Question for those using video cameras in planes
Thread Starter
Question for those using video cameras in planes
Question directed towards anyone using a video camera in a light aircraft.
I've successfully been able to connect up the audio from the headphone jack in the aircraft to the video camera in other aircraft, although 1 aircraft I'm currently flying (C172) has an issue, whereby when I plug in the single plug into the headphone jack on the aircraft, the whole comms in the aircraft get messed up (can barely hear transmissions from other aircraft, and can barely hear the intercom between passengers onboard). The comms all work fine if I pull the jack out, but with it in I can barely hear anything.
Has anyone dealt with this issue before, and found a fix? I've been able to successfully hook it up in other aircraft, its just this 1 aircraft I've come across the issue.
Any thoughts on what the issue could be or whats causing it?
Cheers
V1
I've successfully been able to connect up the audio from the headphone jack in the aircraft to the video camera in other aircraft, although 1 aircraft I'm currently flying (C172) has an issue, whereby when I plug in the single plug into the headphone jack on the aircraft, the whole comms in the aircraft get messed up (can barely hear transmissions from other aircraft, and can barely hear the intercom between passengers onboard). The comms all work fine if I pull the jack out, but with it in I can barely hear anything.
Has anyone dealt with this issue before, and found a fix? I've been able to successfully hook it up in other aircraft, its just this 1 aircraft I've come across the issue.
Any thoughts on what the issue could be or whats causing it?
Cheers
V1
Not....
I cant really answer it with any certainty(so please no flames),but having worked in music studios as an engineer Ive heard more than enough annoying noises to last a lifetime ..
Im sure you've already thought of or had a crack with some of these, but I would try.
a)plugging the other free hole with a spare headset jack
b)Try all coms plugs just to see it wasnt an isolated "dirty" pot although this seems unlikely due to the other issues.
c)Try using high quality 1/4 inch jack plugs(you'll find these at music stores that sell studio equipment possibly even JB.
d)borrow another camera and see if the problem is still there.
I have heard of certain headsets(with power) that cause a few problems in the com system, and possibly you are getting a similar issue..
All these are stabs in the dark, but maybe one will work for you?
Maybe your just freaking out the old bird with modern fandangled technology.
I cant really answer it with any certainty(so please no flames),but having worked in music studios as an engineer Ive heard more than enough annoying noises to last a lifetime ..
Im sure you've already thought of or had a crack with some of these, but I would try.
a)plugging the other free hole with a spare headset jack
b)Try all coms plugs just to see it wasnt an isolated "dirty" pot although this seems unlikely due to the other issues.
c)Try using high quality 1/4 inch jack plugs(you'll find these at music stores that sell studio equipment possibly even JB.
d)borrow another camera and see if the problem is still there.
I have heard of certain headsets(with power) that cause a few problems in the com system, and possibly you are getting a similar issue..
All these are stabs in the dark, but maybe one will work for you?
Maybe your just freaking out the old bird with modern fandangled technology.
Moderator
Probably a microphone impedance mismatch. Talk to an avionics engineer about using an impedance matching transformer.
You're taking a "line out" from the socket to the camera .... unfortunately, the socket is probably "speaker out" ... if it goes to headsets normally.
Some sort of adaptor/amplifier required.
Some sort of adaptor/amplifier required.
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Tailwheel had it half right - it is an impedance mis-match, but not with the microphone, with the differing impedances and signal levels of the headphone output.
An aviation headphone is relatively high impedance, most David Clark headsets run at 150 ohms, with some avionics systems designed for 600 ohm headsets (which is why you sometimes get problems running a DC headset with another brand in the same circuit).
Without getting too much into theory (which I don't remember anyway
), your camera requires a line-level signal if using line in, or a mic-level signal if plugging in as an external mic. What you are effectively doing is shorting out the audio amplifier in your comms system, which is why everything goes quiet.
Does the Cessna have old ARC avionics? if so, that is probably your problem. From memory, You need a simple buffer circuit to match the impedances. Ask an avionics guy.
It's a long time since I had to solve this, so I could be completely wrong, depending on the effective impedance of your camera...
An aviation headphone is relatively high impedance, most David Clark headsets run at 150 ohms, with some avionics systems designed for 600 ohm headsets (which is why you sometimes get problems running a DC headset with another brand in the same circuit).
Without getting too much into theory (which I don't remember anyway
), your camera requires a line-level signal if using line in, or a mic-level signal if plugging in as an external mic. What you are effectively doing is shorting out the audio amplifier in your comms system, which is why everything goes quiet.Does the Cessna have old ARC avionics? if so, that is probably your problem. From memory, You need a simple buffer circuit to match the impedances. Ask an avionics guy.
It's a long time since I had to solve this, so I could be completely wrong, depending on the effective impedance of your camera...
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The other way is to buy a condensor mike, plug it into the video cam and put the mike in your ear piece - or in a spare headset with the cups rubber banded together.
I do this quite a lot and it works a treat, from helo to fix wing, from noise cancelling to ordinary headsets. You hear everything very clearly.
I do this quite a lot and it works a treat, from helo to fix wing, from noise cancelling to ordinary headsets. You hear everything very clearly.
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What made you like that.
Just as an aside and off topic. I am compelled to comment on P Fanelli`s post because it seems to me he represents a larger issue endemic in this industry of ours. I just gotta vent a little here.
Here we have a poster asking a perfectly legitimate question seeking a solution to a problem. All of a sudden out jumps Mr Fanelli like a little hitler-in-the-box all but accusing our man of vandalising somebody elses property. Please. Why man why?Do you exist in a permanent state of self righteous indignation?Or does pointing a finger and apportioning blame for no rational reason just make you feel happy? Help me understand because, in the words of the great Ferris Bueller"Understanding helps people like us tolerate people like yourself."
Sorry if you are actually a decent bloke and just having a bad day.But ,dammit, it sure has describes a few of the w
ers I have had the misfortune of working alongside over the years.
Here we have a poster asking a perfectly legitimate question seeking a solution to a problem. All of a sudden out jumps Mr Fanelli like a little hitler-in-the-box all but accusing our man of vandalising somebody elses property. Please. Why man why?Do you exist in a permanent state of self righteous indignation?Or does pointing a finger and apportioning blame for no rational reason just make you feel happy? Help me understand because, in the words of the great Ferris Bueller"Understanding helps people like us tolerate people like yourself."
Sorry if you are actually a decent bloke and just having a bad day.But ,dammit, it sure has describes a few of the w
ers I have had the misfortune of working alongside over the years.
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Yes I suppose the other point worth mentioning is that nothing you could plug into the aircraft avionics could actually hurt anything... unless of course you are pumping (relatively) high voltages into them... and he isn't.
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Perhaps Mr Fanelli has a valid point.
Just because something is technically possible does not always mean it is legal or advisable.
Viewed in a slightly different light, consider that he was just advising a cautious approach, instead of diving in head first, and maybe displaying some wisdom gained from experience.
Two sides to every coin.
Just because something is technically possible does not always mean it is legal or advisable.
Viewed in a slightly different light, consider that he was just advising a cautious approach, instead of diving in head first, and maybe displaying some wisdom gained from experience.
Two sides to every coin.
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Had a mate who bought a brand new R44. They hooked up a CD player to it at the dealer pre-delivery. It was wired incorrectly and didn't step down the voltage from speaker output to line-in. Subsequently fried the whole set-up with over $20k damage, including a GNS430 with damage. Ouch!
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Mr. Fanelli has most definitely a valid point.
That the camera is causing the comms to go haywire suggests that an unapproved item is being used with aircraft Avionics that should not be tampered with.
If it is your aircraft, then it is merely a legal question of playing with something you're not licensed to do.
if it's someone else's, then apart from the legal question there is also the ethical one of perhaps damaging someone else's property.
And it may not become apparent right away, but the stressed output transistors may well fail while some other poor sod is out trying to contact ATC.
That the camera is causing the comms to go haywire suggests that an unapproved item is being used with aircraft Avionics that should not be tampered with.
If it is your aircraft, then it is merely a legal question of playing with something you're not licensed to do.
if it's someone else's, then apart from the legal question there is also the ethical one of perhaps damaging someone else's property.
And it may not become apparent right away, but the stressed output transistors may well fail while some other poor sod is out trying to contact ATC.
And people wonder why it's getting harder and harder to hire good aircraft.
If I was to invest a 6 figure sum in an aircraft and make it available for other people to use I would certainly not be happy to find someone plugging anything other than an aviation headset into it.
If I was to invest a 6 figure sum in an aircraft and make it available for other people to use I would certainly not be happy to find someone plugging anything other than an aviation headset into it.
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Yeah well while I fully agree with looking after other people's property, some of the suggestions above are just ridiculous.
First if all, the avionics may require approval (well most of them), but you can plug whatever you like into them - the thing you plug in doesn't have to be approved. Show me anywhere in your aircraft's documentation where a specific headset is required, or conversely where another piece of equipment equipped with a 1/4 inch jack is prohibited.
Complete nonsense. The "stressed output transistors" are part of the audio amp, and have nothing whatsoever to do with the transmitter section of the radio, other than being connected to it. There is no way on the planet that a failed audio output transistor could interfere with someone else's transmission... quite apart from the fact that pretty much every TSO'd radio has output transistors with full thermal and overload protection. And in any case, if those transistors were to fail despite the protection, they would almost certainly fail open-circuit (ie no output at all).
The only thing it could POSSIBLY fry is the input section of the pre-amp, which in any case should be either fused or overload-protected. There simply isn't enough voltage coming out of a CD player to do that sort of damage. 20K? Don't think so. What was it plugged into? And unless it was plugged directly into the GNS430, there is no way it could damage that either. Sorry, but that story is highly unlikely. Show me the receipt for the repair and I might believe you...
First if all, the avionics may require approval (well most of them), but you can plug whatever you like into them - the thing you plug in doesn't have to be approved. Show me anywhere in your aircraft's documentation where a specific headset is required, or conversely where another piece of equipment equipped with a 1/4 inch jack is prohibited.
And it may not become apparent right away, but the stressed output transistors may well fail while some other poor sod is out trying to contact ATC.
It was wired incorrectly and didn't step down the voltage from speaker output to line-in. Subsequently fried the whole set-up with over $20k damage, including a GNS430 with damage. Ouch!
First if all, the avionics may require approval (well most of them), but you can plug whatever you like into them - the thing you plug in doesn't have to be approved. Show me anywhere in your aircraft's documentation where a specific headset is required, or conversely where another piece of equipment equipped with a 1/4 inch jack is prohibited.
"Thanks John for letting me hire your Malibu, by the way, I know you're not keen on it but there's no law which says I can't plug my __________ into the headphone jack, so I'm going to do it anyway and you can't stop me. After all, I'm paying to hire it so I'll do what I want with it"
Wanna bet?
It used to be so nice when there was quite a selection of 210s, Saratogas, Senecas, Bonanzas and yes, a Malibu readily available to people who could respect the owners property.
Ascertain the input/output impedances and AC audio levels of both the aircraft comms headset output and the video camera and then get an avionics engineer to specify a suitable audio isolation transformer and,if necessary,any resistive pads (attenuators).This means that there will be no direct connection between your camera and the aircraft comms system,so nothing can be short circuited or be damaged by DC volts anywhere.
Have the avionics engineer declare that the adaptor will not cause any unforeseen problems with the aircraft systems ( it shouldn't if designed properly) and ask the owner for permission before plugging in....
If all that is too hard/expensive/time consuming,then do as a previous poster suggested and just tape a lapel/lavalier mic onto an approved headset speaker and plug that into the camera.
Have the avionics engineer declare that the adaptor will not cause any unforeseen problems with the aircraft systems ( it shouldn't if designed properly) and ask the owner for permission before plugging in....
If all that is too hard/expensive/time consuming,then do as a previous poster suggested and just tape a lapel/lavalier mic onto an approved headset speaker and plug that into the camera.
