Here's the answer to mounting the antenna.
http://www.xtremepowersystems.net/pr...S-24Ant&cat=12

Just got done with setting up my DM8.

I was able to get the entire thing setup without ever breaking open the A9 or the DM8.

Here are pictures and some instructions that helped me.

I purchased all my stuff at the local Radio Shack using parts listed here:

• NPN Transistor, Part Num: MPSS222A
• Resistor, 4.7k 1/4 watt 5%(in place of the of the schematic 6.2k)
• Resistor, 22k 1/4 watt 5%(in place of the schematic 13k)

Total cost $3

Those were the parts I purchased, I used some old PC board to help build the parts, then soldered them all together and then put some heat shrink over the build.

I decided to use a standard receiver connector for the connection into the radio.



Read the other posts on the A9 pinouts, but if you want there are 5 pins, labeled from left to right:
1 2 3
PPM PWR GND

I then used an old computer connector male pins and pushed that into the module and that is labeled as such:

With the DM8 module connector side facing you, and the connector facing on the top, from left to right,
Far right = pin #5 = PPM
Pin #4 = Pwr
(skip pin #3)
Pin #2 = GND
Pin #1 (not used for this)

I then made a replica of the module with a epp type foam that is super strong (from a computer box) and then cut it to fit, and then double stick taped it to the back of the module.

It slides into the back of the radio without a problem to swap modules!


Once that is done, setup a new model on your A9 and make sure you pick modulation PPM/P and your good to go!

everything works like a charm! Time to sell the DX6i

Cost of the DM8 -- $45
Cost of Parts to make it work with the A9 - $3

Originally Posted by bigbobed

Here's the answer to mounting the antenna.
http://www.xtremepowersystems.net/pr...S-24Ant&cat=12

I need to get me one of those, to make this setup even sweeter!

Was using that on a DM8 Futaba 9C combo for about a year. The antenna was great. You can actually get one at some other sites for about $2.02 shipped. I believe 2db is OK.

ShoGinn- thanks for the additional information, instructions and pictures. Its very helpful.

4*60- if you remember where to get the antenna at that price please let us know. It does look better and should be easier to change out modules without the wire and remote antenna.

You can order them off ebay from Hong Kong for about $1.25 http://cgi.ebay.com/2dbi-Wireless-2-...item3f098600bf

If you search ebay you may find some shipped from the US for a little more.

Any 2.4 GHz antenna with a RP-SMA connector should work. The higher the gain(ie higher dB) the more directional the antenna will be. The radiation pattern of a rubber duckie is roughly a donut shape around the antenna with little signal coming off the end so don't point the antenna at the receiver. The higher gain versions basically squash the donut so it is more important to have the antenna perpendicular to the receiver.

PS Antenna I use came from an old dead WiFi router, many of which use RP-SMA antennas.

Great info Jeff!

Here is the Aurora Modules for JR.....its very clean, no more dangling Antenna wire.

Originally Posted by jeffs555

You can order them off ebay from Hong Kong for about $1.25 http://cgi.ebay.com/2dbi-Wireless-2-...item3f098600bf

If you search ebay you may find some shipped from the US for a little more.

Any 2.4 GHz antenna with a RP-SMA connector should work. The higher the gain(ie higher dB) the more directional the antenna will be. The radiation pattern of a rubber duckie is roughly a donut shape around the antenna with little signal coming off the end so don't point the antenna at the receiver. The higher gain versions basically squash the donut so it is more important to have the antenna perpendicular to the receiver.

PS Antenna I use came from an old dead WiFi router, many of which use RP-SMA antennas.

So Jeff, higher gain is a bad thing or a good thing? Is 2 dbi considered high gain? Sorry, I know nothing about this stuff.

PS-FWIW- I did look on XPS's web site and the replacement antenna they sell is 2.1dbi.

I got mine on Amazon, waiting on it to arrive so I can run range checks.

http://www.amazon.com/gp/product/B004BLRMP0

So Jeff, higher gain is a bad thing or a good thing? Is 2 dbi considered high gain? Sorry, I know nothing about this stuff.

I think the standard antenna on most 2.4GHz RC transmitters is around 2 or 3 dbi so no it wouldn't be considered high gain. Higher gain is not necessarily a bad thing, it just means you need to take more care in orienting the transmitter antenna in relation to the model. If you don't need the extra range, then better to stick with a 2-3 dbi antenna.

Gain is achieved in an antenna by taking the transmitter power and concentrating it in certain directions instead of spreading it all around equally. Here is a good explanation which also shows radiation patterns for some typical rubber ducky antennas. http://www.rcexplorer.se/page14/gain/gain.html

I just received that Antenna I mentioned in the post above, took about 3 days shipping not bad!

Screwed it in and did a range check with no problems! Sweet setup now.

i still need a little help the npn has 3 prongs on it ,,how are they connected i did a drawing is this correct ..i dont have the npn just a picture of one that im going off...

o2bergn, what you are describing is a typical transistor understanding error.

the 3 wires coming from the transistor each has a different name.


now if you look at your picture you did not draw it as a schematic just as a drawing.
look at the one drawn up earlier in the posts.



if you look at the transistor you see the flat line parallel to the A9 on the left hand side of the image? reference that along with the arrow on the bottom right of the transistor. it is exactly like the image i posted.

The B C E = base collector emitter.

now look at the actual transistor.



hope that makes more sense or confused you more

i think i got it ,,im very bad at electrical,,,,