In another thread Nik (Hi Nik) was asking about mods to an ASI Air Pro to add an antenna. It just so happens that yesterday I happened upon just such a youtube clip.
The video below shows a modification to the ZWO ASI Pro to add an external antenna similar to that used on the ASI Air Plus and typical of the ~7-10cm long antennae seen used on some wireless routers and similar devices.
Incredibly
* (?) the modification results in an approximately 20dBm (100 x) increase in signal strength (power) and comment from the tester that the signal strength with the modified antenna at 16m is equivalent to that of the unmodified unit's signal strength at 2m ! and that only uses a smallish 7-10cm antenna, not the double or triple height versions with even more gain.
The video also makes reference to another video by the poster where the board level PCB RF connecter is added which in turn attaches via cable to the SMA connector on the ASI Air Pro Housing. Here is the main video.....
https://www.youtube.com/watch?v=5l87enVmkpc
Have fun
Best
JA
* Actually it's not that incredible. The ZWO ASI Air Pro's antenna is encased in a aluminium enclosure with some small gaps / openings. It makes for a fairly good Faraday shield. I once made a simple parabolic RF reflector to increase the gain of a small wifi antenna from aluminium mesh with a 2-4mm opening and it worked just great at not passing too much signal though the mesh, but reflected it just fine.
