- Fri Oct 10, 2014 11:23 am
#1514
This looks awesome! If a complete board was put together as a group buy at a reasonable price I would be all over it..
- Wed Oct 22, 2014 3:43 am
#1826
I hooked up the ESP to my Spectrum Analyzer this morning.
Sorry for the Cellphone Pics , but I couldn't find a CF Card for the SA
Thats the ESP running at Wifi Channel 6 (2437MHz) , connected to my AP (~50cm away)
For comparison here is the same setup but with the ESP unpowered , my AP @ Ch6 is still quite visible.
Quite a lot of spurs from the ESP and the occupied BW is also not that good.
So anyone considering using the ESP in a commercial setup should think, imho, a bit about using an external bandpass filter ... and good luck for the FCC approval
Sorry for the Cellphone Pics , but I couldn't find a CF Card for the SA
Thats the ESP running at Wifi Channel 6 (2437MHz) , connected to my AP (~50cm away)
For comparison here is the same setup but with the ESP unpowered , my AP @ Ch6 is still quite visible.
Quite a lot of spurs from the ESP and the occupied BW is also not that good.
So anyone considering using the ESP in a commercial setup should think, imho, a bit about using an external bandpass filter ... and good luck for the FCC approval
- Wed Oct 22, 2014 7:39 am
#1828
it could be your 50 ohm line like squonk said? the thicknes is not 25-26mill all the way to the connector. looks like lots of reflections there 
My analogue knowledge is very very rusty so please dont take it serious
My analogue knowledge is very very rusty so please dont take it serious
- Wed Oct 22, 2014 8:09 am
#1831
Hmm not sure , even when the full RF power is reflected due to a bit of mismatch (approx 86Ohm @10mil vs 50Ohm @26mil , still terminated with a solid 50.0Z in my SA) , I still don't see how the BW could 'explode' like in the first pic.
Further the mismatch is still present when I did the second measurement with the ESP powered off , but the occupied BW of my AP looks good.
I also tried to put an 10dB attentuator on the RF-In of the SA (SA goes only up to +20dBm), same spectrum but 10dB lower. So definitely no distortion effect of the SA input stage here.
Sjaak wrote:it could be your 50 ohm line like squonk said? the thicknes is not 25-26mill all the way to the connector. looks like lots of reflections there
Hmm not sure , even when the full RF power is reflected due to a bit of mismatch (approx 86Ohm @10mil vs 50Ohm @26mil , still terminated with a solid 50.0Z in my SA) , I still don't see how the BW could 'explode' like in the first pic.
Further the mismatch is still present when I did the second measurement with the ESP powered off , but the occupied BW of my AP looks good.
I also tried to put an 10dB attentuator on the RF-In of the SA (SA goes only up to +20dBm), same spectrum but 10dB lower. So definitely no distortion effect of the SA input stage here.
