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Hi All,

I came accross these this morning and I was wondering if anyone had any thoughts:

http://www.airwave.com.tw/p_2.4ghz.htm

I downloaded the datasheets and they're basically bare OEM 2.4GHz video/audio transmitters from 10mW to 500mW. They have no antenna connector or RCA connectors, so it's far from a turnkey system, but they only require need +5v, antenna, line audio, and PAL/NTSC composite video to get going.

They are available at what seems like an excellent price:

http://www.active-robots.com/products/radi...v-modules.shtml

I'm asking because frankly the prices (US$30 for a 500mW transmitter!!!) seem too good to be true.

Cheers,

-Rob

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I recall reading in another forum (Runryder or RCU) where a fellow had used one of these (no idea on the exact one though). If my memory serves me right, the guy was happy with the results.

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The transmitters/receivers look just like Felsweb (at least the casing, pinouts and frequency bands). Also power ouput levels are the same. I am going to order couple and test them. Thanks for the link!

Matt, do you want to try these for your diversity RX?

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I remenber having seen that they really were the same, but can't find where :unsure:

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Rob,

you are my personal hero of the day! Those transmitters will save me endless hours and headache in building myself a 2.4g amp because my hongkong-cam has only 10mW and less than 100m range which is way to less.

I already had several tries in rolling out my own amplifier but you can guess that they all failed, althought I almost cloned the original evalution-board-layouts from the different ic-manufactures. But I had to use 805 and 1206 sized parts instead of 603 ones. So nothing worked like it should and it only produced bad ghost images across the other 3 receiver channels.

So this $30 transmitter comes in really in the right time and for the right price since I cannot affort much.

Greetz,

Marcus

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Well, now I ordered myself one...

BUT I wonder how to set up the pins when I look at the datasheet. Pin 7 - 10 are marked CH1 - CH4. Oblivisiously this is for setting which channel to use, BUT HOW? By grounding this pin to GND or VCC?

If there is a manual included when it arrives then no problem, but I like to kill problems in advance.

So anyone has a idea about this?

Best Greets,

Marcus

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In the Felsweb TX/RX you select the channel by grounding corresponding pins. I presume this guy works the same.

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Guys,

I can tell you from personal experience that these modules are in fact the same as the Felsweb modules. Only difference being the price.....

Have a look at my website at www.delemarre.ciscon.nl and go to the videodownlinking part to find all you need to get these modules in working order even with a sound amplifier.

PCB layouts are included. The viewing software (also needed to print the PCB's) is also supplied.

greetings from the Netherlands, Hans Delemarre, PH7JDE

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....in fact the address from the UK is not new here on this forum. It has been on the links page for a long time. I got it from there about 9 month's ago and ordered the modules from the UK together with the SMA connectors for rhe antenna. The connector for the TX and RX module to get your wiring in order is from Harwin.

Hans Delemarre.

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Wow! I thought this thread was dead.

Hopefully these modules will prove useful for some people. I can confirm (based on the data sheets from Airwave) that the channel is selected by grounding the appropriate pin.

cyber-flyer and fallenangel3k, did you guys order from active-robots.com? I presume you haven't recieved them yet, but has their service been good so far?

Looking forward to hearing the results!

-TheOtherRob

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In my case the service was perfect. I asked first for more info on the modules and got the answer to my question within 24 hours. Then I asked for availability and it proved that the 500mW modules were on back order. Within a week I got an e-mail telling that they had arrived. I then proceeded to order two modules and the angled SMA connectors. Five days later I had everything delivered by the mailman.

I made one module into a working 500 mW tx (see my website) and it functions beautifully. I also got the new camera from Bill Strong (blackwidowAV) and this is also an improvement over my previous set-up.

I allready had the receiver (actualy two) so I didn't need another. When buying from Fels you allways have to buy (andpay) for a complete set......

Hans Delemarre

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I did receive Airwave TX/RX set from active-robots.com

The shipment was fast but pricey at 20 UKP postage to US.

The Airwave TX worked fine with RX from Felsweb in my ground tests.

They seem identical in any respect so far but cost 70% less.

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They seem identical in any respect so far but cost 70% less.

That is excellent news. Thanks for verifying it.

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Definite Insanity,

Try http://www.delemarre.ciscon.nl/id118.htm

On my PC this gives the page where I start with the actual description of the PCB I made to facilitate the use of these modules.

Hans Delemarre, the Netherlands

Edited by Delcam

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Hello again,

well, yesterday my 500mW-Tx-module from active robots arrived. I ordered last week and paypal took until end of week before money was ready to be sent to active robots.com. So this guys are pretty fast! Also I live in Germany and I only had to pay about 10 Dollars or for postage.

Thanks to Hans for the layout I made myself a slighty modificated PCB which has a Pictail instead of 90° SMA connector only. This way I can mount the Antenna more away from the rc-rx and servos, without affecting CG much as if I has to place the whole TX in a more away place from servos.

2nd modification is that I soldered the module directly to the board, drilling and soldering tiny 0.5mm holes. The is no real reason for this but I couldn't find the required connector with the correct size and pin-count.

3rd modification (and probably most significant) is that I also soldered 2 RCA connectors to the board/module, so that I can hook up other video-equippment very easily.

Look... some photos:

Photo of TX-Module

The bare complete setup of cam, tx and battery

Also I did some first range-tests. Unfortunately the weather was very bad the last two days, so I had to do the test by walking rather than flying. Well I >aborted< after about 1000 feet of PERFECT video-receive. I assume this baby will produce almost full range rated for thumb-formular of 100mW/1000ft, so 500mW is about 5 thousand feet!? Sound reasonable, looking at the quallity of the signal and the fact that I made the test with my homemade-tx-antenna and then UNPLUGGED RX-ANTENNA AT ABOUT 1000FT AND STILL HAD THE VIDEO-SIGNAL ON MY TV, although somewhat noisy!!

So this is very nice stuff. At only 16.50 pounds it's definitively UNDERpriced, you can never bet that in homemade style, not quallity nor the costs. So this Baby is really a gift from heaven for poor people like me who cannot afford the 1000$$$ for the other professional stuff. So I usually make everything myself. But trying to make a working amplifier for the Hongkong-cam was a pain in the ...!

Hope this encourages more people to give it a try and also answers some questions. This stuff is not beginner level but very easy to use/build anyways!

Best Greetings,

Marcus

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Great job ! Thanks for the info, the pictures are good to see.

Not sure about your 100mW per 1000ft rule though, you need 4 times the power to double the range.

Terry

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Guys

Just ordered one of these TX's myself. Too good of a price to let go.

I have a 3 channel 2.4 GHZ receiver. I can't find the frequency that it operates on anywhere. I know it is 2.4 GHZ for sure and about 2 years old and has 3 switches to select channels.

Has anyone had and experience with the receiver in the attached photo or can anyone advise if the frequencies are standard across the range of 2.4ghz equipment? I want to try and use it with the TX I just purchase.

If this is not a good choice can anyone advise a good place to order a new receiver?

Thanks in advance

post-5-1122085998_thumb.jpg

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-AT-Terry

Thanks. I am not sure, too. I know that you need to quadruple ERP to double range by bare formula for RF-science. But sometimes the stuff behaves quite odd and as you all know a well-made homemade antenna can do a miracle!

I have this rule of thumb heared several times and this was first time to prove or disprove myself. (I never trust standart-science-book, only what I can see and do myself or if I feel that it is true I believe.... dont get me wrong on this). It SEEMS to be true and I am really looking forward to have very good range on this.

Today I made first flight test.... ran out of range of my RC-TX. Luckily I have a Slowstick and I cought range after I ran like heck into direction of it. But video was fine all times... this is why if flew out of range... ;c) (I am using a el-cheapo RC-TX/RX with only about 500m range.

-AT-Crash Pilot

Well.. I suggest you buy one of these crappy wireless-sets (Hongkong cam) from ebay for about $50. You get a beginner-level camera (=cmos, no sensitivity to infrared in most cases), a 10mW-2.4Ghz TX (you can hack the camera and remove it from inside, like I did , for other projects with less range-requriement) and finally what your are looking for... a neat and small RX with four channels and DUAL A/V OUTPUT in the new models (208c for example).

This 2.4G RX from the el-cheapo Hongkongcam works really, really great with the active-robots module. I had worries prior to building and tring but they all proved false for our sake... this is a nice combo!

- el-chepo Hongkong-Cam with 2.4G TX/RX $50

+ active-robots 500mW TX-Module $40

+ 720mAh 7.2V Lipo for System $25

------------------------------------------------------------

= less than 150 Dollars for a complete system which gives you probably more range than enough. The quallity of the cam is also enough for the beginning!

The Receiver which is includes with the el-cheapo cam has also an external SMA-connector, so that you can connect your antenna directly without soldering!

Hope this gives you an little answer... this is exactly what I did and I AM TOTALLY HAPPY WITH IT. Again, I only can encourage everyone to buy these modules!

Greets,

Marcus

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The reciever for these modulles is also offered for a ridiculously low price by the same vendor when compared to the HongKong offering...

Hans Delemarre

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fallenangel3k

Thanks for the advise.

I already have one off the 1.2GHZ ones. I have only used this for testing and never really used it outside my house. I have a KX-121 from B/W but never really had the cash to but there 600mw. So this Active Robots module is what I need.

About 2 years ago I purchase the 2.4GHZ set in the picture of my last post. This was not a cheap Hong Kong version and was quiet expensive. The camera and TX were only 10mw so it was pretty useless for putting on a plane. The camera no longer works but I still have the receiver. I will try this receiver on the Active Robots module and hopefully it will work. If it is the wrong frequency It will probably be cheaper to just buy a receiver from B/W because I already have the CCD camera and a stack of cmos cameras.

Thanks for the advise on the 2.4 GHZ Cheap Hong Kong cameras.

Crash Pilot1

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If it is the wrong frequency It will probably be cheaper to just buy a receiver from B/W

Bad idea.

I think I'll share my little frequency list, BTW all these stand on the seller's websites:

Felsweb: 2414, 2432, 2450, 2468 MHz

Blackwidow Set 1: 2410, 2430, 2450, 2470 MHz

Blackwidow Set 2: 2413, 2433, 2453, 2473 MHz

So if you odrer a BW set 1 RX you will be able to use CH3 only.

My HK systems use the same freqs than the Felsweb equipment for the video, but sound doesn't pass through. The audio subcarrier freq can be changed on the Fels TX (one of the pots), so it must be possible to make it work as well.

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Hi Kilrah, thank you for posting the frequencies -- it'a a big help!

I recently have run into a problem where I lose video after about 5 minutes, and I haven't been able to figure out if it is the transmitter, the receiver, or what. Having only one of each makes it hard to troubleshoot! So I am planning on buying another tx/rx pair from BW, because that is what I already have, and your frequency list shows there are no alternatives if I want to be able to mix and match.

The frustrating thing is that this problem has cropped up but I haven't made any changes to the system. I did take the transmitter to a ham friend who has a power meter that can measure power at 2.4GHz, and the tx put out continuous power for 25 minutes -- far longer than I've been able to run without something cutting out. And yes, I ran it from the same power source (battery and voltage regulator) as when I fly. The only change I made was to take off the antenna and connect up the power meter. Oh yes, the other difference is the transmitter and voltage regulator got much hotter than usual because the plane was on the bench instead of flying. Oops, I forgot one more thing -- on the bench I didn't hook up the camera so there was no video signal going to the transmitter. I didn't think that would make a difference.

So that seems to leave the antennas, the receiver, and the video cables from the receiver to the display as being the likely suspects.

Has anybody else run into a similar situation?

--bluegill

Edited by bluegill

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