MW DXing- what's the best receiver?

[Fast1eddie]

Yes. Medium wave is the AM broadcast band ranging from 540Kc to 1700 something Kc. Not certain of where the cut off is, kinda been away from that end of the hobby. You'll hear low power Department of Transportation advisory broadcasts which continually repeat, possibly some remote broadcast stuff, but don't quote me on that. AM is the reception mode, in this case it is Amplitude Modulation.

As far as the Kc (Kilocycles) abbreviation, I am old skool.

MW monitoring is fun and best done late night/dawn hours, Noise level drops significantly in the fall, winter and early spring.

Once monitored WTOP (Washington DC) from my barracks room when stationed in Vicenza Italy. Was using a Icom R70 and a long wire around the circumference of my room. Sent a QSL report in and received a neat card. Lost it in my travels years ago.

Enjoy!

 

[DennisKink]

Thanks Edward.

 

[majoco]

Please excuse me for going slightly off topic,but I have a noob question. Isn't MW the same as AM?

In short - yes. But this is because a lot of radios just mark their tuning scales "AM" or "FM" and sometimes "BC". "BC" is perhaps a bit better - standing for "Broadcast" - but the other two really means the type of modulation with no indication of the frequency.

Anyway, the "AM" band (amplitude modulation) goes from 530kHz (kiloHertz) to 1650kHz and now extends to 1710kHz in the USofA with stations spaced 10kHz apart, Europeans and others are spaced 9kHz apart. The "FM" (frequency modulation) goes from 88MHz (MegaHertz) to 108MHz over most of the world except for Japan. Station spacing is 200kHz in any particular area but you may find some stations in between if you can receive from outside the US. European radios tend to have channel numbers rather than frequencies on their dials ranging from 0 at 88Mhz to 100 at 108MHz

 

[WA8ZTZ]

Per ITU, Low Frequency (LF) or "longwave" (LW) goes from 30 to 300 kc. Medium Frequency goes from 300 to 3000 kc (or 3 mc). The AM broadcast band (AM BCB) is found in this range. In North America, the band goes from 530 to 1700 kc with 10 kc spaced channels. High Frequency (HF) which is known as "shortwave" (SW) goes from 3 to 30 mc.

Hope you liked the old skool abbreviations.
Never did understand why they took "cycle" which is something easy to visualize and renamed it hertz.

 

[majoco]

Back on topic

I know you said 'portable' but surprising results can be obtained from a good (and probably old) car radio. As long as it can be "tuned" to its antenna you may well be in for a treat! Don't be tempted just to run a bit of wire from the antenna socket, it needs the capacitance of the coax cable to be included in the RF amplifier for best sensitivity. Avoid a 'modern' digital radio as they tend to tune in 10kHz steps so you may miss any stations from outside the US.

Going back to Hertz instead of Cycles, that's another thing that we can blame the European Common Market for - and the ITU of course! They changed nearly every scientific measurement that we understood as it was descriptive into something just to commemorate an 18th century scientist! Even simple things like tyre pressures - pounds per square inch I understand, but what is a kilopascal?... and why are some of the bases so small they need a multiplier?

 

[WA8ZTZ]

Back on topic

I know you said 'portable' but surprising results can be obtained from a good (and probably old) car radio. As long as it can be "tuned" to its antenna you may well be in for a treat! Don't be tempted just to run a bit of wire from the antenna socket, it needs the capacitance of the coax cable to be included in the RF amplifier for best sensitivity. Avoid a 'modern' digital radio as they tend to tune in 10kHz steps so you may miss any stations from outside the US.

Going back to Hertz instead of Cycles, that's another thing that we can blame the European Common Market for - and the ITU of course! They changed nearly every scientific measurement that we understood as it was descriptive into something just to commemorate an 18th century scientist! Even simple things like tyre pressures - pounds per square inch I understand, but what is a kilopascal?... and why are some of the bases so small they need a multiplier?

Exactly... like Celsius for centigrade... counterintuitive. Centigrade was 100 degrees between the freezing and boiling points of water. Celsius sounds like some kind of vegetable.

Anyway, a car radio... the older the better. The newer ones just don't seem to pull in the DX like the old ones did. The new digital ones have 10 kc tuning steps which is too coarse. Analog tuning with a digital readout would be ideal such as an old aircraft ADF with a Davtron display.

 

[Boombox]

Please excuse me for going slightly off topic,but I have a noob question. Isn't MW the same as AM?

Yeah. It's generally called the "AM Band" in the US and Canada, and "MW" or "Medium Wave" in the rest of the world (or one of its foreign language equivalents). That's because in other parts of the world SW was more known or popular -- at least until the end of the Cold War. So there was more differentiation between FM, MW and SW.

Here in the US and Canada where SW was more or less unknown to the general public, "FM" and "AM" were adequate to use to identify the two main broadcast bands.

 

[WA4HHG]

The best? Probably an R390A or WinRadio G-33DDC using a Bruce Conti designed, 17 X 36' terminated Superloop. The Microtelecom Perseus is pretty stout, also.

 

[ridgescan]

If you can get hold of one of these, it is a pretty amazing little MW radio. SW FM are mediocre but very good MW. With all the higher end comms receivers and big roof antennas I have here, it's funny how this little gem can stack up regarding long distance and selectivity. Check Ebay.

 

[Lauri-CoyoteFrostbite]

Yes it is Dennis
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The AM broadcast band in the US is ~530 to ~1700Khz's, give or take a few kilohertz.
This is consider'd "MW"
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(btw- there is a "LW" AM broadcast band in other parts of the world, from ~150 to 280 Khz's)
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.Lauri

 

[Lauri-CoyoteFrostbite]

Oppps... did I stray off the topic too?
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When it comes to MW (and especially LW) I think the most important receiver is *The Antenna.*
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I come from a long family line to 'Low'fer' and am no strangers to The Big Loops (and I mean Big-- loops- ones that easily exceed'd 8 feet in diameter, resonated with large open air variable capacitors, wound with #14 copper wire.)
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Living in the UK I would listen to Radio Luxembourg on 240khz. (?) like it was a local AM- Stateside Rock and Roll station-- But it came with the help of a big loop.
Later, from the US East Coast- tuning in KOA AM 850, Denver, or KKOB 770 in New Mexico with the loops was an every- night possibility.
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The actual receiver is important- but the antenna is paramount. Build yourselves the largest, tunable loop you can rotate. The DX will take care of itself.
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Ohh ! .... but steam'd audio, I Heart Radio, Sirus XM, FTA Sat's...etc... have all made this just pleasant, passed memories.........
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Lauri

 

[Boombox]

^^^^^Exactly what Lauri said, actually.

I've DXed with Sony Walkmen using an external loop antenna and similar small radios. in 2012-2013 I did most of my DXing with a Sony WM-FX101, a small 90's era Walkman. Of course, YMMV, but any MW/AM radio with a ceramic filter and decent IF chip inside can pull in a lot of DX with a tuned external loop.

 

[jwt873]

On antennas.. I picked up a Wellbrook medium aperture loop a while back. It made a big difference. I've been using my IC-7600 for MW DX.. I was hearing fairly strong stations using my 80 meter inverted vee, but couldn't make them out because of noise on the signal.

The loop eliminated the noise and I've managed to log many new stations. The loop also works well on the NDB beacons down at 200 to 400 Khz..

 

[Lauri-CoyoteFrostbite]

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I don't think I can over emphasis the importance of a (proper) antenna for medium and longwave reception.
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Since so many L/MW enthusiasts are also radio amateurs, they do the general thinking that goes along with their Shortwave experiences... "the more wire in the air, the better"- Unfortunately this is without regards to the some unique properties of these longer wavelengths.
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For instance- most shortwave signals that are of any consequence are propagated by various forms of Skywave- The shortwave goes up, is refracted off varying layers of the atmosphere and returns a long way off. Not that this doesn't occur at Medium and Long Wave's, but the majority of the useful propagation is by Ground Wave.
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With that term Groundwave, --please don't get it confused with the popular (but mistaken use by hams) for what is consider close in HF communications-
True Groundwave travels vertically polarized along the Earth's surface, and only the 160 ham band exhibits any of Groundwave's real properties. All your local AM broadcasts are coming via groundwave during daylight. During the day, the D Layer of the atmosphere is absorbing all that skywave energy- only that which is coursing across the earth matters. However, and I am sure everyone has heard this phenomenon; as sunset begins, that D Layer begins to dissipate- Signals now start to refracted back to earth as skywaves as well. That AM station which was received so clearly during the day starts to fade in and out- the audio gets distorted- and probably won't be worth listening to again until after complete darkness. This is because of the conflicting phase angles of the Groundwave and the now slightly delayed Skywaves (returning over a bit longer path.) The station will start to 'clear up' as the now the skywaves are propagated farther and farther way from the listener as more of the D layer is dispersed-- so finally this phase distortion does not occur at the listener's location-- and other people- the DX'ers, -they start hearing it in Far Away places..
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Sorry, I did not mean to take off in propagation theory (I did my dissertation in the Long Wave sciences- Its in my blood--- can't help it I'm afraid)
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But let me bring this around to the Longer wavelength antennas. You want to receive those Groundwave signals- they can travel enormous distances , especially at the low end of the AM Broadcast band. But keep in mind, these are strictly *vertically* polarized... that's why dipoles, random wires- things anywhere horizontal don't work well...Also they aren't resonant, or so often, they aren't lying in the Groundwave's plane.
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Here comes in the Loop Antenna.... and also my lunch time---- if this is interesting, let me know and I'll try to finish up with how loops work and why they make all the difference in the world to AM L/MW listening..... mean time, a teaser- think the "windings inside a transformer...."
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Lauri
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[WA8ZTZ]

.
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For instance- most shortwave signals that are of any consequence are propagated by various forms of Skywave- The shortwave goes up, is refracted off varying layers of the atmosphere and returns a long way off. Not that this doesn't occur at Medium and Long Wave's, but the majority of the useful propagation is by Ground Wave.
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Why is LW DX so much better at night?

 

[majoco]

Less ionisation of the atmosphere means less noise and there is also some sky wave propagation too - you can usually tell because the signal has a wavering quality - definitely not to be used for navigation!.

Found this very informative pdf about DXing beacons from the UK....

https://www.ndblist.info/beacons/beacons.pdf

 

[Lauri-CoyoteFrostbite]

That's very true- during the day there are more solar noises, environmental sources like thunder and static-
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When you drop down into the really long wave lengths, those signal can course the earth's surface clear to the other side of the world! Neat stuff, No?
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Lauri

 

[majoco]

Lauri said:

those signal can course the earth's surface clear to the other side of the world! Neat stuff, No?

Definitely - when I was a sea-going Radio Officer in the 60's, the time signal from Rugby Radio on 16kHz was receivable right round to the mid-Pacific - did tend to fade out when going below the equator though.

Very interesting page here....

http://www.xeropage.co.uk/g3nyk/rugbyrs.htm

...especially the bit about antenna efficiency - right up your street, Lauri! No more LF antenna experiments in DC!

 

[Lauri-CoyoteFrostbite]

Rugby was quite a station- and that was a great article about it...
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That is an interesting phenomenon about the LW effects at the equator...I have heard about it before, too- but never explored it further.....
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I wish I had the opportunity to have visited the Rugby station while it was still in operation. I hear it went Big Time SK about 10 years ago with the demolition of its towers.
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As a teenager I remember driving past it outside the towne of Rugby- a family holiday to the Midlands... and everyone had to detour so my father and I could see the antenna arrays....
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And they were impressive!- spanning far across the countryside -- those 800 foot towers.
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Years later, and a now as a graduate student; I was invited to US Naval Radio Station NSS at Annapolis Maryland--- both shortly before and immediately after it was decommissioned. Even with its central 1200 foot tower supporting an enormous Goliath umbrella array, I thought the Rugby antennas even more awesome.
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The passing of true dinosaurs- I doubt the world will see their likes again.
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(But-- I have a "fossil bone" from one ! On the decommissioning of NSS, pieces of the huge tuning coil from its 'Helix House' were cut up into 8" pieces to be given out as souvenirs to guests. I have a piece of that multi-stranded Litz wired-cable sitting on a shelf- its countless silk wrapped strands making up a cable almost 3" in diameter)
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Lauri
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[majoco]

Lauri said:

That is an interesting phenomenon about the LW effects at the equator.

Initially I though it was just a distance thing but I wonder if it's more geometry than that. Most if not all LW stations are in the northern hemisphere including my nearest WWVB. I don't know which tropo layer reflects the low frequencies best but I wouldn't mind betting it's one of the night-time lowest - maybe there is only one ionosphere to earth 'bounce' before the curvature of the earth falls away denying a second 'landing'. I have heard my own round-the-world signal a few times which seems to propagate best along the gray line from a very quiet middle of the Pacific - very strange to hear your own signal in the headphones a second or so behind the sending but that was on HF - probably 4 or 6MHz marine band. I feel an experiment coming on but down here I don't get many signals to play with - although sometimes I used to hear the carrier of 162 France Inter from Allouis before they closed down in 2017.