Hi gain antenna for receiver

[p3jpaavi]

Hi

I am going to build a hi gain antenna for my 2.4ghz receiver. I need to build the higain antenna because my transmitter is only 10mw! Here is what I bought http://www.rangevideo.com/index.php?main_page=product_info&cPath=35_22&products_id=91

The antenna what I like build is a double biquad (http://martybugs.net/wireless/biquad/double.cgi) antenna.

My question is this (http://www.xbitti.net/product/206/sma_valijohto_uros__uros_15m/) the right cable If slip it to two parts?

[vintage1]

Its the right cable , but the wrong antenna.

All that gain is ONLY in one direction.

If you model is pointing in the other direction its about 50dB loss..

But build it anyway. Its a useful exercise.

You COULD use it on the transmitter..if you keep it pointed at the model all the time.

[p3jpaavi]

vintage1,

Thanks for the reply. What antenna do you recomend ?

I ques that I'll ne needind 10+ gain for 1-2km range? Are there any automatic antenna pointers ?

[p3jpaavi]

I found couple solutions with good gain, what do you think of them ?

http://www.digdice.com/tag/pcb-antenna/(The 16dBi version) If I got it right this antenna has also some polarisation problems ?

http://mitglied.lycos.de/kleineronkelz/wifi_hybrid_double_quad.html If I turn two of the quads 90 degree what would the result be ? :confused:

Any comments or suggestions are welcome !

[GlennS]

I am also using a 10mW 2.4GHz transmitter for my video downlink. To improve the signal I made a biquad, a bit like the one you were going to make and an Axial Mode Helix.
The Helix worked very well, but it did need someone to point it at the model for me!
The Helix is circularly polarised, so it copes well with odd orientation of the models transmit antenna with respect to the Helix.
The Biquad is linearly polarised, so you do get more dropouts.
The Biquad was designed by http://martybugs.net/wireless/biquad/
I just put a plastic weather cover over it.

Of course, the problem with increasing antenna gain is decreased antenna beamwidth (you dont get something for nothing!), so you need to point the antenna at the model, which is difficult to do unless someone else does the pointing of the antenna.

Glenn.

[Peter Seddon]

I've used two of these on a diversity receiver system with 10mW video transmitters with good results. http://www.rc-cam.com/gp_patch.htm

regards Peter

[p3jpaavi]

I looked that wlan antennas at ebay are not so expensive.

Panelantenne WLAN 12dBi 2,4 GHz (http://cgi.ebay.de/WLAN-Panel-Booster-Antenne-12dBi-1M-Netgear-D-Link-Wifi_W0QQitemZ230296608885QQcmdZViewItem?hash=item 230296608885&_trkparms=72%3A1239|39%3A1|66%3A2|65%3A12|240%3A13 18&_trksid=p3286.c0.m14)

But is rs-sma right plug ? I think that on my transmitter I have female sma. :confused:

Here is btw. what i got with my 200mW cheap China transmitter. I hope it get better with 10mw system. :mad:

http://vimeo.com/1812226

[p3jpaavi]

After looking for while on Ebay I decided to buy this antenna:

#Antena WiFi @14dBi@ 1M /RP-SMA #TP-Link CISCO D-Link# (http://cgi.ebay.de/Antena-WiFi-14dBi-1M-RP-SMA-TP-Link-CISCO-D-Link_W0QQitemZ370100032079QQihZ024QQcategoryZ61816 QQcmdZViewItemQQ_trksidZp1742.m153.l1262 )

They offering 14dbi antenna with following specs:

Band: 2400-2500 MHz
Gain Level: 14 dBi
Polarisation: vertikal, horizontal
Impedance: 50 Ohm
Weight: 0,43 kg
Angles:
vertikal: 55°
horizontal: 55°
Size: 180mmx100mmx35mm

GlennS, Peter Seddon: Do you have any videos made by yours 10mw system ?

[GlennS]

GlennS, Peter Seddon: Do you have any videos made by yours 10mw system ?

Here is one video from the 10mW TX, but it has a few RF dropouts! Cant remember what antenna we were using at the time. Have been experimenting with a short WiFi type whip, the Biquad and the Helix.
http://www.rcgroups.com/forums/showpost.php?p=9728480&postcount=1
Cheers,
Glenn.