hi guys..

i have a couple of questions re my output..

first up does this look like a standard stereo signal? with no modulation..
https://flic.kr/p/qis6bm
i ask - as to me it looks like its spreads out too far either side? - but having never seen a signal through an analyzer - i wouldnt know..

next this is stereo signal with audio - again looks too wide? thoughts?
https://flic.kr/p/poJMUj

when i plug in my pcs tx with out stereo coder - so mono - signal looks much better to me - https://flic.kr/p/poYguc

my main question is - is this how a stereo signal should look? (like a pyramid of of spikes?)

- i ask as when i install my stereo coder into my tx - the signal looks way too wide. bleeding into frequency's either side. - would this be as im measuring so close to my output - would the signal look better with a bit of distance? ie not bleeding..

im not sure which tx's i was using to do these measurements - got a feeling the first one modulated stereo signal was a Chinese tx. the mono signal is my pcs one.. which to me looks the best.. i wonder what your thoughts are on these. .

thanks nick

I have one and it looks normal to me. I'm not sure on the wideness. It could be down to the signal strength.

First picture is ok. Without modulation and good stereo pilot, it should have two spikes on both sides of the carrier. One thing is not good. Level of your mpx, 19kHz pilot is too large. That is why it is soo wide. Try to reduce level and carrier should go up, and both sidetones (spikes) should go down and closer to carrier.

One more thing, this sdr dongles are only for orientation, they don't give precise results. But for what you asked, it is ok...

thanks - this makes sense - the signal is a Chinese 15w ( i seem to remember)- so i dont think i can adjust the mpx level - but thought it looked little wide .. . im not building, just checking out various transmitters signals trying to understand what i see. .