Cockenzie

& Port Seton Amateur Radio Club Elements

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.

Bob GM4UYZ

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

V o l u m e 2 0

Ma rch

2 0 12

03

2

2011 IOTA Contest how we faired The provisional results are now in for the contest and we were

placed 6th:

Below was what we submitted but as it says it does not in-

clude duplicate QSO’s

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

Dupes are not included in QSO counts neither avg calculations

So what is obvious is that we lost points along the way after

adjudication, so where did we lose them? What is produced

by the adjudicators is a file called a UBN file. This file is there

to help you see where you went wrong and give guidance in

what areas that need improvement.

UBN stands for –

U = Unique

The number of unique call signs that are in your log that were

not worked by any other contest entrant

B = Broken

Entries in the log which when compared with the other station

contacted do not compare i.e. serial numbers, IOTA Reference

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): 2520

The robot/human team has adjudicated 1722 QSO’s

(68%)

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 **

UNIQUES: Your log contains 78(3.0%) unique. (You have NOT

lost any credit for these QSO’s).

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

lost 8 Multipliers and 59 QSO credits. Multipliers are “King” so

loosing 19 multipliers means a huge drop in score)

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 con-

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

30WPM plus it is easy to do believe you me.... To be honest I

think it is nigh on impossible to have no errors at all so our

aim is to have as little or none at all. I really must congratulate

the whole team on the standard of the logging to achieve

what we did.

How the Score is worked Out…

Summary of score using the following formula:

((non-IOTA QSOs+ QSOs with same IOTA)x3 + QSOs with other

IOTA x15) x mults)= Final score

Score before adjudication from 2509 valid QSOs is:

( (1792+8) x 3 + 709 x 15) x 4442 = 7087470 points

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

6 EU008 Tiree IOTA DXPN MS MIX 24H HP

2450 423 6560730

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.

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.

A typical NOAA satellite APT images consist of two frames, side by side as shown in the pictures taken from a the 3rd February 2012 from the NOAA-19 12:31 pm pass . The left-hand image was acquired in visible wavelengths; that to the right was imaged in infrared. These images are transmitted as greyscale images (i.e. no colour). With the exception of the winter months, when solar illumination is relatively weak, software can be used to combine these two monochrome images into a colour composite like the one shown.

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.

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 standards I was pleased by the outcome. See the pictures later on.

The next task was to fit the PCB and all the connectors then cable it all up. Attached the power lead and switched on, phew! No puffs of smoke! I then followed the instructions for setting up the receiver but could not understand why I wasn’t hearing anything out of the loud speaker yet I knew audio was being sent to the volume control. This turned out to be bad connection on one of the pins

(Continued on page 4)

2

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.

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 we’ll publish

here will be the club,

filtered by the current

year, so everyone starts a

new year at 0 contacts.

Club Attire

The club has a design for

Club Tee-shirts, Polo-

shirts, Sweat-Shirts, Fleec-

es 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.

If you wish to add your call

-sign to the logo then

please ask at the time of

the order.

Cost will depend on gar-

ment and should cover the

garment and logo, call-sign

addition will be extra.

Order from:

PATRICIA BEWSEY DESIGNS,

UNIT 11,

FENTON BARNS RETAIL

VILLAGE,

FENTON BARNS,

NORTH BERWICK,

EAST LOTHIAN

EH39 5BW

Tel/Fax: 01620 850788

Mobile: 07970 920431

4

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 receive great pictures. I have done it this way basically as a test to see that it all works before I build a decent aerial.

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!!!!!!!

Even at that poor quality I was thrilled to bits to see that I had at least captured something from the kit that I built. The whole project 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:

http://www.david-taylor.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).

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 from page 3)

(Continued on page 5)

4

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.

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 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

knowing that I am receiving real live pictures. Do I understand what I see? well that is another story.

If you are interested why not give it a go... good luck.

Bob GM4UYZ

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 dis-

ease by donating the

profits from some of the

events we hold, we have

raised over £14,795 since

1994.

Supported by BT Community

Champions

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 founda-tion 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”.

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 ra-dio pack. The Clansman radio system was the core of the Army communication from 1976 to 2010.

The RT-320 is a 2 – 30MHz transceiver with AM, USB, CW modes, a built in ATU and an output which can be set to 3W or 30W. There is an accompanying range of handsets, headsets, long wires, dipoles, baluns and coax feeders. It is powered by a 1AH or 4AH battery for portability, and as the MOD is now adopting the Bowman radio system the clansman sets are being sold off relatively cheaply. Several web sites suggested these 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 op-tion.

Ebay is a plentiful source of RT-320s so I con-tacted 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

1* battery £15 + £7 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

1* noise cancelling headset £25 + £6 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 ver-sion. 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 supply-ing 2.5A @ up to 15V so I wired these in se-ries 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 done). The problem with buying second hand rechargeable batteries is not knowing their condition. Setting up the HP power supplies is also a lot of hassle, especially if I have them set up for use in other projects.

On the antenna side, the dipole elements are cleverly designed dual winders with Kevlar wrapped antenna wire on one side and para-cord ‘throwing wire’ on the other side.

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)

6

A Cheap Way in to HF?

PLANNING PERMISSION Talk by Len Paget GM0ONX

16th MARCH 2012 RESOURCES ROOM 1:

19:30 to 21:30

Len is the Regional Manager for the RSGB District 1 area which covers the Lothians. Len also deals with the ques-tions and problems on behalf of the RSGB arising from

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 No-vember 2011 which Len had to cancel at short notice. I am sure it will be a very informative talk so I hope you will all come along and support the evening.

6

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.

To make the table really interesting it needs as many mem-

bers as possible to keep uploading their logs, CW, SSB or DATA

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!

Callsign 160 80 60 40 30 20 17 15 12 10 6 4 2 70 DXCCs Slots Range

GM4IKT 0 0 0 0 0 16 1 16 0 7 0 0 0 0 36 40 8 yrs

M0RNR 0 0 0 0 0 1 0 12 0 0 0 0 0 0 13 13 13 yrs

GM4UYZ 0 3 0 0 0 0 0 0 0 0 0 0 0 0 3 3 32 yrs

MM0XXW 0 0 0 2 0 0 0 0 0 0 0 0 0 0 2 2 6 yrs

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 sta-tions 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 ex-pect 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

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.

In summary:

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 porta-ble 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/prc320-1user.pdf

(Continued from page 6)

8

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.

Sgurr Gaorsaic is completely encircled by higher hills; Munros over 914m (3000ft in imperial units) so there is no line of sight to anywhere making VHF contact unlikely. Therefore, I started calling CQ on 40m just after 14:00 hours and made 14 QSOs in 25 minutes. Most were in the UK but one was in Holland, Ireland and another in Switzerland. You only need 4 contacts to document a successful transmission.

Despite the rising wind I quickly packed and set off for the main summit buoyed by the speed and number of QSOs on the first hill. I had to use crampons on some ice but reached the top less than 2 hours later and set up the 40m inverted dipole on the lee side of the summit cairn. By now it was snowing, which with the wind meant blizzard conditions. Despite calling for just over an hour I had only 2 contacts; one in Ireland, the second in Surrey. The number of overseas stations blasting in swamped my 5 watt output so, finally accepting it was time to change frequencies, I reluctantly came out from under the shelter of my bivvy bag and looked for the small kit bag with the stubby 2m whip for my FT817. It was nowhere to be found and I can only assume it had blown away taking a couple of coax leads as well. There was little point searching because of the vertiginous 500m drop just a few metres downwind.

All was not lost as I could still use the rear port for my 3 element VHF YAGI, but by now the wind was too strong to safely assemble it. In fact I was surprised the inverted V 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 remote mountain in the area. Discretion is the better part of valour, according to Falstaff, so it was time to just accept defeat and swiftly retreat.

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 for wavelength

2.0162 / 4 = 0.50405m for ¼ wavelength

0.50405 x 95% = 0.4788475m as speed of signal is lower in copper.

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 antennas can operate in one of two principal modes: normal mode or axial mode.

In the normal mode or broadside helix, the dimensions of the helix (the diameter and the pitch) are small in comparison to the transmitted wavelength. The diameter of my lost antenna being less than a centimetre and the pitch but a few millimetres. The antenna acts like a whip and the radiation pattern is omnidirectional, with the maximum radiation at right angles to the helix axis. The design is reported to be efficient as a practical reduced-length radiator when compared with the operation of other types such as base-loaded, top-loaded or centre-loaded whips. They are typically used where reduced length is important.

In contrast the axial mode helix uses helix dimensions at or above the operating wavelength. The antenna produces radio waves with circular polarisation and the radiation pattern is along the axis of the helix. They are often used where the relative orientation of the transmitting and receiving antennas are unknown or cannot be easily controlled, such as in spacecraft. Just make sure it is a compatible right or left handed helix!

So, with my home brew whip antenna should I head back up Sgùrr nan Ceathreamhnan for a second attempt? Perhaps I should just buy a new stubby, £12 from Jaycees!

Thanks to Campbell MM0DXC, Adrian MM0DHY and Andy MM0FMF for their unwitting, but essential help, in inspiring this report.

Colwyn Jones MM0YCJ 24/2/2012

1. Harmonic radiation from a transmitter may be reduced by

a. Adjusting the receiver’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

2. The drawing shows a block diagram of a TRF (Straight) receiver. Which one of the blocks selects the radio signal?

a. Tuned circuit

b. Detector

c. Audio amplifier

d. 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

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

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

7. A station in the 23cm band is being interfered with by an amateur transmitter on the 70cm band. This could be due to the:

a. Receiver audio gain control setting

b. Transmitter using narrow band FM

c. Presence of a harmonic in the transmitter output

d. State of the sun spot cycle

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 Super-hetrodyne receiver. What is the block marked X?

a. Detector

b. Audio amplifier

c. Tuned RF amplifier

d. 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 fre-quencies

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

Test Your Knowledge

8

Tuned Detector Audio Headphones

Contacts

General correspondence,

training and contest en-

tries

Bob Glasgow

7 Castle Terrace

Port Seton

East Lothian

EH32 0EE

Phone: 01875 811723

E-mail:

gm4uyz@cpsarc.com

HF Contests

Cambell Stevenson

mm0dxc@aol.com

VHF Contests

John MacLean

mm0ccc@cpsarc.com

Club Tables

Bob Purves

gm4ikt@cpsarc.com

Contest Reports

Robin Farrer

mm0vtv@cpsarc.com

Newsletter, website,

event calendar

John Innes

newsletter@cpsarc.com

2 March 2012 Club Night

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 Club Night

7 April 2012 Intermediate License Exam

21 April 2012 10 Pin Bowling Night (TBC)

4 May 2012 Club Night

11 May 2012 FIRST 144Mhz DF Hunt Meet in “The Old Ship Inn” Car Park (East) 18:30 for 19:00

1 June 2012 Club Night

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

20 June 2012 CPSARC HF Activity night

19:00—22:00

29 June 2012 Club Night (moved to accommodate VHF Field Day)

7/8 July 2012 RSGB VHF Field Day

28/29 July 2012 RSGB IOTA Contest

Island of Tiree GM2T

3 August 2012 Club Night

10 August 2012 19thANNUAL MINI-RALLY NIGHT

18/19 August 2012 Lighthouses Weekend

Barns Ness Lighthouse GB2LBN

7 September 2012 Club Night

28 September 2012 SECOND 144Mhz DF Hunt Meet in “The Old Ship Inn” Car Park (East) 18:30 for 19:00

Events Column Answers from March 2012 newsletter “Test Your Knowledge”.

1B, 2A, 3A, 4C, 5B, 6B, 7C, 8D, 9A, 10D