VHF DXing
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LAST UPDATED: 1st January 2021

VHF (30MHz - 300MHz) DXing

The VHF (Very High Frequency) part of the RF spectrum begins at 30MHz and continues right up to 300MHz. Obviously these frequencies are defined by society, rather than being a hard and fast nature defined set of frequencies. At the low end of VHF, propagation is influenced by the same things that affect the upper HF bands as well as modes that are the mainstay of VHF. Similarly, at the upper end of VHF, propagation methods tend to have properties more associated with UHF. This variation in propagation, together with enhancements that are strongest at VHF make this part of the spectrum a fascinating place to be.

144-146MHz - the 2m band

First, some background about how I got into VHF:

When I was first licensed back in June 1982, I was issued the callsign G6IUT (my father’s callsign is G6IUS, as his forename is earlier in the alphabet than mine). In those days, a class ‘B’ license, like mine, was limited to VHF. As we had no access to the 6m and 4m bands (50 and 70MHz, respectively), the lowest frequency band we could operate on was 2m (144MHz).

Initially, I was active on FM only, with a 2m handheld (Yaesu FT202R handheld, with a drop-in charger/psu, a speaker-mic) that was limited to 6 crystal controlled channels. I think they were the simplex channels that back then were known as: S20 (145.500), S21 (145.525), S22 (145.550MHz) and the repeater channels: R4 (145.700), R6 (145.750) and R7 (145.775MHz). The FT202R had a power ouput of  just 1 Watt and my antenna was only a quarter wave ground plane (a Jaybeam one I think) at about 8 or 9 feet above ground. Not brilliant, but enough for local chats and to get into the Kent repeater (GB3KR or GB3KN, as it became).

In those days 2m FM was quite busy and during a tropo lift, it was difficult to find a free channel. I remember one day - when it was I don’t know, but it wasn’t long after I became licensed, so around June, July or August 1982, I would say, I heard my dad talking on 2m and sounding quite jovial. When I listened, I discovered he was talking to a GJ station, all the way down in Jersey! Now he was running 25 Watts into a Slim Jim type antenna that was on top of his tower, so about 30 feet up. I switched on my radio and found, to my surprise that I could hear him very clearly. I said that I was going to give him a call - my dad said I’d never get through and shouldn’t bother calling as I would only be creating QRM. I guess that is true, but I called him anyway, probably more out of spite than anything, me being a stroppy teenager! One call and the GJ came straight back - much to my surprise. We had to exchange signal reports and locators on the calling channel (s20, 145.500) as all my simplex channels (all 3 of them) were full with ‘end stop’ QSO’s. A few seconds later it was done and dusted. And that is when the DX bug struck, and it struck hard and deep! To this day I am a DXer at heart. In fact, over the past few months, I have rediscovered  my love for 2m. It’s changed a lot since I was last on the band, some for good and some not so good. The antenna system I had access to back in the 1980’s! it comprised of 4 x 17 element Tonna (F9FT) yagis for 2m, with a box of 4 x 21 element Tonna yagis for 70cms on the inside of the 2m array. These had full azimuth and elevation capability and both had masthead preamps, with Dressler linear amplifiers to give a good 400W output at the antenna. The tower was a 20m telescopic (P60/Strumech - the exact details elude me). It was a potent system, used mainly for amateur satellite comms. Some may say ‘overkill’, and I would not disagree with them! It proved to be very good for tropo lifts too (as you may imagine). I did not use this system much as I was away for work a good deal of the time. I know the Ukraine was worked on Es on 2m, and many, many JA’s were worked via the 70 up/2 down or 2 up/70 down satellites - not by me though! I’ve never really been a fan of high power, but there are times when it is necessary.

My set up for 2m these days is somewhat different, and I am focussed on listening rather than transmitting at the moment.

My main 2m receiver(s) are all SDR’s - I use the Airspy HF+ Discovery as my main 2m receiver together with a 5 element PowaBeam yagi, a very compact yagi with a boom length of just 1m. It is ideal for this QTH as the garden is a very difficult shape to fit anything in, particularly antennas! I also have an Airspy HF+ Dual Port and an Airspy R2. The Dual port and Discovery are fantastic receivers but their VHF coverage starts at 60MHz, thus missing the 6m band on 50MHz. Luckily the Airspy R2 covers from about 25MHz upwards so covers all of the VHF bands and well beyond, into the upper UHF band. I also have a Funcube Dongle Pro Plus, that covers from LW right up up to 2000MHz.

So, what can be heard on 2m with a modest station? A lot more than you might first imagine! I started my locator squares and DXCC tally from zero when I re-ignited my interest in 2m a year or two ago. I am now at well over 200 locator squares and 45 DXCC. My best DX, so far, is around 3000km down to the Canary Islands. 2019 and 2020 saw some spectacular propagation from England to Cape Verde (D4), a distance of over 4300km and broke the national distance record - not just once, but a number of times as stations further and further away managed to make contact. The world distance record was also broken when stations in Europe were also able to work D4. Sadly, I was unable to hear them - not for lack of trying though!

Here is a map of the locator squares/grids I have logged over the past couple of years on 2m.

Grab (G4UCJ) 10-06-2020_1611
Grab 20-10-2018_2146
tn_WP_000408
IMG_9762 yagis
tn_WP_000407
@-20170620_110421
sm-IMG_7069
powabeam crop
FCD
IMG_0785

50-52MHz - The 6m or ‘MAGIC’ Band

6m can be an incredible band, full of far off stations calling and being worked, often at huge signal strengths. 6m can also be an incredibly frustrating and fickle band where there appears to be no propagation to anywhere.

I have put the word ‘appears’ in italics because 6m can be deceptive - even if you hear nothing, no beacons from anywhere - try putting out CQ’s for a few minutes using one of the new breed of digimodes - in particular FT8 or MSK144, and you may well be rewarded with a few contacts. These programmes are designed to seek out signals that are inaudible to the operator and hiding well below the ambient noise floor. Many times I have left my receiver on one of the digital mode frequencies only to see a flurry of activity from a few countries (usually out to about 1500km). When I look at the beacon segment, the only ones I used to see were the local ones - All of the beacons local to me have gone off air for one reason or another. I can quite often hear the Cornish beacon (GB3MCB) and occasionally the one in Buxton, Derbyshire (GB3BUX). Oddly, I can hear it all most of the time on 4m - with nothing more than an indoor dipole.

Thanks to FT8, the way 6m is used, and even thought of, has changed completely. Now you will find activity on 6m every day of the year and at pretty much any time of day. The sheer numbers of people using the band has led to new propagation modes and theories being discussed. 6m has openings far more frequently than was thought. The distances that are being worked has also come as a welcome shock to even seasoned 6m operators. This year (2020) has seen unprecedented openings to Japan, with some UK stations working 30-40 in a single morning session. It has been known for a few years that from around late May to the end of June a path to JA exists but very few had managed more than a handful of QSO’s in any season using CW or SSB. Then FT8 came along, with its 15 second tx periods and everything changed. Suddenly openings to all manner of places were observed, fleeting MS pings, a brief Es openings, a slight tropo enhancement, aircraft flutter, etc. were all observed. Because so many people were now active, nothing was missed. All manner of random openings and DX were noted. Achieving DXCC on 6m used to take years of dedication and having a good station, together with an experienced operator. Now, DXCC can be achieved in a single season with even a modest station, although having a bit of luck on your side always helps. A station with a 100W transceiver (now the ‘norm’ for the majority of HF/6 transceivers on the market) and a 5 element yagi can hope to work a great many stations during the course of a season (well I say ‘season’, that has been pretty much replaced with ‘year’ ,thanks to the proliferation of openings that have been discovered thanks to so many using FT8. Even my single element antennas have almost made DXCC on 6m in a single year - I logged 97 DXCC in 2018 on 6m, which is my personal best. Below are maps showing the 742 grids I have logged on 6m from Jan 1998 to Jun 2020:

6m grids all 250620

6m grid squares logged at G4UCJ (IO92ma): Europe

6m EU 250620

6m grid squares logged at G4UCJ (IO92ma): Africa

6m AF 250620

6m grid squares logged at G4UCJ (IO92ma): Asia & Middle East

6m AS 250620

6m grid squares logged at G4UCJ (IO92ma): USA & Canada

6m NA 250620

6m grid squares logged at G4UCJ (IO92ma): South America & Caribbean

6m SA 250620

My first real experience with 6m came one June day in the late ‘90’s when I decided to build a home brew antenna for the band, having just purchased a shiny new Alinco DX-70 HF/6m radio. I measured out a quarter wave length of wire and attached it to the centre of the coax forgetting it was attached to the rig. As soon as I connected it I heard an EA beacon (by pure fluke I was tuned to a beacon frequency), I nearly fell off my chair as  I was holding a length of hook up wire in my hand, with most of it draped on the floor listening to a beacon in Spain on 6m! That did it, I was hooked!! Fast forward a number of years and here we are now, with well over 100 countries under my belt, still just as hooked on the magic band

9 June 2010 - 6m opens Eu/UK to Japan! For the better equipped stations in Europe and the UK a few Japanese stations were worked, for me I just about heard the strongest one (and that was a very scratchy, marginal copy - the odd letter here and there - so yes I did hear Japan but in all honesty it would not been enough to identify the station had I not known (I could hear the station he was working, so knew it was the JA responding). I am hoping that I will hear a stronger one that I can record this season, but I am astonished by the propagation that 6m is producing at the moment - and this is not even F-layer propagation, we need to wait another year or 2 for that to happen, then the world will open up (so I am lead to believe!). Speed up to 2016/17 and the promises of worldwide DX were not really forthcoming! There were some really good openings, but for us with lower level stations, the real DX was just out of reach. I did make hay while the sun shone on 6m, and was surprised by how many squares and DXCC I could actually hear. As you can see from the above maps, I have now heard quite a few JA’s, plus a few other DXCC in the Far East. This was mainly due to the widespread use of FT8, as already discussed. It is always worth getting up earlier than usual during June and getting on the radio as 6m does open to JA and other places during the month, but the key is to be early - from 0600 to around midday will give you the best chance of getting some JA, BA, BV, HL and others into your log. Persistence and patience are needed though as there will be many, many callers when the band opens. Also, it must be remembered that these openings do not happen every day, by any stretch of the imagination.

Band I TV broadcasting

When I was first licensed, the 6m band was not available to hams in the UK and quite a few other countries due to television broadcasting on ‘band 1’ which covered 41MHz - 88MHz.

Each country, or region had its own channels, falling within that range. In the UK, and parts of Europe our channel numbers were prefixed by ‘A’, so we had A1, A2, A3, A4 and A5. Ireland, for example, had only 3 channels A, B and C. These were at very slightly different frequencies to the UK allocation, but couldn’t be received on a UK tv set of the time because the UK used 405 scan lines on VHF, whilst Ireland, and most others used 625 lines.  Also the intercarrier sound was at a +6MHz offset, rather than the -3.5MHz used by the UK.

All of this was rather confusing and, although 405 transmissions were coming to an end in the UK, my gran had what was called a ‘dual-standard’ set. A dual-standard set had 2 tuners, one for VHF and one for UHF. UHF television is the one in use now, even for Digital ‘DVB’ television (not satellite, that is much higher frequency - around the 1600MHz-2000MHz range).

During the summer, I would ‘borrow’ my gran’s TV for an hour or two whilst we visited. I would flick the tuner on to VHF and adjust the fine tuning to see if I could catch any foreign TV. Quite often I saw logos and foreign text. The definition wasn’t quite right because of the differing line number, however, it was foreign - and that was DX! Because my gran lived in a town called Rye, In East Sussex, I was able to take advantage of it being located right on the coast, with a clear run to France. Even on UHF, I could see French TV. I knew it was French without having to actually see any identification - how? you may ask! France uses (or used) a tv broadcasting system called

SECAM’, which was broadcast at a resolution of 819 lines, as opposed to the UK which ran at 625 lines on UHF). That wasn’t the main give away though. French TV broadcast video in the opposite polarity to most of the world. In the UK, and other places that uses the ‘PAL’ standard (PAL = Phased  Alternate Line). PAL is broadcast in negative video polarity, SECAM is broadcast in positive polarity. If you think of a reel of camera film (if you are old enough to remember when film was used), when you had them developed you would be given the photos, plus another thing that looked like a strip of film. That was the negative of the image, where the picture and colours were inverted. This is the same principle, SECAM is the reverse polarity of PAL. So when viewed on a standard TV, SECAM broadcasts appear mainly black, with white/grey where dark would usually appear. Difficult to describe but easy to recognise.

In the 1980’s I had a keen interest in DXTV and used a 5 element band 1 yagi (slightly larger than a 6m 5 ele yagi) to great success during the annual SpE seasons. I logged pictures from all over Europe and into Russia. There were probably many other countries too. I would certainly like a 5 element yagi now!

Reaching DXCC on 6m

The new ones which took me to the DXCC were: ST2 (Sudan), TR8 (Gabon), A71 (Oman) and SV5 (Rhodes). I was surprised by how strong the ST2 was at one point, although it took a fair amount of waiting before I actually heard him. I watched the DX cluster for spots from G stations and then tuned on to his frequency and monitored - and while I tuned elsewhere I checked back every couple of minutes. Eventually I was rewarded with a signal, which remained audible for over an hour. The A7 was very weak, I did record it (as I did with the ST2) but I have yet to check it to see if it is audible on the recording! I am hoping this season will be a good one as I missed out last year and the year before due to defective / inefficient antennas. The openings seem to be very long at the moment, yesterdays opening was going before I got up, and was still going after I went to bed!  It certainly seems to have got off to a good start. These long openings enabled me to log 44 DXCC in 3 days (which is more than I have logged in some whole years!) and now, barely a month in to the season and I have 64 DXCC in the log (this is including the JA mentioned above, although some would say that it doesn’t count as I didn’t hear the callsign etc. - well as I am not applying for any awards or contests it doesn’t matter, I know I heard it and that is what matters to me ;-) The final year total for 2010 on 6m was 70 DXCC in 252 grid squares.

Fast forward to 2017 and things have progressed nicely. The biggest improvement has come in the form of a new digital mode called FT8, designed to catch the fleeting Es (or tropo ducting, etc), even MS pings, which is does rather well (especially on 2m). So many were active on FT8 last year, and virtually every day of the year it was possible to hear stations in Europe. 2017 saw the standard ‘5 element and 100W’ guys being able to work places like China, Japan, South Korea and deep into South America. Even I was able to get in on the fun and log a few JA’s and others. FT8 revolutionised 6m in 2017.

Here are some statistics from my log about 6m comparing 2010 and 2020

YEAR

DXCC

GRID SQUARES

US STATES

2010

70

253

3

2017

85

447

6

2018

97

538

28

2019

92

478

21

2020 (- June)

73

462

19

OVERALL TOTALS

143

742

32

In the Autumn (Fall) months real dx can sometimes be heard. A couple of years ago when we were at the sunspot peak (the second one of this cycle), the MUF rose high enough to allow signals from North America to propagate into Europe. The signal strengths at times were incredible. VE1YX amongst others were well over s9, in fact I think the best signal I heard from North America peaked to nearly 50dB over s9, which is incredibly strong given that my Icom meter is rather mean! Using just 3 watts I made many QSO’s into Canada and the USA. Other notable contacts from my log over the past 3 years have been into Venezuela, Aruba, Brazil, Zambia and the Lebanon. Now if only I had a 5 element beam and 25 watts! I only need Oceania for my WAC on 6m, but I think that may have to wait until the next solar peak in a few years time! If conditions are good around October, there is the chance of paths to North America etc. opening up (although at this stage of the cycle it is more likely to be via multi hop Es than F2, as F2 requires consistently high Solar flux for a period of time before propagation is likely. We live in hope and will be watching the...

 ....MAGIC BAND!

Suggested 6m European operating frequencies:

(lower part of band only shown)

(Frequencies shown in red should be kept clear)

50000-50080 & 50400-50500

Beacons (Beacons should be moving to 50400-50500, freeing up the low part of 6m for CW)

50080-500100

CW

50090

CW Calling Frequency

50100-50130

Reserved for Intercontinental traffic (SSB on/above 50110) - no Eu-Eu etc.

50110

Intercontinental Calling Frequency (CW or SSB), do not use for QSO’s and do not use for calling inter-Europe! Once QSO has been established, QSY to clear frequency as soon as possible.

50130-up

SSB

50150

SSB Calling frequency

50220-50300 (approx)

Data - below are the commonly used frequencies for popular digital modes in Region 1

 

JT65 50276 - MSK144 (MS) - 50280 - FT8: 50313 - JT6M 50230 - RTTY/PSK 50250

OFF AIR MP3 RECORDINGS OF STATIONS HEARD ON 6M,

MADE BY G4UCJ

Here are some MP3’s of interesting stations/beacons that I have heard on 6m.  All signals below were received using one of the following antennas: Wellbrook ALA1530 (1m diameter active loop) at 4m; 6m/4m dipole in attic. Click your preferred format (ogg, wav or mp3) of the file you wish to hear. The file should play within the browser, but you may need to press the back arrow after the file has finished, to return to this page.

Some of the signals in the recordings are very strong, some are really, really weak (even if it doesn’t sound like it, there really is a signal there - you may need to use headphones, in order to hear the station.

These recordings were made from 2010 onwards, before the band went digital mad (I am a big fan of digital modes, so I don’t see that as a bad thing, although it would be nice to hear some more SSB & CW on the band these days).

The recordings vary in quality and volume!

I have arranged the MP3’s by continent to make it simpler to find one of interest. Where there are multiples of the same station, they were recorded at different times, sometimes even on different months or years. I have only had time to link the MP3 format sound files. I will add the WAV/PCM and OGG links as and when I am able. I think most people can use MP3 files, but for those that can’t, I will get the other formats done as soon as I can.

Europe

Callsign

Mode

Location

Playback Format

CU3URA/B

CW

AZORES

mp3

wav/pcm

ogg

EI9E/P

SSB

IRELAND

mp3

wav/pcm

ogg

EI9FBB

SSB

IRELAND

mp3

wav/pcm

ogg

GB3LER/B

CW

SHETLANDS

mp3

wav/pcm

ogg

GB3LER/B (2)

CW

SHETLANDS

mp3

wav/pcm

ogg

HV0A

SSB

VATICAN

mp3

wav/pcm

ogg

JW7QIA

CW

SVALBARD

mp3

wav/pcm

ogg

JW7SIX/B

CW

SVALBARD

mp3

wav/pcm

ogg

JX7SIX/B

CW

JAN MAYEN

mp3

wav/pcm

ogg

OY1CT

CW

FAROES

mp3

wav/pcm

ogg

OY6BEC/B

CW

FAROES

mp3

wav/pcm

ogg

OY6FRA

SSB

FAROES

mp3

wav/pcm

ogg

OY6SMC

CW

FAROES

mp3

wav/pcm

ogg

SK3SIX/B

CW

SWEDEN

mp3

wav/pcm

ogg

SV5BYR

SSB

DODECANESE

mp3

wav/pcm

ogg

SV9CVY

SSB

CRETE

mp3

wav/pcm

ogg

TF2CL

SSB

ICELAND

mp3

wav/pcm

ogg

TF3ML

SSB

ICELAND

mp3

wav/pcm

ogg

TF3SIX/B

CW

ICELAND

mp3

wav/pcm

ogg

TF8GX

SSB

ICELAND

mp3

wav/pcm

ogg

TF/VE3IKV

CW

ICELAND

mp3

wav/pcm

ogg

Africa

Callsign

Mode

Location

Playback Format

5C12M

CW

MOROCCO

mp3

wav/pcm

ogg

5C13SG

CW

MOROCCO

mp3

wav/pcm

ogg

5T5DUB

CW

MAURITANIA

mp3

wav/pcm

ogg

7X0AD

SSB

ALGERIA

mp3

wav/pcm

ogg

7X2VX

SSB

ALGERIA

mp3

wav/pcm

ogg

C5YK

SSB

GAMBIA

mp3

wav/pcm

ogg

CN8IG/B

CW

MOROCCO

mp3

wav/pcm

ogg

CR3L

SSB

MADEIRA

mp3

wav/pcm

ogg

EA8AAW

SSB

CANARIES

mp3

wav/pcm

ogg

EA9IE

SSB

CEUTA

mp3

wav/pcm

ogg

ST2AR

CW

SUDAN

mp3

wav/pcm

ogg

ST2AR (2)

CW

SUDAN

mp3

wav/pcm

ogg

Asia

Callsign

Mode

Location

Playback Format

4X4DK

CW

ISRAEL

mp3

wav/pcm

ogg

5B4CY/B

CW

CYPRUS

mp3

wav/pcm

ogg

5B8AD

CW

CYPRUS

mp3

wav/pcm

ogg

5B4AIF

SSB

CYPRUS

mp3

wav/pcm

ogg

A71EM

CW

QATAR

mp3

wav/pcm

ogg

A92IO

CW

BAHRAIN

mp3

wav/pcm

ogg

E4X

CW

PALESTINE

mp3

wav/pcm

ogg

UK8OM

CW

UZBEKISTAN

mp3

wav/pcm

ogg

UK8OM (2)

CW

UZBEKISTAN

mp3

wav/pcm

ogg

The Americas

Callsign

Mode

Location

Playback Format

9Y4AT/B

CW

TRINIDAD

mp3

wav/pcm

ogg

FG5FR

SSB

GUADELOUPE

mp3

wav/pcm

ogg

FG5FR (2)

CW

GUADELOUPE

mp3

wav/pcm

ogg

FM5WD

CW

MARTINIQUE

mp3

wav/pcm

ogg

HI3TEJ

SSB

DOMINICAN REPUBLIC

mp3

wav/pcm

ogg

K1GUP

SSB

USA

mp3

wav/pcm

ogg

K1IM

CW

USA

mp3

wav/pcm

ogg

K1SIX

CW

USA

mp3

wav/pcm

ogg

K1TOL

SSB

USA

mp3

wav/pcm

ogg

K1TOL (2)

CW

USA

mp3

wav/pcm

ogg

KB4CRT

SSB

USA

mp3

wav/pcm

ogg

KP2A

CW

US VIRGIN ISL

mp3

wav/pcm

ogg

KP4EIT

SSB

PUERTO RICO

mp3

wav/pcm

ogg

N3DB

CW

USA

mp3

wav/pcm

ogg

NP4A

SSB

PUERTO RICO

mp3

wav/pcm

ogg

OX3VHF/B

CW

GREENLAND

mp3

wav/pcm

ogg

P43JB

CW

ARUBA

mp3

wav/pcm

ogg

PJ6D

CW

SABA ISL

mp3

wav/pcm

ogg

VE1YX

SSB

CANADA

mp3

wav/pcm

ogg

VE9AA

CW

CANADA

mp3

wav/pcm

ogg

VO1BC

SSB

CANADA

mp3

wav/pcm

ogg

VO1FU/B

CW

CANADA

mp3

wav/pcm

ogg

VO1SEP/B

CW

CANADA

mp3

wav/pcm

ogg

VO1VCE

CW

CANADA

mp3

wav/pcm

ogg

VO1ZA/B

CW

CANADA

mp3

wav/pcm

ogg

VP5/W5SJ

CW

TURKS & CAICOS

mp3

wav/pcm

ogg

VP9GE

SSB

BERMUDA

mp3

wav/pcm

ogg

VY0SNO/B

CW

CANADA

mp3

wav/pcm

ogg

W1JJ

CW

USA

mp3

wav/pcm

ogg

W1MU

CW

USA

mp3

wav/pcm

ogg

WP4U

SSB

PUERTO RICO

mp3

wav/pcm

ogg

Download a text file of 6m Beacons throughout the world (G3USF)

The 4m BAND (70-72MHz)

Below is a map showing the grid locator squares I have logged on 4m. Initially, it was fairly slow going as not many countries had access to the band, due to Band 1 tv broadcasting as well as East European and Russian FM broadcasting from 66-74MHz (approx). Band 1 TV has all but stopped in the majority of places, there are still some in operation in a few places in the world, but the majority have migrated to UHF, and some have gone to UHF and digital broadcasting only. Even the OIRT FM band (as it is known) has reduced occupancy, but in the summer you can still hear quite a few Russian type voices at 30kHz intervals (OIRT channel spacing is 30kHz, as opposed to 100kHz up on the more familiar Band 2 (87.5-108MHz, or starting at 76MHz if you are in Japan).

With more countries allowed access to the 4m band, DXing has become more enjoyable and many more DXCC and squares are able to be logged. The front runners seem to be nearing 400 squares logged, in 60+ DXCC. I am at 225 squares and 48 DXCC, but I had started properly DXing on 70MHz until 2019.

4m all squares to12-06-2020

 

 

How to ‘predict’ a Sporadic E opening:

What is Sporadic E? At certain times of the year, most noticeably from May-August, the E-layer of the ionosphere forms ‘clouds’ of highly ionised particles that act like a mirror to radio waves. When a transmitted signal finds one of these clouds, the signal will be reflected back down to earth with far less path loss than would otherwise be the case. Usually, the paths in question have so much signal attenuation that it is not possible to make a contact, the signal just gets lost in the ionosphere, or travels straight through and out into space. When you are lucky enough to encounter an intensely ionised E layer cloud, previously impossible paths open up. In theory, The lower the angle that the signal enters the cloud at, the lower the angle that the signal will leave, thereby giving maximum distance. In practise this is not always the case as the signal can bounce around from cloud to cloud in the ionosphere and land somewhere unexpected> Sometimes you may hear a signal that is very strong but not able to hear anyone else from that area, this could be due to that phenomenon. Another, very useful, feature is that at times of high ionosation, the signal may be reflected to the ground and bounce back up and hit a second Es cloud. This allows contacts out to twice the  single cloud limit.

Well you can’t actually predict a sporadic E opening but you can anticipate when a possible opening may occur as there are certain tell tale signs to look out for:

Because of its nature sporadic E (or ‘Es’ as it’s commonly known) is just that, sporadic! It can pop up at any time but there are warning signs to a possible opening. If you know what these are, you can be prepared, rather than being caught ‘on the hop’. The exact science of Sporadic E is still not fully understood, but it appears to be related to high altitude wind shear creating areas of intense ionization. I have found that SpE has a habit of being around when thunderstorms are in the locality - why this should be I don’t know but it happens quite a bit in the summer. The link between thunderstorms and SpE has been dispelled, but I’m not so sure (maybe the ‘supercell’ thunderstorms create enough high altitude air/friction (and also voltage polarity movement) to cause this shearing effect - I’m not a meteorologist so this is just speculation on my part!

I have just found a useful document on the internet, written by Todd Emslie, which gives the approximate minimum and maximum distances for Sporadic E at various frequencies, for both single and double ‘hop’ events. The full text, including the basic mechanics of the phenomenon as it is understood to work (as of June 2020 this, of course, may be revised in the future as more is understood) can be found here:

http://home.iprimus.com.au/toddemslie/Es_distances.html

To summarise, the distances for minimum, maximum and optimal range for a given frequency range are as follows:

45-70 MHz single-hop Es

Minimum range: 400-650 km (250-400 miles)
Optimum range: 1450-2100 km (900-1,300 miles)
Maximum range: 2200-2400 km (1,350-1,500 miles)

45-70 MHz double-hop Es

Minimum range: 2800-3100 km (1,750-1,900 miles)
Optimum range: 3200-4200 km (2,000-2,600 miles)
Maximum range: 4400-4800 km (2,750-3,000 miles)

45-70 MHz triple-hop Es

Optimum range: 4400-6400 km (3,000-4,000 miles)
Maximum range: 6900 km (4,300 miles)

45-70 MHz multi-hop Es

Distances of around 15000km have been recorded by multi-hop Es. We know it must be via Es as these events were recorded around solar cycle minima with no visible sunspots and therefore cannot be via F2 as the critical and optimum frequencies would be far too low for long distance F2 propagation.

88-108 MHz single-hop Es

Minimum range: 600-800 km (350-500 miles)
Optimum range: 1400-2100 km (900-1,300 miles)
Maximum range: 2200-2400 km (1,350-1,500 miles)

88-108 MHz double-hop Es

Optimum range: 3200-4000 km (2,000-2,500 miles)
Maximum range: 4300-5000 km (2,700-3,100 miles)

Maximum Es FM DX distance record: 6925 km (4302 miles). On 31 May, 2010, 88.7 MHz La Voz de la Luz, a religious station from Salvaleon de Higuey, Dominican Republic,received by Mike Fallon, East Sussex, UK. This extreme distance could involve some form of Es-related ducting propagation, i.e. multiple cloud-to-cloud signal transfer. This could explain the relatively minimal signal attenuation for such an extremely long signal path.

144 MHz double-hop Es

Maximum distance achievable on 2m via sporadic E propagation seems to be around 3900 km (2400 miles).

This site (VHF-DX Toplist) will give you a good overview of the distances that can be achieved on the various VHF bands, and via different propagation modes. You may get a warning about safety when visiting that site as it is not an ‘https’ address. I am pretty sure it is OK but I will leave it to your own judgement whether to click the link or not.

It’s always worth checking 6m (50MHz), 4m (70MHz) (if you have the capability/license) and 2m (144MHz) during May, June and July (April, August and September do produce Sporadic E at higher frequencies (144MHz, for example), but not as often as May, June and July). If possible monitor the DX cluster for reports, also monitor 15, 12 and 10m for short skip stations from around  400km (250+ miles). If you begin to hear those and they are strong, the chances are 6m will open up soon. If the signals on 6m become very strong and the distance, try 4m (70MHz) (if you have it). Also keep an FM radio to hand to check the progress of the MUF. If you start hearing strong foreign stations on the high end of the FM band (100MHz or above), then it’s time to warm up the 2m rig. Also use the real time web-based monitoring systems, such as DX-Sherlock, which can be found at https://vhfdx.eu/ . This shows real time activity on any of the VHF.UHF bands by collating data from DX and web clusters. Also on that site is a real time MUF map which plots the predicted MUF based on real data which is then computed by mathematical models. If you see MUF’s of 50MHz, or higher, over the middle of France (for example) or similar distance (500-1000 km (300-600 miles) or so), there is a very good chance that signals will be heard on 6m. Keep your ear out for G stations working Europeans, if you can’t hear any don’t worry as there is a good chance that the cloud may come within your range at some point. It is not unusual to hear a local station to you working very strong stations you cannot hear, this is part of the fun (and frustration) of Sporadic E propagation.

If you have a beam, start off with it pointing South East, as that is where the majority of Sporadic E comes from. Sporadic E tends to be very localized and a station just a few miles away may receive something at s9, whereas you cannot hear a thing! Sometimes the reverse is true of course, so stick with it and your turn will come. High power is not necessary, just a few watts and a simple antenna will get you contacts. A horizontal beam is preferred for the longer distance stations, but not always necessary.

Be prepared for short snappy QSO’s, particularly on 2m where the openings are much shorter than 6m (only a matter of a few minutes to perhaps an hour or two, where 6m can be open most of the day and into the night). A typical Sporadic E QSO consists of callsign, report and QTH locator (sometimes known as QRA locator). You may find that on occasion names and brief equipment details are passed, but usually the operators are trying to work as many stations as possible in the opening and you won’t make too many friends by passing on your life history during a Sporadic E opening!!

Using a vertical antenna for this type of DXing (although the real 6m operators wouldn’t class these signals as DX!) is that signals can be heard from all round the compass. The disadvantage is that you can end up with multiple signals on the same frequency at the same strength. I think the best combination would be a vertical for general ‘sniffing around’ and a beam for ‘homing in’ on a weak signal. A 5/8th wave vertical mounted at around 10m or more and in the clear will work very well and is not too big at under 4m long. A 3 to 5 element beam mounted about 3m below the vertical will give a good account of itself, giving you up to about 6dB gain (or more if you believe the manufacturers!) over a dipole. 10w into the beam will give you an erp (effective radiated power) of 40w, which is a useful amount of power on this band. Run 25w and you get an erp of 100w (the equivalent of feeding 100w into a half wave dipole). Even with the vertical you will get an erp of 20w for your 10w input — ideal for foundation licensees (come on you M3/M6’s!!). For sporadic E these power levels are more than enough, it’s amazing the signal levels that can be heard when the band is open.

An interesting twist this year has been the extended openings to North America and the Caribbean, presumably by some kind of E-layer propagation. These openings on occasion have been hours long and stations in the UK have reported s9 signals for hours on end from all manner of exotic DX. For me, the signals haven’t been that strong, but certainly strong enough to record. Between 0700 and 1000 on some days even better DX had been worked, namely Japan! I’ve not been lucky enough to hear one of these yet but I am hopeful that I will soon. It’s this kind of DX that makes 6m such an intriguing band and why it has such ardent followers. I for one have been ‘living’ on 6m this year, and have enjoyed the DX but much the same as our British weather you can never tell what tomorrow will bring, maybe a new country or maybe the band will be closed.

To see your signal meter stay over ‘s9’ for extended periods is pretty common and some of these stations are running low power and simple antennas (like 5w from a mobile into a whip on the roof of a car—one of those was on from Italy yesterday and was as strong as the base stations!).

Sporadic E is great fun in the summer and you can work stations running almost no power and not much of an antenna. Make hay from May to September, and possibly a little in November/December because the rest of the year could be quite bare. However, the advent of FT8 has showed the VHF bands to have open paths with far greater frequency (sorry for the pun) than was first thought. I don’t think there has been a day in the past couple of years where I have not heard signals on 6m, usually I will hear at least one station from Europe during the course of the day. 2m is also the same and, again, there are very few days when I do not hear at least one station from continental Europe. I find this incredible as I live so far away from the sea and Europe is at least 400km away. How things have changed thanks to the constant hardware improvements and innovations in both hardware and software.

The DX Cluster or Web Cluster is a game changer. It is still an incredibly useful tool today, it’s like having a few thousand ears all tuning around at the same time! With that many listening there won’t be many openings that don’t get reported. I have the cluster running most of the time, if I am at the radio or not. As soon as I see/hear spots for 6, come up I check out where they are from. If they are from the near continent then chances are we will get an opening sometime soon, but if they are spots from much further afield there isn’t too much point in getting excited! This can of course change given the right circumstances.

Conclusions:

Over the years since I started this website (about 10 years,in one form or another), my interests and equipment have changed a few times - as most people’s do. I’ve always liked VHF, my first amateur radio license was for 144MHz and above. We didn’t have access to 6m or 4m back in those days (1982), but band 1 tv was very much alive and kicking. As mentioned above,I had a 5 element 48-60MHz yagi just above the roof level of my mum’s house, coupled to multi-standard 5 & 7 inch TV’s. In the summer months I saw TV from all over the place: Europe, Russia, North Africa etc. I didn’t have much time to spend DXing as there were things like school, college and work to fill my days. I know I missed out on some incredible openings to the USA, Far East and even Australia, which is pretty annoying! I could probably seen most of those as I had a decent set up and was in a favourable location in South East Kent.

I have a reasonably capable station, let down by antenna restictions, but by sticking to receive only for now, I have managed to obtain a great amount of enjoyment from the VHF bands. Maybe one day in the future, I will be able to put up some modest antennas. My idea of ‘modest’ is nothing too big, say a 4 or 5 element yagi on 6m, a 4 or 5 element on 4m and a 6-9 element on 2m (Maybe a stack of 2 x 6 element wide spaced yagis on 2m with a masthead preamp).

Of course, I would still need something for HF as I still love DXing down below 30MHz. For HF, I would use a wire (a few choices, like an OCFD/Windom; A G5RV variant; a G7FEK nested Marconi; Fan/loaded/trapped dipole, etc.) or a vertical (maybe even a loop of some kind). I would look to have two types of HF antenna so that there is always a choice and it gives greater configuration capabilities. It is possible to use HF antennas on 6m and even 4m. My OCFD that is currently awaiting installation covers 6m as part of its coverage, and when I used one before it worked rather well.

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