Category Archives: SNBCG

August Bank Holiday Weekend of Radio

August is the last Bank Holiday of the year, and with the weather set to be 30c+, it provided the ideal weekend to play some radio.

Members of LEFARS and SNBCG came together at Kelvedon Hatch Secret Nuclear bunker for a 3 day radio weekend, including BBQ and camping. Some members of the advanced party arrived on Friday evening helping to set up the operating tents.

The 40m vertical was the first antenna to go up, this included 4 elevated radials.

The next antenna was the 3e 18 MHz beam, this was fitted onto the 12m SCAM mast.

The operating tent was completed with the IC7300 and IC7610 and Expert 1.3K solid-state amplifier.

Peter was delighted to use the 7 MHz vertical and linear, commenting on how much fun it was to run a pile-up! The weekend was all about having fun and trying out new things, Dick G4DDP completed a number of QSO on 50 and 70 MHz working SPe all over EU.

Special thanks to John who repaired my headset with a mono jack plug he de-soldered from his own headset. Thanks, John!

Vintage Dave also decide to operate in period costume, adding to the nostalgia of his vintage wireless equipment.

The BBQ provided by some excellent food, thanks to Ron and Karen for setting this up and Dave M0MDB for his Chillie.

Thanks to Piotr for this clip, it gives you some idea how busy 7 MHz can be on a field day.

50 MHz Trophy Cup.

The RSGB 50 MHz trophy cup fan over the weekend of 16/17th June, taking advantage of what should be some interesting conditions on 50 MHz. SNBCG have taken part in the contest for a number of years now and typically use the following equipment.

10m pump up mast, 6e Yagi and a solid state amplifier delivering 400w.

The level of activity is dictated by the band conditions, add a little sporadic E and the QSO rates soar to near HF contesting levels. If conditions remain flat, then this is reflected in the number of QSO and the best DX achieved over the weekend.

Sadly on this weekend conditions did not live up to their best, and the sporadic E was a little too sporadic to make it interesting. We did manage to work some nice stations, and over the course of the weekend completed 130 QSO in 18 DXCC.

We closed down overnight, as the activity is particularly low so operating time was limited.

CQWW SSB 2017

The CQWW SSB event runs over the last weekend of October and covers all contest bands from 1.8 MHz to 28 MHz. The event is one of the largest international events of the HF calendar and encourages stations to operate from far-flung and exotic parts of the world.

We opted for the sun-drenched shores near Ongar in Essex, using our contest site at the Kelvedon Hatch Secret Nuclear Bunker. We had decided before the event it would be more of a casual entry, as the contest had started at 00:00 Hrs on the previous Friday/Saturday morning. We have previously taken part in the event, with a most notable event in 2015.

This year we used a 7 MHz vertical, with elevated radials, and a 3e multiband beam for 28/21/14 MHz @ 10m.

3e Multiband Beam7 MHz Vertical

The HF bands remained in good shape, with some good openings on 28 and 21 MHz and the vertical worked well at 7 MHz. The lower HF bands were predictably crowded, so I concentrated on search and pounce on the higher bands.

George M1GEO and Fred G3SVK with a great sunset behind.

QSO and DXCC per band.

28 MHz provided some interesting DX with a lot of station from Argentina, Brazil, French Guiana, Chile, Suriname, Namibia, South Africa, Qatar and Reunion Island.

28 MHz QSO Map

All Bands QSO Map

In total, we worked 417 QSO in 76 DXCC and had some fun on the bands.

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.

Easter Field Weekend

During the long Easter weekend members of the SNBCG came together for a radio weekend. Over the course of the four days, two HF stations were set up; one on 7 MHz and the other roaming between 1.8 and 28 MHz depending on propagation.

Dave M0TAZ decided he would try a 1/4 wave vertical on 7 MHz and use his recently purchased push-together fibreglass poles. These poles are often sold at radio rallies in packs of 5 (each pole 1.3 metres) to give an overall height of 6.5 meters. Using two packs of the poles, the required height of 10 metres was achieved.

Chris G8OCV had made some supporting guy rings, these provided anchor points for the guy lines at approximately 4 and 8 meters. The first attempt didn’t quite go to plan, it simply wasn’t possible to walk up the 10m pole, as we found out when we exceed the bend radius of one of the poles. Lesson learned it didn’t make any difference as the fracture was in the joining section that was simply moved to the first section. In the end, we used 9 poles, giving us a total height of 11 meters with a simple wire running down the side for the radiator.

Six 6 radials were cut, each around 10 meters in length, and the antenna was mounted at the base of a wire fence. The earthing system included the 6 radials and the wire fence, and this provided a reasonable match around 1.5:1 at 7.150 MHz. It would have been much easier to use a push-up fishing/roach style pole but experience has taught Dave that these can be tricky to keep up without guying and tapeing over the joints. As we wanted to run linear amplifiers this weekend, the prospect of the pole moving in the wind and/or falling down made, we made up our minds to use push together poles as the first choice. The antenna was fed with coax with a choke unun (or balun) at its base to stop the coax radiating, and this needed to be capable of high power.

The antenna provided reliable service all weekend, and with the addition of 400W yielded over 200 contacts in 40 DXCC countries. An enjoyable part of the weekend was working DX stations later in the evenings, including the USA, Chile, Mozambique, Guinea-Bissau, Israel, UAE, Armenia and Asiatic Russia all on the 40 metre vertical.

DXCC Breakdown on 40 metre vertical

George M1GEO, Fred G3SVK and others operated the other station. George chased some good DX and Fred worked several hundred stations as “GB0SNB” in CW.

Below we see the DXCC breakdown of the second station using the mast doublet on 160 and 80 metres, and the beam (pictured above) on the higher bands. Some of the DX on the doublet and beam included several QSOs into Japan, Fiji, Trinidad, Guinea-Bissau, Cayman Islands and Argentina.

DXCC Breakdown on 160m doublet and HF beam

We also had time for a BBQ and some excellent curries provided by Fred G3SVK. It was nice to see Camb Hams members Geoff G0DDX and Linda G0TPX, and LEFARS members Derek M0XDC, Dave M0MBD and Dave M0VID. RSGB regional man Peter G0DZB also joined us for the afternoon, making the most of the good weather for a ride on his motorbike, and Bill G0IQK popped in on the Sunday afternoon.

Dave M0YOL worked some data modes using his portable setup. All in all, a good weekend was had by all.

The first 50 MHz contest of the year

Members of the SNBCG took part in the first 50 MHz contest of the year at the Kelvedon Hatch club call M0SNB. The contest ran from for 3 hrs on Sunday morning (10 till 1) the weather was forecast to be 23C and sunny. We opted to operate outdoors using a 5e beam on a 10m pump up mast. The radio was an Icom 7600 and Expert 1.3 K-FA provided 400w power was provided by a Honda EU20 generator.

The band seemed very busy, with lots of stations taking part, and I think the good weather helped encourage more portable operating. Over the course of the next 3 hrs we worked 63 Q with our best DX into EI at 585 KM. Conditions seemed average, but we did have some very rapid QSO on some of the longer paths, sounded very much like aircraft flutter.

A very enjoyable contest in the sun, thanks to everyone we worked.

You can find the claimed scores online.

You can view the RSGB VHF contest calendar online

You can read more about the Kelvedon Hatch Secret Nuclear Bunker and the SNBCG here.

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 MHz Trophy Cup & International Museums Weekend

The weekend of the 18th and 19th of June saw members of the group assemble to operate as M0SNB for the 50 MHz Trophy Cup and GB0SNB for the International Museums Weekend.

Over the course of 24 hours for the 50 MHz Trophy, we made a total of 218 QSOs, with our best DX to UZ5U (2320 km). The map shows our contacts.

Maps and logs from the Museums weekend will be added once the logs arrive from the IWM station manager.

Upminster Windmill on the air

National Mills on the air weekend is a chance to combine amateur radio with the national windmills open day. Although not directly related to the bunker, the SNBCG decided to activate Upminster windmill as it is our local mill – it was a delight to operate on the green opposite the mill once again! The mill has stood on the green in various guises since 1803, and recently thanks to the National Lottery Heritage Fund its just secured large grant to complete some restoration and the building of a education and visitors centre.

Unfortunately due to the ongoing building work members of the public were not able to visit the mill this year, but that didn’t stop them coming to visit us operating radio in the field.

(Back Left Dave M0YOL, From Left John 9H5G, Peter G0IAP, Chris G8OCV and George M1GEO)

This years event was well attending, with our furthest operator travelling from Malta to guest operate. John 9H5G operating (left station) retired to Malta, but often travels back to the UK. We were delighted to welcome him to the team, and he was soon pressed into service on 7 MHz managing the pile-up.

We operated using 2 x Icom 7100, making use of 5, 7, and 14 MHz on HF and 70 and 144 MHz on VHF. Over the course of the weekend we contacted over 30 mills and 150 others stations from all over Europe.

Thanks to everyone we worked, QSL is via eqsl.cc 73

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!