Kategorier
Antenner

Fixed UHF yagis for SatNOGS ground station

For my SatNOGS ground station I have tried several omnidirectional antennas for UHF without success – Dipole, V-Dipole, Eggbeater and Turnstile. I know that several SatNOGS station are using omni antennas for UHF with very good result – but at my QTH it seems not possible. I have high hills surrounding and a high level of local interference on 435 MHz.

So, my solution is fixed yagis. I’m using a lower budget yagi from Vinnant antennas – Y8E446 8 element yagi but tuned for 435 MHz.

Y8E446

This antenna is excellent for it´s price – very good SWR and good quality. At first I used only one antenna and now I could decode satellites when it was passing in front of the antenna loob.

To be able to decode more passes I added one more yagi and stacked the antennas with a short 75 ohm power divider coax cable. I used the instructions from this webpage.

After testing directions at several positions I’m now using an elevation of about 30 degree and azimut of aprox 120 and 240 degree. Of course the signal level is lower than just using one yagi but I can now decode satellites in bort west and east pass.

This is a decoded west pass:

And this is a decoded east pass:

Summary:
For my station this is a solution that makes it possible to receive at least the strongest UHF satellites. To receive better I should probably need a antenna rotor.

Av SM0TGU

Webmaster and member of the AMSAT-SM steering group.

Lämna ett svar

Din e-postadress kommer inte publiceras. Obligatoriska fält är märkta *