Need some antenna help for my smartphone project

[ilovecoffee]

Hey gang,

So I'm thinking of making my own pseudo flytrex live alternative using an old Galaxy S3 I have laying around. The benefit here is that it will have a camera so I can ustream everything, in addition to tracking it. My main idea is to build in the main board INTO the phantom as there may be just enough space between the battery and main board, or main board and gps unit.

The good news is that I'm almost there. I can run it completely disassembled without a screen, speaker, front camera, LED, vibration motor etc. By using Webkey (sort of like a VNC server) I can access the phone as if it were in front of me via a web browser, and can start a Ustream with one click, or a send myself a Glympse (tracking software, but I also have a few other tracking apps on there). I may configure Tasker to make everything more automated.

The weight of it disassembled is only 57g so well within the payload of the PV2+

My only issue now is that the reception is non-existent as the antenna seems to be partially built into the case. HOWEVER, Samsung has included these two ports for 3G/GSM and Wifi so I can easily install an external antenna. I just don't know what the adapter is called. I think it is called an MS705 port...but where can I get a light weight 3G/GSM and wifi antenna?

You can see the plugs here:

Soon I'll be Skyping myself from the sky on my long range ground station missions

 

[itchybeard]

Are you looking for something like the patch antennas shown on this page, ILC?

http://www.rfsolutions.co.uk/acatalog/GSM_Antennas.html

 

[ilovecoffee]

Are you looking for something like the patch antennas shown on this page, ILC?

http://www.rfsolutions.co.uk/acatalog/GSM_Antennas.html

Maybe?! I'm completely dumb when it comes to antenna knowledge. RG174 was also used to describe these external antenna ports, thought that referred to the cable though, not the port. Maybe someone can elaborate.

This is the product made for it but I find it unnecessarily expensive and longer than what I need.
http://telcoantennas.com.au/site/patch- ... y-s3-i9300

 

[itchybeard]

I think the port is an mhc-705 port.

https://www.google.co.uk/search?hl=en&s ... +connector

 

[DBS]

I wouldn't use those particular connectors for antenna hookup... those MHC-705 ports are commonly known as the "test port" for calibrating everything before shipping or testing during repair... people have burned out radios fairly quickly by hooking antennas to those ports (of course, others use them with no problems whatsoever)

anyway ... you're doing some hacking and you have some options there... on one antenna you have a u.fl port to connect to... i would think that's the wifi side but i may be wrong... and on the other port ... you have nice big copper spring lugs to solder to... the advantage with those is they already have all the inductors in line (yellow arrows) to balance the antenna load to make it consistent with the ohms required by the radio... much more likely to have things work properly and for a longer period of time... and also more likely to hold together... those MHC-705 ports and plugs come apart easily ...

took a minute to label the positive and negative and inductors for ya in case you want options

EDIT: when you took the phone apart you must have unplugged a wifi antenna from the u.fl port... that can be plugged back in to get your wifi back... or... order something like this... http://www.ebay.com/itm/2-4-GHz-3-d...osters_Extenders_Antennas&hash=item53fc754630 ... it already has the u.fl attached and can be cut apart to hack out the antenna and save weight (the resulting antenna will look like the ones in your phantom landing gear legs and you have an extra leg to put it in)

For the 3G antenna ... I would order something like this... http://www.ebay.com/itm/GSM-3G-GPS-...683?pt=LH_DefaultDomain_0&hash=item1c46c9b5cb ... cut the cable to desired length... solder outside shield to negative copper spring pin and inside core to positive... :ugeek:

 

[ilovecoffee]

Thanks DBS! Looks like you're quite knowledgeable when it comes to these things! You've given me a lot to look into. I'll report back what I find out!