@evi For receive-only, you can probably just get away with a long wire. Exact length isn't super important unless you're transmitting, though you might still get better performance at that frequency by making the wire the correct length (typically ¼ or ½ of the wavelength).

But I think the most important factor for you will be antenna placement. Keep it away from metal frames or objects that might block or reflect the signal, and have it in the correct orientation for the polarisation of your signal (usually vertical; if horizontal, you'll probably also need to orient the antenna correctly). And typically, the higher up the antenna is, the better.