Shortwave – Page 3 – Engineering Radio

Speaking of Radio…

I was talking to a friend from Russia about history, my job, and various other things that are going on in my life. I received this reply, which I thought was interesting on a number of levels:

I’m glad we are on the same page about the era of the ‘cold war’. We were interested in your life even more than you in ours. We had almost no sources of information except for ‘The morning star’ which is a newspaper of the Communist party of Great Britain. The Voice of America and the Liberty (or Freedom, I have no clue because for us it was ‘RADIO SVOBODA’) were extremely hard to tune on. All foreign broadcasts were jammed. So to listen to the station you should maximize the volume up to the limit which was dangerous. Soviet houses are not at all soundproof and your neighbors could easily rat on you. Since that time I’d been dreaming of a small radio with could receive a clear signal from abroad. Of course we have the Internet broadcasting now but they often use old recording instead of live air and the signal depends on your data carrier. You should be online, you should have an app and unlimited data on your contract, your phone should be charged all the time. Too many conditions. Unfortunately a lot of foreign sites are banned here and the trend is to make this number bigger and bigger.

I find that perspective interesting. We take for granted our ability to listen to information and listen to different points of view, even those we don’t agree with. There are still trouble spots in the world and some people are not as fortunate. It is very easy to block internet traffic and there are several countries that currently block access to some or all of the internet, for the safety of their citizens, no doubt. Ideas are dangerous.

VOA/RFE transmitter site, Biblis Germany. Photographer: Armin Kübelbeck, CC-BY-SA, Wikimedia Commons

In the last ten to fifteen years, many large government shortwave broadcasters have reduced or eliminated their programming favoring an internet distribution model. This is a mistake. It is very difficult to successfully jam terrestrial radio broadcasts. Shortwave Facilities are expensive to develop and maintain, there is no doubt about that. However, as the Chief Engineer from Radio Australia (ABC) once told me “HF will get through when nothing else will.” Ironically, ABC has eliminated its HF service on January 31, 2017.

It seems to me that a sort of “Shortwave Lite” version of broadcasting might be the answer. Use more efficient transmitters with lower power levels closer in to the target areas. Such transmitters could be coupled to rotatable log periodic antennas to target several listening areas with one system, thus greatly reducing the number of towers and land required. Solid-state transmitters with a power of 10-50 KW are much, much more efficient than their tube-type brethren.

DRM30 (Digital Radio Mondiale) has not gained widespread use in the MF and HF bands. Like its HD Radio counterpart, the lack of receivers seems to be one of the adoption issues. As of 2017, there are only four DRM30-capable receivers for sale not counting software plug-ins for various SDRs. That is a shame because my experience with DRM30 reception has been pretty good. I have used a WinRadio G303i with DRM plug-in, which set me back $40.00 for the license key (hint for those nice folks at the DRM consortium; licensing fees tend to quash widespread interest and adoption).

CFRX, Toronto coverage map, average HF propagation conditions

Finally, I have advocated before and still advocate for some type of domestic shortwave service. Right now, I am listening to CFRX Toronto on 6070 KHz. That station has a transmitter power output of 1 KW into a 117-degree tower (approximately 50 feet tall) using a modified Armstrong X1000B AM transmitter netting a 15-32 µV received signal strength some 300 miles away. That is a listenable signal, especially if there is no other source of information available. The average approximate coverage area for that station is 280,000 square miles (725,000 square kilometers). That is a fairly low overhead operation for a fairly large coverage area. Perhaps existing licensed shortwave broadcasters should be allowed to operate such facilities in domestic service.

The point is before we pull the plug on the last shortwave transmitter, we should carefully consider what we are giving up.

Something fun

So, I ~~spent~~ wasted several hours on this SDR website over the holiday weekend:

This is a web-based SDR hosted by the University of Twente in Enschede, Netherlands. I enjoyed listening to the European medium-wave and short-wave stations available. Something that is always fun to check out: UVB-76 on 4625 KHz.

Have fun!

PS: A special thanks to all those who have donated to the cause via the donate button on the upper right sidebar. I had enough money to buy a FUNcube dongle SDR. I think I have all the other necessary hardware to launch one of these sites myself. If or when that happens, I will post a link here.

Those Shortwave Sites

It is a joke circulating in Russia at the moment. Kind of funny when you think about it.

In light of the developing situation in Eastern Europe, it may be wise to retain some of those HF broadcasting (AKA Shortwave) sites. It may be too late for Canada, however, the US government still has a few high-powered HF sites that they may want to hold onto for a while. There are several ways that shortwave broadcasting can be beneficial.

Like all radio broadcasting, quality content is needed to attract listeners. Most of what is available on shortwave are religious or transparent government propaganda. There are exceptions to this, but they are rare. Introduce quality programming, and shortwave listenership will increase.
DRM 30 (Digital Radio Mondial) is still in its experimental phase. It has been demonstrated to work reasonably well on HF. Several digital data formats are successfully being used on HF; HFDL, ALE, STANAG 5066, PACTOR and others. DRM 30 has the advantage that H.264 video can also be transmitted.
The VOA has been experimenting with images transmitted via MFSK, AKA the “VOA Radiogram.”
HF is always susceptible to changing propagation. However, it can be reliable enough, especially when frequency diversity is employed, to overcome these issues when no other method of communication is available.
DRM and MFSK can be decoded using a simple shortwave radio and a computer sound card. A DRM CODEC is required, but those are readily available for download.
Analog shortwave broadcasting using AM is still viable. AM has the advantage of being extremely simple to receive and demodulate. Simple receiver kits can be built and run on 9 volt a battery.
While the Soviet Union had an extensive jamming network, those sites have long since been non-functional. Most countries have discontinued the practice of jamming with the exception of China, North Korea, Cuba, and perhaps some countries in the middle east (the usual suspects).

Sample of DRM reception via shortwave:

If the internet is censored or somehow becomes unavailable in that part of the world, shortwave may be the only method to convey an alternate point of view.

Hopefully, things will settle down and return to at least a civil discourse. However, it never hurts to have a plan.

Horby and Solvesborgs transmitter site

This is a video of Radio Sweden’s shortwave and medium-wave transmitter sites:

Håkan Widenstedt at Hörby and Sölvesborgs Transmitter sites from HamSphere on Vimeo.

This was filmed in 2006. In 2010, Radio Sweden ceased broadcasting on medium and shortwave, thus I believe ~~these sites have~~ Horby (HF) have been dismantled. Medium wave installation Solvesborg is visible starting at 15:30. Two tower directional array 180-degree towers with 600 KW carrier power. Quite impressive.

There is an effort to at save the Solvesborg site, perhaps as a museum.

Transmitters were in Skane, Sweden:

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h/t Shortwave Central