Cockenzie & Port Seton Amateur Radio Club
In this issue 2011 IOTA Contest P.2 WX Satellite Experience P.3 A Cheap Way in to HF? P.6 Clublog Tables P.7 Stubby Antennas! P.8 Test Your Knowledge P.9 Event Calendar P.10
Cockenzie & Port Seton Amateur Radio Club is affiliated to the Radio Society of Great Britain and holds the call signs MM0CPS and GM2T which are used for our special event and contest entries. The Club was formed by Bob Glasgow GM4UYZ in 1984 to help the local amateurs get to know each other. Far from being just a local club we have members regularly attending from the Borders, Dumfries, Strathclyde, Fife and Newcastle. The Club meets on the first Friday of every month (Second Friday of January) in the lounge of the Thorntree Inn on the old Cockenzie High Street from 7pm till late.
Editorial Onto another month and another editorial, already this is the third one for this year, my how time flies by!!!! One thing is noticeable and that the evenings are now beginning to “stretch out” and aiming away from what I call the winter doldrums. Thank goodness for that say’s I. In some respects I like the dark nights where one can get nice and cosy sitting watching the television but if I am perfectly honest I do prefer the light nights as it allows one to get out and about instead of vegetating in front of the “box”. First of all this month I would like to pass on our deepest sympathies to Alex GM3GKJ and his wife Cecelia who sadly lost their daughter Leanne and to Cambell MM0DXC who has lost a dear cousin. It is a difficult time for all of those concerned trying to come to terms with their grief so all we can do is be there for them and offer our sympathies. Ok then what have we been up to this month; first of all we will have had our annual radio check night run by John MM0JXI. It is a great event to put your radios through their paces so hopefully many turned up to take part. Tomorrow, 3rd March, I start the last training session of the winter period by running an Intermediate Course with their exam being on the 31st March so it goes without saying that we wish them well with the course and the exam. My Foundation Course candidates will have sat their exam and hopefully everyone will have passed. I will be setting out the future dates for the winter training period (2012-2013) hopefully
starting in September. I will announce these via a general email and via the cpsarc.com although if you know of anyone who may be interested get them to contact me direct. Our next event in March is a talk by Len Pagent GM0ONX on “Planning Permission”. This will be held in the Port Seton Community Centre Resources Room 1 on the 16th March between 19:30 and 21:30. This was the talk that was originally planned for November 2011 but Len had to cancel at the very last minute. I do hope many of you will make the effort to come along. To the future for the 10 Pin Bowling in April (Saturday 21st April @20:00 Ten-Pin at Fountainbridge) I may not run it as at the moment I have little time to get it organised but don’t worry I have something else up my sleeve in its place which will be very interesting indeed for all ages but at present I am awaiting some confirmation before I announce it. Lastly, if I have any thing to say this month it is the old hobby horse of looking for newsletter input. Thanks to those who have been contributing but we need more. Lots of people indicate that they will but never do. I do struggle from month to month to write articles and I really genuinely could do with some help so this is a plea from the heart for articles. It would be fantastic to have a good pool of articles that John can select from. Right I think that is about it so enjoy club night and the newsletter.
2011 IOTA Contest how we faired The provisional results are now in for the contest and we were UNIQUES: Your log contains 78(3.0%) unique. (You have NOT placed 6th: lost any credit for these QSO’s). Below was what we submitted but as it says it does not include duplicate QSO’s 6 EU008 Tiree
IOTA DXPN MS MIX 24H HP
You have lost 19 multiplier credit(s) and 59 QSOs credit(s) as follows: (Not so good this year as an increase of from 2010 were we
6560730 lost 8 Multipliers and 59 QSO credits. Multipliers are “King” so
loosing 19 multipliers means a huge drop in score) Scores after checking…. BAND SSB/IOTA CW/IOTA POINTS AVG ---------------------------------------80 228 46 152 29 2829 7.44 40 273 62 158 35 3513 8.15 20 667 92 409 50 5889 5.47 15 331 68 130 33 2919 6.33 10 148 15 16 13 981 5.98 ---------------------------------------TOTAL 1647 283 865 160 16131 6.42 ======================================== TOTAL SCORE : 7 146 033
BAD CALL SIGN 24 BAD SERIAL NUMBER 20 BAD IOTA REFERENCE 2 BAD COPY OF EXCHANGE 2 NOT IN LOG 11 Out of the 52 QSO’s they were CW 29 PHONE 23
The worst areas as you can see are the BAD CALL SIGN & BAD SERIAL NUMBER and this is mostly down to recording the conDupes are not included in QSO counts neither avg calculations tact, otherwise our bad typing. On the CW side it was putting the wrong number in, like entering a 7 instead of an 8. At So what is obvious is that we lost points along the way after 30WPM plus it is easy to do believe you me.... To be honest I adjudication, so where did we lose them? What is produced think it is nigh on impossible to have no errors at all so our by the adjudicators is a file called a UBN file. This file is there aim is to have as little or none at all. I really must congratulate to help you see where you went wrong and give guidance in the whole team on the standard of the logging to achieve what areas that need improvement. what we did. UBN stands for – How the Score is worked Out… U = Unique Summary of score using the following formula: The number of unique call signs that are in your log that were ((non-IOTA QSOs+ QSOs with same IOTA)x3 + QSOs with other not worked by any other contest entrant IOTA x15) x mults)= Final score B = Broken Entries in the log which when compared with the other station Score before adjudication from 2509 valid QSOs is: contacted do not compare i.e. serial numbers, IOTA Reference ( (1792+8) x 3 + 709 x 15) x 4442 = 7087470 points missing, etc, etc N = Not in Log Our Callsign does not appear in the other stations log. Output from the UBN Report Total QSO’s submitted (including 25 dupes): The robot/human team has adjudicated (68%)
2520 1722 QSO’s
QSOs in non-recommended frequency sections (i.e. 3560 3600, 3650 - 3700, 14060 - 14125 and 14300 - 14350 kHz):see Rule 3 (You have NOT lost any credit for these QSOs). = 2 ** two OOPS!!! We must be more careful **
Score after adjudication from 2450 valid QSOs: [FINAL SCORE] is: ( (1762+8) x 3 + 680 x 15) x 423 = 6560730 points (-7.43%) From the above we actually lost 7.43% of our score which is nearly double of our 2010 score which was 3.92% of our score. At least from the UBN file it identifies weak areas and from this in future contests they can worked on to make sure they are alleviated. We are looking for the ideal of no errors. Bob GM4UYZ
WX Satellite Experience One of the many things that I wanted to do was receive weather satellite pictures, basically my interest to do this stems back many years as I have always been interested in watching the weather forecasts on the television particularly when they display the weather charts and more so now where they show the cloud cover from the satellites. I decided that the best way forward to do this was as a project for the winter months, so I took the plunge whilst at the Leicester rally back in 2002 and joined RIG (Remote Imaging Group) and bought their RX2 WXSAT Receiver. Like many kits not all the parts are available so again from the above rally I purchased a good box to fit the receiver into plus I raided my junk box for other bits and pieces i.e. signal strength meter from an old scrap CB, PL259 Chassis socket and switches and sockets.
Below is how I went about building the receiver: My first task was to build the kit and by following the comprehensive instructions I managed it with quite an ease, but there again over the years I have built numerous bits and pieces, repaired lots of kit so soldering is not a problem.
Our club has been added to the excellent Clublog system developed by Michael Wells G7VJR. www.clublog.org The system allows members to upload their logs in ADIF format and have them displayed in a table with all the other club members. Clublog also has great facilities for tracking your DXCC status etc so is well worth taking the time to register and get your log uploaded.
The RX2 kit receives signals from the National Oceanographic and Atmospheric Administration (NOAA) of the United States of America satellites. NOAA supports several Weather Satellites in Low Earth Orbit. Currently these are NOAA-15, NOAA-18 and NOAA-19, NOAA-17 is no longer in use. All three satellites broadcast using a system termed Automatic Picture Transmission (APT) in which they scan the Earth, 840 kilometres beneath them, continuously. This results in images that build up line by line, rather like the image on a TV screen. However, a complete APT image takes 12 to 14 minutes to build up at a rate of two lines per second. These transmissions are received on frequencies in the 137MHz band.
The next task was fitting it into the box that I had chosen. My mechanical skills are not the best I may add particularly trying to deal with rectangular holes but I managed it in the end. Both the front and rear of the box was given two coats of white enamelled paint. I then used Dymo Letra Tag for all my labelling before giving both the front and back covers a final coat of varnish. I must admit for my A typical NOAA satellite APT images consist of standards I was pleased by the outcome. See two frames, side by side as shown in the the pictures later on. rd pictures taken from a the 3 February 2012 from the NOAA-19 12:31 pm pass . The left- The next task was to fit the PCB and all the hand image was acquired in visible connectors then cable it all up. Attached the wavelengths; that to the right was imaged in power lead and switched on, phew! No puffs infrared. These images are transmitted as of smoke! I then followed the instructions for greyscale images (i.e. no colour). With the setting up the receiver but could not exception of the winter months, when solar understand why I wasnâ€™t hearing anything out illumination is relatively weak, software can of the loud speaker yet I knew audio was be used to combine these two monochrome being sent to the volume control. This turned images into a colour composite like the one out to be bad connection on one of the pins shown.
To update your log with the next set of contacts (SSB, CW or Data) you can simply upload your whole log again and the system will take care of the duplicates. Alternatively you can export the bits you want from your own log and just upload that. The tables weâ€™ll publish here will be the club, filtered by the current year, so everyone starts a new year at 0 contacts.
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Club Attire The club has a design for Club Tee-shirts, Poloshirts, Sweat-Shirts, Fleeces and Jackets and all of these can be obtained from the address below.
When making an order please quote ‘Cockenzie & Port Seton Amateur Radio Club’ as this will ensure that the Club Logo will be placed on the required ordered garments.
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on the 10-way connector. At last everything was ready to go live. I must say at this stage setting up the receiver was made easier for myself as I have a Marconi Signal Generator and other tools to make the job all that bit easier. The first aerial, as you will see in the picture was just a rough made up dipole pinned to my shack roof so I was certainly not looking for to Even at that poor quality I was thrilled to bits receive great pictures. I have done it this way to see that I had at least captured something basically as a test to see that it all works from the kit that I built. The whole project before I build a decent aerial. although it took a few months to get to that stage overall it gave me great enjoyment. My next aerial and the one I am still using today: I built the proper aerial obtaining the information from the following web site:
If you wish to add your call -sign to the logo then please ask at the time of the order.
http://www.davidtaylor.pwp.blueyonder.co.uk/wxsat/ equipment.htm The antenna is a QFH – Quadrifiliar Helix originally designed by Bill Sykes G2HCG and Bob Coley G0HPO made out of 8mm Copper pipe (micro bore).
Cost will depend on garment and should cover the garment and logo, call-sign addition will be extra.
PATRICIA BEWSEY DESIGNS, UNIT 11, FENTON BARNS RETAIL VILLAGE, FENTON BARNS, NORTH BERWICK, EAST LOTHIAN EH39 5BW Tel/Fax: 01620 850788 Mobile: 07970 920431
The software program that I decided to use back then was the “Demo” version of JVCOMM32. My success rate of actually receiving a picture was absolutely dismal but then I received my first decent picture, it was still not tremendous and I couldn’t make out where it is but I could see cloud!!!!!!!
The pipe was off an old aerial for 70cms, which had been left after a junk night. I bought the 8mm copper pipe from B&Q as they did a 10M length and the 8 x 90° angle bends (I went for the compression type a lot cheaper) from a plumber’s merchant. The picture above shows the final outcome with the aerial in place. The next task was to see how it would (Continued on page 5)
perform. The answer is I have been really impressed. The picture below, which I received from the NOAA-12 Satellite going overhead on the 18th February 2003 at 10:18 is still one the best I have ever received. As you can see the UK really stands out...
As you will see that picture has the word “DEMO” all over it and that is because I was using the Demo Version of JVCOMM32. I am not sure if it is the best program or not but at least it let me “find my feet” as they say. Today I use the WXtoIMG program which I have done for a long time now. It is far superior and it allows colour pictures to be created from the received images. The following are pictures that I received on the 3rd February 2012 from the NOAA-19 12:31 pm pass.
knowing that I am receiving real live pictures. Do I understand what I see? well that is another story.
I hope you have enjoyed my adventure into receiving weather satellite pictures from a receiver on the 137MHz bands. There are far better ways of getting clearer and better pictures by If you are interested why not give it a go... good luck. using a Satellite Dish and the respective software. Maybe one day I will give it a go but up to now I am happy with what I have. I still today find it amazing watching the picture getting built as the satellite goes overhead and
The Club The Club is run in a very informal way, just a group of like minded people doing something they enjoy! This does not mean that we don’t do anything, we enter (and win!) contests, train newcomers, hold talks and video nights and run a popular annual Junk Sale. Our newsletter has won the Practical Wireless ‘Spotlight’ competition on several occasions. The Club supports the British Heart Foundation in memory of a member who died from heart disease by donating the profits from some of the events we hold, we have raised over £14,795 since 1994.
A Cheap Way in to HF? Eighteen months ago during my Foundation course I started looking at some radio kit to get on the air, I wanted something that could be limited to 5W to comply with the foundation licence. As I was just starting out in Ham Radio I didn’t want to spend a fortune so my budget was £”as little as possible”.
1* battery £15 + £7 P&P
During my search I can across the Clansman RT-320, the transceiver at the centre of the British Army’s PRC-320 man portable HF radio pack. The Clansman radio system was the core of the Army communication from 1976 to 2010.
1* noise cancelling headset £25 + £6 p&p
1* battery charger £22 + £5p&p 2* antenna elements £20 + £5 p&p 1* balun £6 + £4 p&p 1* feeder coax £12 + £4 p&p
At this point I had spent £256. (I could probably have saved on the antenna bits but buying ‘compatible’ stuff seemed the best way to get on air quickly).
The battery charger I bought is the 24V version. This was designed to be charged from a military vehicle, most of which run 24V, there is a 14V version available but this is much more expensive. I have two HP power supplies in work that are capable of supplying 2.5A @ up to 15V so I wired these in series to charge the battery. During charging the current limited a fair bit (I presume that the military want their batteries charged ASAP) and I was never happy that the battery had been properly charged (the lights on the charger I got never indicated the charge was The RT-320 is a 2 – 30MHz transceiver with done). The problem with buying second hand AM, USB, CW modes, a built in ATU and an rechargeable batteries is not knowing their output which can be set to 3W or 30W. There is an accompanying range of handsets, condition. Setting up the HP power supplies is also a lot of hassle, especially if I have headsets, long wires, dipoles, baluns and coax feeders. It is powered by a 1AH or 4AH them set up for use in other projects. battery for portability, and as the MOD is On the antenna side, the dipole elements are now adopting the Bowman radio system the cleverly designed dual winders with Kevlar clansman sets are being sold off relatively wrapped antenna wire on one side and paracheaply. Several web sites suggested these cord ‘throwing wire’ on the other side. were excellent radios in their own right… http://g4oep.atspace.com/rt320/rt320.htm http://g0ozs.org/clansman/rt320/index.html One downside is the lack of LSB mode, there are several published modifications to add LSB to the set but these can’t be applied with a foundation license. Never the less this seemed like a good option.
Supported by BT Community Champions
Ebay is a plentiful source of RT-320s so I contacted a vendor and negotiated the purchase of a tatty example (I didn’t care what it looked like) for £115 + £10 postage. This came in a DPM rucsac. To get on air I then also had to buy
There is a table on the back of the set which gives element lengths for dipoles at different operating frequencies. This allows a soldier in the field to unwind the appropriate length (Continued on page 7)
Geoff MM5AH0 so am keep to get the battery properly charged and to get portable and see how the set performs using the full 30W output! Also having got my intermediate licence I’m keen to explore a mod to give LSB.
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for the element then use the throwing wire to secure each end of the dipole. I used a 9m fibreglass pole to support the balun and erected an antenna in the back garden.
I got on the air and have made quite a few QSOs around northern Europe with the set with reasonable reports. One major handicap is that the set doesn’t have a LSB mode which restricts operation to >10MHz, I found 20m to work fairly well. I did have a few reports that my audio was dropping off fairly soon after a charge, a pointer to it being near the end of its life? Another major handicap is that when using the noise cancelling headphones and straining to hear faint remote stations your wife and daughters never tire of sneaking in and surprising you! I took the set to John’s radio test day last year and found that my particular set was not operating as the technical specs suggest it should, it was way down on receive sensitivity. It looks like there are RT320s and RT320s, which you might expect bearing in mind that many have had a hard life. There are ‘serviced’ units available, with LSB added, but these can cost up to £475. I have since bought a ‘main station’ rig in a silent key sale and have found this much easier to use and make QSOs. This is a much more flexible set with 100W output, but it doesn’t have the ‘charm’ of the RT-320. I have since bought a new battery for the RT320 and have just got a ‘beefy’ 24V supply from
If you have a foundation licence and just want to get on the air it might not be the cheapest option. When you’ve bought all the bits it isn’t as cheap as it may initially appear and you can’t guarantee the performance of second have equipment but it’s a reasonably cheap way of getting a very robust portable set up. Portable operation here I come! Nial Stewart MM0KPZ
Next instalment…. Cheap Way In to VHF/UHF? Further reading… http://www.eham.net/reviews/detail/7905 http://www.youtube.com/watch?v=1Rl_UZxWPkQ http://www.armyradio.com/arsc/customer/product.php? productid=2252 http://www.clansman-radios.co.uk/manuals/prc3201user.pdf
PLANNING PERMISSION Talk by Len Paget GM0ONX 16th MARCH 2012 RESOURCES ROOM 1: 19:30 to 21:30
trying to obtain Planning permission for towers, etc. His talk offers the opportunity to ask all those awkward questions that could possibly arise. This talk was the one previously planned for the 18th November 2011 which Len had to cancel at short notice.
Len is the Regional Manager for the RSGB District 1 area which covers the Lothians. Len also deals with the questions and problems on behalf of the RSGB arising from
I am sure it will be a very informative talk so I hope you will all come along and support the evening.
Clublog DXCC Tables This is the new Clublog table for 2012, as you can see, only a few members have uploaded any of their QSOs for the new year.
You can see that there is a rising amount of activity on the higher bands so if you’re thinking about getting active on 10m or 15m then now would be a really good idea!
To make the table really interesting it needs as many members as possible to keep uploading their logs, CW, SSB or DATA
Callsign 160 80 60 40 30 20 17 15 12 10 GM4IKT 0 0 0 0 0 16 1 16 0 7 M0RNR 0 0 0 0 0 1 0 12 0 0 GM4UYZ 0 3 0 0 0 0 0 0 0 0 MM0XXW 0 0 0 2 0 0 0 0 0 0
6 0 0 0 0
4 0 0 0 0
2 70 DXCCs Slots Range 0 0 36 40 8 yrs 0 0 13 13 13 yrs 0 0 3 3 32 yrs 0 0 2 2 6 yrs 6
Stubby Antennas! Late afternoon, Thursday 16th February 2012 saw me out on the highest mountain in Scotland which has not yet had a summit radio broadcast (www.sota.org.uk), the remote Sgùrr nan Ceathreamhnan (1143m) 40 miles west south west of Inverness. The name Sgùrr nan Ceathreamhnan has been problematic, for non Gaelic speakers, and is lazily christened Chrysanthemum by many linguistically challenged hill walkers! The Anglo-Saxon translation is "Peak of the Quarters" referring to the large areas of land it rather confusingly divides with its five; not four long ridges. The name is pronounced Sgurr nan Keravan (SOTA ref; GM/ WS-006) and it is found at the head of Glen Affric in the Scottish Highlands (Latitude: 57 15 17 N, Longitude: 5 13 22 W. Grid Reference: NH 057228, QTH Locator: IO77JG). Walking in from Loch Affric in the east, rather later than planned, I decided to go up the linked Corbett; Sgurr Gaorsaic first (Sota ref; GM/WS-158; 839 metres, which translates as Horror Peak; not sure why!!!). The logic being it would allow a break in the climb and that the fresh westerly wind would be at my back for the return journey; which indeed proved to be the case.
Needless to say I got down safely, although it was dark for most of the descent, but I usefully used the time to do two things; first review the order of the hills I had climbed that day (maybe the wrong sequence with hindsight) and second to calculate the length of a home brew ¼ wave antenna to replace the commercial aerial. A bit of stiff copper wire and a BNC plug should do the job; maybe even add a counterpoise wire! Or so I thought. First thing was to work out the length of the wire; the lost antennae being about 20cm long. 300 X 106 /145.500 MHz = 2.0162m
2.0162 / 4 = 0.50405m
for ¼ wavelength
0.50405 x 95% = 0.4788475m lower in copper.
as speed of signal is
However, a 47.9cm whip antenna is more than twice as long as the FT817 stubby antenna and it seems the commercial whips (rubber ducks) are "normal mode helix" antennas.
A helical antenna is a conducting wire wound in a constant parallel spaced helix or spring. In most cases, helical antennas are mounted over a ground plane and that was me with the FT817; essentially humans are a bag of isotonically salty water and are useful as a ground plane for handies. Helical Sgurr Gaorsaic is completely encircled by higher hills; Munros antennas can operate in one of two principal modes: normal over 914m (3000ft in imperial units) so there is no line of mode or axial mode. sight to anywhere making VHF contact unlikely. Therefore, I In the normal mode or broadside helix, the dimensions of the started calling CQ on 40m just after 14:00 hours and made 14 helix (the diameter and the pitch) are small in comparison to QSOs in 25 minutes. Most were in the UK but one was in the transmitted wavelength. The diameter of my lost Holland, Ireland and another in Switzerland. You only need 4 antenna being less than a centimetre and the pitch but a few contacts to document a successful transmission. millimetres. The antenna acts like a whip and the radiation Despite the rising wind I quickly packed and set off for the pattern is omnidirectional, with the maximum radiation at main summit buoyed by the speed and number of QSOs on right angles to the helix axis. The design is reported to be the first hill. I had to use crampons on some ice but reached efficient as a practical reduced-length radiator when the top less than 2 hours later and set up the 40m inverted compared with the operation of other types such as basedipole on the lee side of the summit cairn. By now it was loaded, top-loaded or centre-loaded whips. They are typically snowing, which with the wind meant blizzard conditions. used where reduced length is important. Despite calling for just over an hour I had only 2 contacts; one In contrast the axial mode helix uses helix dimensions at or in Ireland, the second in Surrey. The number of overseas above the operating wavelength. The antenna produces radio stations blasting in swamped my 5 watt output so, finally waves with circular polarisation and the radiation pattern is accepting it was time to change frequencies, I reluctantly along the axis of the helix. They are often used where the came out from under the shelter of my bivvy bag and looked relative orientation of the transmitting and receiving for the small kit bag with the stubby 2m whip for my FT817. antennas are unknown or cannot be easily controlled, such as It was nowhere to be found and I can only assume it had in spacecraft. Just make sure it is a compatible right or left blown away taking a couple of coax leads as well. There was handed helix! little point searching because of the vertiginous 500m drop So, with my home brew whip antenna should I head back up just a few metres downwind. Sgùrr nan Ceathreamhnan for a second attempt? Perhaps I All was not lost as I could still use the rear port for my 3 should just buy a new stubby, £12 from Jaycees! element VHF YAGI, but by now the wind was too strong to Thanks to Campbell MM0DXC, Adrian MM0DHY and Andy safely assemble it. In fact I was surprised the inverted V MM0FMF for their unwitting, but essential help, in inspiring dipole was still in one piece! The hour was late and I was in danger of being marooned at the top of the highest and most this report. remote mountain in the area. Discretion is the better part of valour, according to Falstaff, so it was time to just accept Colwyn Jones MM0YCJ 24/2/2012 defeat and swiftly retreat.
Test Your Knowledge 1. Harmonic radiation from a transmitter may be reduced by a. Adjusting the receiverâ€™s audio gain control setting b. Fitting a low pass filter in the antenna feeder to the transmitter c. Placing a high pass filter in the mains lead d. The state of the sunspot cycle
6. A carrier wave on 28400 KHz is amplitude modulated. The upper sideband is 28402KHz the lower sideband is a. 28396KHz b. 28398KHz c. 28404KHz d. 28406KHz
2. The drawing shows a block diagram of a TRF (Straight) 7. A station in the 23cm band is being interfered with by an receiver. Which one of the blocks selects the radio signal? amateur transmitter on the 70cm band. This could be due to the: a. Receiver audio gain control setting Tuned Detector Audio Headphones b. Transmitter using narrow band FM c. Presence of a harmonic in the transmitter output d. State of the sun spot cycle a. Tuned circuit b. c. d.
Detector Audio amplifier Headphones
3. A radio receiver is set to receive a signal of 14.1 MHz and the local oscillator is set to a frequency of 13.6 MHz. What will the intermediate frequency be? a. 500kHz b. 13.6MHz c. 14.1MHz d. 27.8MHz
8. To minimise the radiation of harmonics, which one of the following filters might be fitted between the transmitter output and antenna? a. High pass b. Key click c. Braid breaker d. Low pass 9. The drawing shows a block diagram of a simple Superhetrodyne receiver. What is the block marked X?
4. The demodulator for a FM receiver a. Requires a beat frequency oscillator b. Requires a narrow band pass filter c. Could be a frequency discriminator d. Could be an envelope detector 5. The block diagram shows a Morse Code transmitter. Which one of the following does block X represent? a. AF Oscillator b. RF Oscillator c. Demodulator d. Modulator
a. b. c. d.
Detector Audio amplifier Tuned RF amplifier Loudspeaker
10. The intermediate frequency of a superhet receiver is the a. The sum of the RF and the local oscillator frequencies b. Difference between the RF and the local oscillator frequencies c. Sum or the difference between the AF and the local oscillator frequencies d. Sum or the difference between the RF and the local oscillator frequencies
Events Column 2 March 2012
3 March 2012
Intermediate License Course begins (fees to be paid by 4 December)
16 March 2012
Talk by Len Paget GM0ONX on “Planning Permission” Port Seton Community Centre Resource Room 19:30 to 21:30
6 April 2012
7 April 2012
Intermediate License Exam
21 April 2012
10 Pin Bowling Night (TBC)
4 May 2012
11 May 2012
FIRST 144Mhz DF Hunt Meet in “The Old Ship Inn” Car Park (East) 18:30 for 19:00
1 June 2012
2 June 2012
Port Seton Gala Day
10 June 2012
PW 144MHz QRP Contest
16/17 June 2012
Museums on the Air Weekend Museum of Flight—East Fortune GB2MOF
VHF Contests John MacLean email@example.com
20 June 2012
CPSARC HF Activity night 19:00—22:00
29 June 2012
Club Night (moved to accommodate VHF Field Day)
Club Tables Bob Purves firstname.lastname@example.org
7/8 July 2012
RSGB VHF Field Day
28/29 July 2012
RSGB IOTA Contest Island of Tiree GM2T
Contest Reports Robin Farrer email@example.com
3 August 2012
10 August 2012
19thANNUAL MINI-RALLY NIGHT
Newsletter, website, event calendar John Innes firstname.lastname@example.org
18/19 August 2012
Lighthouses Weekend Barns Ness Lighthouse GB2LBN
7 September 2012
28 September 2012
SECOND 144Mhz DF Hunt Meet in “The Old Ship Inn” Car Park (East) 18:30 for 19:00
Contacts General correspondence, training and contest entries Bob Glasgow 7 Castle Terrace Port Seton East Lothian EH32 0EE Phone: 01875 811723 E-mail: email@example.com HF Contests Cambell Stevenson firstname.lastname@example.org
1B, 2A, 3A, 4C, 5B, 6B, 7C, 8D, 9A, 10D Answers from March 2012 newsletter “Test Your Knowledge”.
Published on Mar 5, 2012