Tag Archives: 144 MHz

VHF NFD

VHF NFD is a great time to experiment with new equipment. At GB0SNB over the years we have had great success experimenting with EME and Meteor scatter on VHF, and on this occasion, we wanted to try out Richard 500w 144 MHz Linear Amplifier.

We used the 9e LFA, masthead preamp and LMR 400 coax, mounted on the 10m pump up mast. The Icom 7100 provided the all mode VHF radio.

We could only operate for around 4 hrs, but that was enough to work 70 stations in 10 countries.

Ireland, Northern Ireland, Scotland, Wales, England, Isle of Man, France, Germany, Belgium and Netherlands.

Our best DX was GM4PPT at 522 KM.

Altogether a very enjoyable afternoon in the sun

RSGB Christmas Cumulative Contest

The RSGB have a series of Christmas Cumulative contests covering 50/70/144 and 433 MHz. The contest is a chance to put down that turkey sandwich and head out to play some radio in the winter sun. The contest run for 2 hrs, and activity is over 4 days. You can read the rules online, and activity is typically quite high.

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This year I joined George M1GEO at our contest site the Secret Nuclear Bunker

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The setup included.

Icom 7100, 9e Portable Tona and RF power was provided by a Linear Amp 300w solid state amplifier. The mast was a Racal PU 12 at 5m as the band was wide open with tropo propagation, this provided some interested DX. Mains power was provided by a silent running 2KW Honda generator.
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We managed to work 51 stations, with our best DX into Spain, EA1FDI in IN53 at 1143 KM.

The QSO map showed some great openings to the South and East.

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The temperature dropped quickly once the sun set, providing a spectacular sunset and the motivation to pack away quickly. Altogether a great afternoon playing radio, with some great propagation for a change.

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Thanks to everyone we worked, and all the best in 2017.

EME and MS Weekend

Members of the Secret Nuclear Bunker Contest Group (SNBCG) assembled at Kelvendon Hatch to try 144 MHz (Earth Moon Earth) EME and MS (Meteor Scatter) over the weekend of the ARRL EME event As a group we have tried with some success MS QSO and this helped lay the foundation for this weekend’s EME event.

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EME is particularly challenging due to the great distances involved and extreme path loss of the signal after its travelled close on 500,000 miles! The equipment and format of the QSO is similar to MS, we used the WSJT-X 1.7 (currently in Alpha) and  WSJT provided free from Joe Taylor K1JT website.

The weekend of the ARRL EME event was selected as it provided the best chance of working some of the EME “big guns”. Our equipment was quite modest by comparison, but included a

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9 Element LFA antenna designed by Justin G0KSC,

DG8 masthead preamp as designed by Ian GM3SEK with the kit available to order from hupRF.

Linear amp UK  Gemini 2 VHF amplifier delivering 300w.

Low loss LBC600 / LMR600 coax.

Icom 9100.

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We found we could often decode signals, and even the thrill of decoding signals from the K2VEE in EM79 via the moon was incredible…then it happened.

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We answered a CQ call by HB9Q and to our surprise they replied. This was our first and it turned out only EME QSO that weekend.

We continued to have quite a few MS QSO working Italy, Slovenia, Denmark and Norway and also a number of SSB contacts with 30 or so UK stations over the course of the weekend.

It is always nice to try a new mode and to succeed, you must never underestimate how difficult it is to achieve a QSO over that incredible distance. We achieved our goal of making an EME QSO, and regular decoding of signals via the moon. If this has inspired you to have a go I would encourage you to check out  K4MSG guide to small station EME. Also have a look at W5UN monster EME array that has bagged him over 11,000 EME QSO !

QST also published an interesting article “A Basic Approach to Moonbounce” that you may find interesting.

Plans are already being made for the next EME event in November…

50/70/144/432MHz Christmas Cumulatives

The RSGB 50/70/144/432MHz Christmas Cumulatives Contest series run from the 26th to the 29th of December each year and are intended as a bit of fun in the contester’s calendar.  The contest exchange is the usual RS(T), Serial Number and 6 character locator (e.g. JO01DQ).  These contests are really easy to become involved in, and often provide a good excuse to escape the house after Christmas.

This year, Dave M0TAZ, Dave M0YOL and George M1GEO decided to operate alfresco from the Bunker for the final two days (George having put in token entries on the 26th and 27th for 144 MHz from Home).  We operated on 50 MHz, 70 MHz and 144 MHz for the full 2 hours on a picnic table, in large overcoats on cold winter afternoons, packing up in the dark!

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144 MHz was to be our main band. For that we used an Icom IC7100 transceiver, DG-8 masthead-preamplifier (GM3SEK design/M1GEO construction), and 9-element tonna (10m AGL), powered from a large 60 Ah sealed lead acid battery.

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50 MHz and 70 MHz were run as a sub station. Again, using an Icom IC7100 transceiver and an InnovAntennas 6-element dual band (50/70MHz) yagi (7m AGL), with an 85 Ah leisure battery. The battery also provided mains power via a small inverter, which charged the logging laptops.

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The table below shows the number of QSOs made per band on each day, as well as the best DX station callsign, locator and distance. In order of fairness, we switched callsigns on the second day, all points awarded to the SNBCG.

Band  Info 28 Dec 2015 (M0TAZ/p) 29 Dec 2015 (M1GEO/p)
144 MHz # QSOs 30 40
DX MI0SMK
(IO64XL 525km)
GD8EXI
(IO74PC 430km)
70 MHz # QSOs 7 10
DX G4ASR
(IO81MX 226km)
G4YHF
(IO92XW 141km)
50 MHz # QSOs 8 13
DX GW5NF
(IO81KQ 236km)
GD8EXI
(IO74PC 430km)

The map below (click to zoom) shows the worked locators for the Contest. Almost all of the DX was worked on 144 MHz. Produced by OpenContest’s EDI Visualiser.

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A very enjoyable activation.  Even if it was a little cold! Lots more photographs here.

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