Transmission1

This appears to be a continuous data transmission from somewhere in the area of Salisbury Plain (so presumably military in source).
I say 'appears' because if you listen for long enough you may hear some voice too (I was only monitoring it whilst passing thru the area in order to try and narrow down down where it was coming from).

As the voice transmission sounded like a repeater, there is undoubtedly an associated (input) frequency.

The voice tx was too brief and vague to ascertain any useful info.

Could be some sort of telemetry going over the voice channel

Not sure about military but PBR repeaters usually have +4.8 or +6.5 MHz split, give it a try

Edit: have you checked WTR for the frequency?

This is in the Digital section of the Amateur 70cm band, but no repeaters or gateways listed for that frequency.

Ah yes how did I not realise...439.150 is just an allmode simplex freq on 70cm. It's probably hams playing around with digital kit...