i am the person running the radio station on 87.8 in wakefield.
i also run a duplicate service on the airband on 109mhz with 7w of power so pilots can listen to music while flying*
here are some answers to some questions i have seen:
the station is local to the SDR, it is only 0.2 watts
the reason the audio is sometimes quiet is because the android phone playing the music loves to turn down the volume "to protect my hearin g"
if anyone know how to force android to keep the volume at full that would be very useful.
i feel safe confessing now because i am moving in 10days and the station will be shut down.

*joking

Instead of using a phone switch to a raspberry Pi, a model 3 will be sufficient for you.

It was heard on the other sdr in wakefield too before that closed, I wasn’t saying anything, too low power to reach over here, (I felt I shouldn't of commented on the topic again sorry about that) 0.2w is same as the bug I used to have years ago, first time I heard a signal 1km, a different topic, so excited me at the time. I wired into walkman would driven round with a tape of dream fm, the first in car transmitter, mostly around town one time it went over the county. The only song I remember playing was the the klassic mix of Carleen Anderson true spirit, I was going to post about it another topic got diverted to about chip transmitters, i’ve come close to having enough of this, all joy been zapped out of fm, I feel there maybe difference of opinions, we can't get along.

Interesting to have something going near to one, guess it was close to it anyway, it is in a really good location the sdr, i’ve tried scanning at weekends as thought with it been nearer to places like huddersfied that something might be recieved but nothing heard. I suppose maybe different to years ago when you had a transmitter some were which never had any, it seems ominous with there been no pirates there. I downloaded a load of dream fm recordings the other day, don’t think its something I could listen now, some of the songs I don’t mind the long pauses for the adverts!, some of the ads do grate on me too now . Good luck anyway if you want to do this else were, I don’t think anything was been done here that was that illegal, I don’t want to get into the legality of these things i’m out.

On my Samsung yoke the sound setting you want goes:
Settings - Sound and Vibration - Volume
At the top right there are three dots that you press and hold that brings up "Media Volume Limit" You can turn it off or set a custom limit. I knew I saw that setting somewhere, now I need to charge the bugger...

Theres meant to voluming levelling in itunes, weather it does anything I don’t know, I think it does lower volume of loud tracks, when their lower I don’t think it does the opposite of bringing them up, my stereo encoder has resistive mixing mostly for audiophile listening round the house, I can just about get enough volume.