Author Archives: Rob Wagner

Tecsun S-8800 – The Birdie Problem

Recently, Tecsun announced and released onto the market the new S-8800 receiver. Thomas Witherspoon has indicated that sensitivity, selectivity and audio fidelity are very good for this new unit.

BUT…..in his post on February 12, 2017, entitled Tecsun S-8800 Update, Thomas discovered that his new S-8800 has a serious fault, one that could potentially drive radio enthusiasts mad! In tuning around the dial, he found the radio has many “birdies”. In the same post, he notes that Bertrand Stehle F6GYY also found birdies on 4 spots in the mediumwave band and 63 frequencies across the entire shortwave spectrum. Not good!

In reading the comments that followed Thomas’ post, I noted that a few writers seemed a little confused about what a birdie is and how it differs from radio frequency interference. Hopefully, the following explanation will shed some light.

The term “birdie” is, I guess, derived from the type of sounds that are emitted from a receiver having this problem. It can take on a variety of forms, like a squealing or whistling sound, or perhaps a warbling sound, or a hash noise, or indeed, even a silent carrier. In a particular radio, a birdie could appear on one or many frequencies across longwave, shortwave, mediumwave or into the VHF spectrum. And it will usually be permanently there on the same frequencies every time.

Occasionally, you will find birdies smack bang on the very frequencies where you might want to do some listening. But, unfortunately you can’t really do anything to get rid of these nuisances because the design faults are in the the receiver itself. You can test to see if what you are listening to is a birdie by simply disconnecting the antenna. If the squealing/whistling/warbling/hash/silent carrier is still there without any antenna, then it’s a birdie – an internally generated carrier by the receiver’s own circuitry.

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Rob Wagner, VK3BVW, is the author of this post and a regular contributor to the SWLing Post. He also blogs at the Mount Evelyn DX Report.

Radio Australia – The Last Two Minutes – January 31, 2017

Hi Folks,

Today I listened to Radio Australia for the very last time. 15240 kHz and 15415 kHz were plagued with local noise and not especially strong signals. So 17840 kHz was the best option for my final moments with this grand old shortwave broadcaster. Mount Evelyn is about 200 km south of the Shepparton transmitter site – not far enough for proper F layer reflection and off the side of the beam, so the signal was a bit scratchy. But I was there for the end and that’s the important thing!

Thank you to all the SWLing readers who have been so kind in their comments about our national broadcaster. I know RA meant much to so many people around the globe. But I’ll have more to say on this in the near future. Thanks to Thomas for helping to promote the Save Radio Australia cause. The fight is not over yet!

Here are the last two minutes of the broadcast today, including the audible switch-off click and a few parting comments from me.

73 and good DX to you all.

Rob Wagner VK3BVW

Radyo Pilipinas From 1973

One of the things I now regret is that I didn’t make more recordings of radio stations from my listening days in the 1970s and 80s. I have very few audio examples of stations operating at that time. So disappointing!

However….a few weeks ago, I stumbled across a recording I made in December 1973 of Radyo Pilipinas, The Voice of the Philippines (DZRP).  After a bit of audio engineering on the deteriorating old cassette tape, I’ve managed to somewhat improve the tone quality. I also found an image of the QSL card from that exact transmission on December 11, 1973 on 9580 kHz. I’ve posted the recording on YouTube – click the embedded video below.

This is for those of you who can remember and for those who enjoy some radio history!

These days, Radyo Pilipinas still has a small presence on the shortwave bands with the following schedule:

To the Middle East in English and Tagalog from the Tinang relay site (250 kW)
0200-0330 on 15640, 17700 and 17820 kHz
1730-1930 on 9925, 12120 and 15190 kHz

73 and have a great weekend everyone!

Rob Wagner VK3BVW

Rob Wagner, VK3BVW, is the author of this post and a regular contributor to the SWLing Post. He also blogs at the Mount Evelyn DX Report.

Tecsun PL-680: Just How Sensitive is This Radio?

More than two months ago, in the Mount Evelyn DX Report I posted a review of the Tecsun PL-680 portable receiver, entitled Tecsun PL-680 Beats Expectations. In that article, I pointed out many of the positives and a few of the flaws surrounding the unit. At the end of the review, I promised I would do some sensitivity tests on the radio.

Well, I finally got around to completing the tests, and the results are in. Below is a YouTube video showing a practical demonstration of the receiver’s capabilities in this area of performance.

The portable Tecsun PL-680 receiver is a hot little radio! As these tests show, it appears to be very sensitive to weak signals. Here, we put the little 680 up against one the best HF transceivers on the market today – the Yaesu FTDX3000 transceiver. The receiver in the 3000 is quite brilliant! And it has all the “bells-and-whistles” to make it even better at digging out weak signals and reducing adjacent channel interference.

However, in these tests we turn off all the fancy facilities on the FTDX3000 and just run the two receivers side by side to see how the 680 compares. We use the same antenna and we plug both radios into the same external speaker, adjusting as close as we can to equal volume and tone quality. We select a variety of shortwave broadcast stations over a range of frequencies from the 60 through to the 16 meter bands. I think you’ll discover that the Tecsun is really a very good performer when it comes to sensitivity!

My Tecsun PL-680 Beats Expectations review in MEDXR is an updated version of a column I wrote for the August issue of The Spectrum Monitor magazine.

As always, your feedback is much appreciated.

73 and good DX to you all,

Rob Wagner VK3BVW

Rob Wagner, VK3BVW, is the author of this post and a regular contributor to the SWLing Post. He also blogs at the Mount Evelyn DX Report.

How to Identify Changes in Station Schedules

The shortwave bands are in a constant state of flux. And radio reception varies with the seasons. As a result, radio stations often need to alter their frequencies and times for best all-year-round reception at the listener’s location. There are two seasonal changeovers: the “A” transmission period coincides with the northern hemisphere summer (March to October), and the “B” transmission schedule for the winter period (October to March). Leading up to these changeovers, broadcasters plan their schedules for the coming season. The B16 transmission season began last weekend.

Want to improve your understanding of shortwave propagation characteristics? Study a few of the strategies employed by broadcast engineers at international radio stations during the twice yearly schedule changeovers. You’ll quickly learn much about how it all works!

Frequency changes by international broadcasters allow you the opportunity to observe the factors that come into play at BOTH the transmitter site and the reception target zone in another part of the world. Broadly speaking, we know that when winter arrives reception of the higher frequencies declines and the lower frequencies provide better reception. The reverse applies in summer – reception on the higher frequencies are enhanced and ionospheric absorption of signals increases at lower frequencies.

In addition, these characteristics change for both daytime and nighttime reception in summer and winter. Furthermore, some interesting reception opportunities occur in certain regions of the world during the summer and winter equinoxes. On top of this, factor in the 11-year sunspot cycle and the current monthly smoothed sunspot number (SSN). So, station engineers have quite a few variables to consider while selecting their preferred shortwave bands when targeting their signals to the listener’s location in some other part of the world! Perhaps one could even consider that these calculations as both a science and an art!

hfcc-big-logo

Next, the engineers representing each station have to sit down with their colleagues (competitors?) from other broadcasters and negotiate suitable frequency allocations in each of the preferred bands. This is why we have the existence of the High Frequency Coordination Committee (HFCC). Working together to find and register suitable frequencies that don’t interfere with other transmissions is an important part of successfully ensuring that everyone “wins”. The HFCC describes its role this way:

The main objective of the HFCC is to provide the representation and services for the promotion of an efficient and economical use of the short-wave radio spectrum, and the improvement of radio reception of shortwave broadcast transmissions worldwide……

HFCC’s main activity is a direct coordination of frequencies among frequency managers and specialists of broadcasters, administrations, transmission service providers and other organisations with the aim to facilitate the resolution or minimisation of mutual interference on short waves…..

Membership of the HFCC is open to all individuals and organisations that provide frequency management and planning for recognised shortwave broadcasters.

And it has to be said that the HFCC does a very good job at trying to resolve potential conflicts and clashes in frequency registration. But we didn’t always have this informal governing body. HFCC was only formed in 1990. Prior to that, there was much “rough and tumble” as stations tried to sort it out for themselves and avoid getting in each others way. Remember also, in the 1970s and 80’s there were many more shortwave broadcasters than there are today, each with very large operating schedules. For younger readers here, imagine the international bands being six or seven times busier than they are today!

Understanding propagation characteristics, frequency allocation, antenna beam headings, different time zones and many other aspects of international broadcasting have been a source of fascination for me, both as a shortwave listener and as an amateur (ham) radio operator.

Here are some things to consider when monitoring the change in transmission seasons:

    • Learn the basics of shortwave propagation and the characteristics on display over a 24-hour period, seasonally, annually, and within the sunspot cycle. It’s a big topic and takes a while to really absorb it all!
  • Familiarise yourself with which part of the spectrum the broadcaster can be expected to successfully utilise during a certain season.
    • When finding a station on a new frequency (NF), try to locate and note down the formerly used frequency. Sometimes, that same station will return to the deleted frequency at the start of the next season (the next half of the year).
    • Noting the deleted frequency often reveals that another station has taken up position on that channel.
    • Check to see if the same transmitter site is used for the NF. With so many stations using a variety of relay sites these days, you cannot just assume that the same relay is being used for the NF as it was for the old frequency.
    • Some station schedules are complicated and can be hard to decipher. Time changes, language changes, an increase or decrease in the number of frequencies the station employs for a particular service, daily broadcasts, weekends only, weekdays only, or only certains days of the week can make it tricky to reveal how the NF relates to the old frequency. Expect that you might sometimes get it wrong!
    • A few stations (e.g. China Radio International or Radio Free Asia) use so many outlets for some broadcasts that it can be too hard to tell what was the replaced frequency. In those cases, I just throw up my hands and move on!
  • Maybe the target location of the broadcast has changed. Checking the transmitter’s azimuth beam headings can help here.

Like other “old dudes”, I have spent many years observing and documenting the schedule changes of shortwave broadcasters. This is a part of the hobby that I personally find quite absorbing. However, I’m aware that it’s probably NOT something that some others might enjoy quite so much!

Since the B16 changes came in one week ago, I have been busy monitoring the bands to find the NFs and the deleted frequencies (the ex’s) and any other variations to the broadcasting schedules of each station.

There are HUNDREDS of changes to discover. But I can’t find them all – I also have to eat, sleep, and get on with life!

However, here is a list of the 93 observations I have made over just the past few days:

NOTE: Frequencies in kHz, Times in UTC
ABBREVIATIONS: NF = New Frequency, ex = deleted frequency, QRM = interference, // = another or parallel frequency used at the same time, As = Asia, SEAs = South East Asia, etc. Af = Africa, WAf = West Africa, etc. Eu = Europe, EEu = Eastern Europe, etc. NAm = Nth America, ENAm = Eastern Nth America, etc. Oc = Oceania
FORMAT: Freq – Country of Transmitter site – Station Name – Transmitter Location – comments.

5885 NTH MARIANA IS. RFA – Tinian. Korean to EAs at 1710, NF and good signal, Nov 4.

5910 OMAN. BBC – Al Seela. S/on 1700 in Dari to SEAs, NF, good signal, Nov 4.

5955 ROMANIA. RRI – Tiganesti. Italian to SEu, 1715, NF (ex 5910) and fair signal, Nov 4.

5965 NTH MARIANA IS. RFA – Tinian. Mandarin at 2030, NF and heavy jamming, Oct 31.

5970 TURKEY. VoT – Emirler. French to Eu, 2035, NF (ex 9635), fair signal Oct 31.

5980 TURKEY. VoT – Emirler. Turkish to Eu 2005, NF (ex 9460), good signal, Oct 31.

5990 ROMANIA. RRI – Galbeni. Romanian to Eu, 2040 to s/off 2100, NF (Believed to be ex 9500), good signal, Oct 31.

6010 CHINA. CRI – Urumqi. S/on 1800 in Amoy (Min Nan Chinese), NF (ex 13700) fair signal but QRM from Korean jamming on 6015, Nov 4.

6025 IRAN. VOIRI – Sirjan. German to Eu at s/on 1720, NF (ex 9660), good signal, Nov. 4

6040 CHINA. CRI – Urumqi. Russian to EEu at 1745 to s/off 1757, NF (possibly ex 11875 for this txer site) and excellent signal Nov 4.

6050 TURKEY. VoT – Emirler. English to Eu at 2015 to s/off 2025, NF (ex 9785), fair signal, Oct 31.

6060 IRAN. VOIRI – Zhaedan. Arabic to NAf at 1802, NF (ex 7285), fair signal, Nov 4.

6070 CHINA. CRI – Beijing. Russian to EEu at 1815, NF (ex 9560), very good signal Nov 4.

6090 OMAN. BBC – Al Seela. English WS to CAs and ME, 1820, NF (ex 7375), good signal and // 6195 also heard via Al Seela, Nov 4.

6100 CHINA. CRI – Beijing. English to Eu at 1800-1900, NF (ex 9600), excellent signal and // 7405 (via Beijing) which is also a NF and well heard on Nov 4.

Click here to continue reading the remaining 78 new frequency observations

 

2016-shack-part-shot-3

Part of Rob’s shack. Top Row: Two power supplies. Middle Row: Bose powered speaker, Kenwood R5000 receiver. Bottom Row: Kenwood TS2000 transceiver, Yaesu FRG100 receiver.

Rob Wagner, VK3BVW, is the author of this post and a regular contributor to the SWLing Post. He also blogs at the Mount Evelyn DX Report.