Repost: Hidden 2.4ghz transmitter aerials
Posted: 09 Jan 2021, 15:11
Reposted from 2016, which was in turn a repost from 2012
Internal aerials are sometimes very convenient and dont adversely affect range if done properly.
As an example heres my 6EX home-made aerial inside the plastic handle. This set is used exclusively for soaring, often at extreme range - no problems, and actually fewer RSSI pips than I had with the standard aerial, possibly because of the 'ideal' orientation. Originally I used a 'gutted' plastic aerial but once I'd realised how simple they are I now make my own from coax & brass tubing. Not having a fragile external aerial is a real boon when battling through 6' ferns to retrieve a downed soarer!
Untidy inside: .
But tidy outside! . .
Cut the tubing to the exact length first, by rolling under a new scalpel. clean and very lighty tin the rim at the 'whisker' end.
Cut the cable with a couple of inches of excess length, then thread the cut cable through the tubing BEFORE stripping and fanning the braid.
Strip & fan out the braid like flower petals the solder the braid around the tinned rim quickly and carefully to avoid damaging the dielectric.
Trim off any whiskers, and finally cut the 'inner' to length. Measure twice cut once!
Try to accurately follow the measurements - they have been carefully optimised for minimum vswr at 2.4ghz.
4mm OD brass tubing:
http://www.ebay.co.uk/itm/Brass-Tube-2m ... 0813916387
Here's a genuine Frsky transmit module aerial, the whisker is to the left. The short stub to the right
(30 to 31cm) is the remains of the feeder where I cut the connector off.
Cheers
Phil
Internal aerials are sometimes very convenient and dont adversely affect range if done properly.
As an example heres my 6EX home-made aerial inside the plastic handle. This set is used exclusively for soaring, often at extreme range - no problems, and actually fewer RSSI pips than I had with the standard aerial, possibly because of the 'ideal' orientation. Originally I used a 'gutted' plastic aerial but once I'd realised how simple they are I now make my own from coax & brass tubing. Not having a fragile external aerial is a real boon when battling through 6' ferns to retrieve a downed soarer!
Untidy inside: .
But tidy outside! . .
Cut the tubing to the exact length first, by rolling under a new scalpel. clean and very lighty tin the rim at the 'whisker' end.
Cut the cable with a couple of inches of excess length, then thread the cut cable through the tubing BEFORE stripping and fanning the braid.
Strip & fan out the braid like flower petals the solder the braid around the tinned rim quickly and carefully to avoid damaging the dielectric.
Trim off any whiskers, and finally cut the 'inner' to length. Measure twice cut once!
Try to accurately follow the measurements - they have been carefully optimised for minimum vswr at 2.4ghz.
4mm OD brass tubing:
http://www.ebay.co.uk/itm/Brass-Tube-2m ... 0813916387
Here's a genuine Frsky transmit module aerial, the whisker is to the left. The short stub to the right
(30 to 31cm) is the remains of the feeder where I cut the connector off.
Cheers
Phil