This file is not intended to be read by humans. Please go to the formatted index
# htmlentities() run on access: Mon 01-Jun-2020 17:53:11 +01:00. Delete this line to re-run it. # format auto-updated on access: Mon 01-Jun-2020 17:53:11 +01:00 CREG Journal 110 (0-24) This issue has a cover date of June 2020 and was published on 1 June 2020. Front Cover (1) Mike Bedford, in an archaeological lime kiln, conducting preliminary tests on the use of ordinary coaxial cable as a low-cost leaky feeder for communication along cave passages. Photo: Contents (2) List of contents and masthead information. Evaluating Coaxial Cables for use as Leaky Feeders (3-5) Ordinary low-cost coaxial cable can be used as a leaky feeder for communication along cave passages. reports on tests to compare the performance of two main types of cable, and to determine the optimal operating frequency. Underwater Robot for Minimally-invasive Cave Research (6-8) reports on his use of the commercial Navatics Mito underwater robot for exploring flooded caves. Letters to the Editor (9) PIC Microcontrollers , Flashgun Slaves . The Adventures of GREG (9) Illustration by , and words by . Battery Connectors for Caving (10-11) The underground environment places substantial demands on connectors. compares a number of connectors that can be used to interconnect battery packs to cap-lamps and be useful in other underground applications. Web Watch (11) A solitary link this time, from . Building Blocks (12) Considerations when adding ‘processing power’ to a project. By . Regenerative Brake Charges Your Caving Lamp Whilst You Abseil (13-16) A caver abseiling down a pitch will lose potential energy, which is converted into heat in his abseiling device; but what if it were converted into useable energy instead? explains the principles behind regenerative braking and how you might use the braking energy to charge a battery. However, this is for theoretical interest only, and definitely not something to try out in practice! A Store-and-Forward Repeater for use with PMR Radios (17) Low-cost store-and-forward units allow a PMR radio to be used as a single-frequency simplex repeater unit as reports. Early Radio Broadcasts from Caves (18-19) delves into several high-profile radio broadcasts from caves dating back to the 1930s. Overview of Radio Repeater Types (20) presents the main types of radio repeater, and explains the key differences between them. This article is #4 in our Fundamentals series. Flashgun Slave Redesign Notes (21) David Gibson’s design for a flashgun slave unit first appeared in the CREG journal almost 30 years ago. It had a number of unique features that meant it was ideal for cave photography. Nowadays, cheap wireless slave units are readily available and there is probably no need for a home-built optical design. But, were a ‘retro’ optical device ever to be needed, explains how he would modify his earlier design. We Hear (22) Roundup of news and events: brings us the latest to impact the world of cave radio and electronics. The Search for Life in Martian Caves, Introducing the Cave Rover Project, Lidar: From Cars to Caves. goTenna – Mesh Networking for Off-grid Communications (23-24) , Product Manager at goTenna, introduces this technology, outlining how it could find applications above ground during expeditions or for rescue, and describing how it has also been employed underground.