CREG Journal 108 (0-24)
This issue has a cover date of December 2019 and was published on 1 December 2019.

Front Cover (1)
A high-power HF amateur radio station in Yordas Cave during the Autumn CREG Field Meeting. Photo: <span class="author">Ian Cooper</span>

Contents (2)
List of contents and masthead information.

The Adventures of GREG (2)
Illustration by <span class="author">Adrian Higgins</span>, and words by <span class="author">Mike Bedford</span>.

Introducing the UNEXMIN Robot for Surveying Flooded Underground Spaces (3-6)
UNEXMIN is an underwater robot that was developed for exploring flooded underground mines. <span class="author">Steve Henley</span>, of Resources Computing International Ltd, describes the vehicle and illustrates its achievements by referring to trials in the flooded sections of an archaeological mine and a natural cave.

Building Blocks (7)
A review of options for building signal sources, by <span class="author">Tony Haigh</span>.

A Lesson from Thailand: GIS for Cave Rescue (8-11)
<span class="author">Chanist Prasertburanakul</span>, ESRI Thailand, <span class="author">Songkorn Seangseubchart</span>, GIS Co., Ltd. and <span class="author">Dr. Somsak Wathanaprida</span>, Thailand Department of Mineral Resource, describe how GIS was used to bring about a successful outcome to the rescue in Tham Luang Nang Non.

Temperature Logging: Does Ogof Gofan Extend Inland? (12-15)
One of the most unusual and attractive small caves in Wales has been the subject of diverse research including archaeology, bat ecology and physical data logging. The cave can only be accessed by abseiling from high sea cliffs. <span class="author">Stuart France</span> reports on air temperature variations he studied to evidence if this cave continues inland.

Web Watch (15)
<span class="author">Peter Ludwig</span> with a couple of interesting links from a recent trawl of the Internet...

We Hear (16)
Roundup of news and events &ndash; <span class="author">Mike Bedford</span> brings us the latest to impact the world of cave radio and electronics. Handheld Laser Scanner with Imaging Capability, Forget Photogrammetry, Meet Videogrammetry, Compact VLF Antenna Thanks to Lithium Niobate.

The Tinytag Connect System and its Application in the British Cave Monitoring Centre (17-20)
<span class="author">Paul Blewett</span> of Gemini Data Loggers provides an overview of the Tinytag Connect System and data loggers supplied to the BCRA’s British Cave Monitoring Centre based at Poole's Cavern.

The Hidden Earth Projector Shutters (21-22)
The UK's annual caving conference &ndash; Hidden Earth &ndash; required a remotely-operated shutter for its video projectors. <span class="author">David Gibson</span> came up with a solution, using pieces of cardboard, motors, reed switches, and a generous quantity of steering diodes.

Autumn 2019 CREG Field Meeting (23-24)
A well-attended field meeting was held in the Yorkshire Dales at the end of October. <span class="author">Robin Gape</span> reports on the weekend's activities.