Tag Archives: M1GEO

Suffolk RED Field Day

Members of the SNBCG ventured out of Essex into Suffolk on the weekend of the 14-15 July 2018 to take part in a weekend of radio with Suffolk RED. The forecast was set fair with temperatures up to 30C, and with the offer to camp overnight on site.

George M1GEO, Chris G8OCV and Dave M0TAZ setup a VHF and HF station for some radio fun.

The VHF station comprised of a 9e LFA beam, LMR-400 coax and a DG8 masthead preamp. The Icom 7100 provided multimode support on 144 MHz, with the focus for the weekend on FT8. We managed to work 50 stations from 20 Maidenhead locators all over Europe, using a sold state 300w amplifier from Linear Amp UK.

Some highlights from the VHF log included.

DL3GAK at 662KM

F4CYH at 673 KM

OZ1BEF at 693 KM

OZ1BP at 698 KM

You can see a map of the stations worked below.

Power was provided by our 2kW Honda generator.

On Saturday we enjoyed an evening BBQ, and a chance to catch up with other members of the club.

Conditions on HF were not so good. Using an IC7610 and an Expert 1.3k-FA linear operating as M1GEO, only European contacts were made. We operated through the night.The 90 QSOs from the HF operation were loosely broken as follows:

SSB: 41 QSOs
CW: 35 QSOs
FT8: 14 QSOs

The packing down process took some time in the scorching heat. You can see the grass (or lack thereof) was also suffering.

Upminster Windmill GB2UW 2017

We arrived at Upminster Windmill at 9am on Saturday 13th May 2017 to begin setting up. The local council allowed onto the grounds and opened up the visitors centre for us.

Within 10 minutes we had the VHF antenna assembled and up. The HF doublet followed shortly after.

Dave M0TAZ quickly got setup inside the staff room at the visitors centre.

Web SDR Installed

Over the weekend of 31 March to 2 April 2017, a small group of us installed a KiwiSDR into the equipment rack at GB0SNB, alongside GB7KH repeater. The KiwiSDR (pictured below) is a cape for a BeagleBone single board computer, similar to the Raspberry Pi. It was kindly provided by David G7UVW, who also helped with the install. A direct link to the WebSDR at GB0SNB is found here: http://sdr.gb0snb.com/.

A new run of high quality CTF165 connects the receiver hardware inside the Shack to the WellBrook Loop antenna mounted on the mast.

This is the first stage in the installation, and the next step is to reduce the electrical noise present at the receiver; unfortunately, this may not be quite so easy in a bunker the size of this!

The receiver is available for public use, and may be found on SDR.hu. A direct link to the WebSDR at GB0SNB is found here: http://sdr.gb0snb.com/.

SSB AFS Contest

With snow on the ground and the sun in the sky it must be time to do some winter contesting. This weekend members took part in the RSGB affiliated society SSB contest, this takes part on 7 and 3.5 MHz from 2 till 6 PM.

With a small amount of snow on the ground, and ambient temperatures around +1C we opted for the inside operating position. The station comprised of an Icom 7600, Expert 1.3KFA solid state linear and a doublet antenna at 30m on the bunker tower.

Band conditions on 7 MHz only supported “long skip” with some good signals from Scotland and Ireland, although after a short while even these distances proved difficult. The maximum usable frequency had moved down to 4 MHz, and so a switch to 3.5 MHz was required.

A look on the Hack Green SDR confirmed 3.5 MHz was very busy, and we soon realised it was hard to find a run frequency. We also noticed a large amount of rasping electrical noise on 3.5 MHz, and so decided to investigate further. At times the signal meter was reading S9 or s9+10dB and so hearing weaker signals was proving impossible.

We changed the mains supply over from fixed to generator, and the noise floor dropped by 3 to 5 S points, interestingly it would seem the noise was coming from the mains, and so this would require some further investigation and most likely a mains filter project for Chris G8OCV.

The generator proved to be a little problematic, for some reason it was running a little lean, and so the engine was sounding rather more stressed than usual. This caused the generator to “brown out” a few times as it coughed, wheezed and spluttered in its attempt to generate circa 2KW at 240v. As they often say if something could go wrong, then it most probably would while your out in the field.

Hopefully the generator will be a simple fix, probably just needing a clean to the carburetor and no doubt another job to be added to the “to do list” before our next event.

While we had some fun, drank some tea and generally worked a few people I think its safe to say our score wont be breaking any records. As always we learnt a bit, had fun and generally tried to stay warm.

RSGB IOTA contest

Members of the SNB Contest Group came together to play some radio in the RSGB IOTA Contest. Some stations make the trek to far flung Islands in exotic parts of the world, we opted for the contest site close to Kelvedon Hatch in Essex.

The SNB contest site has the added bonus of a 50m onsite mast, making an ideal platform to hang dipoles. George M1GEO and myself decided to operate or respective calls from the two radio setup, using 3.5, 14, 21 and 28 MHz. George also added his 50/70 MHz beam on the mast, and this provided some interesting contacts using MS and JT65.

With the able assistance of Dave G7UVW, Chris G8OCV, Peter G0IAP we soon had the antenna ready.

Two pump up masts provided the following setup.

Clark 12m: Tri-band Beam A-3S covering 14, 21 and 28 MHz, with a 50/70 MHz beam.

Clark 10m : 15m 4e homebrew monobander.

Bunker: 3.5 MHz dipole at 30m centre

At various times we added some RF power from either the solid state Expert 1.3KFA or the HAL1200_Atlantic amplifier. We had some interaction between the close sited antennas, and at times this dictated the operating modes/times.

Fred G3SVK provided joined us as our CW operator, Fred can often be found in the lower pasts of the bands chasing big DX.

No sign of the great man this weekend, but, we live in hope.

70 MHz Trophy Contest and CW QRP HF

George M1GEO and Dave M0TAZ took part in the RSGB 70 MHz trophy contest this weekend at the Kelvedon hatch Secret Nuclear Bunker contest site. The weather was ideal for alfresco operating, using the Icom IC-7100 and homebrew 6e beam at 10m on the Racal PU12 mast. Using 50W and a 85Ah leisure battery we operated from 11am till 4 am.

Here you can see the PU12 and home-brew 6e 70 MHz beam. Operating from the base of the mast provided quick access to turn the beam. We managed to work 59 QSO with best DX into Scotland at 518 KM. The QSO map is shown here.

Meanwhile Rob M0VFC was operating QRP HF on 3.5, 7 and 14 MHz using a range of dipoles. Unfortunately the HF bands have been a challenge at the best of times during the day, and QRP provided to be interesting. After a few hrs operating Rob had completed 30 QSO, and under the conditions that counts as a sterling effort! Here you can see Rob operating from the boot of his car. No appearance from the great man.

Altogether another great weekend of alfresco operating in the sunshine.

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!

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.

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.

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
144 MHz	DX	MI0SMK (IO64XL 525km)	GD8EXI (IO74PC 430km)
70 MHz	# QSOs	7	10
70 MHz	DX	G4ASR (IO81MX 226km)	G4YHF (IO92XW 141km)
50 MHz	# QSOs	8	13
50 MHz	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.

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

GB0SNB/MX0SNB/M0SNB – Kelvedon Hatch Secret Nuclear Bunker

RSGB affiliated amateur radio contest group & special event station in a RGHQ 5.1 Cold War Nuclear Bunker, hidden in the depths of Essex!