ver0776

Background:
I run RC trucks for home security and FPV drive-by-video applications. The range on standard wireless cameras was horrible and I could barely get to the end of my short driveway. So I started looking for antennas and new transmitters. Weight not being a big issue since it is not flying. I need omni directional antennea so I can drive all the way around my house. I wanted to learn more before dropping $400 at BWAV.

So here is part 1 of my video improvements

I bought this antennea:
http://www.wifi-link.com/product.php...&product_id=16

This company is awesome! Good prices, COMPLETE selection. I bought the 2.4ghz 8db antennea, a low loss 9' cable and some SMA adapters from them.

The results? It is true that a receiving antennea is the cheapest way to drastically improve your range! Just this 8db antennea, NOT mounted as good as it should be, trippled the range of my car. I have driven past 3 houses on either side of me and kept clear video.

I was worried about picking up additional interference, but the interference and reflection I suffered before has not changed. So I still have reflection issues to deal with, but that is not the fault of this fine antennea.

So if you are playing with cameras that have built in transmitters, definitly start by getting a better receiver antennea. Watch for the connector types. Network antenneas are Reverse Polarity so when you see (RP-SMA connector) or the such, it will not work on these video receives unless you get an adapter. But the company I link to in this message sells normal SMA and N type connectors, but has the adapters and cables to reverse the polarity or change connector types.

Next steps:
1. Upgrade to a CCD camera.
2. Get a 100-600mw transmitter.
3. Diversity receiver.

Now that I know how much this 8db antennea helped, I may just buy thr 15db model they sell too and see if that does not tripple my range again. If it does, there is no need for a powerful transmitter and I may just buy a 100mw one.

I will try to shoot videos with all the different equipment so RC car drivers can see what to expect. I will also put a photo of my rig up, but I am at work now.

Vaughn

JettPilot

My Feedback: (6)

That antenna is a great solution for your use. It has gain because it takes signal from the top and bottom of the antenna and directs it out towards the sides. The more the gain the more the signal concentrates towards the sides, which could pose a problem for you. The 15 dBI antenna is so directional towards the sides, that if you mount it higher than your truck (on your roof), the reception area will be great 15 feet high, but will be very poor on the ground where your truck is. So the 8 dBI might be better for you, as the signal is not quite so tight on just the sides of the antenna (it works a little above and below also). How far out are you going ? The further out, the better the 15 dbi antenna will work, because the best signal area on the sides of the antenna is like a wedge shape and it gets bigger as you get further away so exact heights are as not much as a problem. The antenna must be mounted exactly vertical for it to work well in all directions, or one side will just shoot up into space.

Another thing you can do to improve performance greatly is mount the receiver right at the base of the antenna, and run a video line to the inside of your house. Coax is HUGELY lossy at 2.4 ghz and even just 10 feet can reduce your signal by a lot.

I would highly recommend that you get the 600 mw black widow transmitter, its about the same size as the 100 mw and just a little more expensive. Your video quality will be much better if you are not always at the edge of your reception, it will overcome intereference much better, and your range will be more than doubled from your 100 mw.

Good Luck

JettPilot

ver0776

Thanks for the reply JettPilot, that is good info!

Here is my follow up:
I bought this CCD camera for $35:
http://cgi.ebay.com/ws/eBayISAPI.dll..._BIN_Stores_IT

The vendor shipped it the same day. It was super cheap and included all cables needed. I tested the setup on the street this morning and it looks soooo much better than my $100 Swann wireless. I am very pleased with Mavin and the camera. At $35, you can't lose with this!

I also bough this 200mw Transmitter & Receiver for $159:
http://www.microcameras.com/video_tr...ransmitter.htm
Microcamera.com shipped the same day also, and their sales/web site are very professional. Compared to BWAV or TinyWireless, this is an excellent company to do business with. The product mounted on my car easily, had every cable I needed and performed very well.

These two products, along with my antennea above are yeilding fabulous results. I only tested the car this morning, but I drove it 4 houses away with perfect video clarity and VERY LITTLE reflection/interference. This package eliminated all of my ground issues and I am very happy. I wish someone like BWAV had a complete package like I bought or at least someone would have recommended the equipment I bought.

So, now I am recommending this setup to anyone looking to buy a new video rig.
$38 + $35 + $159... With all the batteries and everything, this setup is under $250 and is a no-comprimise setup for ground & air.

The companies I bought this equipment from sell everything needed to change the configuration to an air based one (patch antenneas, uncased transmitters, etc)

I hope it helps someone enjoy RC video projects.

And JettPilot, despite being a vertically aligned antennea, I get great reception in my half basement even though the antennea is on the roof of the second floor. I was shocked at how little reflection I am getting after hearing all the nightmare stories about indoor usability of 2.4ghz systems. I am so happy... Now to get the pellet gun mounted =)

Vaughn

JettPilot

My Feedback: (6)

Very Cool Vaughn,
Sounds like it will be a lot of fun to play around with, and the pellet gun would put over the top Post some videos, I would love to see them...

I also use antennas with lots of gain, it makes a bid difference. You are lucky in your setup, because below your antenna in your basement, you are so close to the antenna that the signal will get to it even though it does not perform well above and below. If you are close enough, you will get your signal to the antenna no matter where you are. Where the best performance is needed, is far away, and thats where your vertical antenna kicks in, around the sides and not so much above and below. Mount your reciever right at the antenna, get rid of that 10 feet of coax and you will be pleasently suprised how much your signal improves. 10 feet of coax at 2.4 GHZ is very lossy.

Post some pictures of your setup, I would love to see it !

ver0776

JP,
I will try to get rid of the coax. Did you look at the specific cable I bought from Wifi-Link, or are you just working on the premise that all cable is bad? I was hoping the special low-loss cable I got would be good enough that it would not make much difference.

Anyways, at lunch I got my digital camera put back together (I dropped it =(, so I will be taking some pictures tonight. Right now I have the RX going straight to my TV, but I will also try to feed it into one of my PC/TV capture cards and make a movie too, but that might be a couple extra days.

Vaughn

Dennis H.

Hey Vaughn, Thanks for the head up on where you got your suff, I've been looking around for a long time, Just way to much $$$$$$$, I'll be getting the same, as you post here!
Dennis

ver0776

Here are my pics. The Pellet gun is not properly mounted yet, but very close. I might have to switch to an Airsoft gun so I don't get arrested for having a UAV weapon of minimal destruction.

Again, I just got everything yesterday, so I have unweildy adapters hooked up rightnow, so the cabling should get a lot neater.

Vaughn

JettPilot

My Feedback: (6)

Cool setup ! I also do alot with 2.4 GHZ wireless, and use a calculator that tells you the loss for certian cables at different frequencies. I buy special very expensive microwave low loss cable, and even that at 2.4 ghz and a 10 foot run starts to really eat up the signal. ( LMR 240 ). The thin stuff is really bad and 10 feet is not even practical because it eats most of the signal. What kind of cable are you using ? I will run it on the calculator and tell you exactly how much signal is being lost.

JettPilot

ver0776

The cable I got is:
http://www.wifi-link.com//product.ph...class2_id=278#

NP-NP-400-3.0

The link I gave works, but if you click on the product info for the model I gave you, the link is broke /shrug.

So I bought the 400 series, it looked like the best they have and it is 3 meters.

Thanks for checking on it I will remount it if you find some some bad numbers.

I made a video already, but it was interlaced and looked bad. Just as I got the CODEC settings decent, it started raining. I am also having a bad time with Adobe Premire 1.5 =( But I should be able to get some outdoor footage out in the next day or two so you can see if my results are decent or if I should continue to pursue improvements.

Vaughn

JettPilot

My Feedback: (6)

I looked up your cable, its listed as LLC 400, which I think is LMR-400 cable, very good stuff. It is pretty thick and has very low loss at microwave frequencies. The calculator said its loss is minimal and 85 % of your signal is getting through if everything is done right. At 85 %, its hardly worth the trouble of putting your receiver outside. You got the right cable. The calculator is at:

http://www.ocarc.ca/coax.htm


Adobe is hard to use, great for editing, but the file sizes and codecs dont turn out very good for posting on the web. I use Adobe to do some very complicated editing, but my finished product is always made with Windows Movie Maker. Its easy to use, and gives the most excellent quality for the file size. I would have never thought Movie maker would be great being that its packaged with windows and all, but the results are far better than adobe Microsoft got something right !!

JettPilot

ver0776

Thanks JP,

At lunch today I just switched to VCD format, fixed the audio and shot a test clip. Then I stick the car outside and it stopped working. Everytime I pushed it forward or backwards it would work for a bit then stop... THE CURSE! I think the ground wire on the motor was touching something it shouldn't. I fixed that but that ate all my time and I could not shoot another video ARGH =) But nothing should be able to stop me from getting a decent video done as soon as I get home (HA! I challenge the fates again despite their constant victories over me hehe)

Once I get a decent clip done, I will try to make something higher quality and will try MovieMaker... Maybe I will read more about it while I am stuck in this PERL class...

Vaughn

ver0776

http://www.youtube.com/watch?v=_76vy-ZIeUs

Ok, I am using the excuse of this is my first video. I had much better takes than this, but between it getting dark and low batteries, I just had to settle on this little clip. It really looks and feels so much better live through my TV than it does through the ATI TV capture card...

Anyways, I have no idea what the norm is so I am just showing an average clip[ so maybe I can get some feedback to make it better...

Vaughn

Dennis H.

Hey Vaughn, I was looking at the Tx. again, Are you a Amateur Radio operater? If not You'll need a licensce for legal operation. Of that Tx. If not, getting your Amateur Radio licensce is very easy

Dennis
KC7KIU

ver0776

I am not, BUT I bought the ARRL book from their web site and will be certified soon. I ordered the book and read half of it before I even ordered my TX. I could just read the pratice exams and go take it right away, but I found the book very interesting and am thinking of even going to the 2nd or 3rd level... Until then I just keep my usage low =)

At least I didn't order a 5w one ;-)

Vaughn
Call sign coming/

Dennis H.

Cool, Just don't get caught, That about a $1000. fine a day! just do a serach for a club near you, You will find people who will be glad to help you get your ticket { that a [licensce] Plus you DON'T need to take mores code, to get started. And if I can help, drop me a line. I;ll try my best to point to where you need to go.
Dennis
KC7KIU

twinturbostang

Definitely get your HAM license. I just got mine a few weeks ago, so that I can legally operate my video Tx as well. It was not hard at all, as long as you study the question pool. It's definitely worth it.