Today, we’re going to turn you into a competent basic radio operator. It may be a much longer report than usual, but it’s a four-day weekend for many, so what the hell, right?
Much of this morning’s discussion will apply to radios other than the ATS-25 (and its many variants) that may be purchased on eBay or via Amazon. The biggest part of any “radio success” is always the operator, closely followed by the antenna and time of use. After that, dumb luck figures in, too. Bringing up the tail-end is the actual radio itself.
HF radio bands begin at 3 MHz and span upward to 30 MHz. Above this, you get into VHF, and over 300 MHz you’re into UHF. The part below 3 MHz down to the bottom of the AM broadcast band is the Medium Wave (MW) band.
The lower bands tend to be noisier, especially in the summer months due to heat lightning. Winter nights though, bands quiet down. Working DX (distant) stations is extremely enjoyable here. Summers are fun, too. However, you’ll be using the higher bands (above 5-6 MHz) most of the time during daylight.
In the winter, even a moderate receiver on the low bands with average sensitivity (-125 dBm for example) can be satisfactory. On the high bands, manufacturers know sensitivity and selectivity matter. So, the extremely good (many times the price of an ATS-25) professional grade receivers will sniff down to as low as -146 dBm. Exotic preamplifiers and high gain (Yagi or dish) antennas rule up in the VHF region where line-iof-sight and noise figures become a preoccupation.
But I digress. Put your ears on now and pay attention. We’ll begin with the basics first….
An Operational Context
As an aware human, you no doubt realize there is a solid chance the world could blow itself to smithereens any second. Or, one of the belligerent nations (which sadly includes us) could decide pre-emptively to launch cyber warfare with the objective of taking down the Internet.
These are not simple “prepping problems” to address.
Nuclear War prepping includes reading Kearney on Nuclear War Survival Skills ($1.99 on Amazon for Kindle). Cyber warfare involves having a workable strategy to ensure you can pay your bills, put a little food on the table, and pay property taxes, all while defending yourself and loved ones from…whatever.
Regardless of the way Future unrolls before us, the “high ground” is Communications. We cannot navigate the coming shit storm unless we have a pretty good idea where the adversaries are, who’s planning what and have skills to minimize our risks.
Strangely, most people seem to get more excited about “talking on a radio” than learning the art of concentrated, focused, listening with intent.
There’s a great deal of focus here on the “art of electronic intelligence” (including how to design and build your own home intelligence platform) in the Peoplenomics archives.
Before we get into specifics of owning and using a reasonably inexpensive shortwave (and more) receiver like the ATS-25, we need to begin with our contexts and from this evolve our “use cases.”
Planning for Calamity
A reader scolded us recently for spending so much time on global affairs. “People are much more likely to suffer from a hurricane coming ashore, extreme weather like tornadoes, and even perhaps earthquakes.” Which is absolutely correct. But just one (rare) world war could be terminal.
Which is why the shortwave (and other band) radios are really your third (and maybe fourth) lines of defense.
The first line of electronic defense is the “electronics in front of you.” This includes your phone being set up to receive push notifications from one of the weather sites and even going so far as to also follow one or two news channels. Not long bursts of talk shows, or anything like that. No, just the short two- or three-minute news summaries that typically roll by on AM news stations at the top and bottom of each hour. Basic awareness.
In the car, where we assume you don’t text and drive, there’s the car radio. Have you deliberately filtered all the stations in your area down to the one (or two) that have the best news, traffic, and weather? Days and nights? Summer and winter? Sometimes, one station in a big metro area is great in the morning commute but manages to get sucky in the afternoon.
With the phone/LT/car sorted out purely for their information content, the next prepping/survival radio is a competent NOAA All-Hazards Radio. This should be in use 24/7 in your home. Plugged into the wall, of course, but also checked for battery back-up twice a year when checking your home’s smoke/fire detectors.
These are just some basic competences in living a survivable lifestyle, but like they say in football: Most of the game comes down to “blocking and tackling.” Having a home/family meet-up plan is another “should be basic” concept to have ironed out.
Constructing a Gap Analysis
This may seem a bit pedantic – since I will be teaching you how to set up a competent radio monitoring plan – but I can’t count the number of people who “fall in love with the idea of a thing” and promptly waste their whole investment of time and learning because of boredom.
An aside here:
Living on my sailboat for more than a decade, it always struck me that typical “stink potters” (powerboaters) would get into boating for a few years and then get out of what’s a wonderful hobby. The reason, near as I could figure, was that over time, spending all that time on the business end of a varnishing/brightwork brush, applying several coats isn’t what they thought boating would be all about.
Which is why, on Friday’s after work, I’d be off on a fresh adventure (new port every weekend) while the typical short-term burnout candidates were sanding teak. It was really quite remarkable.
Now we get to the point: If you are going to get into serious radio use, the “Number-One Thing” is to have an idea about what you want to listen to.
In this article (and another follow-on piece on setting up a software defined radio – SDR) the very FIRST agenda item is having a plan to gather specific information.
Before setting up the radio (plug in the USB-c cable and get it charging while you’re reading) we need to share basics of how the radio bands work.
The radio spectrum evolved from very low frequencies – with long antenna wavelengths up the spectrum to very (even super and ultra) high frequencies – with shorter antenna wavelengths over time.
All of these frequencies behave in specific ways of great importance to us. First, all antenna lengths are variations of the formula for a radio half wave [468 / frequency in MHz.]
Knowing that I hang out on 3.806 MHz on holiday mornings, you can calculate a good half wave antenna length would be [468/3.806 MHz.]. Rounds off to 123-feet.
Now, we split this half wave antenna in half, stick an insulator in the middle of it, and connect one side to the center conductor of the radio antenna port. Two quarter waves. The other side, grounding the coaxial cable’s shield to the radio chassis, should yield very useable results. Two 61.5 foot quarter wave wires comprise a half wave dipole. Simple.
Well, except it’s not. The reason that AM radio bands require much taller towers is simply because the divisor gets to be smaller. At 1500 KHz on the AM band (which is 1.5 MHz when you slide the zeroes…) the “quarter wave vertical antenna” becomes ½ of [468 / 1.5]. A vertical stick about 156-feet tall.
Now let’s consider a station toward the low end of the band. WLW is in Cincinnati, Ohio at 700 KHz. Sliding the zeros, that’s 0.7 MHz. So an ideal quarter wave length tower for them might be 334-feet! Literally, you can drive around the country and get a good estimate which end of the radio dial a local station is on, just eyeballing the height of an AM tower!
The higher the radio tunes in frequencies, the shorter good antennas become. At 100 MHz on the FM band, a quarter wave antenna is down to 2.34 feet, or about 28.1 inches.
This actually brings us to a key switch on the back of the ATS-25: The one that says FM in one position and everything else in the other. If you’re unable to get anything to be heard, check that the switch is in the correct position. And even then, manufacturing does make mistakes now and then, so try both positions and use the one that works best.
Build A Listening Plan
We’ll start at the lowest end of the spectrum and work toward higher frequencies as we go. What we’re after are radio frequencies that MIGHT be useful in an emergency.
Longwave Band: Once upon a time, the longwave bands (30 KHz up to the bottom of AM Broadcast band) was useful for radio direction-finding. Aircraft NDBs (non-directional beacons) are still audible here if you’re near one.
The easiest way to find local NDBs is to visit Airnav.com. Since we live near Palestine, Texas (airport code KPSN) the NDBs near us come up as:
NDB name Hdg/Dist Freq Var ID
CROSSROADS 141/21.3 215 02E CSZ -.-. … –..
PYRAMID 095/25.5 418 06E PYF .–. -.– ..-.
Now, as long as you’re on the local (to you) airport page, there are some additional frequencies to make note of. These will not apply to the ATS-25 (first receiver) users. But if you graduate to an SDR (software-defined radio) this gets to be really useful stuff to have on hand.
The ATIS or AOWS frequency is useful. The Airport Terminal Information System or Automated Weather Observing System. Which (for us) is AOWS on 118.025 MHz. The tactical use here is 24/7 local weather via radio. No internet needed!
The second VHF radio frequency – which will matter when we get into SDRs in a week or two – is the regional Air Traffic Frequencies used by the FAA. Three-quarters of the way down the page for us (here: AirNav: KPSN – Palestine Municipal Airport ) you will find the IAPs. Instrument Approach Procedures. These are the useful parts:
On one sheet, you know where to call up live weather from the automated weather, who to call (“Fort Worth Center this is Beech…“) once airborne and what the local Unicom frequency is. Unicom is where plane-to-plane and plane-to-ground is worked at untowered airports. Going too fast for you?
Close the “future frequencies to keep” notebook, we’ll get into a ton more in the SDR project.
For now, let’s stay focused on the ATS-25 capabilities. It’s basically a low band radio, except for the FM broadcast band. We’ll do the VHF bands when we get into our mini school on SDRs.
AM Radio Band
Long-time reader William of Radio Ranch was kind enough to share a handy one-page summary of many of the so-called clear-channel AM radio stations that you may be able to home in on with an ATS-25 and a basic 25-75 foot single wire receiving antenna.
Click here to download it.
Ham and Shortwave Bands
All of the ham radio bands are listed in the American Radio Relay League Band Plan chart here.
In addition, whenever there is a big emergency – like a hurricane coming ashore, for example, or after an earthquake – the ARRL will put out advisories as to emergency nets that will be meeting to pass traffic (like health and welfare inquiries for people unable to communicate via normal methods).
There are several key things about the ham bands that are useful.
First is understanding the basic modes of reception. You will no doubt already know that AM means amplitude modulation. But SSB – single sideband – may not be as familiar.
The way SSB works is pretty cool: You take a signal (like in AM where there is a carrier at the center of the transmission) and then you either filter or phase out the modulation on one sideband and while you’re at it, the carrier is also balanced out.
This is why single sideband has 8 to 9 times more “talk power” than an AM signal. It’s just very efficient and only utilizes less than half the spectrum compared to wider AM.
The hip shot here is on frequencies below 10 MHz, or so, convention is that LSB – the lower sideband is used. While on higher frequencies, like the 20-meter band around 14.3 MHz, you’ll hear only upper sideband typically. The 40, 80, and 160-meter bands are typically lower sideband when listening to hams.
There will be marine and commercial stations below 7 MHz that us upper sideband. This is something of a convention of the ITU – the International Telecommunications Union.
The latest models of the ATS-25 may also have a Morse decoding routine written in. For this, adjust the radio (using the attenuator function) to prevent overloading. Distortion from overpowering the antenna will garble copy.
Last, but not least, give a try evenings on the 3985 KHz/ 3.980 area and look for some of the AM fone nets still going on. Extremely different sound than the SSB nets. The AM Forum – Index (amfone.net)
Also bookmark the ARRL ham net search tool here: ARRL Net Directory Search. NTS is the National Traffic System.
Select Military Frequencies
While WoRR and I might drop ears onto Hickam Field, now and then, a much more in-depth summary of military HF SSB is found here: Top 100 Military Shortwave Frequencies (ik4hdq.net).
HF Weather Fax Frequencies
Here’s another one to file away for possible future experiments: With an inexpensive sound card adapter – push the audio coming out of the ATS-25 headphone jack into a sound card line in – can be used to drive your computer. When you hear warbling sounds and it’s not in the ham bands, may you can find it in here: WORLDWIDE MARINE (weather.gov). These are mostly WeFAX.
Once you have the audio coming to the computer? We’ll get into that after we get the radio fired up. But where?
Shortwave Listening Guides
Several good websites where manufacturers have searchable guides:
In addition, several good websites to look through:
As if we don’t have enough to keep our ears and eyes going, click over here and copy over to a local file the list of CB radio frequencies. CB Radio Frequencies and Channels | Right Channel Radios This can be entertaining, at times. (Children’s Band we called it…)
Times to Listen
The shortwave bands operate very differently depending on time of day, time of year, and even where we are in the Solar Cycle.
At the clock level, the higher frequencies work best in the daytime, say 10-12 MHz and higher. Night time, the lower frequencies begin to bounce off the F2 layer better, so the frequencies from 8 MHz and lower (even to the bottom of the MW AM broadcast band in winter) are where the best “radio station fishing” will be found.
Setting Up Your Radio
The first step is to get it charged up before using. Honestly, I just tossed mine on the charger workstation in the shop where we can charge literally anything…
Give it a couple of hours to charge, but this is time you can spend devoted to what kind of antenna to use and your frequency list with listening plan.
A “get started” antenna can be any old piece of wire, 20-feet or longer plugged into the antenna port of the radio. To make life easier, for a buck or ten you can get a BNC connector (the type on the back of the radio is a BNC female) into which you plug in a BNC male connector test lead. This gives you alligator clips to try on whatever is metallic and might work as an antenna.
My friend Jeff is always in the Strange Antenna Contest and he’s not only transmitted on railroad tracks and an Army tank on display at the local Guard HQ but lots of other places as well. Even a barbed wire fence (not electric!!!) will work dandy. If it’s metal, it’s a potential antenna.
The Amazon part for the preassembled connector is BNC Male to Alligator clips. Until it shows up, just stick one end of 20-feet of whatever wire in or alligator clip something onto the whip antenna.
That little whip looks OK, and it works on the FM band. But, for much better lower band performance, get a longer antenna into the radio.
With the antenna plugged in, at last, the moment of truth arrives. Will you hear anything?
Power Switch is on the back.
Make sure the antenna switch is in the correct position for what you wish to listen to:
Power will come up (after a boot version message) and look similar to this:
A sharp ham radio sort will see how this radio is set up: For listening to low-speed Morse code (CW stations) that might be working around the 14.050 calling frequency for the SKCC and FISTS code preservation groups gather. 14.049 is toward the lower end of the 20-meter ham band.
Their frequencies are dandy places to find good, hand keyed, Morse.
Some Notes from the Manual
My radio came with a manual, whip antenna, and a stylus to push the touch screen. You’ll want to keep the stylus around, since if you have big fingers (or like me, you’re “all thumbs”) it reduces errors.
Notice in the picture above I have the bandwidth set to 1 KHz? Listening to voice *(up in the phone portion of the ham band) I’d open that to 2.2 or 3.0 KHz. If you don’t, the bandwidth is sharp enough that voice can become harder to understand.
Listening and Tuning
The “normal” mode of the radio when first booted up has the receiver’s big knob in tuning mode. Press in on the knob and it will then control the volume. Another press (after adjusting the volume) will get you back in the “tuning” mode.
As the manual explains things:
“1.VOL: press “VOL” to adjust audio volume using encoder, press VOL again to exit.
2.Mute: press “MUTE” to activate mute radio.
3.Preset: press “PRESET” to activate, select using encoder Fm stations pre-recorded in skech. when there are no stations programmed and ignored, press “AGC to exit.,” (this read oddly to me…Is this how they describe the preset memory for bands?)
4.Step: press “STEP” to activate. It only works on MW, SW and LW frequencies. You can select the frequency step in Ikhz, Skhz, 9khz and lOkhz. Once selected to go back to the previous step, press “STEP” again and choose your preference.
Pick smaller steps for SSB and CW/Morse/Data use.
5. Mode: press “MODE” to activate, select the type of modulation in the MW, SW and LW ranges, it can be LSB, USB or AM. Not work when FM active.
6. Ham: press “HAM” to activate, select the reception bands with LSB or USB. to exit press “BROAD” and choose the track without “HAM”.
7. Broad(broadcasting}: press “BROAD” to choose FM, MW, SW and LW band.
“Ham” is self-explanatory. MW refers to the Medium Wave band – nothing more, or less, than the regular old AM radio band. SW gets you into the preset ranges of the “normal shortwave bands” and in the evenings late this time of year, the 39 and 49 meter bands can be interesting.
Although these are ATS-25 instructions, generally the same names or control conventions can be found on most SW radios.
A Short Course on Noise
Shortwave radios like this are prone to noise. Not so much because of their design (which isn’t bad, save a few bits of mechanical instability, but still way better than what any of us grew up with) but because modern home electronics generally suck. Most people’s lives are online streaming, on FM radio, or coming in on cable, AM radio has been left as a kind of poor bastard child to the more “modern media.”
The main noise culprits are generally anything that uses a triac, SCR, or PWM controller. Dimmers for the lights can be deadly to enjoyable listening. Good Hack-a-Day post over here The RFI Hunter: Looking For Noise In All The Wrong Places | Hackaday will aid you in your search.
Best, cheap, noise detector is a dollar store transistor radio, tuned to the high end of the AM radio band and turned up so you can hear static. Walk around the house and hold the radio’s built-in ferrite loop antenna this way and that. If the noise is getting louder, you’re probably getting closer to a noise source. Turn things on and off, adjust the lights, and so on till you find the culprits.
Be sure to turn the radio while you’re RF sniffing, though. Ferrite loops are highly directional. After all, they’re at the core of all those old radio direction-finders.
60-years ago, my late mother was always courteous when I was working DX (distant) stations on my basement radio set up. She had an old Kenmore Sewing Machine with a foot controller that – I swear – would blow your ears off, if you weren’t expecting it.
More Modes? Download FLDigi
This is a cross platform digital decoding program available open source. With minimal cobbling, you can run a little audio from the ATS-25 into your computer soundcard, diddle with the levels and get capable not only of getting WeFAX forecasts, but also pull in all those hams on PSK-31, Morse (there’s a converter in FL-Digi), radioteletype, and more. (See how the radio is really getting some “legs” under it here?)
Since the ATS-25 has a small “waterfall display” a visit to the people behind FL-digi’s short course here might pay handsome dividends: Sights & Sounds (w1hkj.com).
Otherwise, the download page for the app is: fldigi download | SourceForge.net. Skip most of the setups (like your name and callsign and such as you won’t be transmitting with an ATS-25!) and just concentrate on the IO and getting comfortable with the modes.
The idea is simple: Take the audio out from the ATS-25 and plug it into the “Line In” sometimes called the “Aux In” on your sound card.
The most useful starter modes are likely PSK-31 (try 14.070-14.075 in USB) and also FT-8. There is a Morse reader in FL Digi, as well. Manual speed tuning of the CW reader speed is often needed. Go back to the “sights and sounds” link to practice your ear a bit and it will reduce guesswork.
The process is: Tune in to a digital station with headphones. Not too loud.
Then unplug headphones and use a 3.5 male-male cable into the sound card.
Begin FL Digi session. Adjust FLD for mid range level using your computer’s sound mixer control settings. With a good balance, you should be able to copy many stations. IF you overload the soundcard, it will be a great time sink. In digital work, it’s the quality of signals, not how loud, that matters.
An Oddity for the Road
One last point – and it’s a kind of pet peeve of mine. Insulation. Yes. In-the-wall insulation in your home can be a radio shielding material. America went through a phase, a decade (maybe two) back when all the good custom homebuilders were using foil-faced insulation.
Sure, it kept a little additional heat in (reflective to infrared at some level) but the devil of it was the AM radios in homes no longer worked as well. With weak signals, and aluminum facing didn’t help, the eventual replacement of the AM radio stations by less noise prone sources was all but assured.
This still plagues certain homes (and even office tenant improvements from the period) and the hint in this direction is routers have shitty range and you end up putting Wi-Fi extenders or going mesh.
Ah, progress, right?
There, have fun. With a little practice, the ATS-25 can be a real joy to play with.
And if the you-know-what hits the fan, you’ll at least be able to hear what hams and far-distant radio sources are telling of what has happened. Assuming someone is left, mind you. Put the movie “On the Beach” on your rewatch list.
HF will be down – mostly out of commission – for up to a week, and perhaps longer, after an initial round of nuke lobbing, due to all the ionizing radiation. Normally, though, the bands will open up again in a few days’ time. That’s when the real value of robust communications will start to shine.
Since the Fourth is a holiday, a few comments on various antenna options. For now, a piece of #22 bell wire stuck in the BNC connector and 20-12,000 feet long will work.
Write when you get rich,