28 November 2006

ofcom considering alternatives for am/fm frequencies

Ofcom, the "independent regulator and competition authority for the UK communications industries", is considering alternate uses of the radio spectrum currently servicing AM and FM broadcasting. The article says: "Radio has suffered from an exodus of younger people, many of whom have opted for MP3 players such as the iPod and other forms of digital entertainment such as social networking."

The full article is on redherring.com:
Brits mull radio's end

latest mediumwave adventure

This evening turned out to be excellent for mediumwave DX. I've been chasing after 900 KNUI in Hawaii for a while. I haven't picked it up yet, but the signal I heard on 900 khz was CKMO, a 10 kW station in Victoria, BC, Canada. I confirmed a total of 5 AM stations in about an hour and a half.

While looking for KNUI information, I found this discouraging news:
[IRCA] 900 KNUI change in programming

I hope to log that station in its current format while it's still there.

26 November 2006

peculiar broadcast on 1690 khz

I tuned to 1690 khz with my Sony ICF SW7600GR. My target was a station in Colorado. After a couple commercials at the top of the hour, a new age-style song came on. And it kept coming for the next 15 minutes! It's a simple melody with a pan-flute type instrument, backed by a piano.

I looked up the possible stations for 1690 khz in the USA, and found these at the FCC site:

KDDZ: Arvada, Colorado
KFSG: Roseville, California
WMLB: Avondale Estates, Georgia
WPTX: Lexington park, Maryland
WVON: Berwyn, Illinois

I can't find a website for KFSG. If I could, I'd see if it had a live audio stream so I could compare it with the broadcast. But it's supposed to be a spanish station and the ads I heard were in english. KDDZ is Radio Disney, so that doesn't seem to be a candidate either.

Stations in Toronto, Montreal, and the Virgin Islands also use this frequency. Maybe this is a new station that has commercials ready but no actual content, or they're testing a transmitter. I'll keep monitoring this signal to see if I can solve the mystery.

23 November 2006

people with shortwave radios are suspicious

I'm amused by news stories like this one, in which a suspected Russian spy was arrested in Montreal by border security. Apparently, even in 2006, possessing a shortwave radio increases your likelihood of being a spy:

Ambassador hasn't 'foggiest idea' about suspected spy

help needed with mexican am station

I believe I received a mediumwave station from Mexico this evening. The frequency is 1630 khz, and I heard an announcer speaking in spanish, mentioning Tijuana and Mexico. I heard what sounded like an identification at the top of the hour, but I couldn't understand it since I don't know spanish.

Can anyone suggest possible identifications for this station? I haven't found any lists of Mexican AM stations that include a station on 1630 khz.

grundig g4000a and sony icf sw7600gr sales

Today on Amazon, the Grundig G4000A is listed for just below US$80. This is a slightly updated version of the Grundig YB-400PE. Also, the excellent Sony ICF SW7600GR is listed at just below US$125. I also included Passport to World Band Radio below because it is a widely-read book among shortwave enthusiasts (and the article looks better with three items).


[Edit: The G4000A price has returned to just under US$100.]

18 November 2006

mediumwave images on the sw7600gr

I love my Sony ICF SW7600GR. I haven't used it much recently, because it is one of the older radios in my collection and there are newer radios that I am trying to get to know. But it is a really great product.

Another Sony radio that I own, the $10 ICF S10MK2, is exceptional. Early this year, I put alkaline batteries in it, and they are still going after more than 300 hours of use. It has surprising audio quality given its low price.

My experience has been that Sony portable radios are built well, sound great, and perform exceptionally.

My SW7600GR frustrates me in one area: mediumwave images within the longwave frequencies. Tuning to a particular frequency in the 150-500 khz range, I may hear a mediumwave station that is actually 910 khz above the tuned frequency. 190 khz and 350 khz are used up by local mediumwave broadcasters, while several other frequencies have fainter mediumwave images.

This radio uses dual conversion for AM reception, so I am not sure why this image problem exists within this frequency range. Is it possible that the longwave frequency range uses single conversion?

The only signal I have picked up near the longwave range is the airport beacon in Montague, California on 404 khz. But the mediumwave images I am hearing dissuade me from investigating longwave further.

17 November 2006

mediumwave frequencies with 9 khz separation

I searched online for mediumwave resources, such as a list of mediumwave frequencies using 9 khz separation (used outside of North America). Since I couldn't find such a list, I wrote a simple perl script to generate the list for me. So here are the mediumwave (AM) radio frequencies 522 - 1620 khz with 9 khz separation:

522, 531, 540, 549, 558, 567, 576, 585, 594, 603, 612, 621, 630, 639, 648, 657, 666, 675, 684, 693, 702, 711, 720, 729, 738, 747, 756, 765, 774, 783, 792, 801, 810, 819, 828, 837, 846, 855, 864, 873, 882, 891, 900, 909, 918, 927, 936, 945, 954, 963, 972, 981, 990, 999, 1008, 1017, 1026, 1035, 1044, 1053, 1062, 1071, 1080, 1089, 1098, 1107, 1116, 1125, 1134, 1143, 1152, 1161, 1170, 1179, 1188, 1197, 1206, 1215, 1224, 1233, 1242, 1251, 1260, 1269, 1278, 1287, 1296, 1305, 1314, 1323, 1332, 1341, 1350, 1359, 1368, 1377, 1386, 1395, 1404, 1413, 1422, 1431, 1440, 1449, 1458, 1467, 1476, 1485, 1494, 1503, 1512, 1521, 1530, 1539, 1548, 1557, 1566, 1575, 1584, 1593, 1602, 1611, 1620

12 November 2006

voice of korea's fake bush quote

Thanks to WFMU's Beware of the Blog, I visited the Voice of Korea (DPRK) website. It includes this amazingly fake George W. Bush quote:

"I warn you that don't even think about your lives in the diversity ! The reason is simple. I am the ruler of the United States and the rest of the world. Do you need more reasons than this ? Therefore, every primitive nation must follow American rules and should obey to USA system. I will tell you what to do and you just do what I say. That's enough to make the world secure. Therefore, you just shut up and follow me otherwise I will teach you with my gun and I will shoot your ass as I did to dirty and smelly Afghanistan and Iraq". The president of USA and the rest of world, George W Bush (Junior !).

wbcq qsl

WBCQ wins the QSL race! Via postal mail, I sent two reception reports for 7415 khz and a self-addressed stamped envelope on 20 September 2006. I got my envelope back with a QSL card on 02 October 2006.

Here's the QSL card I received:

This is a notable achievement because the orientation of WBCQ's shortwave transmitter is not favorable for California. Within WBCQ's daily schedule, there's a small window of west coast reception available. Shortly after things get good, they go off the air.

Allan H. Weiner wrote the reception details on the card (which is a postcard). On the back, the card has a box at the top right corner that is labeled "SNALE MAIL STAMP" (sic), and this caption: "This is the official QSL post card of radio WBCQ - The Planet. Our studios and transmitters are located at Monticello, Maine USA."

08 November 2006

de1103 prices increased on ebay

Degen DE1103 shortwave radios on eBay now cost $49.90, with a shipping/insurance cost of $24.00. That reflects an increase of $5 for the radio. This significantly narrows the price gap between the Chinese and USA versions of this product. Some KA1103 radios listed on eBay come with free shipping in the USA.

I don't think it's worth the risk of getting a DE1103 from China, just to save a few dollars. My transactions with eBay sellers in China have been fine, but I usually buy from them to get radios that aren't available in the USA otherwise. If I were buying an 1103 now, I would get the Kaito version from an American reseller.

05 November 2006

using the de31/ka31 loop antenna

A thread on rec.radio.shortwave started with a complaint about poor performance from the Degen DE31 active loop antenna. I and some others posted our thoughts on the DE31, and noted that the wires needed to be connected a certain way. A few posts later, the thread originator followed up to say that this solved the problem, and he retracted his complaints about the antenna. This article will explain how loop antennas work, summarize my experiences with the DE31/KA31 antenna, and provide links that were shared in the newsgroup thread.

The Degen DE31/Kaito KA31 active loop antenna amplifies the magnetic component of a radio wave without amplifying the electrical component. As the electrical component is usually comprised of local interference, this process strengthens radio signals with clarity. The loop consists of a wire running through a thin gray rope. Structure for the loop is provided by a horizontal telescopic bar, which is not a receiving component of the antenna.

This antenna is called an active antenna because it receives power from two AAA batteries. An email from Kaito USA told me that "decent" batteries would last over 100 hours. The Duracell AAA batteries that I installed in my DE31 in late 2005 are still working and producing around 1.45 volts each.

The pieces of this product can fit together more than one way, so it is important to follow the product diagram to get the intended performance. The long wire goes between the antenna loop itself and the tuner box. This positions the power source far from the loop, but it places the power switch and tuner dial close to your radio.

Visit the Kaito KA31 product page to see a diagram of how the pieces fit together:
* Kaito KA31 Shortwave active loop antenna

In some cases, clipping this antenna to the whip of one of my radios can strengthen the signal to a usable level. When I use the antenna unpowered, it's acting as a random length wire antenna. (The phrase "random length" refers to the fact that the antenna length has no specific relation to the desired wavelength.)

When I turn on the tuner, I can boost the signal after tuning the antenna to find the right spot. It depends on the signal and the conditions as to whether powering the loop antenna will provide a benefit in my case. My understanding is that the tuner operates in a linear fashion across its supported range (3900 - 22000 khz). Using a small tuning range to map to this large frequency range means that tiny adjustments are required to find the best setting for each frequency.

My loop antenna hangs in a window, with the hole facing north/south. I have not tried rotating it to face east/west, because it's not convenient for me to hang it that way. Regarding how to position a loop antenna, the Radiointel antenna review that is linked below noted that changing the direction of a loop antenna had more of an effect on nulling local interference than increasing or decreasing radio signals. Shortwave signals traveling large distances to reach you will cover a wider area than interference caused by a nearby electrical device.

Here's a Radiointel review where Sony's AN-LP1 loop antenna is compared to the DE31/KA31 loop antenna:
* Degen DE31 vs. Sony ANLP-1 Active SW Loop Antennas

The thread on rec.radio.shortwave also produced some images showing the insides of the DE31 tuner:
* DE31_inside.JPG
* DE31_inside1.JPG
* DE31_inside2.JPG

If you want to learn more about loop antennas, I recommend the radio antenna Wikipedia article:
* Antenna (radio)

Thanks to craigm, danr_18, Jim Hackett, N9NEO, and Telamon for participating in the DE31 thread with advice and links.