DCRO Shout at Peak Cavern

Later in the evening the phone rang around 19:50 and I answered it. It was Ralph saying someone was lost in Peak Cavern and we should stand-by in case of a call-out. About 15 minutes later he rang back to say that the call-out was going ahead and to make our way to Peak Cavern.
We collected our gear together, including warm surface gear as usual in case we were asked to do a job on the surface. On arrival at the car park for Peak Cavern we found Keith in control and I asked if I might remain on the surface as I was feeling under the weather probably after the earlier walking on a warm day and probably not drinking enough water.
It turned out that a caver had been left behind by two parties who each believed he was with the other one as a group split into two while some slower-moving cavers curtailed their trip to exit via Peak Cavern. The missing caver had decided to follow this group but failed to catch then up while in the region of Block Hall.
Karen was asked to take charge of a Heyphone at the Bottomless Pit in Speedwell Cavern while I was to take on up to the top of Longcliffe above the road from Peak Cavern to Winnats Pass, marked “Cow Low” on the map.
It was quite a steep climb up to this position some 85 metres higher than the Peak Cavern car park. I soon had the Heyphone set up at around 22:00 and once the underground party had reached Block Hall and set theirs up, we tried to talk to each other but this proved to be unsuccessful. I could only just hear Mick's weak voice above the usual background crackling noise and he obviously couldn't hear me.
I radioed back to Control to say I would relocate and try again. Moving some distance away and with the aerial points set quite a long way apart, still no success. I tried moving the aerial points through 90 degrees but still nothing.
It was soon dark and I tried periodically to see if there was any communication with Block Hall. I was told that a party was making its way with a spare Heyphone but couldn't see them. I could see a light in the general direction of Rowter Farm, which is where they were coming from, but this turned out to be John and Howard  at the entrance to Titan at nearby Hurdlow.
Eventually Jen and Dave arrived with the spare Heyphone and then left to return to Rowter Farm. I set up this second Heyphone but this didn't connect with Block Hall either so the problem wasn't with the Heyphones – probably a degree of mineral in the intervening rock. Of course we had tested out the Heyphones back at the DCRO van before setting out anyway, and they had been fine.
I heard on the radio others passing messages that the missing caver had been found in the White River Series and was being accompanied out.
By now, well past midnight, most of those underground were back on the surface and as my Heyphone wasn't doing anything useful, I was told to pack up and return to Base.
All were back and after checking in gear and getting changed we set off for home at 01:25 to finally get to bed at nearly 02:30. It was a pity I had to be up at 06:25 for work though!