Samson CR77 hiss

[beely]

Hi.

I bought a Samson CR77 UHF wireless unit a few months ago.
It works well enough, but there is a noticeable hiss that peaks and decays with the strength of the note being played and disappears completely when the strings are muted.
It sounds very much like the hiss you get when a UHF radio signal is not quite tuned spot on.
I had a play around with the Squelch setting and the volume control but that doesn’t make any difference.
The signal strength from the guitar, a 4001, seems a bit weak and only ever lights up as far as -10dB on the audio scale. Having said that, there is no shortage of volume.

I don’t think it is something that can be heard over the noise of a 5-piece band in full flow, so it’s probably not too much of an issue from that point of view.
I’m just curious to find out if there is something wrong with it or if that’s just how it is.

Thanks in advance for any help/info.

Cheers.