Tag Archives: Southgate ARC

Caroline North on air this weekend

Southgate ARC: What Is a Balun and How to Make One Cheaply

Ham Radio – What Is a Balun and How to Make One Cheaply

A Balun is a transformer which allows coaxial cable, which is an unbalanced lead to be connected to a balanced load, for example a resonant aerial.

The 1:1 balun is often called a choke balun, it works by eliminating Radio Frequency currents flowing on the outside of your coaxial cable, this is important because it prevents the pattern of the dipole becoming distorted and prevents the braid of the coaxial cable radiating.

Connecting coax to your resonant dipole which can be configured in a V shape or in a sloping fashion, however serious power loss and feeder radiation can occur without the use of a balun transformer. No one wants to induce Radio Frequency currents into Television receivers or Broadcast equipment as it may result in disputes with neighbours and could possibly lead to your station having to close down. Try to keep the centre of your aerial away from buildings as it may induce Radio currents into the mains wiring.

Building a choke is not difficult all you need is some plastic pipe available from many Do It Yourself outlets and warehouses. I use a length of about 1 foot of plastic pipe and 21 feet of coaxial cable, the length of the pipe and diameter is chosen because it works well if using R-G-5-8 coax the ends of the pipe can be sealed after placing a SO-239 connector for your coaxial lead. I use two bolts and solder tags at the other end of the pipe to connect the ends of the dipole to the choke.

When wrapping your coax around the pipe don’t use too much force as it may damage the inner braid and space the turns away from each other by a millimetre or two. R-G-2-1-3 coax around 21 feet used with 5 inch pipe will handle 400 watts pf power. Wire ties can be used to hold the turns together along the length of the pipe. Using these measurements your choke will cover all of the ham radio bands from 1.8 Megahertz through to 28 Megahertz and will keep the radiation pattern.

Using a dummy load connected to the choke and transmitting 100 watts from my transmitter indicated an S.W.R. readings of around 1.5 to 1 at 3.5 Megahertz when testing 28 Megahertz the S.W.R. reading came down to 1.1 to 1 which is an excellent match. Using the choke as it should be at the feed point of a dipole cut for 40 metres give an S.W.R. reading of 1.2 to 1. The highest reading was 1.5 to 1 when using 18 Megahertz but the rest of the High frequency bands gave me very acceptable matching.

By
John Allsopp G4YDM
https://g4ydm.blogspot.co.uk/

Article Source:
http://EzineArticles.com/expert/John_Allsopp/1925417

Article Source:
http://EzineArticles.com/9615600

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Oops…Dutch regulator removes FM broadcaster’s antenna

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(Source: Southgate ARC via Mike Terry)

Dutch regulator removes broadcaster’s antenna

It is reported the Dutch Radiocommunications Agency dismantled the antenna of a legally operating broadcast station

It appears they thought Vechtdal NL in Ommen on 105.6 MHz was a pirate but the station, an associate of Vechtdal FM, was correctly licenced. The Agency says that something went wrong with the checking of licences.

The antenna was on the watchtower of the State Forestry Besthmenerberg Ommen near Nieuwleusen. It is unclear if the Radiocommunications Agency will pay compensation for the damage.

Radio.NL article
http://radio.nl/812498/legaal-radiostation-vechtdal-nl-door-at-uit-de-lucht-gehaald

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GigaParts opens new distribution center in Las Vegas

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(Source: Southgate ARC)

GigaParts opens new distribution center in Las Vegas

After Amateur Electronic Supply went out of business in July, GigaParts began hiring the AES staff in Las Vegas and working on moving the operation to a new location less than 5 minutes from the famous Las Vegas Strip and just 3 miles from the former AES building.

Although the retail showroom won’t be ready for visitors for another few months, starting today, the Las Vegas store becomes the primary distribution center for GigaParts shipments to the western half of the US. That means fast, affordable shipping to the huge population of hams in California and other western states, without sales tax!

Former AES customers will see some familiar faces at GigaParts Las Vegas, including AES’s former shipping manager, Terry Spaulding, and store manager, Julio Suarez. “I’m excited to be back and I’m looking forward to helping all of my old friends again,” said Julio. “AES was iconic in ham radio and it was sad to see it die off, but we have an opportunity with GigaParts to do things better than we ever could before,” he continued.

In addition to the new and improved facility, another improvement over the AES business model will be a single toll free number for customers wishing to place orders by telephone: (866) 535-4442. Sue Stephens, Customer Service Manager for GigaParts: “Technology has come a long way in the 70 years since AES first opened. Our state-of-the-art call center in Huntsville handles calls and online chats from all over the world. The guys in Las Vegas are going to be a huge asset to us by helping with employee training, adding new product lines and even backing up our reps on the phones during peak call times.”

Jeff Sinclair, the e-Commerce Division Manager at GigaParts, states, “This is a significant move forward for GigaParts as we continue to expand our distribution capabilities in North America. The new facility in Las Vegas doesn’t just mean faster shipping to our west coast customers, but the employees there add decades of experience in customer service and ham radio product knowledge.”

Initially, the Las Vegas store will carry the complete lines of amateur radio and maker equipment with more product lines being added later. Understanding that hams come to Las Vegas from all over the country and all over the world, GigaParts plans on making the retail showroom more of an interactive showcase of the latest equipment rather than a self-service shopping experience common amongst other amateur radio outlets. Today, GigaParts Las Vegas is stocked with ham radio gear and is ready to fill your order! To welcome AES customers, GigaParts is offering a $25 gift certificate to every former AES customer.

See www.gigaparts.com/AES for details

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With switch from AM to FM, some Polynesians now in the dark

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(Source: Southgate ARC)

Some inhabitants of French controlled Polynesia are unhappy at the switch over from Medium Wave AM to VHF FM broadcasting

Radio New Zealand reports Radio Polynesie Premiere switched to an all FM service at the beginning of December, leaving pockets of inhabitants in valleys and on remote atolls without any local radio service.

The broadcaster added five FM transmitters to its network of 48 to improve its reach but in an area the size of Europe, the signal fails to reach all communities.

Concern has been expressed that vital weather warnings are no longer heard.

The mayor of Makatea in the Tuamotus Julien Mai said there is a risk to public safety because people have always been advised to have an emergency kit that includes a radio when severe weather strikes.

Source:
http://www.radionz.co.nz/international/pacific-news/321809/loss-of-am-radio-irks-french-polynesia

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The Icom SP-38: A matching external speaker for the IC-7300

BBC Monitoring: A tour of Caversham Park

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HalliDial
(Source: Southgate ARC)

A tour of Caversham Park before it closes – the home of BBC Monitoring – a historical BBC World Service department which has been monitoring some of the world’s most seismic events for 75 years

Caversham Park became the BBC Monitoring Headquarters in 1941 and in light of recent news that, due to a £4million pound funding cut, it’ll be closing its doors for good, Rajan Datar visits the iconic building.

Coordinating Editor, Chris Greenway gives a tour of the building and a sense of its history, while Lina Shaikouni gives a taste of what the service provides today.

Over to You – The Home of BBC Monitoring
http://www.bbc.co.uk/programmes/p044jj9h

First broadcast on Saturday, August 20 the podcast should now be available at
http://www.bbc.co.uk/programmes/p002vsn8/episodes/downloads