Canopy Externa antenna mod

Hello all I know this is probably a no no question but still I have to ask
has anyone ever modded an sm to have a n connector pigtail to allow use of external antennas any feedback would be appreciated

Regards

MD

It could be done, we make our own conectorized.

Hello erkan
I appreciate your reply would you care to give out some details on how exactly you do that ie what points do you solder the pig tail to and
do you remove the old antenna completely or do you leave it in place

Thanks for you feedback

Regards

MD

erkan

i would be interested in this also but am concerned about FCC type acceptance in the states. i would like some horiz pol equipment in an attempt to mitigate interference.

george

FDDI Systems does it. We get a portion of our 2.4 SM’s connectorized.

Simple mod - void warranty - possible damage to the board if you don’t know how to solder very well, too much heat. :shock:

Desolder the panel antenna and use a short fly-lead of RG-58 or 142. Solder the shield onto the ground plane of the board, solder the center conductor to the through-hole that the panel is soldered to. Make sure to use a good strain-relief setup (like the 900 connectorized) to avoid stress on the solder joints (hot glue the cable to the board just below the solder joint might help too). :wink:

As for the FCC - download and read the regulations. Many are more picky for omni-directional apps but more lenient on point-to-point (directional) stuff. You could, in theory, use a 2450-360.15 Cyclone (my favorites) and a home-built connectorized 2.4 SM with a 4 foot dish. :smiley:

BE CAREFUL - READ THE REGULATIONS - CHECK EIRP!!! :!:


Aaron

Thanks Acherman

Could you please describe to me or even better send a picture as to what you refer to as the ground plane.

Do you mean the two lower solder connections where the old antenna was attached
I am clear about the center point but there are a couple of possible points for the outer cable shield could be soldered to
At the middle there is the center point
to its right looking at the board antenna up there is an exposed copper trace in a side ways U shape
to the left of the center point there is another small square copper trace and above and below it are two more small circular solder points.
Just trying to be clear on which points to solder to

As for the warranty I am not very concerned about that
especially if I can make a CPE use a grid to get a better signal on a few of the more challenging shots. I am also using a Cyclone 15db unit and it is my fav as well.

We are in Canada and have no aspirations to exceed effective EIRP :slight_smile:

I have already done some experiments with leaving the integrated antenna on and then soldered the shield of the cable to the U area I described above and then the middle cable lead to the center point
it seems to work I am just not shure how much power I will loose this way my thought was that I could revert back to a standard SM if necessay I am shure best practice would be to remove the old antenna
any thoughts on that.

Thank You everyone for the feed back it is greatly appreciated

Best Regards

MD

Ummmm… if you’re not sure what the ground plane on the board is, perhaps this is not the best idea for you to do. :lol: Use a DVM, ground is ground - the two lower points that the panel attached to are both common with the U-shaped pad as well as the small square and the two points above and below it - they are not common with the center point. :wink:

And yes, it is best to remove the panel - you will effectively be dividing your power between the antennas if you don’t (almost defeats the purpose of the higher gain antenna, can introduce interference). :frowning:

As for being in Canada - I am as well. Check here for the regulations:
http://strategis.ic.gc.ca/epic/site/smt-gst.nsf/en/sf01320e.html
Read carefully - they are little vague at some points, typical for government. :roll:


Aaron

Hello again acherman

well not to sound like an idiot but no I am not familiar with the term ground plain.

I make no claims to be an electronics tech but I am handy with a soldering iron.

Perhaps its not the brightest idea I have ever had but I still wish to try and pull it off
I do know what a Digital Volt Meter is although I am not exactly certain where you want me to put it or what you want me to do with it lol!

I suspected range would suffer from not removing the internal antenna but I didn’t think about self interference being an issue Thanks for pointing that out.
I appreciate your feedback and I am now looking to find a for dummies guide to do this mod …I may be having a sale soon on SM’s with no internal antennas hehe

Best Regards

MD

haha No worries - the ground-plane is simply the large area of the circuit board (many traces and pads) that is at ground (in this case, negative DC potential, or 0 VDC). You can use your DVM or just regular ohmmeter to check for continuity from the ground to the point you would like to solder the shield of your flylead to (or between pads around where the panel antenna was).

The best way to practice is if you have an SM or two that have other issues (ie. do not power up, bad ethernet chipset, etc).

The interference note I mentioned was not self-interference - rather, if the panel was still in place (parallel with the flylead) and you just hang the radio in a random position, you risk pointing the radio with panel antenna at a source of interference. Also, as I said, you split your power to each antenna - half TX power to each antenna (think the 25 dBm minus 3 dB to each antenna). Then, whatever your flylead antenna receives, half of that will go out the panel antenna and not to the receiver (receive -75 from an SM, and the receiver only gets -78 dBm).


Aaron