Jump to content
zub

Poor quality video - any ideas why? Have a look at this clip and see

Recommended Posts

This is my first post on this forum, so please bear with me...

I have a Multiplex Easystar which I would like to transmit live video - eventually doing FPV flying.

I have installed an RF Concepts wireless kit, 100mW, as shown here

http://www.rfconcepts.co.uk/wireless-kits.htm#Kit_3

together with a bullet cam. This morning I did my first video flight, the power source was a rechargeable 9v PP3 battery and the antenna was the standard antenna that came with the tx, mounted on top of the plane (in front of the prop).

I've got to say the results were pretty disappointing given the great videos I've seen here! I have put a clip online so you can see what I mean:

http://video.google.co.uk/videoplay?docid=...21&hl=en-GB

Much of the time the video cut out completely, and that is when the plane is only 20-30 metres away from me. Note that I have compressed the video so don't worry about the blocky pixels etc, I'm concerned about the constant cutting out and bad picture quality.

Where shall I go next? Any guidance would be much appreciated. Do I need to get a different tx/rx unit, or maybe an 8dB patch antenna on the rx side - some guidance from someone experienced would be much appreciated.

BTW I live in London, UK, if that makes a difference - reason I say that is there are prob lots of wifi transmitters around, but I'm not convinced that's the problem otherwise the video would be a poor quality ALL the time, not just some of the time.

Z

Share this post


Link to post
Share on other sites

Is there anywhere else you can post your vides to? Google is playing it as a flash vidio and I'm sure that may be part of the problem as far as sharpness of the image goes.

Share this post


Link to post
Share on other sites
This is my first post on this forum, so please bear with me...

I have a Multiplex Easystar which I would like to transmit live video - eventually doing FPV flying.

I have installed an RF Concepts wireless kit, 100mW, as shown here

http://www.rfconcepts.co.uk/wireless-kits.htm#Kit_3

together with a bullet cam. This morning I did my first video flight, the power source was a rechargeable 9v PP3 battery and the antenna was the standard antenna that came with the tx, mounted on top of the plane (in front of the prop).

I've got to say the results were pretty disappointing given the great videos I've seen here! I have put a clip online so you can see what I mean:

http://video.google.co.uk/videoplay?docid=...21&hl=en-GB

Much of the time the video cut out completely, and that is when the plane is only 20-30 metres away from me. Note that I have compressed the video so don't worry about the blocky pixels etc, I'm concerned about the constant cutting out and bad picture quality.

Where shall I go next? Any guidance would be much appreciated. Do I need to get a different tx/rx unit, or maybe an 8dB patch antenna on the rx side - some guidance from someone experienced would be much appreciated.

BTW I live in London, UK, if that makes a difference - reason I say that is there are prob lots of wifi transmitters around, but I'm not convinced that's the problem otherwise the video would be a poor quality ALL the time, not just some of the time.

Z

Hi Zob,

Do you have a link to the camera? It looks like a CMOS from the look of the video? I'm surprised that you're getting poor signal strength out of a 100mw transmitter. We use 10mw only and we have superb picture quality and range. Is the aerial on the transmitter correctly connected?

100mw is illegal in this country BTW (I'm also in the UK).

I'm not convinced that the 8db antenna that I use is actually any better for the flights that I do, and its a pain because it needs to be pointed at your aircraft, which isn't alwasy easy to do whilst flying, FPVing, recording and everything else!

I would suspect the transmitter is at fault. Or perhaps your transmitter and receiver aren't quite on the same channel. I've got 5 receivers here in my kit box and channels 1, 2, 3, 4 are slightly different on each. I think quality control for these things is to make sure the camera and receiver match as they leave the production line, rather than to make sure channel 1 is X Mhz, 2 is Y Mhz, etc. That said if you bought your transmitter and receiver together you *should* be ok on that.

If I were you I'd probably try a better aerial (that'll probably come in handy whatever happens), and then a different TX.

I hope this helps

Simon

www.firstpersonview.co.uk

Share this post


Link to post
Share on other sites
This is my first post on this forum, so please bear with me...

I have a Multiplex Easystar which I would like to transmit live video - eventually doing FPV flying.

I have installed an RF Concepts wireless kit, 100mW, as shown here

http://www.rfconcepts.co.uk/wireless-kits.htm#Kit_3

together with a bullet cam. This morning I did my first video flight, the power source was a rechargeable 9v PP3 battery and the antenna was the standard antenna that came with the tx, mounted on top of the plane (in front of the prop).

I've got to say the results were pretty disappointing given the great videos I've seen here! I have put a clip online so you can see what I mean:

http://video.google.co.uk/videoplay?docid=...21&hl=en-GB

Much of the time the video cut out completely, and that is when the plane is only 20-30 metres away from me. Note that I have compressed the video so don't worry about the blocky pixels etc, I'm concerned about the constant cutting out and bad picture quality.

Where shall I go next? Any guidance would be much appreciated. Do I need to get a different tx/rx unit, or maybe an 8dB patch antenna on the rx side - some guidance from someone experienced would be much appreciated.

BTW I live in London, UK, if that makes a difference - reason I say that is there are prob lots of wifi transmitters around, but I'm not convinced that's the problem otherwise the video would be a poor quality ALL the time, not just some of the time.

Z

Zob,

I forgot to say that the CMOS is the reason for the weird effect when you point near the sun and I would be very surprised if local WiFi is causing you the issue, although I could be wrong.

Simon

www.firstpersonview.co.uk

Share this post


Link to post
Share on other sites

I have to agree with Datona. I don't think wifi is a problem unless that is, you're flying down town on Main street. 300 feet is about the max for wifi and these systems R/C receivers are using FM and your transmitter being the closest should "capture" the signal and block all others out.

As to the wifi & video link, if it's causing the trouble, again which I highly doubt, you must be the unluckiest pilot in the UK.

Forgot to add http://www.rcgroups.com/forums/index.php A great forum as well which may help.

Edited by W3FJW-Ron

Share this post


Link to post
Share on other sites

Looks like multipathing and general antenna performance issues to me. First things on the list to try: If you are using a whip style antenna on the Rx, then replace it with the GP Patch antenna. On the Tx, install the whip antenna so that it is below the model, pointed down. The video was too low quality to see, but if the site you are flying in has metal fences (a.k.a. cyclone) and other nearby RF reflective structures, then find another flying site

Lastly, the CMOS camera is not doing you any favors. So, consider upgrading it to the KX-131 or other model that has proven to work well in our application.

Share this post


Link to post
Share on other sites

Thanks for the guidance. The camera is a v high quality 550 / 580 line (can't remember) bullet cam, it is broadcast quality I usually use it in my race car. It's def not the camera. I'll try and post another video somewhere, not quite sure where.

The antenna on the tx and rx are the ones in the pic from rfconcepts (link above), ie normal whip. I have a wifi mag mount antenna which I can try dangling loose from below the model and see how that works.

Any recommendations (UK preferrably) for a patch antenna?

Finally, I was under the impression that 100mW legal in the UK for radio amateurs, which I am, but I must say I need to check the spectrum plan again. Presumably it is 10mW ERP for unlicensed use, and given the poor quality of the system at the moment it's probably working at 1mW!!!

Any other guidance / advice is much appreciated. I am new to this stuff so appreciate the help.

Z

Share this post


Link to post
Share on other sites
Finally, I was under the impression that 100mW legal in the UK for radio amateurs

This is the problem though "2(14) The Licensee shall not establish or use the Station in any aircraft or other airborne vehicle."

Terry

Share this post


Link to post
Share on other sites
This is the problem though "2(14) The Licensee shall not establish or use the Station in any aircraft or other airborne vehicle."

Terry

Hmm - shows how long ago I did my radio exam! Thanks for this!

Share this post


Link to post
Share on other sites
Thanks for the guidance. The camera is a v high quality 550 / 580 line (can't remember) bullet cam, it is broadcast quality I usually use it in my race car. It's def not the camera. I'll try and post another video somewhere, not quite sure where.

The antenna on the tx and rx are the ones in the pic from rfconcepts (link above), ie normal whip. I have a wifi mag mount antenna which I can try dangling loose from below the model and see how that works.

Any recommendations (UK preferrably) for a patch antenna?

Finally, I was under the impression that 100mW legal in the UK for radio amateurs, which I am, but I must say I need to check the spectrum plan again. Presumably it is 10mW ERP for unlicensed use, and given the poor quality of the system at the moment it's probably working at 1mW!!!

Any other guidance / advice is much appreciated. I am new to this stuff so appreciate the help.

Z

Hi Zub,

I think a lot of your problem is the CMOS badly handling the sunshine to be honest. You may not have had such a big problem with that in a car?

We have a suitable (and very popular with FPVers) 8dBi panel antenna in stock with RP-SMA connector and we're in the UK. http://www.firstpersonview.co.uk/default.a...e&prodID=69

I can do free postage and send it tomorrow morning if you like, just order through the website as normal.

Thanks

Simon

www.firstpersonview.co.uk

Share this post


Link to post
Share on other sites
The camera is a v high quality 550 / 580 line (can't remember) bullet cam, it is broadcast quality I usually use it in my race car. It's def not the camera.

I agree, the reception problems are not due to the camera. I commented on the camera because it does not seem to be ideal for aerial applications (light handling issues). But, if you find that it works well for you then that is all that matters.

The antenna on the tx and rx are the ones in the pic from rfconcepts (link above), ie normal whip. I have a wifi mag mount antenna which I can try dangling loose from below the model and see how that works.

Assuming the stock 3dBi Tx whip antenna is not defective, I would recommend sticking with it.

Any recommendations (UK preferably) for a patch antenna?

The GP Patch. Available in every country that sells roofing tin.

Share this post


Link to post
Share on other sites
Hi Zub,

I think a lot of your problem is the CMOS badly handling the sunshine to be honest. You may not have had such a big problem with that in a car?

We have a suitable (and very popular with FPVers) 8dBi panel antenna in stock with RP-SMA connector and we're in the UK. http://www.firstpersonview.co.uk/default.a...e&prodID=69

I can do free postage and send it tomorrow morning if you like, just order through the website as normal.

Thanks

Simon

www.firstpersonview.co.uk

Simon

Camera is a very nice CCD camera, not a CMOS one - this is the one I use

"550/580TVL Bullet camera kit Our 550 (PAL) Sony bullet camera uses the latest HQ1 chipset. This gives a finished result that gives very sharp results, for all uses including dvd and playback on large sized tv screens. As used by the BBC and numerous other TV companies. "

>>We have a suitable (and very popular with FPVers) 8dBi panel antenna in stock with RP-SMA connector and we're in the UK

Just been on to your site and have bought it - let's hope it does the trick! I've paid by paypal, pls ship it tomorrow as I am on hols later this week and have some time to play with it!

Many thanks for your help

Z

Share this post


Link to post
Share on other sites
Simon

Camera is a very nice CCD camera, not a CMOS one - this is the one I use

"550/580TVL Bullet camera kit Our 550 (PAL) Sony bullet camera uses the latest HQ1 chipset. This gives a finished result that gives very sharp results, for all uses including dvd and playback on large sized tv screens. As used by the BBC and numerous other TV companies. "

>>We have a suitable (and very popular with FPVers) 8dBi panel antenna in stock with RP-SMA connector and we're in the UK

Just been on to your site and have bought it - let's hope it does the trick! I've paid by paypal, pls ship it tomorrow as I am on hols later this week and have some time to play with it!

Many thanks for your help

Z

Hi,

Its strange about the camera. The effect on the video looks very much like the CMOS lighting effect.

Hopefully the new antenna helps you. I will put it in the post tomorrow.

Thanks very much

Simon

www.firstpersonview.co.uk

Share this post


Link to post
Share on other sites

Just curious... Would fastening the antenna to the back of the transmitter so it's always aimed at the airplane have any effect on signal reception for the good or the bad??

Share this post


Link to post
Share on other sites
Just curious... Would fastening the antenna to the back of the transmitter so it's always aimed at the airplane have any effect on signal reception for the good or the bad??

If you used a sort of wedge to point it more upwards that might work. I've seen people with the antennas on poles above their heads attached to backpacks and all sorts.

When we're recording video one of us points the panel antenna at the plane all of the time for the best possible quality. I seem to get on fine with the stock antennas for flying FPV itself. I guess I'm not too adventurous at the moment and just tend to do big circles in front of me most of the time! I'm usually fiddling with some new gizmo, testing, etc.

I've got everything just about right now, so this season its time for some more adventurous flying!

I've just ordered a tri-pod to try out - I'll let you know how I get on with that.

Thanks

Simon

Edited by Daytona

Share this post


Link to post
Share on other sites

Too bad you don't live next door. You could use my tripod.

From what I understand, those patch antennas have a 67 degree vertical bandwidth so a slightly upward look would have the plane in sight 99% of the time. That might be the way for me to go although I'd build a 4 or so element yagi. That would be good for something like (guessing, don'r have my handbook by my side) 11 to 13 dbi gain. Another thought is to put one of those small video cameras on my head as I'm always looking at the plane so should have good video of the flight.

Maybe I'll just get a surplus infantry helmet and mount everything to it.

Edited by W3FJW-Ron

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×