I’m slowly working towards hopefully getting a SatNOGS station setup in the future. A little strap for cash at the moment, so I decided to build a Turnstile antenna following this guide (which is in use in this station by @mwheeler and this station by @IZ7BOJ). Here’s my rendition:
I borrowed a N1201SA Antenna Analyzer to measure the performance of the antenna. At 437.2 MHz, which is the frequency I’m most interested in, the VSWR was ~2.3 (not great…). Impedance was ~48 Ohm, which I think isn’t too bad. Not sure how to interpret the other results (resistance and reactance), here they are:
And here are some pictures of the VSWR over several frequencies:
As you can see, great VSWR at ~600 and ~1300 MHz haha But on the 70 cm band, VSWR is between 2.2 and 2.4.
I’ve been able to at least hear some satellites with this antenna, here’s an example of GRIFEX:
What do you guys think of these values? For a homebrew antenna, is this what’s to be expected or could it be improved? And if so, any ideas on how to improve it? I’ve yet to buy an LNA, which would be the natural next step, but I’d like to squeeze more performance out of this if possible…
Any help will be kindly appreciated.
P.S. Some additional pictures of the measurement setup with the N1201SA and of the interior of the antenna: