On 12/08/20 15:54, Chris Busch wrote:
I personally prefer a Lindenblad or quadrafilar helix for an omni antenna. My 2M Lindenblad is approx 10db worse than my Az El tracking CP yagi. If I were relying on an omni, I’d definitely consider using a good GasFET preamp, but ymmv.
I haven't attempted the 2m Lindenblad yet, but it's something I'd like to try.
On the LNA front: I'm currently interested in in the Minicircuits PGA103+ device (on W6PQL's page https://tinyurl.com/yyd5mx4b ) for the excellent IIP3. This is an internally-matched E-PHEMT device, much more rugged (and affordable) than GaAsFET devices of the past.
I have a cellphone "watertower" near me, pumping out stuff all over the band, but mostly 600-750 MHz, easily seen as -40dBm signals on a 2m rubber ducky stuck to the front of my spectrum analyzer. Some sort of input filtering, or a crazy-high IIP3 followed by appropriate filtering, is a must at my QTH.
--- Zach N0ZGO