intermodulation as well as radio harmonics and sub-harmonics. With a bit of research he should more readily understand why Cell towers and other repeater sites are best avoided by radio controlled devices UNLESS the equipment is the absolute top spec and even then it is dangerous! The problem he experienced was not the fault of his radio equipment but rather his lack of knowledge about the radio environment around such a Radio hotspot. Even Telco operated drones used for inspecting the antenna arrays for damage or corrosion do so at a safe distance and use telephoto lenses to allow the detailed inspection required. They are not allowed to fly within 10 metres of the tower and it is their property!

Different rules for different countries I suppose but here such a flight would contravene a number of laws including some of the fringe anti terrorism laws!

As for any possible claim against a manufacturer in that instance sadly NO! Most have some vague warnings about using their products near high powered equipment including power lines! Sadly the very lax of lack of legal requirements in providing suitable and accurate guidelines allows manufacturers to get away with vague general warnings and definitions more suited to getting the end users money rather than providing a suitable product!

This thread is more what to avoid than a specific recommendation as all current entry level systems have their problems. All on air protocols work well enough for a beginner and can provide adequate communications range IF the antenna issues could be sorted! The new Rx you mentioned has already drawn complaints about range problems on another thread in this forum and the first one in use at our local club lasted 2 flights before it was replaced with something better after the plane was repaired.

Have fun!
 

rockyboy

Skill Collector
Mentor
#49
As a friend of mine tried to fly his quad copter around a cell tower and lost his FPV quad so he blamed the radio system he was close enough that the quad ended up on the tower when LOS happened.
For most instances in the US, people should have at least a HAM amateur radio technician license for flying FPV (certainly for anything over 25mw VTX transmission power) - and in the course of studying for and passing the HAM he would have learned enough about radio signal propagation and bleed to know exactly why the system failed in that scenario.

Sadly, most people I know who fly FPV (and RC in general) seem to have no interest in learning the radio signal side of the hobby and view the idea of getting a HAM license as "stoopid govmint overreach" and miss out on a fantastic learning opportunity!
 

Hai-Lee

Old and Bold RC PILOT
#50
Talk about opening one heck of a can of worms getting more government involved to me is NOT the answer. Free market decides what companies survive if there product does not do the job then people will quit buying it. As you have said yourself most LOS`s are from a poor setup, and this usually comes from beginners not knowing the difference. At our club we have not lost a plane to LOS that I know of, most losses are from pilot error or some mechanical problem. The last plane I lost was a Nitro the on-off switch failed in midair so do we need the manufacturer to go thru government qualifications to guarantee the switch would never fail?
You are correct about free market forces BUT even in a free market the government still can and does set the rules as to what can and can't be sold. If the consumers are unaware of the issues or stick their head in the sand and say "I have never had a problem and therefore the problem must not exist" it actually becomes necessary for the legislators becoming involved. I think it was Ralph Nader with his expose "Unsafe at any speed" forced legislators to bring the US Auto industry in to the modern times. At the time an american car was built like a tank and the occupants were free to bounce around or even fall out in the case of an accident whilst in other countries seat belts, crumple zones and the like were already standard equipment. It took the legislators to have it changed!

In current times we are now on/in the fringe of the Aviation industry, whether we like it or not, judging by the responses on this thread alone, the inherent dangers and the scope of the problem is not understood or appreciated! Like everything else some have no issues in their application and so see no need for change. The manufacturers will keep making and selling substandard equipment as long as it sells because there are no other controls or incentives! If they can't make a decent product then perhaps they shouldn't be in the market at all!

They already know of the necessary/proper antenna system and Spektrum even says what is needed on it best practice on antenna setup BUT because people refuse to buy the expensive product and will readily buy the cheaper though ill suited products they just keep making and marketing them. How do we change it? Look at the evidence, evaluate the issues, and stop recommending the cheap substandard equipment OR we will find that we need the regulators to get involved!

Have fun!
 

Hai-Lee

Old and Bold RC PILOT
#51
For most instances in the US, people should have at least a HAM amateur radio technician license for flying FPV (certainly for anything over 25mw VTX transmission power) - and in the course of studying for and passing the HAM he would have learned enough about radio signal propagation and bleed to know exactly why the system failed in that scenario.

Sadly, most people I know who fly FPV (and RC in general) seem to have no interest in learning the radio signal side of the hobby and view the idea of getting a HAM license as "stoopid govmint overreach" and miss out on a fantastic learning opportunity!
Yes and No!

With all my training and years of experience with Spread spectrum technologies I still bought a bad radio based upon internet recommendations and immediately set about destroying every plane I could get into the air! Why? it just did not dawn on me at the time that anyone would sell equipment with a recommendation even though is was far from fit for purpose!

It took me a while for the penny to drop and I started looking for a better radio and whilst the radio I purchased is far superior to the original radio it also has its own issues. I have spent a lot of time researching this very subject and have even had one of the RC equipment manufacturers engineering teams agree with my research. They are holding off any design/manufacturing at this time as the market is a little unsure with a lot of the new laws in force, coming into force, and being drafted!

Have fun!
 

Bricks

Well-known member
#52
I always wonder why a radio system will work super great for one person then not the next, and of course all one hears is the bad. It is to be expected to hear more complaints about the most selling units as there are just more out there which puts then in the hands of many newbies. One of the radios that is becoming more popular is starting to get more complaints from users for LOS and I think that is normal there is no system that is infallible, either in setup or manufacturing. Then it comes down to which manufacturer will stand behind there product, a friend just got a new Horus less then 2 weeks he lost all control on the left stick, he has been trying to get something done to fix the issue and it has been 3 weeks between E-Mails and phone calls not much luck yet.
 

Hai-Lee

Old and Bold RC PILOT
#53
I always wonder why a radio system will work super great for one person then not the next, and of course all one hears is the bad. It is to be expected to hear more complaints about the most selling units as there are just more out there which puts then in the hands of many newbies. One of the radios that is becoming more popular is starting to get more complaints from users for LOS and I think that is normal there is no system that is infallible, either in setup or manufacturing. Then it comes down to which manufacturer will stand behind there product, a friend just got a new Horus less then 2 weeks he lost all control on the left stick, he has been trying to get something done to fix the issue and it has been 3 weeks between E-Mails and phone calls not much luck yet.
Again you are quite correct!

A quality supplier supports their product whereas there are some that seem to be un-contactable when a problem arises!

As for the difference in performance for different users sadly their approach to the plane antenna setup is the most common cause! Often I hve been asked to help with what is either interference or the like to notice the brand new Tx, (top of the line), but when I check the plane antenna layout I discover the cheapest possible radio inside that brand new retail bird. For some reason the message about antennas and quality Rxs does not seem to get through!

This thread is not about the radio reliability or even the after sales support but rather the various manufacturers products being unfit for purpose in relation to fixed wing model aircraft. Try getting a manufacturer to refund your monies if you discover that your low cost radio system is not suitable for your application! The manufacturer will not refund and the LHS will not normally allow you to "Change your mind" unless you are willing to buy that far more expensive radio system as a replacement!

Have fun!
 
#54
They are labelled as "Sport" receivers though there is no explanation as to what that is supposed to mean! Whilst I do not know for sure, I suspect it is a special range or lightweight receivers for Quads which are forever ripping antennas off in crashes especially those who participate in FPV racing! Ripping an antenna off of a Rx in a crash with a fixed wing is somewhat uncommon to rare!

Have fun!
Look at this:
 

Piotrsko

Well-known member
#55
Hmmmmm. $30 more or less plus shipping with stocking issues for the 4ch vs $10 or so for bangood, and it has a cell phone style semi directional amplified antenna in a case that's less than a wavelength. Gotta bind every time you turn on and keep it "couple of inches" away from metallics/semiductors. What could go wrong here?
 

Hai-Lee

Old and Bold RC PILOT
#56
Hmmmmm. $30 more or less plus shipping with stocking issues for the 4ch vs $10 or so for bangood, and it has a cell phone style semi directional amplified antenna in a case that's less than a wavelength. Gotta bind every time you turn on and keep it "couple of inches" away from metallics/semiductors. What could go wrong here?
I obviously saw or heard things that you may have missed.

Firstly the Antennaless range were designed to replace the cheap "Wire antenna" Receivers. Who really buys them anyway? Only those with little or no money and even less knowledge of the dangers they pose! A lot of effort was spent in mentioning installation performance variations over and over along with how to do a comprehensive range test!

No actual radio range figure given but they had tested them to beyond visual range. (It is not how far it can work but rather how far it will ALWAYS work that is important). The only real range mention was a percentage range increase over the old cheap wire antenna Rxs which is a very poor reference when installed in a fixed wing aircraft.

The Rx has extended features which whilst nice are only to be needed if radio communication is lost! Does this mean an increased expectation of LOS events? They mention an internal antenna! Does this mean it has one antenna polarity? If so I will be avoiding them like the plague because I like the planes I own, build, and fly, far too much!

Initially the antennaless radios were initially thought to be great for "Surface" and it was only after extensive beta testing that they were released for aircraft use, (as a replacement for the cheapest wire antenna Rxs only)!

Summary: Just as I had described and it is good to see that the laws of Physics in relation radio transmission and reception are still in force! With all the recommended setup steps and checks that I doubt any newbie will ever undertake you may soon see a plethora of issues in relation of interference, (it must be interference because the sales video said it can work to beyond visual range).

Good points: Has telemetry functions that all receivers should have anyway. Will help Horizon Hobbies sell more foamies and replacement parts!

Unanswered questions! Why the change in type of aircraft mentioned from "Lightweight park fliers" in the pre-release documentation to the Horizon/Spektrum video release which claims up to 60 sized parkfliers? Could it be that Horizon will be installing them in all of their parkflier offerings purely based upon price point? Shows how much Horizon thinks of those it sells its products to!

What I have said throughout this thread still stands and nothing has been encountered which disputes the laws of physics or the attitude of radio manufacturers to the end users investments in time and money as I have described!!

It is what they do not state which is eye opening in itself!

Have fun!
 

Piotrsko

Well-known member
#57
I noticed much that I did not comment on.
Their maximum "advertised" reliable range is "about" 6-800ft. I believe that is the telemetry limit that they seem to focus on. It might be they report LOS to the transmitter. (???)
I suspect this system will not be adequate for FT foamy applications
 

Hai-Lee

Old and Bold RC PILOT
#58
I noticed much that I did not comment on.
Their maximum "advertised" reliable range is "about" 6-800ft. I believe that is the telemetry limit that they seem to focus on. It might be they report LOS to the transmitter. (???)
I suspect this system will not be adequate for FT foamy applications
Well done, Young Padawan!:unsure:

Have fun!
 

Bricks

Well-known member
#59
Telemetry range is hardly ever the same range as radio range.

Another issue that comes up is from what I have read is a false bind, when the transmitter is to close to the radio and the receiver picks up echo frequencies, the receiver is bound but range is greatly diminished.
 

Piotrsko

Well-known member
#60
Telemetry range is hardly ever the same range as radio range.

Another issue that comes up is from what I have read is a false bind, when the transmitter is to close to the radio and the receiver picks up echo frequencies, the receiver is bound but range is greatly diminished.
That might be harmonics, sidelobes, or sidebands, all of which are too squirrelly to deal with here but generally are common in close proximity to the powered source. Even a crystal oscillator is "dirty" when your right on top of it and AFAIK, the hardware is PLL synthesized so who knows what the seed frequency is. You get a similar issue when you bind to the null point