Tag Archives: Southgate ARC

The new Cross Country Wireless HF Preselector

(Source: Southgate ARC)

Cross Country Wireless release HF Preselector

Cross Country Wireless have released a HF Preselector.

It is a passive high Q design that does not use an amplifier or external power.

It tunes from 0.5 to 52 MHz.

It is ideal for use with simple SDR receivers like the RTF-SDR dongle with upconverter or SDRPlay. It can also be used with the new receiver socket modification on the IC-7300.

The web page has more details including network analyser plots showing the selectivity of the Preselector.

The web page is:
http://www.crosscountrywireless.net/preselector.htm

VOA Museum celebrates VOA 75th anniversary

Photo from the control room at the VOA Bethany museum.

(Source: Southgate ARC)

National VOA Museum to celebrate 75th anniversary of Voice of America

There’s an important birthday celebration in West Chester this year: the 75th anniversary of the Voice of America.

“We’re planning a series of events and exhibits this year to celebrate the VOA’s commitment across America and the world to embrace best practices in telling the truth in order to let the world decide,” said Jack Dominic, museum executive director.

The VOA was formed in 1942 as a way to counteract Nazi propaganda in Germany and provide war news to American troops and Allies overseas.

“WLWO, a division of WLW, was transmitting news via shortwave radio overseas long before 1942,” said Dominic. “In fact, broadcasters from WLWO provided the nucleus of the early VOA broadcasting team. Cincinnati’s shortwave technology and its broadcasters truly helped the U.S. win the war.”

The reentrant rhombic antennas at the VOA-Bethany station in West Chester were so powerful that they became quickly known as the “siege guns of radio” for their capacity to reach the far corners of Nazi-occupied countries with little audible distortion. A frustrated Adolph Hitler was known to call the VOA “those Cincinnati liars.”

The VOA-Bethany station transmitted VOA news to Europe during WW II and South America during the Cold War through its innovative shortwave rhombic antenna network developed by the Crosley Corporation. The Bethany station was decommissioned by the federal government in 1994, after shortwave radio technology was supplanted by television and satellite technology.

“The men and women who made up the VOA broadcasting system were our journalistic beacons of light during the 20th century,” said Ken Rieser, president of the VOA museum board.

“Elmer Davis, John Houseman, Edward R. Murrow and Robert Bauer all had positions of leadership within the VOA.

“We hope that the VOA enjoys many more years of embracing the highest of journalistic standards in its reporting so it inspires people in war-torn and oppressed countries to hope, dream and work toward democracy.”

The Voice of America, based in Washington, D.C., is the world’s largest international broadcaster, providing balanced and comprehensive news and information in 47 languages to 236 million people each week, according to the VOA website. It continues to reach people in countries lacking a fee press today and its languages include: Russian; Ukrainian; Azerbaijani; Serbian; Armenian; Thai; and Somali.

The National VOA Museum of Broadcasting is located in the art deco Bethany station building and houses three collections: Gray History of Wireless radios; VOA-Bethany station’s Voice of America control room; and the Media Heritage Cincinnati Museum of Broadcast History. The West Chester Amateur Radio Assn. operates station WC8VOA from the museum building.

The VOA museum now offers an annual $50 membership that provides free admission for the member, an adult guest, and up to three children under 12. Members also receive updates and advance information about new exhibits and programs.

For $250, members receive the benefits above, as well as a 50 percent discount on any and all lectures, programs or visiting exhibit tickets.

The National VOA Museum of Broadcasting is open the third Saturday of each month from 1 to 4 p.m. Admission is $5 for adults and $1 for children. The museum is located at 8070 Tylersville Road in West Chester.

Museum will be open this Saturday, Feb. 18

For more information, visit the VOA Museum website at www.voamuseum.org or call (513) 777-0027.

To access Voice of America programs, visit www.voanews.com

The VOA Bethany museum is certainly worth a visit! I went there in 2015 and was most impressed with the work these volunteers have accomplished.

Click here for our short photo tour.

Caroline North on air this weekend

(Source: Mike Terry via Southgate ARC)

Caroline North is back this weekend

Caroline North is back this weekend live from the MV Ross Revenge on the River Blackwater Estuary near Bradwell, Essex.

Relayed on 1368 kHz with a transmitter power of 20kw from the Isle of Man.

According to Manx Radio’s website as well as being heard in the Isle of Man, the AM service is also audible in Southern Scotland, in the North West, in North Wales and in the West of Ireland and Northern Ireland.

Also online worldwide.

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

(Source: Southgate ARC)

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

Oops…Dutch regulator removes FM broadcaster’s antenna

(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