sandbox: Journal 128 has gone to press and is due for publication in December 2024
CREG Journal 128 (0-24)
This issue has a cover date of December 2024 and was published on 1 December 2024.

Front Cover (1)
Tony Haigh experiments with a low-cost baseband cave radio prototype. Photo: <span class="author">Mike Bedford</span>

Contents (2)
List of contents and masthead information.

News and Notes (2)
Editorial Team, Spring 2025 Field Meeting.

Photogrammetry for 3D Mapping of Caves (3-5)
<span class="author">Jarmo Ruuth</span> describes the use of a simple GoPro camera in combination with a bright light source to make 3D images in a couple of caves using photogrammetry.

QDX-M Update - Digital Radio using a Phone as a Terminal (6-8)
Previously, <span class="author">Ian Drummond</span> described how he'd obtained encouraging results using a modified QDX-M amateur radio transceiver as a text-based cave radio. Here he describes how he's made the setup more portable, cave‐proof and better suited for use by non‐skilled users. This involves the use of an Android phone and the Radiomsg app, which was written for amateur radio use.

Handling Tilt in Water Depth Measurement using Echo Sounders (9)
In the last issue of CREGJ, <span class="author">Guy Van Rentergem</span> described the construction of a small remote-controlled boat for surveying in caves. Here, he illustrates the mathematics associated with these measurements, with particular emphasis on the relationship between beam width and the angle of the boat, and hence between the beam width and the angle of the cave floor.

Cave Radio the Easy Way - a Cost-effective Solution (10-12)
Some of the earliest cave radios were baseband designs, but were superseded by better-performing radios operating at LF. However, more recent trends overcome some of the drawbacks of old baseband radios. As <span class="author">Mike Bedford</span> suggests, therefore, this could  make the approach suitable for certain applications, and their inherent simplicity would offer benefits to those with a limited budget or beginners in cave communication.

The Vangelis Mesh-based Cave Communication Project - Overview and Testing (13-15)
Building on his previous discussion of LoRa and Meshtastic for in-cave communication, Pawe&#322; Krawczyk describes his Vangelis system and presents the results of using it in a couple of underground locations. Guidance is also provided for those who wish to build the system themselves.

Dan-yr-Ogof Telemetry Update (16)
Previously, <span class="author">Stuart France</span> described his system to provide intending cavers with recent river depth and rainfall data to inform pre-visit risk assessments.  Here he reports progress and problems over the past year.

We Hear (17)
<span class="author">Mike Bedford</span> reports: the strange world of subsurface detectors, lava tube discovered on the Moon, ONERugged outdoor rugged tablets.

Building Blocks (18)
Coaxial cables part 2 by <span class="author">Tony Haigh</span>.

Actions to Words and Words to Actions: Rob Gill as CREGJ Editor (19-20)
<span class="author">Stuart France</span> offers his reflections on two decades of CREG and its Journal under Rob Gill's editorial guidance, his skills at finding a diversity of underground projects from around the  world, and informing and stimulating new projects.

UK's National Caving Conference: Hidden Earth 2024 (21-22)
Hidden Earth took place in Llangollen, North Wales, in September. <span class="author">Tony Haigh</span> reports, with particular reference to two technical workshops, one organised by the Cave Surveying Group and the other concerning video photography.

Flash Placement - Analysing Published Images (23-24)
Ever struggled to get underground photos that meet your aspirations? As <span class="author">Chris Howes</span> argues, you can learn a lot about how to improve your own photography by analysing images that you admire, sometimes for minor nuances. And the best positioning of flashes is a case in point.