Crawley Amateur Radio Club

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Naval Engineering

Not amateur radio but club members have an eclectic mix of interests which include general engineering, military history and aircraft amongst other things. In that light I thought that I would share two books that I have just finished reading. The first is Hurricats by Ralph Barker. The book was a serendipitous find in a second hand book shop in Stow on the Wold, the UK capital of used book stores. This book details the story of the hurricanes that were used for convoy protection during WW2. These aircraft were considered disposable in that they could not land back on the ship that launched them, and it was considered by may to be a suicide mission by the pilot. The truth is that by no means all the aircraft launched were lost and the majority of the pilots survived. The story starts in August 1940 when the German Airforce converted the Focke-Wulf FW 200 Condor to an anti-shipping aircraft to attack allied conveys. This caused alarm in the Admiralty because the allies had no effective ...

SSB DX-ing Tips by G4PEO

Although far from exhaustive, here are a few tips and observations, relating to SSB DX-ing, not only pertaining to the HF bands, but also where appropriate, VHF/UHF as well. If there is just one takeaway to be derived from this list, it would be, listen, listen and listen again before jumping in with both feet…! Transceiver Settings Apart from employing a suitable microphone, possibly with an insert whose audio frequency response is tailored for HF/DX communication such as a Heil headset/boom, it is important that mic gain, audio equalisation, (if used), and compression settings are correctly adjusted and checked. Reading the manual obviously helps, (who reads manuals!), but there are also a number of other ways that can be employed to hopefully avoid on-air embarrassment, whilst just as importantly allowing you to present a clear intelligible signal that a DX station will hopefully more easily discern through the noise and myriad of stations ca...

Free to download radio magazines

We all enjoy some radio related reading, especially around the Christmas holidays. We've found four great magazines which are completely free to download. If you know of any that we have missed please do leave a comment. Merry Christmas from Crawley Amateur Radio Club SWR: https://fliphtml5.com/site/85123127/index.html The Logger's Bark: https://w7dk.org/newsletter Ham Radio Ireland: https://www.docdroid.com/KBZHEAV/hrivol31225-pdf The Communicator: https://www.calameo.com/accounts/7665474

FreeDV Digital Audio Transceiver Build

Members of the Crawley Amateur Radio Club have been busy with their soldering irons building a Digital Voice HF transceiver that was featured in the December issue of Practical Wireless magazine. Members supported each other with the builds, and had a hands on construction session at the shack. By the end of the session we all had working transceivers, and had successful QSOs with each other. We are planning a Digital Voice net over the Christmas break so everyone can test their builds. The kit was the work of Eric Edwards GW8LJJ, and works on the 60m band. It's designed to work with FreeDV which uses Radio Autoencoder (RADE) technology to send speech over HF radio. It combines Machine Learning (ML) with classical DSP to send high quality speech over HF radio at SNRs as low as -2dB. Find out more details here - https://freedv.org/ The club would like to thank Eric for his support during this project.

The LF operation from the Decca station at Puckeridge 11th April and14/15/16 April -

This article first published in the CARC Newsletter of April 2000 remembers the pioneering work on LF done by Derek G3GRO and Lech G3KAU sadly both now SK. Having just about recovered from the weekend’s activity and travelling upto Puckeridge again yesterday (Tuesday18th) to recover the remaining bits of gear including tables and chairs etc and the loading coil and variometer used by all of the operating groups involved, I thought that I would post an initial report of the activity pending a more detailed study of the logs and incoming reports. Firstly, thanks to all those who participated and to all those sent in signal reports and messages of encouragement. The exercise was arranged at very short notice and word spead around the LF operators living within reasonable reach of the site to invite one or two groups of operators to take part. Apart from the Decca mast and an RF thermo-couple ammeter , none of the original equipment such as loading coils etc was used. For 136Khz ope...

NVIS

First published CARC Newsletter April 2000 For a little while I have been interested in a type of HF propagation mode known as NVIS sys tems. This short article summarises what I have found out about subject. WB5UDE (see below) gives a good introduction to the subject. “NVIS, or Near Vertical Inci dence Skywave, refers to a radio propagation mode which involves the use of antennas with a very high radiation angle, approaching or reaching 90 degrees (straight up), along with selection of an appropriate frequency below the critical frequency, to establish reliable communications over a radius of 0-200 miles or so, give or take 100 miles. Many of us have used this mode when making nearby contacts on 160 meters or 80 meters at night, or 80 meters or 40 meters during the day. We may have thought of these nearby contacts as necessarily involving the use of ground-wave propagation, but many such contacts involve no groundwave signal at all, or, if the...

XLT125 Scanner Repair

Club member Eddie was disappointed when the centre pin of his antenna broke inside his Uniden UBC XLT125 radio scanner . Rather than send the radio to landfill, Eddie decided to repair it. After asking advice from other club members, he purchased a replacement BNC aerial chassis mount socket from RS , The job took took about two hours to complete, and the finished result looks very impressive. Nice work Eddie!