Jump to content

Recommended Posts

Like the article or not, his point is valid - that if glitches or loss of control is in any way possible by the closeness of a phone to the Tx, and, mitigating against it is as simple as having your phone in your back pocket rather than the front, then why wouldn't you? (A metre away would be far better but hey..)

 

I'm sure there's been more than one loss of model over the years this way and expect that there was usually no explanation ever found. 

 

Who remembers putting a mobile phone next to a hifi amp and getting a horrid noise from the speakers as a call comes in? 

Link to comment
Share on other sites

Posted (edited)
3 hours ago, Andy Gates said:

Having said that, I do have the utmost respect for Dave Blandford and the assistance and development he has given to the FrSky / Open TX community and the testing he has done on all of our behalves for  a better RC world.


The BMFA News article was written by Dave Blandford, not Mike Blandford of erSKY TX and Frsky Delta RX firmware fame. I am confident there is no way someone like Mike who has so much technical domain knowledge would ever publish an article so lacking in facts and data.

Edited by MattyB
  • Like 1
Link to comment
Share on other sites

I've only just received my BMFA news and haven't read the article fully.

Many transmitters are now storing radio and model data on a SD card. Since many 'phones allow a SD card to be used in them, I would be very surprised if using a 'phone near a Tx would corrupt the SD card contents. I would think the 'phone would corrupt its own SD card if that was likely to happen!

 

Mike

Link to comment
Share on other sites

19 minutes ago, Mike Blandford said:

I've only just received my BMFA news and haven't read the article fully.

Many transmitters are now storing radio and model data on a SD card. Since many 'phones allow a SD card to be used in them, I would be very surprised if using a 'phone near a Tx would corrupt the SD card contents. I would think the 'phone would corrupt its own SD card if that was likely to happen!

 

Mike

Excellent point!

Link to comment
Share on other sites

It is feasible that a powerful EMP could corrupt electronic storage devices. The military systems I worked on were tested for susceptibility to both radiated and conducted emissions to ensure they weren't damaged or corrupted by such events. However, there doesn't seem to be formal evidence that this occurs with our R/C gear. It occurred to me that my phone is frequently adjacent to a whole bunch of safety critical electronics when in my car, but there are no safety warnings about this. I shall keep an open mind, but certainly will keep my phone more than a couple of inches away from my R/C gear.

Link to comment
Share on other sites

32 minutes ago, Trevor Crook said:

It is feasible that a powerful EMP could corrupt electronic storage devices. The military systems I worked on were tested for susceptibility to both radiated and conducted emissions to ensure they weren't damaged or corrupted by such events. However, there doesn't seem to be formal evidence that this occurs with our R/C gear. It occurred to me that my phone is frequently adjacent to a whole bunch of safety critical electronics when in my car, but there are no safety warnings about this. I shall keep an open mind, but certainly will keep my phone more than a couple of inches away from my R/C gear.

 

All true Trevor.

If you look inside our electronics gear, you will see that sensitive gear is enclosed inside metal boxes ( Faraday Cages ), including Sim cards.

As you say

 

It is feasible that a powerful EMP could corrupt electronic storage devices.

 

Distance is key

Link to comment
Share on other sites

1 hour ago, Ron Gray said:

there is absolutely no risk in having my mobile ‘phone with me on the flight line whilst I’m flying?

 

Ron

 

You've phrased that in terms of asking for disproving a negative. Let's not go there.

 

That said:

 

I have never seen any positive proof that a mobile phone (excluding mobile phone base stations and various other assorted permanent installations) causes

 

a) interference with 2.4Ghz gear

b) corruption of permanent storage e.g. FLASH or NVRAM such as used on SD cards or internal storage on microcontrollers

c) corruption of temporary storage i.e SRAM or CPU caches

 

If anyone has seen genuine evidence for the above, and I mean peer reviewed evidence of a good standard, then I am happy to shift my position.

 

A point to note is that mobiles do not transmit on 2.4GHz and like our radio kit, transmit with a fixed power limit, with tightly controlled spread to nearby bands.

 

In the day job I work in an industry which is absolutely concerned with random bit errors. RF transmissions from communications kit, as a cause of this sort of random error, is not something I have ever heard of. The calculations for determining how often this kind of error shows up are singularly focused on radiation with altitude being a determining factor in my business particularly and in nuclear industries you would be looking at the particular location within nuclear sites to dictate the radiation levels and thus frequency of bit errors. Die size of the memory affects this too, larger chips are less vulnerable and smaller, newer chips do tend to come with e.g. ECC ram which can correct itself in the event of single errors.

 

Corruption of permanent storage is again not something I have heard of full stop.

 

EMP corruption of devices, safe to say that kind of scenario, you're well beyond a mobile phone in normal operation.

 

Any oddities you get in your TX are almost certainly due to programming errors.

 

The article is pure FUD.

 

  • Like 1
Link to comment
Share on other sites

1 minute ago, Peter Christy said:

I refer you to my post from the 27th of April, under the topic of "Bluetooth interference" (about half way down the page):

Bluetooth interference

 

Nigel R: You are correct in mobile phones not using 2.4 GHz for transmissions, though many do have wifi and bluetooth capabilities (2.4 GHz, but relatively low power), however, the main issue is the ability of short bursts of quite high power level of RF to break through into poorly screened electronics.

 

Going back a few years (35 MHz, and just before the start of the 2.4 GHz era), I witnessed a very expensive and large scale helicopter crash when the pilot's mobile phone rang while he was hovering. The subsequent investigation (for which I was present) demonstrated that this was repeatable. The transmitter in question was a very expensive European manufactured set. Similar tests with Japanese manufactured sets showed no such problems.

 

That was many years ago. Manufacturers these days are well aware of the issue, and are mostly unwilling to risk the loss of reputation that such a flaw would create. In any event, tighter FCC and CE regulations have pretty much eliminated this problem.

 

It is a very rare occurrence these days, and can usually be traced to a fault elsewhere.

 

--

Pete

 

Link to comment
Share on other sites

I deliberately said nothing of old 35MHz gear. There are many reasons why 2.4GHz is a better and more reliable schema.

 

A further point regarding bluetooth and wifi. Range is shorter (and power is lower) by comparison to our kit. And both use listen before transmit. They are - to the best of my knowledge - as likely to cause packet collision with your own TX/RX, as a second flyer standing next to you. Or, a telemetry module in your airframe. In fact, far less likely to cause packet loss than an old DSM2 type system.

 

10 minutes ago, Peter Christy said:

It is a very rare occurrence these days, and can usually be traced to a fault elsewhere.

 

absolutely agree

Link to comment
Share on other sites

2 hours ago, Ron Gray said:

Interesting points, @MattyB, so are you saying that there is absolutely no risk in having my mobile ‘phone with me on the flight line whilst I’m flying?

 

I think I clarifed that in line 1 of my post...

 

19 hours ago, MattyB said:

Even though I agree with him that mobiles are potentially capable of causing the kind of transmission (note - not reception!) issues that David Blandford talks about in the BMFA News, personally I thought it was a poorly written and badly argued article...

 

However, despite accepting that there is a very slim possibility that the factors Mr Blandford discusses could cause an incident, as per @Nigel R's excellent post above I have never seen any evidenced proof of a mobile phone causing a modern 2.4GHz TX to cease transmission or have transmit corrupted/altered packets. I've also never seen evidence of a mobile corrupting temporary or permanent storage in a transmitter. I have observed 2 incidents where a mobile was initially suspected as a contributing factor, but on investigation it was clear other issues were the root cause (human error and battery failure). For these reasons (and because I've direct experience of the value of a mobile in a healthcare emergency) I will continue to keep mine in my back pocket when flying alone or a few feet away when in the company of others.

Link to comment
Share on other sites

Posted (edited)

PS...

 

2 hours ago, Trevor Crook said:

It is feasible that a powerful EMP could corrupt electronic storage devices. The military systems I worked on were tested for susceptibility to both radiated and conducted emissions to ensure they weren't damaged or corrupted by such events. However, there doesn't seem to be formal evidence that this occurs with our R/C gear. It occurred to me that my phone is frequently adjacent to a whole bunch of safety critical electronics when in my car, but there are no safety warnings about this. 

 

1 hour ago, Denis Watkins said:

All true Trevor.

If you look inside our electronics gear, you will see that sensitive gear is enclosed inside metal boxes ( Faraday Cages ), including Sim cards.

As you say

 

It is feasible that a powerful EMP could corrupt electronic storage devices.

 

1 hour ago, Nigel R said:

...EMP corruption of devices, safe to say that kind of scenario, you're well beyond a mobile phone in normal operation.

 

 

As Nigel suggest, based on everything I have ever read about EMP the term is being misused by the article author, as a mobile phone is just not capable of generating one. Yes, it does generate an electromagnetic field (EMF) during transmission, but that is many, many orders of magnitude lower in power than a true EMP capable of permanently knocking out electronics over a distance of miles. Mobile phones have a max power of around 2W; nuclear bombs denotated at high altitude (the mechanism generally thought of as the most likely basis of an EMP weapon) are a bit more powerful than that!

 

Again, something that could easily have been picked up with some additional research by the author and/or a more judicious edit.

 

 

Edited by MattyB
Link to comment
Share on other sites

Never mind r/c Tx corruption problems, be very carefull to avoid close proximiy to anyone with a 5G device. There is irefutable evidence that these can cause and spread covid. 

  • Haha 3
Link to comment
Share on other sites

Just now, PatMc said:

Never mind r/c Tx corruption problems, be very carefull to avoid close proximiy to anyone with a 5G device. There is irefutable evidence that these can cause and spread covid. 

 

It is even worse than that - mine turned me ginger! Oh no, wait, that might have happened a bit earlier on... ?

  • Haha 1
Link to comment
Share on other sites

3 hours ago, Nigel R said:

I deliberately said nothing of old 35MHz gear. There are many reasons why 2.4GHz is a better and more reliable schema.

 

My point was that that was the one and only time I've ever seen irrefutable evidence of a mobile phone causing an issue, and it was quite a long time ago.

 

I think we're both singing from the same hymn sheet! ?

 

--

Pete

 

  • Like 1
Link to comment
Share on other sites

All I can say is that if there is even the slightest risk of my mobile ‘phone (and watch!) causing interference with my Tx system then I would rather leave them in the car or switch them to ‘airplane mode’. Nothing I’ve seen / read proves that they do or do not interfere so it’s an unknown but I would rather take that risk out of the equation.

 

For the record, I have been on the flight line and seen that a model’s flight was affected (by something) at exactly the same time as a mobile ‘phone received a message, coincidence or not, who knows, but said person has not had any similar issues since leaving his ‘phone in his car.

Link to comment
Share on other sites

2 hours ago, Ron Gray said:

All I can say is that if there is even the slightest risk of my mobile ‘phone (and watch!) causing interference with my Tx system then I would rather leave them in the car or switch them to ‘airplane mode’. Nothing I’ve seen / read proves that they do or do not interfere so it’s an unknown but I would rather take that risk out of the equation.

I'm most certainly with you on that one but maybe not quite to the same extent, I leave my phone back with RC Gear TX case etc, that's at least 25 meters away, even if it's a minuscule chance why would you not?

 

After all while I'm flying I'm not going to be answering a call, reading a text or browsing the net so why would I want it on me anyway?  

  • Like 1
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...