Hello,
I'm using an RFM69HW at 433MHz and would like the antenna to be mounted on my house roof, probably tied to a chimney stack, as I have a number of sensors out in the fields, and the house is situated well at a high point.
I'm using an SMA connector, so have tried both a
"rubber needle" and
magnetic base whip antenna attached directly to the PCB.
Despite the different rating (3dbi vs 6dbi) I have detected negligible difference in transmission power. Maybe this is to be expected.
My question is around best practice for mounting at a decent distance from the power supply (mains):
1. Do you keep your power supply and pcb as close as possible to the antenna e.g. build a weatherproof enclosure and stick the antenna straight out of the PCB or
2. How far can you run a coax from your pcb to your antenna before you run into issues (e.g. use a
15m sma extension cable)
3. Or do you do a bit of both - I can get power quite far as it's DC, and I could use an e.g. 5m antenna extension cable for convenience.
I'm just moving into the "physical installation" stage of electronics so any tips or general rules of thumb appreciated.
Cheers,
Amadeus