{"id":1216,"date":"2015-06-02T11:18:39","date_gmt":"2015-06-02T11:18:39","guid":{"rendered":"http:\/\/www.tsgarc.uk\/?p=1216"},"modified":"2015-06-02T21:18:00","modified_gmt":"2015-06-02T21:18:00","slug":"field-weekend-2-operations","status":"publish","type":"post","link":"https:\/\/www.tsgarc.uk\/?p=1216","title":{"rendered":"Field weekend (2)"},"content":{"rendered":"

\"TSGARC<\/a>This is the second post in a three part series regarding the late May field weekend of the Thornbury and South Gloucestershire Amateur Radio Club (TSGARC).<\/p>\n

The trouble with camping during May is it gets light early! \u00a0Setup had been a long and busy day but the birds knew nothing of our endeavours and were chirping their happy, annoying\u00a0song at first light. \u00a0John (M3EQQ), despite\u00a0slumming it at the house, was up just as early as the birds and made sure everyone was awake also \ud83d\ude09 \u00a0To his credit he woke people\u00a0with a cuppa but it was clear there was to be no sleepy lie-in… \u00a0Mind you, it was going to be a busy day as there was food, rotor cable and plugs to purchase not to mention the completion of tasks outstanding from the previous day, delayed due to the extended time working upon the trailer tower.<\/p>\n

Generally speaking the noise floor at field\/portable sites is very low so you can hear almost everything, but making yourself heard is harder. \u00a0For this event I wanted to make the club\u00a0heard. \u00a0I’d heard many good stories and good signals from stations around the world using hex beams, so I purchased a Hexbeam from Anthony (MW0JZE)<\/a>. \u00a0This was fed with 400w from an\u00a0Ameritron AL-811XCE<\/a> amplifier. \u00a0The result was fantastic, not only could we hear the DX but we could also work it \ud83d\ude42<\/p>\n

\"MW0JZE<\/a>A large part of Saturday morning was spent assembling the hex. \u00a0Yes, it took a while as I was careful to assemble it correctly and as per the YouTube video instructions. \u00a0The antenna does not come with instructions which is a nuisance but the video instructions are excellent – just accessing them from a remote field is a little challenging… \u00a0Next time, however, assembly will be much quicker.<\/p>\n

After the hex was on the tower,\u00a0John (M3EQQ) and I went to get the much needed food and cable to replace the damaged rotor control cable. \u00a0The little castle town of Berkeley<\/a> has some good shops so food was not a problem, but cable needed a drive further afield. \u00a0Fortunately there is a branch of Attwoolls<\/a> not far away and they were able to supply 30m of cable and new connectors. \u00a0On our return it was clear the other members had been equally busy as\u00a0we now had a full sized vertical 80m loop and a\u00a0Beverage<\/a> receive only antenna for the 80m band. \u00a0Both the 80m loop and Beverage were connected to Rob’s (G4RNK) Kenwood TS-2000<\/a>.<\/p>\n

The Beverage was the creation of John (M0HFH) who\u00a0had read much about its ability to overcome noise on the lower frequency bands; the field weekend gave the ideal opportunity to try a 1.2\u03bb,\u00a080m Beverage. \u00a0Researching the many methods of construction John (M0HFH) came across some old papers published by the BBC<\/a> research team at Crowley. This gave in-sight into the height of the antenna from the ground and some surprising information, higher is not always better!<\/p>\n

The Beverage in various designs has been around since inventor Harold H. Beverage<\/a> developed the antenna design based on designs used by Edmond Bruce at the Otter Cliffs <\/a>US Transatlantic listening station in 1919. \u00a0The antenna used during our field weekend was the simplest form of this design and consisted of a 9:1 home-made balun feeding a long wire (120m galvanised steel electric fence wire) terminated at its far end with a non-inductive resistor into a copper earth stake with 4 x 15m radials. A similar ground plane earth system was set up at the feed end to be the earth point for the coax feeding the radio. The antenna was set at 1.5m above the ground.<\/p>\n

We attempted to match the Beverage terminating resistor to the earth system using a method adopted by W8JI<\/a>\u00a0which involved measuring the range (not the value) of SWR indicated on an MFJ-259 antenna analyser sweeping a frequency range from 1.8HHz to 7MHz and varying the termination resistor until the variation in SWR was minimised. \u00a0Kyle (M6KBP) recorded the values of SWR in the form of a table whilst John (M0HFH) varied the terminating resistance using a switched resistance box; communications from one end of the Beverage to the other by 2m handheld. \u00a0We settled for a termination resistance of 640 Ohms after some discussion of the results.<\/p>\n

Listening to weak signals on the lower frequency bands, in particular 160m, 80m, 40m, the Beverage revealed a substantial reduction in background noise and an increased signal to noise ratio as compared to the TSGARC\u00a0vertical with radials.<\/p>\n

Rob (G4RNK) was responsible for the 80m loop. \u00a0It was made from hard drawn, PVC coated, copper wire\u00a0about 265ft in length. \u00a0Its\u00a0matching stub was made from 75 Ohm coaxial cable a quarter wavelength long, (66%). \u00a0This matching stub was then connected to 50 Ohm coax which\u00a0ran back to the TS-2000 transceiver in the radio tent. With a view to working stations to the East (Europe) and the West (USA and beyond!), the loop was orientated to face East\/West with its nulls to the North and South. \u00a0The feed point of the loop was 1ft above\u00a0ground, the top of the antenna was at 30ft, suspended between to masts, so the mean height of the loop was 15ft for 80 the 80m band. This sort of antenna can be tuned for use on other bands with a transmatch antenna tuner.<\/p>\n

\"TSGARC<\/a>The hexbeam replaced the 2m beam on the trailer tower as at 12kgs it needed a strong\u00a0support. \u00a0The tower will support something much heavier but the other masts would have been overloaded. \u00a0It was raised to about 13m above ground where it pretty much remained for the rest of the weekend. Feeding the hex was an Icom IC-7200 and the aforementioned amplifier. \u00a0The system worked faultlessly and some nice contacts were made, my personal favourite being Tokyo. Lots of contacts were made by myself and the mic was shared with John (M3EQQ) and Kyle (M6KBP). \u00a0This gave John and Kyle the opportunity to see a capable station in operation and to talk with stations further afield.<\/p>\n

Around 20:00hrs GMT about S3 of pulse type interference was observed from the West, this continued till we shutdown just after midnight. \u00a0Interestingly the interference seemed to start around 14MHz and spread across all higher parts of the spectrum up to 50MHz. \u00a0Higher frequencies were not checked. \u00a0The interference was not observed on lower frequency bands – nothing was heard on 3.7MHz using the 80m loop. \u00a0Swinging the hex to the East also greatly reduced the interference. \u00a0In the adjacent field on the Western side there is a large overhead power line, but we understood this was not in operation… \u00a0If the interference was emanating from the power line I would have expected it to hear it on 80m. \u00a0A mystery, but there was speculation that it may be some farm machinery in the big shed located to the West.<\/p>\n

\"Tonna<\/a>Sunday morning dawned with another early call, cuppa and breakfast from John (M3EQQ). \u00a0 \u00a0 \u00a0 \u00a0The remaining 10m masts were erected. \u00a0With these we now had an impressive selection of antenna’s and the site looked great in the sunshine. \u00a0In total there was the 12m trailer tower, 2 x 10m masts supporting the Tonna 2m and 6m antennas plus 2 x 12\/10m masts supporting the 80m loop. \u00a0With this selection of antennas it was a shame that we didn’t have more radio’s and operators. \u00a0However, Rex (G4RAE) made use of the 5-element, 6m Yagi making several Morse contacts.<\/p>\n

HF propagation was superb, strong\u00a0phone contacts\u00a0were had with Aruba on 20m, 17m and 15m, \u00a0St. Helena and numerous other stations in the USA. \u00a0It was clear that the hex, amplifier combination was delivering good performance. \u00a0Band conditions remained excellent till shutdown soon after midnight. \u00a0The mic was again shared with John and Kyle allowing them to make some excellent contacts. \u00a0The interference noted the previous evening was not present till a similar time when it returned with exactly the same characteristics.<\/p>\n

Shirley, John’s (M0HFH) partner, lent the club her wood burning fire. \u00a0Its an excellent piece of kit that burns wood exceptionally well and provides lots of surface area on which to cook. \u00a0So late in the afternoon, John (M3EQQ) started to barbecue chicken and sausages. \u00a0Whilst we ate the food a friend of Rob’s (G4RNK) arrived with his quadcopter. \u00a0The quadcopter had a small camera attached and despite it being a little windy good photo’s of the site were captured.<\/p>\n

\"9-ele,<\/a>Monday was very different, the HF bands appeared to be in good shape for a few hours in the early morning when we had some great contacts, but soon after deteriorated leaving signals either well down on preceding days or non-existent. \u00a0Andrew (G0RVM) took the opportunity to run an antenna workshop with Kyle (M6KBP). \u00a0The workshop started with the basic principles of the dipole then progressed to calculating its size, construction and finally adjustments for resonance and on-air testing. \u00a0The dipole was made for the 17m band and it clearly worked when compared with the hex. \u00a0Another Foundation class member,\u00a0Derek\u00a0(M6xxx) got involved, helping Kyle with the physical construction of the dipole.<\/p>\n

Nighttime arrived and conditions appeared to improve greatly. \u00a0Again many contacts were made culminating with an excellent conversation between Kyle (M6KBP) and Ray (N4LEM)<\/a>\u00a0using his Collins HF-80<\/a>.<\/p>\n

Andrew<\/em>\u00a0G0RVM, John M0HFH and Rob G4RNK<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"

This is the second post in a three part series regarding the late May field weekend of the Thornbury and South Gloucestershire Amateur Radio Club (TSGARC). The trouble with camping during May is it gets light early! \u00a0Setup had been … Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":7,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[5],"tags":[32,9,10,11,39,27,12],"class_list":["post-1216","post","type-post","status-publish","format-standard","hentry","category-news","tag-2m","tag-antenna","tag-cw","tag-morse","tag-portable","tag-tsgarc","tag-vhf"],"aioseo_notices":[],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.tsgarc.uk\/index.php?rest_route=\/wp\/v2\/posts\/1216","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.tsgarc.uk\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.tsgarc.uk\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.tsgarc.uk\/index.php?rest_route=\/wp\/v2\/users\/7"}],"replies":[{"embeddable":true,"href":"https:\/\/www.tsgarc.uk\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1216"}],"version-history":[{"count":20,"href":"https:\/\/www.tsgarc.uk\/index.php?rest_route=\/wp\/v2\/posts\/1216\/revisions"}],"predecessor-version":[{"id":1300,"href":"https:\/\/www.tsgarc.uk\/index.php?rest_route=\/wp\/v2\/posts\/1216\/revisions\/1300"}],"wp:attachment":[{"href":"https:\/\/www.tsgarc.uk\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1216"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.tsgarc.uk\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1216"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.tsgarc.uk\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1216"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}