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2m EME and moonrise ground gain at ON7EH

The main intention of this page is to provide some audio files, representative for the strength of signals that are reflected off the moon on a modest gain antenna, without a low noise amplifier and under typical moon conditions on the 144MHz band.(2m moonbounce)
The morse speed is medium and most signals are better than average so you do not need to be very CW-skilled to enjoy the sounds that have travelled through outer space.

Here starts my story:

After having heard greek amateur station Jimmy, SV1BTR before, via the moon, he was heard again on my 18 September 2005 moonrise.
His signals were rather good and at the lowest moon elevations, he was called by many european EME-stations, including several single yagi stations, I could hear, on tropo.
At this time, I was called away from the station to provide necessary assistance to the XYL.
Kids usually do stupid things when left unattented, we are no exception...

I came back to the station 1 hour later and Jimmy was still heard calling CQ around 144.048 MHz.
Midwhile, the moon had risen to an elevation of about 13°.
The antenna here is an old single 12element Mē without elevation control, fed by about 8m of old Aircom+ coaxial cable. (10mm diameter) (see here)
The yagi antenna with a boomlength of under 6 meters is sited 10m above the ground and fixed to the house wall.
It clears the rooftop by less than 0.5m and the antenna remains close to the photovoltaic cells on the roof.
The QTH is suburban and evolving to urban but still 25m above sea level.
The eastern headings (moonrise) are mostly fields with some farmer housing in some directions. The slope to the east is slightly rising but further away dropping.

For the 2m setup on the attic, I decided earlier not to use any receive low noise amplifier for several reasons.
The hard to reach antenna position, the low antenna line loss, the high RF interference environment (very near to airport with plenty of paging, cellular towers)
being the most important ones.
The system noise figure is estimated to be in the 1.5dB range. (cable loss + PA relay bypass loss + transverter noise figure)
The audio samples are unprocessed and they are heard as I've heard them through my headphones of my shortwave transceiver's 500Hz Xtal-filter.

Here, you can hear SV1BTR calling CQ:   and .        
You may have to play with your mixer sound control settings to hear the dits and dots.
The MP3-files are in excess of 100kB and require a decent internet connection to be enjoyable.
You should be able to clearly hear his message, containing CQ CQ CQ de SV1BTR on several occasions.
The signals are rather strong and consistent.

After this CQ-period, I called him with a message like this: SV1BTR de OO7EH OO7EH OO7EH
(this is called a "1 by 3"-call sequence to stress my own call)
Bare in mind that my call is not yet known at the greek side.  BTW: my calling periods were not recorded.

SV1BTR clearly had difficulties recognizing, who had been calling him, by his sending of many periods of QRZ's: , , and .
The first sequence is the weakest but his signal gradually gets better and better to become fully readable.
I am not willing to let him go so I peacefully continue calling him, period after period, with a "1 by 3"-call sequence, in between his many periods of QRZ.

After some time, I am lucky since he copied, at least enough morse characters, to think it is OO7EH calling him...:Listen here: and .
You can very clearly hear QRZ QRZ OO7EH with some '? ? ?' indicating, there is still some doubt about my callsign.

Knowing he's struggling but also knowing he's finally got my call correct, I start my next transmission with some RRR's, to confirm he's got it all right, followed by several other
"1 by 3"-call sequences to make up a full calling period. (1 minute)
Once he's really convinced of my callsign, Jimmy starts sending both calls. He must have been really excited since he starts sending some errors: Could you locate them?

Immediately after both calls (OO7EH de SV1BTR), he adds a report being 'O''O''O': (it is typical on 2m and frequencies higher up, to use TMO-reporting)

When I hear the O's (and already having heard both calls so many times), I start sending "report confirmation sequences" RO's.

Apparantly, Jimmy copied the RO's easily since he quickly turns into sending both calls with series of RRR's:   and even RRR with GL (good luck's).
The latter sequence is getting weak which is not so surprising with the moon at nearly 18° of elevation and leaving my last workable antenna lobe.
It is clear that ground gain helped a lot to enhance the signal level on the albeit modest  gain antenna.(12.85 dBd)

I hope you enjoyed the EME-signals, as much as I did!
Thanks Jimmy for your nice signals and the QSO!

In the QSO with SV1BTR, the power at the antenna was about 250W. His nice antenna consisting of 16 x 6el can be seen, here.
How you can make improve your signal by another 6dB is explained, here


This text was written on special request for a friend and for the commemoration of my father ON5SP, Roland, who
respectfully died on the 12th of November 2005.

 

Michel (Mike), OO7EH 

The special OO-prefix was used in 2005 for 175 years of belgian independence.
OO7EH is a difficult EME call just like ON5RR, whose 23/13cm EME station I regularly operate.
From January 1st, I'll be signing ON7EH again.

 

On 9-11-2007, Marc, ON5RR and I, helt a presentation with the title: "Introduction to EME" to a local radio club.
It can be found, here. Although the text is in dutch, there are plenty of pictures in English...!

A brief recap of the agenda:
ON7EH concentrated on the global part and 2m.
Marc described his adventures on 23 and 13cm EME.
The bloc diagrams of the different stations were shown and detailed.
ON5RR's latest masterpiece is also included, a homemade hydraulic elevation system, based upon a reworked 24" actuator!