Moonbounce on 6m, Environmentally Friendly Antenna Mast, Vintage Radio Station, Band Reports & more ...
March April
Worthing & District Amateur Radio Club Established 1948
http://www.wadarc.org.uk - email info@wadarc.org.uk President: G8FMJ John Slater
Life Vice President: G8MSQ Peter Robinson
WADARC meet alternate Wednesdays, 8pm in the Lancing Parish Hall, South Street, Lancing BN15 8AJ. All that have an interest in radio communications and associate subjects, whether a licensed amateur or not, are invited. WADARC can also arrange training for people to undertake the Radio Amateur Foundation, Intermediate & Advanced licenses. WADARC Committee 2011 - 2012 Kelvan! ! Rod! ! Sandra ! ! John ! ! Richard! ! Jonathan! Peter! ! Pete! ! Andy! !
M0KEL! ! M0RDV! ! G0KAG! ! G8FMJ! ! G7NLZ! ! G1EXG! ! G4LKW! ! M6PAP! ! M6RFE! !
Chairman! ! Secretary! ! Treasurer! ! President! ! Ordinary Member!! Ordinary Member!! Ordinary Member!! Ordinary Member!! Ordinary Member!!
WADARC Ex Officio 2011 - 2012 John ! Peter! Chris ! Graham Phil! Martin !
! ! ! ! ! !
G8FMJ! ! G8MSQ! ! G3NDJ! ! G4FNL! ! G4UDU! ! M0ADY ! !
Publicity!! ! Membership Manager! Awards Manager! ! Contest Manager!! Ragchew Editor! ! Club Webmaster! !
WADARC Foundation, Intermediate & Advanced Courses & Licensing Kelvan! !
M0KEL! !
Training Officer! !
WADARC Club Nets - all times are local I am currently obtaining new information on club nets. 2m on 145.425 is an often used frequency
Contents From the Editor's Keyboard!
1
Chairman’s Chatter!
1
Presidential Ponderings!
1
6m EME!
3
Genetically Engineered Antenna Masts!
12
A 1939 Vintage Radio station - Part 1!
18
Band Reports!
21
Significant Achievement!
23
Club program, activities and dates for the diary!
25
From the Editor's Keyboard At last we have the next issue of Ragchew. It has been a bit of a struggle with the pressure of work over the last couple of months and there has been a lot to do plus a large amount of driving around the country but compared to our president's workload I have been sitting around all day with nothing to do! There are some interesting articles to read and I must thank those who have contributed and please can we have more. Members profiles, just send me a description of your way into amateur radio plus your operating interests as we all have favourite operating modes. So enjoy Ragchew, I will keep it short as we have a lot of pages in the issue. Phil G4UDU
Chairman’s Chatter Well its now March the end of the three month trial of meeting twice a month, can the committee have your comments on how you think its going. I have some feedback - some members saying can we meet 2nd & 4th Wednesdays, ok as it is, and go back to weekly. The main problem is we need someone to organise the programme so any volunteers please. No volunteers, no programme Also looking for storage of tent. The programme we have had so far has been good and the club membership is standing at 60 Hope to see you all at club meetings and on the air. 73 Kelvan Gale M0KEL
Presidential Ponderings Time for another Ragchew and a vote of thanks to Phil for his efforts in the producing this for us all and keeping up the fine traditions of past editors. And talking of Ragchew, I would like to say how much I enjoyed reading Ben’s article in the last edition and I'm looking forward to the next chapter.
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I am usually a fairly positive person and always try and look for the Up-Side of any situation but I am finding this increasingly difficult where the club is concerned, having tried my best by most means possible it seems that we do not have anyone in the club who is willing to have a go at organising the club programme. I have done this for some years now and managed to balance this with a full-time job running my business but my situation at the moment leaves me little or no spare time for the foreseeable future It is NOT a difficult job and I would be more than willing to assist in an advisory capacity to start with AND we are likely to continue with twice monthly meetings so it is half the work it used to be. I do believe that if this role is not taken up fairly soon the club will just drift along and start to lose members as there will be nothing to attract them to club meetings. Surely in a club with a membership in excess of 60 there must be someone who could do this job. I would like to thank the regular Hard-Core of members that do attend the club meetings, some of whom come long distances to support the club. The meetings are always a good time to get together and chat, to find out what other members have been up to and to seek advice on almost any subject. It would, however, be nice to see a few more faces. As a club we have various special events coming up this year, Mills weekend, Lighthouse weekend, Selsey Lifeboat weekend and so on. All of these events boost the club's profile and although they involve a degree of work to set up, they are usually enjoyed by all who take part. If you have not got involved in the past, please give it some thought for this year. Even though there is not always a lot to report, I will keep up my usual weekly ramblings and would like to thank all those who have emailed me back on various subjects. It is very gratifying to know that so many of you do read them. I hope to be back at the club on a more regular basis once the dreaded switchover has been completed and my customers stop moaning about having to retune their TVs, poor darlings‌ I hope the next one will be on a more positive note. 73, John G8FMJ
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6m EME Dick G1CWP/G0LFF Moonbounce or Earth-Moon-Earth (EME) communications, those three letters conjure up thoughts of giant steerable antenna arrays and high power beyond the means of most hams. For example, G4DEZ, G5WQ and G8BCG all have experimental NOVs for 32dbw (1500W) at the array. However, as the average EME path loss at 50MHz is -242.9dB, I wondered if EME would be possible with a modest station consisting of a twenty-year-old Icom IC-726 (10W on 6m), a 100W BNOS amplifier and a short boom (0.7 wavelength) five-element Yagi without elevation wall mounted just above the roof of the house. The moon is a passive reflector and when it is rising in one part of the world, it will be setting in another so there will be a common horizon moon for any two stations round the world at least once a month. Bearing in mind it has an elliptical orbit, its distance varies by some 50,345 kilometres with a path loss difference of some 2dB. I decided in 2010 to start on a project to test my theory. First on my list was a new 5-element Tonna Yagi that I was familiar with from my 6m DX in the eighties. Next was a low-noise USB soundcard interfaced between the rig and the laptop and a download of the WSJT DSP program that’s used almost exclusively for Meteor Scatter (MS) and EME. Both EME and MS require accurate timing for TX and RX periods and the PC clock is just not accurate enough so it was necessary to replace it with a downloaded atomic based clock. The results were quite good on medium to long range MS, with just the odd decodes on EME. The next job was to source another antenna because CAD designed antennas have come a long way since Frank Tonna F9FT designed his Yagis. The buzzwords seemed to be Loop Fed Array (LFA) designed by Justin Johnson G0KSC so I chose to build the 4.4m five-element LFA Yagi with a claimed 8.48dBd forward gain to fit within my flowerpot size garden. Ken Gibson G3WYN volunteered his antenna analyser to tune the LFA, which happened to be spot on with a 50 Ohm 1:1 match following Justin’s dimensions. Living in an urban environment, I was astounded with the loss of local hash – it is a very quiet antenna. Completing the setup coincided with the Lunar Perigee and I immediately decoded Mario K2ZD off the setting moon – now the challenge was really on. Next I changed the feeder to Andrews LDF4-50, which the late Eric Letts G3RXJ made up for me some 25 years previously for my low power 2m/70cm satellite array. I also invested in a low noise masthead GaAsFET pre-amp. By using the
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LDF4-50, the low noise pre-amp can be placed just before the receiver rather than at the masthead, with all the complexities that involves.
Earth and its moon as photographed from Mars Each month at Perigee I would listen for EME signals with the moon setting westwards as that is my best direction out on VHF. Results were interesting with the moon passing through the antenna lobes. Then, on Saturday 22nd October 2011, I tuned to monitor Lance W7GJ as he announced he was calling CQ for
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Europe moonset. I soon decoded Lance running his 1500W into 4 x 9-element M2 6M9KHW long boom (2.5 wavelength) Yagis with 18.7dBd gain, giving him in excess of 100kW ERP – not only that, he was audible in the speaker.
The short boom five element LFA yagi mounted just above the roof I contacted Lance via the ON4KST chat site to let him know that I was receiving him with speaker copy with the moon at 20 plus degrees above the horizon. He immediately responded with “call me” and so the QSO began. Without a doubt Lance is one of the most efficient and biggest 6m EME stations in the world. Located in Montana (DN27ub), he runs his fully steerable EME station and specialises in looking for fixed horizon stations at their moonrise/set. Everything looked fine with copy both ways. I waited patiently, transmitting every second period as the moon passed through my second lobe into the null, then at 13 degrees he was back in again, now on my first lobe where I had loud, very loud copy in the speaker and the QSO completed with Lance receiving me 0/-26dB.
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The following day I attempted a sked with Mario K2ZD, with negative results my end but he copied me and posted his decode of me afterwards.
RXing W7GJ on my 2nd lobe with a best of -21db with the moon over 20 deg above horizon So, it is possible with a very modest setup with careful attention to detail. In fact, Lance has worked a station running just 100W into a three-element Yagi looking out over a sea path with ideal lunar conditions. 50MHz is arguably one of the LEAST suitable and most challenging bands for EME. Signals are almost always marginal, susceptible to geomagnetic interference and subject to high degradation from background sky noise but what
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else do you do on 6m during the solar cycle minimum when F2 conditions are nonexistent? Don’t put away the 6m equipment for 10 years, think outside the box and make long path contacts instead. I mean really long path contacts like half a million miles (800,000 kilometres)!
My first 6m QSO complete with no DSP filtering activated (Freeze unticked) Small stations are capable of EME and working real long path on 50MHz is now very possible and unquestionably brings the magic back to the ‘Magic Band’ – no matter where we are in the solar cycle or how poor the solar cycle turns out to be. In fact, what many term ‘poor band conditions’ are often the most ideal 6m EME conditions!
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50MHz EME is a challenge but contacts are now within reach of most well equipped stations with a bit of patience. To date, I am assured there are only about 100 6m stations worldwide with confirmed EME QSOs. What Makes 6M EME Possible Now? Until 2002, an accomplishment such as making a contact on 6m EME was about an ‘S Unit’ or two beyond a QSO for most stations. On 6m moonbounce, where signals are just on the threshold of detection, 5 to 10dB is a HUGE amount! However, several very significant developments have combined to make QSOs possible. A single Yagi aimed at the horizon can develop additional ground gain. This is extra gain that can often make the antenna perform more like two or even four times as many antennas! This extra 3-6dB is only available at certain elevations and it depends on the local terrain, the ground conductivity, the antenna gain and its height above the ground.
The third GG lobe equates to roughly the free space antenna gain when aimed skywards
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The signals reflected up to the antenna create sharp ‘ground gain lobes’ and when the moon passes in front of these lobes, signals can be greatly enhanced. The trick is to aim at the rising/setting moon and catch it as it passes through the elevated antenna lobes. In my case, when working W7GJ, my first and strongest decodes were when the moon was just over 20 degrees above the horizon, passing through my second lobe. The next period was at 13 degrees, passing through my first lobe. The higher you can mount the antenna, the lower the lobes become. In an urban environment, it is quite common to receive stronger signals on the second lobe due to ground clutter, houses, cars and so on. That is how smaller single Yagi stations on 6m without elevation are able to complete EME contacts. The first two lobes are significantly stronger than the third, which is about equivalent to the free space gain of the antenna when pointed skywards. When the EME signals are enhanced by the moon passing briefly through the lobes for a particular antenna installation – and if the polarity of the signals also happens to be properly aligned – the Yagi aimed at the horizon will receive the weak EME signals. The specialised weak signal mode of JT65 (included in the WSJT computer program developed by Dr Joe Taylor K1JT) provides an improved sensitivity of more than 10dB compared to CW. These innovations, along with computeroptimised Yagi antennas, have significantly improved both receive and transmit capabilities. The difference between the old ubiquitous Yagis of 30 years ago and the computer-optimised Yagis of today is substantial and noticeable even during non-EME contacts. Combined, they have turned very difficult weak signal accomplishments like 6m EME into very real possibilities and will not go amiss during the rough and tumble of terrestrial DX chasing. 6M Meteor Scatter (MS) 6M MS contacts are easy compared to the higher VHF bands, with longer and stronger bursts and MS QSOs are possible on most days of the year. During predicted MS showers, activity is quite intense with many rare grids, including wet squares, being activated by portable stations. With the height at which meteors ionise when entering the Earth’s atmosphere and the curvature of the earth, the maximum distance a QSO is achievable is about 2,250 kilometres, which covers most of Europe.
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As my first lobe is up at about 12-13 degrees due to lack of antenna height and the terrain, my MS limit is just on the 2,000 kilometres mark during predicted MS showers. The preferred mode in Europe is JT6M from the WSJT program, with ISCAT being beta tested. I have also had terrestrial QSOs into Africa, Asia and North America on 6M using WSJT modes with multi-hop Sporadic-E propagation. There are several ZS6 stations working WSJT via TEP to Europe as the sun approaches sunspot maximum. 6m Sporadic-E, Aurora & F2 propagation Multi-hop Sporadic-E propagation occurs annually during the summer months from May through to July and occasionally in December too. Signals vary from the very weak, almost EME level, to S9+++. The footprint of the received signals can be very small, with stations just a few kilometres away giving vastly different reports. Openings can vary from just a few minutes to hours on end.
The G1CWP/G0LFF temporary station with the Bird showing just 90w TX while working W7GJ
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It is possible to work Africa, Asia, North America and the Caribbean with just a ground plane vertical on multi-hop Es as I have demonstrated. Last year, Max Wild DK1MAX achieved WAC inside 24 hours via multi-hop Es, not bad for solar minimum. Nearing solar maximum, TEP propagation up to the Mediterranean can get a lift by Sporadic-E to north Europe, giving access to South Africa and South America on 6M. Auroral propagation is most evident during solar activity nearing the solar peak. Again, it is a mode of propagation that allows inter-Europe contacts with both stations beaming towards the dancing auroral curtain. CW sounds very weak and raspy and SSB is also distorted, sounding very ghost-like and those not familiar with it sometimes check their receivers for faults. F2 propagation is only available during solar maximum with worldwide openings sometimes lasting just minutes. There are many 6M DXpeditions to activate rare countries/grids during the solar peak. I Worked all Continents (WAC) back in 1989 after working a host of VK8s who were on a local net in Alice Springs to get Oceania in the log. As with any QSO by whatever mode of contact, there are two constants always needed: propagation and, of course, someone at the other end.
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I am happy to try to answer any queries about using WSJT, digital mode operations, EME and MS procedures, bearing in mind I am not an expert, just a Radio Amateur. Email: G1CWP@burgess-hill.co.uk Reference EME 2010 Hand book by Dr Joe Taylor K1JT: http://physics.princeton.edu/pulsar/K1JT/EME_2010_Hbk.pdf WSJT DSP program by Dr Joe Taylor K1JT: http://physics.princeton.edu/pulsar/K1JT/wsjt.html Atomic Clock: http:// www.thinkman.com/dimension4/ 6m longest path comes of Age by Lance Collister W7GJ: http://www.bigskyspaces.com/w7gj/6mEMEtoday.pdf SignaLink USB interface: http://www.tigertronics.com/slusbmain.htm 5 element LFA by Justin Johnson G0KSC: http://www.g0ksc.co.uk/5el-44mtrboom-lfa.html G0LFF building the LFA: http://www.mwadui.com/G0LFF/LFA.htm Low noise masthead Preamplifier: http://www.ssbusa.com/gaasfet.html
Genetically Engineered Antenna Masts A primary problem facing every Amateur Radio enthusiast is in providing adequate and reliable supports for whatever type of antenna is deemed suitable for their envisaged activities. Of all the equipment comprising a radio station, the choice of antenna is critical to performance and results on air. An inadequate antenna is akin to a Lotus sports car being fitted with square wheels. A group of scientists in south west England, having been heavily involved in genetic engineering for agriculture since the beginning of the technology, suddenly found themselves redundant due to lack of research funding. The situation was serious, all of them having families and ongoing financial commitments, they set about seeking alternative employment, until one of them – a short wave listener since his schooldays and being well aware of the difficulties
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experience in obtaining and erecting antenna masts – suggested to his colleagues that they might invest their redundancy monies and combined experience into growing antenna masts! After the laughter died down and another round of beer, his friends realised he was dead serious. Thus, G-Masts Nursery was born. The next problem was how to make the idea work. Several weeks went into investigating various tree species as likely candidates, each in turn being discarded for one or more reasons, usually being too slow growing. A chance viewing of a TV documentary revealed the solution, not to use trees, but to adopt a type of grass – bamboo. Bamboo turned out to be the ideal choice as an antenna support for several reasons. Primarily because it is the fastest growing plant species on Earth and because it is completely self supporting with no need for either guys or a specially constructed foundation. When fully seasoned it is extremely strong and lightweight. So another application for the plant was added to its already long list of uses. Giant bamboo (Gigantochloa Verticillata) out of the thousands of bamboos was the variety chosen for the project. Bamboos are perennial and have massive growth rate, achieving 121cm (48 in) in a day; they have been known to achieve that growth in an hour, for short periods. Giants can exceed 25m (80ft) and bamboo diameter reduces very little over its height. Europe and Antarctica are the only regions not having native bamboos and since the startling growth rates are best attained in the natural, warm, humid tropical habitats, the plants needed genetic modification to replicate that performance in Europe’s temperate climate. This was achieved by modifying the bamboo with genes from two other plants. First, from Rhubarb which, while also possessing a massive growth rate, is very comfortable in very cold conditions. That property was essential in ‘acclimatising’ the bamboos. Second, to further boost the bamboo’s growth rate, genes were transferred from peonies, another quickly growing species. All those characteristics combined, resulting in a bamboo variety capable of reaching full growth in the UK from a spring planting, by mid-summer.
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Figure1 shows a fast grown light weight bamboo mast about 60 feet high, with a base diameter of about 20 inches.
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Other genetic changes became necessary and though more challenging, were successfully incorporated. The most important was to prevent the plant growing towards the Sun. That is less of a problem in climates where the Sun is mostly overhead. The result is bamboos which grow almost perfectly straight upwards, regardless of our Sun’s lower angle. Two variants of Giant Bamboo have been developed; A faster growing bamboo intended for taller masts and lower load bearing, such as wire antennas; and a slower grower for a shorter sturdier substitute for supporting heavier beam antennas and rotators.
Figure 2, is a sturdier 40 foot bamboo with about 30 inches base diameter supporting a 10m beam.
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The whole concept is to grow masts in situ where they will be used. Consequently, it is impossible for the nursery to hold a stock of ‘ready made’ masts. Seedlings are supplied to order at which time the seeds are planted. Growth of a seedling takes about ten days from sowing in a warm glasshouse. This has the advantage that the nursery does not need much ground space for storing plants. For each order, when the seedlings are sufficiently established, they are dispatched by courier; direct in the UK or by air overseas. Each consignment is fully guaranteed and comes with detailed instructions for planting, feeding and cultivation. Initially the operation is UK based but if interest conforms to market research, as it appears to be doing, then other nurseries can be established around the world. On delivery, seedlings should be planted in their planned location, with readily available fertilisers applied as directed. Then the plant is left to grow on its own, with very little to do apart from keeping the growing medium moist. Excepting the growing tip, there is no leaf growth. In the unlikely event that side shoots develop, on the stem or near the base, they can be pared off close with a sharp pruning knife. SAFETY WARNING: Unlike the young shoots of most bamboos which are edible, those of Giant bamboos do contain cyanide, so should be composted or disposed of safely. When the desired mast height is reached, growth must be stopped by cutting off the growing tip. Then the bamboo needs to be killed to prevent side growth, by injecting a proprietary weed killer into the base of the stem, (syringes such as those for printer ink cartridge refilling kits are ideal for this). The bamboo will gradually dry out and become seasoned during the following 12 months, when it will gradually reach full strength. However, antennas can be installed straight away. The wall thickness will be approximately one inch and will take wood screws for the usual antenna fastenings. For beams and rotators, it is best to have a custom made assembly welded up by a local factory or car repair shop for bolting or clamping to the top of the mast to support the rotator and beam. While use of beam aerials with bamboo masts might still require planning permission, use of a ‘live’ antenna support obviates many problems such as complaints from neighbours. Your local council might actually impose a Tree Preservation Order on your mast!
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The author has used smaller bamboo poles several times and found them very successful; as a framework for tri-band cubical quads and as a framework for a wire two element 20m Yagi. The useful life for the bamboo masts is expected to be 10 to 15 years and at the purchase price of only about 20 pounds (comparable with fruit tree saplings), can be economically replaced. The scrapped mast can be sawn into logs and used as heating fuel. During development, several ‘hiccups’ occurred; a giant mutant rhubarb caused some amusement but was too woody to be of any commercial value. Genetic engineering, although thoroughly understood, is not absolutely predictable. So there is an extremely remote chance a customer’s mast might sprout enormous rhubarb leaves, which tend to be very noisy in windy conditions. They can be easily be pruned off and will not reoccur. The future: Development of bamboo masts is ongoing to further improve the product. Special interest is in climate change, which for 100 years has shown a gradual warming. The global sea ice charts on the Internet show this since records began 30 years ago. For the past six years ice areas have remained fairly constant, suggesting the ‘warming’ may have bottomed out. The charts over the next few years will show whether the warming is about to reverse and become cooling. Consequently, genetic changes are being sought so the bamboo can withstand the much colder climates the UK has experienced in the past, when ice skating on the Thames was an annual event. An extensive marketing campaign will begin as soon as the product is market ready. As well as radio amateurs, commercial and military customers have shown great interest. Watch this space. Denzil Roden, G3KXF.
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A 1939 Vintage Radio station - Part 1 Peter Dodd G3LDO This article describes a project to build and operate a 1939 era vintage radio station. The purpose of this project was to provide a demonstration working station on the 7, 10 and 14MHz amateur radio frequency bands using CW and to experience what it was like to operate equipment of this era. The article is in three parts – the first describes the receiver and the second the transmitter. Experience operating this vintage station and how the transmitter and receiver were integrated will be described in part three. The National HRO Receiver. The receiver of choice was the National HRO receiver because it is a genuine vintage receiver designed and produced in 1935. Furthermore, there are quite a lot of these receivers about and they work well when restored to their original condition. The National HRO was the primary receiver for the early period of the last war so it must have been highly regarded. It was used for intercept operation, diplomatic communications, aboard ships and at shore stations as well as for clandestine use. There is an abundance of material on the internet (Just type ‘HRO receiver’ into Google) regarding this popular receiver so the HRO description here will be brief. It is a single conversion superhet with an IF of 456kHz. It has two stages of tuned RF amplification before the mixer on all frequencies, mainly to give improved image rejection and later became the standard method used in single conversion superhets. The HRO uses several plug-in coil modules, each covering a range of frequencies rather than an internal coil pack and a band switch. The plug-in coil arrangement ensures each coil is enclosed in a shielded compartment, thereby minimising stray losses. Additionally, this receiver has two IF stages with six tuned circuits and a crystal filter, a BFO and an audio output stage. The layout of the HRO is shown in the following photo.
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Top view of the HRO receiver showing the component layout My HRO receiver uses glass valves with loctal bases. These types of valves were used in the earlier models so I feel confident that my receiver is an early model. Front Panel Controls The most noteworthy feature of the front panel is the main tuning dial. It comprises a micrometer type epicyclic unit with an outer dial marked with 50 graduations and an inner dial marked with the numbers from 0 to 500 in steps of 10. This dial is connected to the four-ganged tuning capacitor via a 20:1 ratio gearbox spring loaded to eliminate backlash. The end result of this combination is a smooth, large tuning control with 500 widely spaced graduations allowing resetting the tuning capacitor to within about one part in 2000 or better and results in a readout precision of a linear dial nearly 4m long.
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The controls on the front panel include AF and RF gain, crystal filter Selectivity and Phasing, BFO, AVC On/Off switch, S-Meter switch, B+ switch. The BFO is adjustable from the front panel and has markings of OFF and ‘0’ to ‘10’. When changing coil modules the HT must be switched off using the B+ switch. This is to prevent the possibility of an HT short or an electric shock (I speak from experience).
Front view of the HRO receiver showing the controls The HRO Coil System Originally there were four coils supplied with each receiver, which gave continuous coverage from 1.7MHz to 30MHz. Additional coils for the lower frequency bands could be purchased as extras. The individual HRO coils are identified by a letter and number stamped into the insulator block. The frequency range is designated by a letter as follows: A = 14-30MHz B = 7-14MHz C = 3.5-7MHz
D=1.7-4.0MHz
Power Supply The HRO receiver requires an external power supply provided filament voltage 6.3 volts and approximately 240 volts at 70 mA for B+. When I bought my
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receiver it came without its power supply so I built one, which is housed in a wooden case together with a suitable speaker. Operating the HRO Using this type of receiver in today's crowded bands can at first be rather disappointing. One of the characteristics of the early models is that the local oscillator stage is run from an unstabilised HT supply so frequency stability is poor. Instructions for this receiver advocate using it in what might be called the ‘standard AM mode’, that is with AVC on and the RF Gain at maximum and the Audio Gain rather low. This allows the receiver's front-end gain to be controlled by the AVC in response to whatever the strongest signal happens to be. This works fine when listening to strong AM signals. However, often the desired signals are weak in the presence of strong adjacent frequency interference or atmospheric noise. In my case communication is done using CW and to get the best out of this receiver on this mode requires a different operating procedure. For this the BFO must be turned on and the AVC switch turned off. Best signal-tonoise ratio is obtained by increasing the audio gain control and controlling signal level using the RF gain control. The BFO control effects the characteristic pitch of CW note. A crystal filter is used to increase selectivity and is switched in by means of the phasing control, which is set to about midscale. While this does improve the peak selectivity considerably, it takes come getting used to compared with using modern receivers with bandpass filter characteristics.
Band Reports I've been enjoying 12m as its the only band I can Tx on. The last two months have given me: PR7AH (Brazil), HS0ZJU (Thailand), 9H5BZ (Gozo) not really DX but nice :-) also today (13th March) I called CQ into a quite band and UX6IA called right back so even though its sometimes 'flat' there are people out there so its worth calling. Jonathan G1EXG
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10 metre band report Worked CW: TR7CA Gabon! ! 7Z1SL Saudi Arabia! 6U7I Sudan! ! SS0ZGQ Egypt!! C5BXA Gambia! 3B8CF Mauritius!
! ! ! ! ! !
Heard: ZD7FT St. Helena ssb !
PJ2/K8NDU Netherlands Antilles VU2BGS India E21EJC Thailand ZD7XF St. Helena 3C0E Pagalu J88DR St. Vincent
VK2,4 and 7 CW
73, Ted G3EUE
I have been using the vintage rig exclusively on 14MHz this year running 50 or 60w to the quad antenna so I don't know what is going on on other bands. The morning long path had shifted from Japan (last year) to other parts of Asia and I worked V85SS, 3W7W (a nice long CW chat with an American in Trang City), DU7HF, BV20HQ, some ZLs and a lot of VKs. Worked some new ones in the BERU contest, J88DR, ZF1UM, VP9/G3PJT, XL3T & FM/F6AUS. This week conditions not so good, very little Asia and ZL but lots of VKs. Peter, G3LDO
In Feb, I was active in the FOC Marathon contest. I operated from home for this event, where I now have S8-9 noise from nearby plasma TVs that makes life tough on the HF bands. However, I did manage to work all over the world with 100W and a doublet at 30ft. So far this year, I have made 1604 QSOs this year to date (16/3/12). Last year (2011), I made 5007 QSOs. I have started using data modes (PSK31 & RTTY) and recently have been discussing techniques with others around the UK, trying to understand the complex nature of setting up computers, TNCs and the associated software. I have discovered that it’s a good deal more complicated than traditional modes. Most recently, I have tried to investigate how to have two VFOs running, and hence two receivers, with PSK31 on one and RTTY on the other, to try to boost
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my score in the 80m data contests. Currently, I haven’t had much success in the results on data modes but I am determined to improve and hence the time spent reconfiguring and taking equipment apart to try to make it all work as intended. In February and March this year notable QSOs were ZD7XF on 14MHz and 10MHz and also 3DA0PW, TN2T, VP6T and HK0NA on 14MHz 73 Graham G4FNL
Significant Achievement Bob G3VXJ has been busy chasing SOTA’s (Summits On The Air) for over 18 months now and has reached the status of “Super Sloth”.
The awards on this scheme are “Mountain Goats” for those who win points by activating the summits around the world and “Shack Sloth” for those that sit at home and work them. The points vary on the degree of difficulty to access the site, with a 1 point on a simple summit such as Chanctonbury Ring and a 10
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points for a remote summit that takes several hours to climb in a remote mountain range. Most operate in this award scheme and work everything that comes on the bands, but Bob has now worked 10,000 points by working each summit once only (they are classed as uniques) - easy at the start but it gets more difficult as time goes on. I am not sure what the next award is, I think he has rewritten the rule book by adopting this approach so they will have to think up a new target for him to work towards.
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Club program, activities and dates for the diary Meetings are now back to every week - any ideas for future lectures or topics will be welcomed.
Items for Sale If you have any equipment you would like listed here, please send me the details via email.
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