NOTICES

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Sound Mirror Visit Denge!!!!

Anyone interested in having a club visit to the Sound Mirrors at Denge? contact Karl Davies on 01227 710120 or email karl.davies@talk21.com.

Further information.....

see the website: http://www.rmcp.co.uk/NoticeBoard.php

SUMMER 2010 VISITS TO THE SOUND MIRRORS - OPEN DAY

The concrete structures at Denge are the remains of part of an acoustic early warning system, designed to detect engine sounds from approaching aircraft. They are known as 'Sound Mirrors' and were constructed in the years 1928-1930. The Denge mirrors were part of an intended chain defending the South East. At Lade Pits, on the island are a 20ft mirror, a 30ft mirror and a 200ft wall.The Sound Mirrors are Scheduled Ancient Monuments and English Heritage commissioned repairs and improved access in 2004 to safeguard these structures.
The sound mirrors are only accessible on one of our guided tours and we have been leading free tours out to the Sound Mirrors for 13 years now. They are on an island, connected by a locked swing bridge on a private gravel workings (owned by CEMEX).

There will be an 'Echoes from the sky' open day on the 18th of July from 10:00am - 4:00pm. The Open Day is free of charge and there is no need to book, although we do ask for a donation. For the open day only you will need to park at Lade car park and follow the signs to make your own way to the Mirrors. Staff and volunteers will be stationed at key places to help direct people and will be positioned at the bridge and on the island.

For more information, please see the activity list below or please contact us if needed:
Tel: 01797 367934
Fax: 01797 367934

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Hilderstone Radio & Electronics Club

Invite you to join us for our Annual Field day

This could be our finest WOK!

From 11am on Saturday 7th August 2010

at the Westgate-on-Sea Community Centre field.

Barbecue and refreshments! Free tea and coffee!

Free Admission and Car Parking but Donations encouraged!  

Something to sell? Bring it along.

 But please take away unsold items when you leave.

Listen on all bands for G0HRS

 Talk-in on GB3EK and GB3KS

Meet up with friends old & new



Amateur Radio data mode ROS proving popular

Although it's only 3 months since the first HF contact with the new Amateur Radio data mode ROS, it's proving popular with plenty of activity on 14.101 MHz.

ROS is a digital spread spectrum mode but with a narrow total occupied bandwidth of about 2.2 kHz. The software has two Symbol Rates: 16 and 1 baud (the latter aimed at weak signals down to -35 dbs of S/N) and can automatically synchronize any Symbol Rate.

Initial reports talk of it being able to copy signals so weak that they don't show up on the Waterfall and there are early indications that it is several dB better than Olivia. However, HF with its Fading, Doppler, Multi-Path and Interference is a hazardous environment for digital signals and only time will tell how well it performs against the other modes.

One issue the mode has thrown up is the restrictive Amateur Radio License conditions in the USA. Here in the UK we are used to the "Technology Neutral" approach adopted by our regulator Ofcom. This permits us to devise and use any mode we like with any bandwidth as long as the transmission fits within the Amateur band.

The United States is not so fortunate, there the FCC specifies which modes Amateurs can use and where. Some Amateurs in the States are concerned that FCC regulations appears to prohibit the use of Spread Spectrum below 420 MHz and ROS is a Spread Spectrum mode.

To be fair to the FCC they did try back in 1977 to change from a mode based band plan to one based on bandwidth. At the time the ARRL opposed the change and was successful in defeating it, as a result the development of digital modes was crippled for decades to follow.

In recent years the ARRL has been trying to get the FCC to re-introduce band planning by bandwidth and hopefully they will be successful.

You can download ROS from

http://rosmodem.wordpress.com/

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Icom has moved!!!
see Adobe pdf files below:

icom_letter

icom_uk_on_the_move
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Posted: 12 December 2009

Wanted: 4m Tranceiver

Ted G3ISD Tel: 01795 477431

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Wanted
 Plessey IC's    Sl1612 Sl1621 Sl1640 Sl1627 Sl6270   

Contact David G8URC 
  01227 368803

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