This file is not intended to be read by humans. Please go to the formatted index

# format auto-updated on access: Mon 27-Nov-2017 11:28:57 +01:00

CREG Journal 84 (0-24)
This issue has a cover date of December 2013 and was published on 5 December 2013.

Front Cover (1)
Ken Smith carries three radiolocation 'Pingers' into Kilsby's Cave, South Australia. Photo: Richard Harris

Contents (2)
List of Contents and masthead information

The Pinger - a Simple Underwater Radiolocation System (3-8)
Ken Smith describes the philosophy behind his 'Pinger' radiolocation system for cave divers and provides full constructional details.

We Hear (9)
News and events - Mike Bedford brings us the latest to impact the world of cave radio and electronics, including Surveying with Biobots, Cave Data Logging Goes Mainstream, RF Super-sensitivity, Laser RX, Sferic Navigation and 73kHz Returns.

The 'Simple' Approach to Detecting & Logging Bats (10-13)
Converting their ultrasonic calls to audio frequencies is a common way of detecting bats. Tony Messina describes his Simple Bat Detector and provides full circuit details before going on to outline how additional circuitry allows its use for logging bats. The logger circuit is a low-power design for use over protracted periods.

Personalising QR Codes (14)
The error correction built into QR codes provides an opportunity to modify the code whilst maintaining readability. Ian Todd describes the personalisation process.

Web Watch (14)
Peter Ludwig comes up with yet more interesting websites; some practical, some a little fanciful.

Early Radio Tests in Mammoth Cave and Carlsbad Caverns (15-16)
People have tended to assume that radio reception in caves is a recent phenomenon, but the archives of the New York Times show that experiments were carried out as early as 1922. John Rabson reports.

State-of-the-Art Overview of Caving Lamps - Part 1 (17-20)
The bewildering range of currently available caving lamps makes it difficult to decide which to buy. Mike Bedford reviews the state-of-play to help you draw up a shortlist.

Letters and Notes (21)
A Slight Change, Frequency, Web Publishing.

APRS Underground - a New Communications Strategy (22-24)
Bob Bruninga outlines tests with APRS radios in Mammoth Cave, Kentucky. By using a self-forming network, these VHF or UHF amateur radio rigs allowed text communication and position reporting from the entrance to a mile underground.

The Adventures of GREG (24)
Illustrations by Adrian Higgins with words by Mike Bedford.