Monday, May 17, 2021

New 40 MHz propagation beacon in the West of Ireland - EI1CAH


17th May 2021: There is now a new 8-metre propagation beacon in the west of Ireland using the callsign EI1CAH and it is operating on 40.016 MHz. The locator square is IO53CK.

This new beacon is designed to compliment the existing EI1KNH beacon which is situated near the east coast of Ireland. While EI1KNH has a superb take off the East, it is blocked by mountains to the West. By contrast, the new EI1CAH beacon has a good take off to the West and is poor to the East.

The EI1CAH beacon runs PI4 every second minute as well as CW. Its power is approximately 25 watts and the antenna is a horizontal dipole running roughly NW/SE.

The beacon keepers are using a QRPLabs Ultimate 3 (previously used on EI0SIX) to generate the 40 MHz signal and it has a matching internal QRPLabs 6m low pass filter which was modified to cut in closer to the 8-metre band.

They are using a NXP MRF101 based power amplifier to generate the required output power.

Analysis: This new 8-metre beacon is an excellent addition to the European suite of 40 MHz beacons and will be very useful in exploring Sporadic-E and F2 propagation paths across the Atlantic.

Site Profile: The graphic below shows the elevation profile for the EI1CAH beacon site.


There are some serious hills to the East which will block off a lot of low angle propagation paths. A typical Sporadic-E signal may be down around 5 degrees which as the image shows will be blocked by the local hills.

This is the likely maximum range due to one hop Sporadic-E...


As you can see, under short skip Sp-E conditions, reception of this beacon may be possible in say the SE of England, Belgium, Netherlands, N France and the fast west of Germany. As the antenna is running NW-SE, the signal towards Spain will be poor.

What is key however is the low elevation to the West ...towards South America, the Caribbean and North America.


Under multi-hop Sporadic conditions, this 8-metre beacon will be heard across the Atlantic and the most likely people to hear it are those out around the 4000km mark in Nova Scotia and Maine. There is also the potential that it will be heard anywhere in the eastern half of the USA.

Likewise, it will reach the Caribbean at times and will certainly make it down to Brazil and Argentina.

Solar Maximum: Around the time of the Solar Maximum, there should be some East-West openings and this 8-metre beacon could be heard anywhere in the Americas.

Value of a 40 MHz beacon: The real value of this beacon is that there is a huge 20 MHz gap between the 28 MHz and 50 MHz bands. As the maximum usable frequency (MUF) for Sporadic-E and F2 propagation rises, it can be very difficult to know where exactly or how high it is.

By having a beacon at 40 MHz, it will allow serious 50 MHz stations to monitor the rising MUF and be ready for any potential 6-metre opening. 

I think this beacon will be of real value as we get close to solar maximum and North American stations are checking for a 6-metre opening to Europe.

Thanks to Tim, EI4GNB and Tony, EI7BMB in getting this beacon up and running.

For more information on the 40 MHz band, see the information on my 40 MHz page... https://ei7gl.blogspot.com/p/40-mhz.html

6 comments:

Photon said...

I'm definitely going to try 4m now!

Anonymous said...

On 19/05/2021 I have been receiving EI1CAH for over 3 hours (0930 - 1300 UTC). Despite its path obstruction to the east, PI4 codes were very clear in JO20MV at 1047km.
Phil ON4TA.


Anonymous said...

I am located in SE Netherlands and I received EI1CAH today (19/05/2021) shortly after 1200utc using an RTL-SDR.

My location is 1095km distant from IO53CK, on a bearing of 111° (i.e. ESE).

Knowing that Sporadic-E paths can sometimes be very short-lived I grabbed my phone and filmed the computer's audio and waterfall display. A short recording is up on my YouTube channel for anyone who is interested.

Paul PE7B

Andy G7IZU said...

Received in SW England IO70WJ at 13h52UT 19.05.2021. Very short skip at 515km!

Andy G7IZU

Anonymous said...

Beacon can be heard every day last week, loud and clear in JO59BC
Tore LA3FV

Allan Nelsson said...


EI90IRTS, S59F and S50B using FT8 heard this afternoon at 15:30 +/- UTC on 40.680 MHz in JO55PQ. EI90IRTS +11 at the best, S50F -15 and S50B -2.

RX IC7300 and antenna Delta loop for 6 meters dir. NW/SE.

Vy 73 de OZ5XN/5P9R, Allan.