LFA-50MHz
After having worked with the 2el DK7ZB yagi for several months, the desire to have an antenna with a bit more directivity and better suppression of urban noise became stronger.
Following instructions off Justin G0KSC's website, I'm now building a 3el LFA yagi for 50MHz (can't go any bigger because of limited (garden) space. According to Justin, LFA yagi's have a very good F/B ratio and clean pattern.
Originally I'd planned to build the LFA antenna during my summer holiday, but I was a few days late ordering the aluminum tubing materials: one week before construction industry holiday ("bouwvak vakantie"), so the supplier delivered the stuff about a week after my holiday had ended.... :-(
Shopping list:
2x 6m Aluminum 6060T66 tubing 12mmx10mm
2x 6m Aluminum 6060T66 tubing 10mmx8mm
1x 6m Aluminum 6060T66 tubing 8mmx6mm
1x 6m Aluminum 6060T66 box profile 30x30x2mm
Stauff clamps PP (green) 12mm
Stauff clamps PP (green) 10mm
A2 Stainless steel bolts DIN933 M6x60
A2 Stainless steel hex nuts DIN934 M6
A2 Stainless steel rings DIN433 M6
GB OX-100 Electrical Anti-Oxidant Compound (Ebay)
Tools:
Hacksaw
Pipe bender 6-8-10mm (Ebay)
Pipe cutter
Caliper
Center punch
Tapeline (3m)
Drill 6mm
Wrench 10mm
Methylated spirit (to lubricate while processing aluminum)
Here are some construction photo's
Bending and cutting the 10mm loop-connection tubes.
The feed-point (center of D1).
The antenna-balun connection to feedpoint.
The finished antenna put on a 3m pole in the garden for alignment.
Return Loss / SWR after loop adjustment: Well below 1:1.2 between 50.0 and 50.44MHz (measured with miniVNA)
New 3el LFA-50MHz yagi antenna ready and placed on top of my telescopic antenna mast (not yet raised)