GB3EA “BIG EARS” Switches On   April 30th, 2008

The new repeater from Wickhambrook, near Sudbury in Suffolk, GB3EA has gone live in a big way. Officially named the East Anglian Repeater, it is causing a lot of excitement because of its immense coverage. Here in Hockley it is a good workable signal from a mobile operating position and seems to be good in parts of Kent. It certainly has “big ears” and an equally “big mouth.”

If you want more information then follow the link below~:

http://gb3ea.blogspot.com/

Input 145.0875

Output 145.6875

CTCSS 110.9Hz

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Website Product Prices   April 30th, 2008

I have noticed a few phone calls from customers about products on the website not having the correct prices displayed. This is a common problem for a lot of users of any website, and is caused by a page being saved to your computer, and then loaded from memory as opposed to loading from the website. This function serves to save resources for both the customer and us, as neither have to load the web pages each and every time, but can have an adverse effect when the user is trying to see the most up to date information.

The way to solve this, is by what’s called an “unconditional refresh”, which forces your web browser load the page from the website and not from memory. You can do this on most Windows based browsers by holding the “Control (CTRL)” button and pressing the “F5” button at the same time. You can do the same on Mac OSX by holding the “Command (CMD)” button and pressing the “R” button at the same time.

Hope this helps any of you that were having problems with this.
– Dave.

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Common Antenna Problems   April 30th, 2008

There are a few common problems that occur time and time again when new antennas are erected.

1 The coax plugs are not connected properly or are short circuited. Get yourself a cheap test meter – around £5 – and make sure everything checks out OK. With the coax feeder removed from the antenna and transceiver, check for continuity on inner and out conductors and make sure there is an open circuit between inner and outer. Never make assumptions or rely on visual checks. It only takes a single strand to cause a short circuit!

2 Check all mechanical joints of the antenna and protect them from corrosion.

3 Measure the sections that are adjustable and make sure that they are correct with the manufacturer’s instructions and measurements.

4 Measure VSWR across the band and plot a curve – do not just make one spot frequency. This will indicate if the antenna is resonant in the band or just outside the band. Remember, increase length to lower frequency and reduce length to raise it.

5 A very high VSWR on all bands points to coax, connectors or something that is very close to the feed point and common to all bands.

6 High VSWR on just one or two bands should prompt you to examine items of the antenna that are only common to those bands.

7 Don’t overlook even the simplest of things. Take time to think the problem through – you will learn quite a lot in the process.

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Miracle Ducker TL   April 29th, 2008

The Miracle Whip manufacturers have introduced a new model known as the Miracle Ducker TL. 

Working on the same principle as the original Miracle whip, this model has a detachable BNC 57″ telescopic whip and permits the user to tune anything from a short rubber duck antenna to a wire or dipole. The total frequency range is 3MHz to 150MHz. Above 30MHz (VHF) tuning relies on the length of the whip. Maximum power handling is 25W pep. 

It is worth mentioning that unlike copies, this original design is still the only one that does not need a radial for correct tuning, and that it is also the only one to offer continuous tuning throughout the HF range. Price is £99.95. 

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RadarBox Distribution Changes   April 29th, 2008

Waters & Stanton PLC were appointed a few months ago as world distributor for all countries other than Germany and Austria. As from May, Waters and Stanton PLC will also take over the distributorship for Germany and Austria. 

This move will consolidate the marketing of this market leading product and marks a new chapter in the future development of RadarBox from AirNav Systems. For full details of the product, please visit www.airnavsystems.com

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Spring is Antenna Time!   April 26th, 2008

With the good weather this weekend (at least here in the south) it is a reminder that now is the right time to give some thought to antenna systems that have just emerged from the ravages of winter. Water and wind bring corrosion, and this is one of the enemies of an efficient antenna system. 

It has always been a good idea to grease all jointing surfaces and wrap them in tape. This makes for good electrical contact and ease of future adjustment. And on the subject of adjustment,  it is quite common after winter winds, for telescopic elements to slip and change length. So get outside and check your system in the coming days. 

A final thought: most amateurs spend far too little on antennas and looking after them. Often the antenna is the weakest link in the station and the most neglected!

More on antennas later.

 

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Weather Stations   April 25th, 2008

We will have more W-8681 weather stations coming into stock in early May. This product is in great demand and sells out quickly, so order yourself one now and avoid missing out!

RadarBox New Software   April 25th, 2008

Please note that version 1.5 of the software is now available for download.

The link is:

http://www.airnavsystems.com/radarbox/support.html

At last – new channels for the Southend-on-Sea (Hockley) Repeater

Many local operators will know that the launch of our D-Star repeater was dogged with problems. It began with poor sensitivity on the receive side and this was rectified by Icom. Then we found the coverage was not as good as we had hoped, so a high gain antenna was installed and the mast height raised.

At first we thought the problems were behind us. But not so. A dramatic loss of receiver sensitivity at random times showed that the repeater input was suffering from data interference. And to make matters worse, the input frequency was also on channels shared by low powered domestic data devices.

We are NOW glad to announce that new channels have been allocated and that the repeater should be back on the air around the 26th April. So please give it a try.

THE NEW FREQUENCIES ARE:

REPEATER INPUT 430.7375MHZ

REPEATER OUTPUT 439.7375MHZ

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The Heil professional series of microphones are gaining popularity for broadcasting and music reproduction.

On voice they produce a lovely crisp presence sound and the reproduction is very faithful. But they are also ideal for ham operators who want the very best in transmitted sound. And even though SSB has a very restrictive audio spectrum, tests show that starting off with a high quality microphone such as the Heil professional series, does pay off.

We recently did some classical music recording using a pair of these microphones and the results were quite amazing. They were particularly good at close in voice reproduction and also worked well on string instruments. The response would have done credit to condenser microphones costing several hundred pounds more. And compaired with other well known dynamic microphones, again costing more, there was really no contest.

On voice, very little frequency EQ correction was needed. The recorded tracks were just fine as they were. On guitar the amount of detail was quite astonishing, producing a lovely transparent sound. The extended frequency response meant that on strings, a few dB of top cut was used post production to tame the bow noise when close in. But this is fine because at least you have the full spectrum available to work on.

There was a definite, but subtle difference between the two microphones. There was a small amount of colouration on the PR-30 when compared to the PR-40 and a slight drop in the HF response. In fact the PR-30 would probably be preferable for string recordings, whilst the PR-40 would be the choice for voice and plucked instruments.

The Heil professional series are probably one of the discoveries that many people involved in recording have yet to make. But what a reward awaits them when they finally do come upon them!

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