cobalt pet shortwave / mediumwave weblog

31 December 2005

leap second recording

Here's a recording of the leap second on WWV on 31 Dec 2005. This was previously discussed in my article, "december 31 leap second". I recorded this with my Sony ICF SW7600GR tuned to 15 mhz. Notice that during the station identification at the start of hour 0, there are doubled ticks during the first three seconds. So for now, UT1 = UTC + 0.3 seconds. Here's the recording:

31 dec 2005 leap second wwv 15mhz.mp3 (412 kb)

bbc springs more leaks

I stayed in upstate New York for the last two weeks in December. My Kaito 1102 was with me, and I scanned the usual places looking for expected stations and new receptions. This was my first good opportunity to hear shortwave broadcasts intended for Europe.

Her Majesty's BBC was received, due to the inexact science of directed shortwave broadcasts. In case you don't already know the back-story, feel free to read my previous article titled "focus on the bbc".

Now I'll enter a rant about shortwave listeners' misconceptions about the BBC. I have seen forum postings and radio reviews where a North American listener says they bought a shortwave radio to listen to the BBC, and ended up disappointed when the radio couldn't receive it. That is not always a good reason to blame the radio. Primetimeshortwave.com is a good place to research schedules for English-language broadcasts on shortwave. In some cases (and this is true for most of the BBC broadcasts listed), they list the originating location of a broadcast.

Anyway, here are my receptions of the BBC from upstate New York. My descriptions of what was heard are on the terse side because I was more interested in scanning than writing detailed reception reports.

21 Dec 2005 0421 UTC: 7130 khz (via Cyprus, to Europe) - SIO 333. Discussion of Chinese literacy.
21 Dec 2005 0422 UTC: 7160 khz (via Ascension Island, to Africa) - SIO 333. Sports news. Announced an upcoming two-part series on mobile phones. They say worldwide mobile phone ownership is 1 billion. This show is called Network Africa.
22 Dec 2005 0249 UTC: 5975 khz (via French Guiana, to Central America): SIO 434.
22 Dec 2005 2201 UTC: 5975 khz (via French Guiana, to Central America): SIO 444.
23 Dec 2005 0333 UTC: 5975 khz (via Delano, CA to Central America): SIO 434. US President George W. Bush asking for a 6-month extension to the Patriot Act; Congress granted 1-month extension. Democrats worried about the extension of powers. New Orleans rebuilding has been very slow after Hurricane Katrina. 25% of residents have returned. Much of the city is still in darkness. Discussing video blogging: "there are a lot of boring things occuring on the Internet."

17 December 2005

asking the experts

Although I have learned much about shortwave listening, there are still things I haven't figured out entirely. I compiled a list of questions and am seeking answers from my knowledgeable readers. You're also welcome to ask additional questions in the comment section. Later on I will try to update this entry with the best questions and answers, and I'll credit each contributor. Be sure to leave your name, call sign, or alias if you wish to be credited.

Note that I'll be away for the last two weeks of December 2005. See you next year!

1) For introductory purposes, how long have you been listening to shortwave radio?

2) Can you describe what chuff means? This word is used in shortwave receiver reviews, and involves tuning a digital receiver, but I can't determine the exact meaning.

3) How should fading be accounted for when determining an SIO code? Is fading caused by interference?

4) How are the electronics of a dual-conversion receiver different from a single-conversion receiver?

5) Can you explain how images (reception of a signal on the wrong frequency) occur? What bands can be affected by images?

6) Why is it that a single sideband signal needs to be fine-tuned?

7) Can someone describe the difference in the sync detect between the Sony ICF-2010 and the SW7600GR?

8) Is there any way to determine how many atmospheric bounces a received signal has made? I know that an atmospheric bounce will introduce attenuation, so a signal that has bounced more will be weaker. Are there any other identifying characteristics?

13 December 2005

tecsun r-9012 review


I recently received a yellow Tecsun R-9012 which I ordered from tquchina on eBay. Tecsun released this radio at the end of September 2005. It is a single-conversion analog-tuned radio that receives AM (525-1610 khz), FM (76-108 mhz), and ten shortwave bands (75m - 13m). It measures approximately 5 inches wide, 3 1/8 inches tall, and 1 1/8 inches thick. It has a lot in common with Tecsun's R-911 and R-912 models. tquchina currently sells the R-9012 for US$14.90 plus US$4 shipping. Liypn recently listed this radio for the same price but did not have it listed on eBay when I wrote this.



This article will describe the R-9012, and in some cases, compare it with the slightly smaller but similar R-912 (shown in silver in the accompanying photo), which I acquired a couple months ago. I used a digitally-tuned Tecsun PL-200 (rebranded as the Eton E100) for reference signals.


Here are the frequency ranges printed on the R-9012 tuning scale:


FM: 76-108 mhz
MW: 525-1610 khz
SW1 75m: 3.70-4.20 mhz
SW2 60m: 4.65-5.20 mhz
SW3 49m: 5.90-6.40 mhz
SW4 41m: 6.90-7.40 mhz
SW5 31m: 9.25-9.95 mhz
SW6 25m: 11.55-12.10 mhz
SW7 22m: 13.25-13.80 mhz
SW8 19m: 15.00-15.75 mhz
SW9 16m: 17.45-18.05 mhz
SW10 13m: 21.20-22.05 mhz


The R-9012's tuning range is about 1 1/2" wide.

For comparison, here are the frequency ranges printed on the older Tecsun R-912:
FM: 87-108 mhz
MW: 525-1610 khz
SW1 75m: 3.55-4.00 mhz
SW2 60m: 4.70-5.25 mhz
SW3 49m: 5.90-6.30 mhz
SW4 41m: 6.95-7.40 mhz
SW5 31m: 9.40-9.90 mhz
SW6 25m: 11.55-12.00 mhz
SW7 22m: 13.30-13.90 mhz
SW8 19m: 15.00-15.60 mhz
SW9 16m: 17.40-18.05 mhz
SW10 13m: 21.35-21.90 mhz

The tuning range for the R-912 is approximately 1 3/8" wide.

Here are some simple usage instructions in case you're unfamiliar with radios of this type. The on/off switch is on the right side of the radio, and the volume dial is on the left side. The tuning scale includes rows for each of the 12 supported bands. Slide the switch at the bottom of the radio so a dot appears below the band you want. Turn the knob to move the needle to the desired frequency, which can be estimated with the printed frequencies on the tuning scale. Be sure to extend the telescopic "whip" antenna if you're listening to FM or shortwave.

The only item inside the R-9012's box is the radio itself in bubble wrap. The R-912 came with a cloth carrying bag which is useful for storage and transportation.





The R-9012 sports a simple, clean-looking plastic case and very legible labeling. On the side of the radio, the R-9012 has flatter edges whereas the R-912 has unnecessary ridges. Perhaps the ridges are intended to partially hide the side-panel controls when viewing the front of the radio. Construction-wise, the older R-912 radio feels more solid because the outer casing is more tightly held together, the band switch feels firm (the R-9012 band switch rattles somewhat), and the "DC In" jack is in the right location. Although I'll never use it, my R-9012's DC In jack is not properly aligned with the hole in the side of the radio. The center pin for the jack is at the edge of the hole. I put the tip of a ballpoint pen into the jack and was able to move it around, so I'm sure I could fit a plug in there.


The R-9012's whip antenna is nearly 22 inches long, which is the same length as the PL-200 whip, and about two inches longer than the one on the R-912. My R-9012 is labeled in English whereas my R-912 has several Chinese labels. The Chinese labeling on the R-912 does not complicate usage though. Attached to the top left side of the R-9012 is a simple cord loop wrist strap.

The speaker on the R-9012 seems to emit less treble and more lower frequencies than the R-912's speaker. Between the two, I prefer the R-9012's speaker. It sounds smoother and less harsh because of the frequency range differences. Perhaps the speakers are identical and the audio processing inside these two radios is slightly different. While using iPod headphones, both radios sounded equally good. Whether using the speakers or headphones though, there were moments with each radio that I wished for a high/low tone switch to help deal with the noise level. Noise tends to gradually sweep in and out of shortwave signals, possibly due to subtle drifting.

The tuning knob on this radio provides a good tuning experience and feels sufficiently tight. The knob is about the same size as the knob on the Tecsun PL-350.

How is the R-9012's shortwave tuning accuracy? I used WWV as a reference signal because three of its frequencies correspond almost directly with three frequencies printed on the radio's tuning scale, and WWV is reliable at most times of day. WWV on 5 mhz was received with the needle between the two zeros in "5.00" on the 60 meter scale. WWV on 10 mhz was heard with the needle over the decimal in "9.95" on the 31 meter scale. WWV on 15 mhz was found with the needle to the left of the 1 in "15.00" on the 19 meter scale. This radio doesn't receive 2.5 mhz or 20 mhz so those WWV signals weren't checked.

For more shortwave evaluation, I located Radio Japan at 17825 khz on a Tecsun PL-200. After a moment of fine-tuning in the 16 meter band, I found the same signal on the R-9012. Letting go of the radio significantly reduced the reception, so I had to hold the radio to hear it. I carefully adjusted the tuning knob to reduce the whistling noise, but it was drifting slightly and I had to make continual adjustments to reduce noise. The PL-200 picked up some of this noise too, but it was not emitting the sharp high frequencies that the R-9012 was.

The BBC on 5975 khz was easier to find and the R-9012 did not have drifting problems. The PL-200 was able to receive that signal between 5972-5979 khz, and had 4-5 bars of signal strength on 5975 khz.

The R-9012 was able to dig out a weak Radio New Zealand International signal on 17675 khz. Drift was a problem here and it would have been difficult to tune into this broadcast without a reference signal from the PL-200 (which showed only one bar for signal strength). This broadcast had a narrow usable range of 17674-17677 khz.

Voice of Korea on 13760 khz was barely coming in on the PL-200. I know I passed the signal a number of times on the R-9012 but was unable to zero in on it.

Radio Havana Cuba is one of my shortwave favorites. The 6000 khz signal was very strong whereas the 6060 khz signal was more muffled and required a bit more tuning precision. While making slight tuning adjustments to get the best signal and reduce noise, I preferred the tuning knob of the R-9012 over the thumb dial of the R-912.

Now I'll evaluate FM. Note that about 1/3 of the R-9012's FM tuning range covers 76-88 mhz, which you may not find useful. This causes the high end of the tuning range, 103-108 mhz, to be very tight. Additionally, note that this radio does not receive FM stereo through headphones, although the R-912 does.

I found two FM stations in the 104-105 mhz range on the R-9012. One of the signals was so wide on the tuning scale that the second station appeared between the signal of the other, unless it was actually an imaging problem. I could not reproduce this on the R-912, which received both stations adequately.

96.5 mhz was found on the R-9012 with the tuning needle just about centered on the "96" in the FM band. On the R-912, the tuning needle was just to the left of the "98" when receiving the same station. Both of these radios seemed to receive the same broadcast when tuned to 89.3 mhz which I suppose was an image.

I found a strong signal for a station I'm not familiar with on 91.7 mhz. The signal was picked up easily on the R-912 about midway between the "90" and "94" labelings in the FM band. On the R-9012, I traveled through the 88-95 range several times and with very minute turns of the dial, but was unable to find the same broadcast.

To evaluate the higher end of the FM band, I tuned to 105.7 mhz, a spanish-language broadcast, on the PL-200. Dialing past "104" on the R-912's FM scale, I found the signal easily. On the R-9012, unfortunately, I only heard the broadcast belonging to 106.9 mhz for most of the range between "103" and "108" on the FM scale. With a bit more effort, I found the 105.7 mhz broadcast in a narrow range while the needle was centered over the "103" label.

Finding FM stations is easier on the R-912. The R-9012 requires more effort, and in some cases, signals may be lost amongst images.

While tuning through the AM frequencies, the R-9012 seemed to receive a bit more noise and interference when tuned to a strong signal. The R-912 had clearer reception on the same frequencies. Both radios had similarly clear reception of a strong local signal on 740 kHz (KCBS). The R-9012 was more likely to null a signal with rotation. I'm not sure if this means that the R-9012 has a better ferrite bar antenna, or the R-912 actually achieves stronger reception. The R-9012's listed frequency range for AM is 525-1610 kHz, so reception in the upper 1620-1710 kHz range is not possible.

Here's my complaint about a tune LED on a radio. I found an AM station with adequate reception on the R-9012. When I looked at the radio, the tune LED was flickering. It was taking away from the listening experience and didn't help me improve the signal.

I'm curious to know why the R-9012 expands the frequency coverage of many of the shortwave broadcast bands, as the R-912 already had full broadcast band coverage. Presumably the R-9012 is based on the electronics from the R-911 and R-912 radios. Is the ability to receive more frequencies worth the reduction of fine-tuning ability? This is particularly perplexing with the FM band on the R-9012. Is the 76-88 mhz range heavily used in Asia?

Eliminating noise and locating broadcasts in the shortwave spectrum are probably the two main challenges for SWL novices. To put it bluntly, the Tecsun R-9012 makes you confront those issues head-on. With patience, I was able to make this radio do what I wanted in most cases. This is a good radio for the price, but it is better suited for the curious listener than the dedicated enthusiast. My advice to someone intending to be a regular shortwave listener would be to spend more money and get a digitally-tuned dual-conversion receiver.



11 December 2005

satellite radio

I decided that if I could get a free satellite radio receiver, I would try a subscription for a few months. Exposure to different types of music would be my main interest. I'd probably listen at home or at work, as opposed to in my car.

So I am on the lookout for satellite radio giveaways that are legitimate and not a big hassle. At this point I don't have a strong preference for either XM or Sirius. If you have knowledge of such giveaways, please leave a comment!

08 December 2005

this is radio havana calling

Tonight I found the time to listen to Radio Havana Cuba during approximately 0500-0545 UTC (09 Dec 2005). This was on 6000 khz with my Tecsun R-9012 receiver. The SIO code was a sparkling 555. Some of the major reports included:

* Rendition: The United States continues a policy of transporting terrorists to questionable locations where interrogations are held. RHC article: Legal experts say Washington's defense of rendition makes no sense.

* Waterboarding: A form of torture (in my opinion) where a detainee is strapped to a board and dunked in water. Radio Havana Cuba claims that the United States is using waterboarding during interrogations of terror suspects. A quote from the article linked above: "the Bush administration has adopted an exceedingly narrow definition of abuse and torture," in order to claim that they do not commit it.

* Banana and sugar trade: Caribbean countries are concerned about trade agreements with the European Union. An inability to export bananas and sugar would have seriously detrimental effects on the Caribbean economy. BBC Caribbean article: Bananas and sugar rows continue. EU Business article: Caribbean sugar producers press demands for better compensation from EU.

06 December 2005

eton update

A couple quick notes about the Eton website. First, the p7132 has been renamed to the p7136, although you will still see p7132 on the website in a couple spots. Second, the G2000 is no longer listed.

I could never find a Chinese radio manufacturer equivalent for the G2000 so I don't know where it originates. A lot of current offerings from Eton have equivalents in the Tecsun catalog.

03 December 2005

december 31 leap second

Here's a recording of the leap second announcement on WWV (03 December 2005 @ 2304 UTC, 15mhz, Sony ICF SW7600GR):

2005 leap second announcement from wwv.mp3 (0:58, 463kb)

Transcribed:

"Your attention please. At the recommendation of the international time bureau, a leap second will be inserted into the time broadcast of radio stations WWV, WWVB, and WWVH. Commencing at 23 hours, 59 minutes, 60 seconds UTC on December 31st, an extra second will be inserted into the NIST time scale. This adjustment is required to maintain internationally coordinated universal time in close agreement with UT1, or astronomical time."

Edit: Thanks to shortwavemusic for resolving the "NIST time scale" part of the transcript.

01 December 2005

waiting for porsche design

When I first visited the Eton website around July 2005, they were advertising two Porsche-designed shortwave radios: the P'7131 and P'7132. The P'7132 is still nowhere to be found, and when I emailed Eton about it a couple weeks ago, their response was "it will be at least six months before we have anything specific on this model." Following the P'7132 "product specification" link on the Eton website results in a "details coming soon" page.

I don't understand why they leave this pre-announced product on their website. A few weeks back, RadioIntel published news about the Degen DE1106's rebranding as the upcoming Eton E5. The E5 briefly appeared on the European Eton website. Supposedly it is also appearing in print advertisements with a list price of US$150. It will be interesting to see when that product reappears on the website and when it is released.

The XM-capable P'7131 has turned up in a couple places. Unfortunately, Eton's specifications for this product are not detailed enough for anyone who's serious about shortwave radio. With a Froogle search, I found a vendor called Surray Luggage that carries the P'7131, and they told me it is in stock. There was also a recent eBay auction with someone selling a P'7131 demo unit for $299.

(04 Dec) Update: The p7132 just appeared on the Universal Radio catalog pages as a future product.