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phillbar723

Newbie Having Problems With First Aerial Videa System

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Hi All,

OK, so I recently purchased the following complete Aerial Video System from range video:-

http://rangevideo.com/index.php?main_page=...;products_id=20

And I'm having some problems with receiving the signal.

My Setup:-

Plane: Twinstar 2, Nimh batteries and standard electric motors. Transmitter for ailerons etc etc is the old standard around 35MHz.

AVS: (See above link) (PAL version)

CamCorder: Panasonic NV GS5 - PAL

Location: In a tool shed (not airborne yet)

Problem 1

I have my receiver connected to a portable TV on the ground... just two phono cables yellow for video and white for the mono sound. When I connect it all up I see the image and I also hear sound from the plane (as tested by tapping the mic on board the plane)! Obviously this proves that it's working OK. However I'm hear a low humming noise from the TV. It sounds like there is interferance coming through from somewhere. It remains constant with the motors on or off (i.e. it doesn't seem to affect the interferance). What could this be? Is this normal??? The visual looks 100% perfect... just the audio seems to be interferance.

Problem 2

When I connect my AV receiver to my camcorder I will at first get nothing shown on the screen, but then I will get a signal that looks distorted. I'm pretty sure I have the camcorder on the right mode.

The audio that comes through the camcroder sounds indentical to the interferance on the TV.

Could these issues be linked?????

Obviosuly I really need to get this working with the camcroder.

Any ideas?

If I have been unclear in this post, let me know and I will re-word or add a comment.

Any help would be much appreicated and I promise to upload the final video once I get this thing working.

Thanks,

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1. Does the noise go away when the video signal is disconnected from the transmitter?

2. Are you sure the camcorder's video input is setup to match the video mode (PAL / NTSC) of the video camera?

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Hi Phil where abouts in Devon are you ?

Are you able to post any video of the problem here ?

Terry

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Thanks very much to your replies.

I have some further info...

OK, Problem 2 has been solved. Read on if your interested: I discovered yesterday it is actually a problem with the camcorder and not a problem with my setup.

Problem 1

I can't tell if the noise goes away when I disconnect the visual since then my TV stops showing anything all together and I get no audio. However the interferance could be coming from the video since we did a test at night with all the lights off (i.e it was 100% pitch black) and the noise did go away. Now the problem is I don't know if the TV was still actually displaying the signal (i.e. it could have sensed nothing was being transmitted, just black, and then cut off the displaying AND audio). I should ahve spoken into the mic and listened for it coming out on the TV but it didn't occur to me.

I also did another experiment whereby I disconnected all the servos, motors etc etc from the plane so just the av system was powered up and still the same problem remained. I also tried outside in a field away from the tool shed and again the same problem was there.

Terry, I was near a town called Bradworthy it's my parents place and I have now gone home after the Christmas break. Just before I left I took a video clip of the problem (I filmed the TV using my camera). I will upload this video later as it's possible to determine the frequency of the interferance (it remains a constant tone). Perhaps the video will give you guys a better chance in finding/solving the problem. Until then any other ideas?

Edited by phillbar723

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I know where you were, I was not far at Holsworthy the other day :) now back at Bridgwater.

I cant think what it may be, hearing it would help a lot. Can you try it on another TV ?

Terry

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OK, I have uploaded the video to youtube:

So just to re-cap, this video was taken by a camera filming the TV which was receiving the audio and visual signal from the AVS on board the plane. The slight flickering is due to the fact that the camera is filming a TV which causes aliasing I believe.

The image is moving around as I was waggling the camera on board the plane... I don't quite know why i did this but I'm sure I had a very clever reason at the time.

Any ideas?

All the best for the New Year!

Edited by phillbar723

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I can't tell if the noise goes away when I disconnect the visual since then my TV stops showing anything all together and I get no audio. ... I should have spoken into the mic and listened for it coming out on the TV but it didn't occur to me.

If disconnecting the video signal from a typical TV set makes the audio go silent then I think that indicates that the A/V system is defective. However, a repeat test, where you speak into the mic, would be the nail in the coffin.

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(Sorry to sound all paternal, but as you're a self-professed newbie I'll say this anyway: bear in mind that when it all works, your 500mW transmitter will still be illegal to operate in the UK.

10mW is the legal max for video here, and I get plenty of usable, flyable range from 10mW.

I know it's maddening seeing the 2.4GHz band clog up with wifi, and while I understand that increasingly the middle classes' distinction between right & wrong is "that which you can get away with", I don't want FPV to get a bad reputation - we should no more consider using illegal FPV transmitters than we'd consider illegal R/C transmitters... okay, I'll shut up now!)

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And there ends the sermon by the right honourable reverend Doofer. :D

Just kidding. ;)

It is a problem here in the UK that is getting worse, wifi ruins and video I record on the ground, people dont like watching flashing white lines. :o

Doofer is right of coarse 10mW is the legal limit here and it is usable. Even now I use 10mW for most of my flights but I do confess to using 100mW at times. 100mW is not as big an increase as you may think, it will give you an increase of about 2.5x on your range. As far as causing interference to others the chances are tiny. If I had to fly the plane within 100ft to cause interference with 10mW then I would need to fly within about 250ft with 100mW. So as long as you dont fly too close to houses (500ft or so) then there is no problem.

A lot of people I know in the UK have given up using 2.4Ghz video senders due to wifi interference and people with video senders are the only people we are likely to interfere with. The majority of users will be using wifi and due to its spead dose not suffer from interference from our transmitters until very close (often less than 50ft).

My problem is that I have my take off site close to houses (1000ft) and then fly out accoss open fields, so I get the wifi interference but my plane is too far out to be received by anyone even if they wanted to.

That said it is still not legal, but its your choice.

ps. I am just waiting for my new 1.394Ghz video gear to arrive, bye bye 2.4Ghz :)

Terry

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This discussion has gone a bit off topic. Sorry about that. Hopefully the OP has determined the cause of the audio noise problem (I suspect it is defective A/V equipment). I'm about to muddy it up too ...

10mW is the legal max for video here ...

Ahh, but there is more to that simple criteria. In the UK and many other European countries the license free RF equipment must have the required declaration of conformity. Approved RF systems will be clearly labeled as such (the mfg's provided consumer instruction manual will indicate the equipment's conformance). For more UK/Euro RF compliance info: http://www.ofcom.org.uk/radiocomms/ifi/tech/RTEE/rtte_faq/

Long story short, if you intend to operate legally with license free equipment, then careful product choices must be made. Otherwise, illegal is illegal. FWIW, a ham radio license sometimes takes care of this issue. But I understand that some countries have ham rules that forbid using wireless video in aircraft apps (not a problem here in the USA :) ).

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In the UK and many other European countries the license free RF equipment must have the required declaration of conformity

Yes correct again, good point. If you make up your own gear you must use modules that are compliant with Mpt1329 and if you sell it you need to CE mark it to show its compliant with EMI regs.

FWIW, a ham radio license sometimes takes care of this issue. But I understand that some countries have ham rules that forbid using wireless video in aircraft apps

That is true for here in the UK, I know of some hams that have used planes, kites and balloons with transmitters but I guess they are as illegal too. No one ever stopped them though.

If OFCOM get their teeth into us I think they will ban any transmitting from model aircraft.

Terry

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If OFCOM get their teeth into us I think they will ban any transmitting from model aircraft.

Terry

I guess that's my worry: If we are seen to not care at all, it'll all get banned. It might take just one joker swooping around their estate kicking out 500mW to draw attention to the issue, and no doubt, here in Gordon Brown's 'Central Control' Britain we'll go the way of tax relief on private pensions... I can see the headlines now: "Ban on Suicide Bomb planes" - The Sun etc. That's why I raised the issue, despite the risk of sounding horribly pompous :(

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That's why I raised the issue, despite the risk of sounding horribly pompous

Not at all, I understand your reasons for bringing this up but I can't miss out on an oppertunity for a joke ;)

If we are seen to not care at all, it'll all get banned. It might take just one joker swooping around their estate kicking out 500mW to draw attention to the issue

You are very right and I urge us all to use no more power than needed for the flight and not to fly over houses. If we do this no one will even know about us, let alone care.

Terry

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