Many thanks to SWLing Post contributor, Dan Greenall, who writes:
What is your longest DX (from transmitter to receiver)?
Assuming we are limiting the discussion to planet Earth, Perth, Australia would be represent one of the farthest land based locations to hear at 18145 km or 11275 miles as the crow flies from my receiving post in southern Ontario, Canada.
That would mean the ABC outlet that I received on 9610 kHz in the early 1970’s is the winner for me. Not far behind, however, would be tiny Amsterdam Island (part of the TAAF, Terres Australes et Antarctiques Francaises) in the Indian Ocean at 18031 km or 11204 miles. I was able to log marine radio FJY4 on 8690 kHz CW on a number of occasions and even managed to extract a PFC QSL direct from the station in 1973.
There are a number of distance calculators for this on the internet, such as Free Map Tools at
https://www.freemaptools.com/how-far-is-it-between.htm
Of course, the longest DX may not necessarily be the best. CKZN running 300 watts on 6160 kHz from St. John’s, Newfoundland from right here in Canada was harder to hear than the ABC in Perth, Australia!
Who can top this distance? What is your longest DX? Please comment!
My furthest DX from Huelva in the South of Spain was the religious station HCJB Global Voice broadcasting from Kununurra, Australia (a town located in the northwest of this country) in English for Asia on the frequency of 11750 KHz tuned to an ETON E5 Radio and Outdoor long cable antenna of about 15 meters. Heard at the beginning of July 2010. According to the Free Map Tools distance calculator, the distance between both towns is 16075.7 Km.
Sometime in the 1980″s I caught a MW station in Belize via grayline in Detroit MI.
That was my best MW catch ever.
Zack S
7ZR 936 Hobart, Tasmania, Aus 10-kw from 8000 miles/12,000km away in Alaska…. interviewed live on 7ZR and ABC Newsbreakfast TV
Back in the 60’s I listened to HCJB and Rodio Netherland, at the time i thought those distances were astronomical. I lived near Carlisle Pennsylvania, using an old Silvertone radio with a 30 or 40 ft. long wire antenna. It’s amazing the great radio and TV reception living way ot in the country.
HCJB from Quito Equador would have been 4,489 km or 2789 miles, and Radio Netherlands, would have been about 3700 miles or 5954 km.
Back then I had QSL cards from them, but the were probably tossed out.
I received HCJB in the 90s. My location was Shanghai, and the transmitter was (I believe) in Ecuador. It was in USB mode and the frequency was 21455. A broadcast station in SSB mode was rare by the way. I wrote a letter to it and happily received a reply.
I picked up Radio Australia from the UK, not long before it shut down. I assume it wasn’t a relay, but I forgot to check at the time.
I was working at Mobile Radio / WLO as overnight CW operator. We watched 500 kc/s then. I heard VIS on 500 kc/s one night. Thinking it was hearing a Canadian, I got out the ITU List of Coast Stations. I found out it was an Australian coast station! On 500 kc/s! MF is amazing.
Those darn “V” callsigns can be deceptive! One evening on 15 meters I heard VP6MW and thought, “Oh, a Caribbean station.” Fortunately I was able to realize it was Pitcairn Island and managed to get Meralda in the log and exchange QSL cards. 🙂
I think my longest DX from Germany was pirate station Kiwi Radio from New Zealand on a 7 MHz channel. Around 350 watts.
Some weeks ago I was lucky to log a 6-m-QSO (50 MHz) with K1TOL in Maine. 10 watts digimode into a 5-element-yagi on my side.
vy73
Harald DL1AX
Harald, I heard and communicated with them at that time as well. I recall a great paper QSL, too. Of course, I was a little closer to them in Victoria, BC!
Correction:
The furthest distance across the earth’s surface from the Hamersley (Perth) WA is near the island of Bermuda at a distance of 20021 km as a Great Circle distance. On a flat surface the path appears curved where as on a sphere it is a straight line.
Hamersley -31.85472, 115.8194444 near Bermuda 31.854722, -64.18055556
ie the antipodal latitude is the same distance either side o the equation. The Longitude is that 180 – longitude.
https://www.heywhatsthat.com/profiler.com
Australia on long path with 1W WSPR in 2015 is my only documented distance record (23810km). I had several longpath SSB QSOs. Including 9N7AA from Nepal on 10m. I consider that as best ODX.
I’ve also heard near antipodal DX, including Zambia from Hawaii, and Perth, WA from Toronto. In more recent years from off the NW coast of BC on Haida Gwaii, I regularly hear LRA 36, often at armchair level, a distance of 14561 km, with a power of 1 kW on 15476. Even more favourite are the numerous X-banders in Australia that run 400 W, or less, at distances over 12000 km, or the 1 kW 1485 from Svalbard at 5127 km and the numerous hobby SW stations in Europe running very low powers, or my all-time favourite QSL from Radio Free Bougainville running 40 W on 90 meters, a distance of 9880 km. And who can ever forget Radio St Helena’s annual SW broadcast. That was 13686 km from me. Yes, it’s not just the distance, but the power and for me, the “exotic index” that counts!
Does hearing long-path signals count?
Good point, Jake. It’s pretty common to hear the short and long path echo at times. And I’ve heard moon bounce and Jupiter, too….the list goes on and on!
ABC Perth here in suburban Chicagoland back in the 1980s.
Well. When I was at the University of Florida a
Colleague and I built a unified S band receiver and
Tracked the Apollo spacecraft into TLI. Just the
Carrier but I still recall the excitement even today!
Distance is why I became a Ham 45 years ago.
My favorite saying is, ” I like to squeeze blood out of a turnip”.
I have been MW DXing since 1962, SWL 1964, CB’er and TV DXing in 1972 and finally a Ham in 1979. As a Ham I have prided myself in doing a lot with a little. All my rigs but one are second hand. My antennas are no better that a Yagi for a specific Ham band and a lot of wire, loops and verticals.
What I lack in stuff, is a very good understanding of Radio Propagation from MW to UHF. You can’t hear them or work them unless you know when and where.
So here is 62 years of stuff:
Medium Wave: 2,647 miles S. Oregon to Havana Cuba (Portable and 4′ Box Loop). A lot of Asian Hets, but no audio.
Analog TV: 1705 miles Houston TX to Calgary AB Channel 4.
FM BC: 1335 miles Arizona to Louisiana/Mississippi with a $17 RTL-SDR into a Log-Periodic @ 15 feet.
Ham Stuff:
SW/HF:
10 Meters (28 MHz): 9050 miles Malawi several times. Reunion Is. 10610 miles.
I received a 200 mW WSPR signal from Germany, 5543 miles. It equaled 22,715 miles per 1 watt.
My Blog post about it: https://ka5dwipropagation.blogspot.com/2015/01/when-you-have-propagation-anything-is.html
He had a 1/2 antenna on a Bamboo pole stuck out his apartment window.
VHF:
6 Meters (50 MHz): Also, Malawi on 10 watts 9050 miles and 150 watts to Australia 9075 miles all on SSB.
2 Meters (144 MHz): My only listed DX Record. 1595 miles. Tropo Over-Land from N. Texas to Maine. I have done 2M Sporadic Es of 1605 miles. Everything on SSB.
Patience, persistence, propagation (understanding) and of course being there.
73 Art
I’ve received Radio Australia from FL, which is very nearly my position’s antipode.
The maximum is half the circumference of the earth which is between
North/South is 20,003.9315, East/West 20,037.5085 km.
This is the over the surface distance. The actual distance travelled will be much greater being bounced between the Earth and the Ionosphere more than once.
The Hamersley WA transmitter site is -31.85472222, 115.8194444 degrees.
The greatest distance from it is 58.1452777 , -64.18055556 is 17096 km away in a National Park in Newfoundland, Canada.
https://www.heywhatsthat.com/profiler.html select parameters True line of sight, curved circle and great circle because the world is not flat but is a sphere.
Neumayer base in antarctica from central Italy, received on an MSI SDR using a linear loaded dipole installed on a balcony
https://swling.com/blog/2020/12/how-to-build-a-simple-linear-loaded-dipole-for-low-noise-shortwave-radio-listening/
🙂
It seems my longest DX was ZLB Awarua Radio, a utility station from the South of New Zealand, roughly 18500 km from where I live in the northwest of Germany. The QSL I have says the reception date was February 28, 1987, 1050 UTC on 12740 kHz with 5 kW of power. My receiver was a JRC NRD-515.
Just 30 km nearer was RNZ’s old transmitter site at Titahi Bay which I received in 1980, broadcasting with only 7.5 kW. And this was on an ordinary Grundig radio, not even a dedicated SW receiver. I do miss those days!
Many (many!) years ago, listening on my Hallicrafters S-40A, I received WWV long path from Illinois. I believe this is probably my longest DX. How did I know it was long path? I could tell because I could hear double ticks: “tic-tick … tic-tick …”. The delay was too long to be WWVH, plus I could not hear the WWVH ID. At the time I did a quick calculation and concluded that the long path delay should be about 1/7 second and I thought the perceived delay *seemed* about right.
As a ham I vaguely recall working a station (east coast, I think) from Michigan and commenting to him that I could hear an “echo” on his signal. He confirmed that he was beaming long path at the time, so that was probably, another example of double reception (direct and long path).
I know it’s outside the scope of this discussion, but I’ve received three stations off the moon. Never done any EME work myself, but was able to receive using my satellite antennas. I did get an SWL card from one of the stations. As I recall, it took me about a half hour of listening to get a positive ID. This was back in the days of CW EME, so reception was “by ear.”
What about “reverse DX” from transmitter to receiver? I routinely receive reports on 10M using my 200mW WSPR transmitter and a modest repurposed 11M to 10M ground mounted vertical antenna to all over the USA, Europe, South America from northern New Jersey. In my opinion, truly magical!
Back in 2015 I picked up Germany running 200 mW into a Bamboo 1/2 wave sticking out his window on WSPR. My vertical and 7 watts on WSPR has made it to Reunion Island.
https://ka5dwipropagation.blogspot.com/2015/01/when-you-have-propagation-anything-is.html
22,715 Miles per watt.
Australia and New Zealand in the 90s to NE UK
it’s not about distance, it’s about which signal you can get a ‘bounce’ from..
example on CB radio Australia and such places are easy to get, yet furthest away.
but Japan and China, Korea harder as the skips bounce over them usually at a high peak, so you either need different type of skip or hope to hear them via a different path.
Not really DX, but back in the days when DW still had their relay station in Sines, Portugal, that used to be about as far away as you could get from my home in Marahau, New Zealand. The “How Far Is It” says ~19700 km.
Back in the early days of DRM the Sines site often provided excellent reception of DW/BBC DRM signals, sometimes good enough for me to relay on my hobby LPFM station.
I remember one of the engineers at Sines telling me “from here every direction is towards New Zealand” 🙂