Many thanks to SWLing Post contributor, Matt Blaze, for the following guest post:
Matt’s 2022 Portable Loop Antenna Shootout
by Matt Blaze, WB2SRI
Followers of this blog may be familiar with my “shortwave radio shootouts” that I post from time to time. The idea is to compare how well different radios demodulate the exact same signal. Basically, I take a bunch of radios, hook them up to the same antenna via an RF distribution amplifier, tune the radios to some distant signal, and record the audio output from them simultaneously. Sometimes that kind of comparison can be more revealing of actual real-world performance than lab measurements or technical specifications.
The other day, I decided to do the same thing, but for antennas instead of radios. Essentially, I inverted the setup. Instead of hooking up different radios to the same antenna, I hooked up identical radios to different portable antennas and recorded them demodulating the same signals at the same time.
In this first of perhaps a series of these antenna shootouts, I wanted to compare three portable amplified magnetic loop antennas. When I say “portable” here, I mean broadband antennas that can pack reasonable compactly for travel and that can be set up and broken down easily for use “on location”, say on a picnic table or hotel balcony, or perhaps installed temporarily on a roof, without too much fuss.
The antennas are:
– TheWellbrook FLX1530LN with a 1 meter diameter loop of LMR400 coax. This is my “standard” portable antenna (I use a telescoping broom handle for the support; I wrote about it here as the “signal sweeper” last year). Excellent performance, but on the bulky side for travel. Performs well from LW through HF. Not cheap, at about USD 225 including shipping for the amplifier and power injector, but not including the loop, mounting hardware, or feedline.
– The Wellbrook FLX1530LN with a 0.5 meter diameter loop of RG142 (a stiff “aircraft grade” version of RG58 that holds it shape well at this size). I used some 1/2 inch PVC pipe as the vertical support. Because of the smaller diameter loop and thinner coax, it packs down to a much smaller and lighter package than the 1 meter LMR400 version.
– The K-180WLA, an inexpensive (about USD 60) 0.5 meter loop from China, sold on eBay and Amazon. The loop is steel wire (which can be wound down to a small diameter for transport), and the kit includes everything you need, including a rechargeable power injector. (However, the power injector uses a noisy voltage booster, so I substituted my own bias-T injector for these experiments). Ostensibly covers LW through VHF, but the low end coverage is, shall we say, somewhat aspirational, as you will see.
– I also recorded, for comparison, the built-in ferrite bar (for LW/MW) and whip antenna (for HF) of the receiver.
This is, of course, only a small sampling of portable loop antennas, both commercial and homebrew. But I wanted to start with what I had on hand and with what meets my own needs. (I omitted from consideration loops that require tuning, since I want to be able to install the antenna without needing access to it every time I change frequency).
For each signal captured, I oriented and positioned each antennas to maximize signal quality, taking care to move them away from each other and interfering metal objects. So you’re hearing (approximately) the best each antenna had to offer (on my roof under suboptimal band conditions).
The receivers I used were four Sangean ATS-909×2 portable LW/MW/SW/FM/Air radios. I believe this to be the best currently available (relatively inexpensive) portable shortwave receiver on the market. It has excellent performance (and is admirably resistant to overload and intermod when used with an active antenna). It lacks a sync mode, but that’s rarely implemented well on portable radios anyway. As a practical matter, it has a good line-level output jack, and I already happened to own four of them.
As in my other shootouts, for each signal, there are a total of five recordings: a monoaural recording of the audio from each of the four antennas, plus a narrated stereo recording comparing a reference (the 1M Wellbrook) on the Left channel with each of the other antennas in succession on the Right channel. The stereo recording is intended as a quick overview, but it will only make sense if you listen in stereo, preferably with good headphones. (You can switch the earcups to get a quick comparison as you listen.)
Many thanks to SWLing Post contributor, Jonathan Marks, who notes that BBC Director General Tim Davie announced a digital strategy along with a number cuts following the BBC licence fee settlement. This was all outlined in his “A digital-first BBC“ speech to staff this afternoon.
I’ve pasted the full copy of his speech below, but regarding the BBC World Service, here is an excerpt:
“The Government’s commitment to extend its £94m annual funding for the World Service for a further three years is very welcome. But UK licence fee funding for the World Service, which has been around £254m in recent years, is now running at over £290m including World News – a level that is unsustainable following the licence fee settlement.
We will set out plans in the coming weeks for how we will initially reduce licence fee spending on the World Service by around £30m by the start of 2023/24, while protecting the full breadth of languages.
At the same time, our strategic review will identify the right longer-term model for a digital-first World Service and lay out a strong case for more investment from government over the coming years. This case for a strengthened World Service is compelling but we can only expect UK licence fee payers to fund so much.”
In addition, they hope to save £500m annually by cutting services such as Radio 4 Extra, Radio 4’s Long Wave service, and Radio 5 Live’s mediumwave transmitter network.
The Director General’s speech to staff, of course, primarily focused on being a world-class digital and on-demand provider.
BBC Director-General Tim Davie’s speech to staff on 26 May 2022
Published: 26 May 2022
Good afternoon everybody.
Today, in our centenary year, I want to set out a vision of how we keep the BBC relevant and offer value to all audiences in an on-demand age.
I will cover three things: the pressing need to build a digital-first BBC; how we spend our money now that we have the certainty of public funding for six years; and how we keep reforming the way we work. Continue reading →
Mr Grahn of https://www.grahn-spezialantennen.de/ had to stop working for a couple of months (medical reasons) but now he is back and I was able to get one of his highly sensitive Very Low Frequency modules to fit on my Grahn GS5-SE antenna tuner.
As before, the delicate device (“treat like glassware, do not throw”) was extremely well packed for its safe and intact arrival.
Many thanks to SWLing Post contributor, Bob Colegrove, who shares the following guest post:
Calculate Station Distances Using Excel
By Bob Colegrove
On occasion, I’ve wanted to know just how far away a station was from my home. I’ve never been much of a contester, but I know distance can play a part in the results. There are a number of Internet cites which let you enter latitude and longitude information and then calculate the distance across the surface of the earth. These are alright on an occasional basis, but I often wind up getting the data mixed for the two locations, and it is not handy when you want to make several measurements. Here’s a way to generate the distance from your home to thousands of stations with just a little effort.
Many years ago, armed with my faded knowledge of high school trigonometry, I used Excel to calculate the surface distance between any two points on earth. I managed to find the spreadsheet (file dated 1998) which has no fewer than 11 steps in the algorithm. Although it worked, when I came back to it a few months later to make a change, I couldn’t remember my thought process. There are Internet sites which develop earth surface calculations in highly esoteric terms and heavy-duty math. But life is short, and I wanted to cut to the chase. There are, in fact, several formula variations which have somehow managed to distill all this down to a neat single-cell calculation, and they seem to work very well.
The spreadsheet figure below is the simplest form used when you have decimal latitude and longitude data as input. The convention is to use negative numbers for the Western and Southern Hemispheres. Home is your reception location and all other locations are compared with that to determine the distances. If you’re curious, the home location (yellow cells) used in these examples is the monument marking the geographic center of all 50 US states in Belle Fourche, South Dakota. Google Maps is one easy source to determine the exact latitude and longitude of any point on earth.
To calculate the distance between any two points on earth, copy the formula below directly into a cell, then change the reference cell names as appropriate, and you’re ready to go.
$B$5 and $C$5 are the cell references for your home address (yellow in the figure above). Of course, the dollar signs indicate these data remain fixed in each calculation. B9 and C9 are corresponding latitude and longitude for the example radio station, WTOP (green). Change these four cell locations as necessary. The constant, 3959, at the end of the formula is the average radius of the earth in miles. Use 6371 if you want kilometers. The data cells in Columns D and E are populated with the formula and produce the result. These values are dynamic and can be replicated down the columns for the rest of your station location data.
Degrees, Minutes, and Seconds Format
The US FCC on-line database contains latitude and longitude tower locations for medium wave stations in Region 2, North, South, and Central America. However, coordinates are in degrees, minutes, and seconds format and must be converted to digital format for calculation of distances. The conversion process can also be done in Excel.
In this case, the inclusion of the coordinate hemispheres, N or S, and E or W is important. Whereas, the hemispheres in the decimal example were signed + or -, the inclusion of the appropriate letters here is necessary. Cell L5 reads
and cell Q5 is similar for longitude, except “W” is substituted for “S.” These formulas are then replicated in columns L and Q for each data item. Columns R and S contain the distance calculation formulas as described above. Line 14 is not necessary, but can be used to see if your formulas are correct; that is, the distance from home to home should be zero.
Let Excel Get the Information for You
What follows is for anyone tired of copying cumbersome latitude and longitude data. Unfortunately, it only works on the current version of Microsoft 365 Excel, and apparently goes off into the big cloud in the sky to instantly download the information.
Enter the town followed by either the US state, Canadian province, or other country name (Column A).
Copy these locations to the next column (Column B). The cells in Column B will become temporary geography cells. Note: As shown above, the data have already been converted to geography format (Step 4).
Make sure you have all the geography cell locations selected (Column B).
On the Data ribbon select Geography. A map icon will appear at the left of each cell, and the state, province and country will be truncated.
For the first latitude (Cell C7), enter =B7.Latitude; likewise, =B7.Longitude in Cell D7.
The formulas in C7 and D7 can be replicated down your list.
Columns for miles and kilometers (E and F) can be added using the distance formula as described above.
The geography data (Column B) cannot be replicated. If you want to add data later, you will have to reapply the geography format for the new data. Or, latitude and longitude can still be inserted manually for any additional entries. The geography data (Column B) are not needed beyond this point and can be deleted or hidden.
Note: I logged on to my first mainframe computer in September 1976 and have never ceased to be amazed at what these confounded things can be made to do. I tried as best I could to trip the system with small, obscure towns in faraway places, as well as duplicate names. I finally succeeded with a relatively large city, Ulaanbaatar, Mongolia. To be fair, I tried to get it to accept alternate spellings. So, if you need that one, you’ll have to enter it manually.
Medium Wave Example
This example is for medium wave DXers in Region 2, the Americas. It makes use of the FCC AM database at https://www.fcc.gov/media/radio/am-query. The database currently contains more than 24,500 entries, many of these are duplicate entries for stations using different daytime and nighttime powers.
Download the database as a pipe-delimited text file.
Import the file into Excel.
Create additional columns to convert the latitude and longitude data from degree-minute-second format to decimal as described above.
Add some rows above and enter your home coordinates in decimal.
Create another column to calculate the distance from home to all the stations, again using the base formula above.
Hide any columns in the FCC database that you don’t need.
Finally, by creating an Excel table from all of the data, except your home location, you can do some on-the-fly filtering.
The example below shows some of the stations near our example home in Belle Fourche, South Dakota. The Distance column on the right has a filter applied to limit the listing in the table to stations within a 150 mile radius, that is, it only lists potential daytime stations. You could also use the conditional formatting feature of Excel to highlight the same information in the unfiltered data.
The AOKI log, http://www1.s2.starcat.ne.jp/ndxc/, has listings for all of the recent broadcasting cycles, B21, A21, etc. The Excel format files are zipped for download, and include the latitude and longitude of each station. Unfortunately the coordinates are not only in degrees, minutes and seconds, but they are all mashed together in one cell for each listing. Excel to the rescue again. Select Text to Columns in the DataTools portion of the Data ribbon. This feature will allow you to divide the single column into four columns each for latitude and longitude, that is, degrees, minutes, seconds and hemisphere. Then you can use the conversion formula to change degrees-minutes-seconds to decimal. Note that the first three digits used for longitude are minutes (they go up to 180); the remaining numerical columns have two digits each (up to 60 or 90), and the hemisphere columns (alpha) one character each.
Here are a few things affecting accuracy:
The constants 3959 or 6371 used in the formula for miles and kilometers are generally accepted averages for the earth’s radius. The difference between the equatorial (longer) and polar (shorter) radii is about 13 miles.
If you are using town locations in your data, remember that the actual distance to the tower in that town is likely to be different. The FCC and AOKI data are assumed to be station tower locations.
Some decimal sources of latitude and longitude data have less resolution, which could lead to a slight error.
You’re on Your Own
You may have noticed the examples shown in the figures all have multiple station locations. My thought in doing this was provide some test for accuracy and secondly to provide a seed for developing the spreadsheet into a more inclusive log of stations. There is likely enough basic Excel knowledge among the folks gathered here, and each person will likely have an individual preference in designing a spreadsheet. Nevertheless, the spreadsheet shown in the figures can be downloaded by clicking this link.
The first sheet shows Figures 1 and 2 from this article; and the second sheet, Figure 3. The link in Cell I2 of the second sheet describes how to use the geography feature of Microsoft 365 Excel. The third sheet is a recent copy of the FCC AM database (Figure 4). To facilitate storage and downloading, only stations from 530 kHz to 600 kHz are included. Numerous unused columns from the FCC AM database have been hidden; so you can still copy the full, pipe-delimited FCC database into Columns A through AH. The FCC database has been converted to an Excel table; the Home location is not part of the table. Try substituting your own location for Home (Cells AI2, latitude and AJ2, longitude) and setting a distance filter from your home in Cell AK4. In the example, the distance filter has been set limiting the list of stations to less than 600 miles from our example in South Dakota. Note also that the Conditional Formatting feature on the Home ribbon has been used to highlight stations less than 100 miles from home.
If you have any interest in developing your own spreadsheet, perhaps you can comment on what you have done, or provide the rest of us with something I have missed. Hopefully, I have provided enough information to get you started.
Radio Waves: Stories Making Waves in the World of Radio
Because I keep my ear to the waves, as well as receive many tips from others who do the same, I find myself privy to radio-related stories that might interest SWLing Post readers. To that end: Welcome to the SWLing Post’sRadio Waves, a collection of links to interesting stories making waves in the world of radio. Enjoy!
This issue concerns High-Frequency Trading (HFT) transmissions, and three prospective stations seeking entry into the International Broadcast service.
Several stations licensed in the Experimental Radio Service (ERS) transmit data for automated trading to foreign exchanges in the shortwave or high-frequency (HF, 3-30 MHz) spectrum.
High-Frequency Trading (HFT) is a form of automated trading that employs low-latency, high-speed telecommunications to minimize response times. The term is not related to the shortwave or HF spectrum, but this article concerns transmission of HFT messages on HF frequencies.
HF signals can traverse great distances by refraction from ionized layers of the atmosphere, a phenomenon known as ionospheric propagation. Several ERS HFT stations have operated in the HF bands for years out of the public view. Bob Van Valzah blogged extensively about these stations starting in 2018.
These ERS stations’ licenses are public records, but the licensees typically ask the FCC to withhold access to station details and experimental plans. The Commission’s routine acceptance of these confidentiality requests makes public oversight difficult. [Continue reading at Experimental Radio…]
Radio Bulgaria back on shortwave
Many thanks to SWLing Post contributor, Richard Langley, who writes:
As I reported to Glenn Hauser’s group today, Bulgarian National Radio’s Radio Bulgaria is back on shortwave.
Their weekday roughly 22-minute podcast in English, called “Bulgaria Today,” is being aired by ShortwaveService from Kall, Germany, on 3985 kHz from 18:30 until about 18:52 UTC.
Today (30 January), the podcast dated Thursday, 27 January, was broadcast. The program consisted of news, COVID-19 information, weather, travel, and the “Music Slot.” Reception using the U. Twente SDR receiver was fairly good.
There is also a German broadcast before the English one beginning at 18:00 UTC. The ShortwaveService tuning signal is used to fill out the half-hour slot in each case.
Many thanks to Markku Koskinen who discovered that Icom published the following notice on their website regarding their latest firmware update to the IC-R30:
Thank you for using Icom products.
A defect was found in the IC-R30 firmware (Version 1.12) released on our website on January 13, 2022, so we are currently withdrawing the firmware.
We apologize for the inconvenience caused to users. We will let you know when there is any new firmware update information.
[For users who have updated to the IC-R30 firmware (Version 1.12)]
You can continue to use the IC-R30 as before by installing the IC-R30 firmware Version 1.11 again. Please download it from the links [on this page].
[…]We sincerely apologize for any inconvenience that we might have caused to our customers.
NEW YORK — Howard Hesseman, who played the radio disc jockey Johnny Fever on the sitcom “WKRP in Cincinnati” and the actor-turned-history teacher Charlie Moore on “Head of the Class,” has died. He was 81.
Hesseman died Saturday in Los Angeles due to complications from colon surgery, his manager Robbie Kass said Sunday.
Hesseman, who had himself been a radio DJ in the ’60s, earned two Emmy nominations for playing Johnny Fever on CBS’ “WKRP in Cincinnati,” which ran for four seasons from 1978-1982. The role made Hesseman a counterculture icon at a time when few hippie characters made it onto network television. [Continue reading…]
Many thanks to SWLing Post contributor, Uli (DB1ULI), who writes:
I started to enjoy BCL and SWL some week ago (again). I have a HAM license for many years, but was QRT for the past few years. Now, the HAM bug bit somehow again and I’ve been listening to the bands via a Tecsun H-501 but changed this one to a Reuter Pocket already.
The Reuter Pocket (Source: Reuter)
The Pocket is a really great receiver including also the FM Bands and the popular (in Europe) Digital Broadcasting DAB.
Still, it is just a receiver. So for now I am searching for a new rig, too. The current offerings are all tempting, FT-DX 10, FT-991A, IC-7300, IC-705 and so on. I really like the new models due to their features, and most due to their displays. My former rig was a Yaesu FT-897.
I already read your and the other reviews of the IC-705 (especially the BC receiving parts) and it could replace the Reuter in many ways. I am just a little bit reluctant because I like the longwave band a lot (we still have stations here) and there is no info to find anywhere how it works below 500kHz. MW seems to be on par with most other receivers.
Do you have an idea about a source of information concerning the capabilities of the IC-705 below 500kHz?
All the best and 73,
Great question, Uli. I’m hoping that some of our European IC-705 owners may be able to help you here. Although I’ve spent a lot of time on mediumwave with the IC-705, I’ve done little exploring of longwave.
Please comment if you have thoughts on the IC-705’s longwave performance!
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