NØJY Antennas
The satellite antennas, Cushcraft 20 element V band antenna set for right hand
circular polarization with a Landwehr preamp; homebrew 31 turn right hand
circular polarization helix (modeled after the VE3NPC array design,
click here for the PDF) with an SSB
Electronics UTM 1200 DLX 15 watt upconverter for L band; KLM 40 element U band
antenna with switchable polarization and an SSB Electronics SP-7000 preamp;
K5GNA modified downconverter with BBQ dish for S band with a homebrew RHCP patch
feed. The 2m/70cm antennas share a common LMR-600 feedline using diplexers
at each end. The feeds are switched at the shack through an arrangement of
relays and diplexers in order to achieve various satellite uplink/downlink
modes. Click here
to download a PowerPoint presentation of the switching arrangement in Office
2007 format, or here to
download it in Office 2003 format.
Another look at the satellite antennas. Yes, they're in the attic! I
specifically had the architect design an area in the attic at our new QTH to
hold these antennas and clear the walls and ceiling at any az/el position. The
house is encapsulated in foam insulation, so there is no metal between the
antennas and the outside. Just a bit of wood and shingles.
RMS Packet gateway antenna, a KB9VBR
j-pole.
A Cushcraft Ringo Ranger II for the packet weather station and Comet GP-6 for
2m/70cm FM are hidden in here too!
The antennas do very well from the attic, the insulation has very little (no
noticeable) effect on the frequencies up to 450 MHz. I can work repeaters
as well as if they were mounted outside at the same height. Repeaters 50
miles away are no problem with 5 watts from the FT-817!