Upload
others
View
7
Download
0
Embed Size (px)
Citation preview
Lock-down
Scout
Harpenden and Wheathampstead (+Kimpton) Scout District
Our Magazine for Isolated Scouts
9th May 2020 FreeIssue No. 7
For as long as it takes
New story:Lost in St Helena
Special message this week:
“Please help the Round Table support the vulnerable in ourcommunity”.
9th and 10th May
See page 8
Glitter surprise
Beavers: A home for insects
Cubs: Hovercraft
Scouts: Hooey stick
Explorers: Crystal set
Round Table appeal
Story: Part 1
Thought for the week
Amazing knots: Single Cat’s Paw
Recipe: Microwave mug cake
Puzzles
Name Six trees
Scout art
Project Supplement: Crystal set
Lock-down ScoutContents
Make a Hooey stick
Plus:Crystal setsupplement
2
Lock-down Scout
Did you see the stunning rainbow that arced over us on Saturday afternoon, 2nd May? It was so strong the second arc was easily visible. A neighbour snapped the adjacent
picture and caught a laburnum in full blossom into the bargain.
The rainbow showed for just a minute and was gone. You just had to stop what you were doing and wonder at it or the magic was lost.
So, all you young Scouts, seize the moment! Good things come, but rarely are they obvious like a rainbow and all too often their stay is likewise brief. Be ready for them.
It is why our motto is: ‘Be Prepared’
rv.
Feedback and contributions to [email protected]
School comes first. Organise your workplace and do the assignments. This is a priority.
Don’t get in the way of your parents working at home. They need space to succeed. As far as possible be self-sufficient. Share time when it is okay to do so.
You are a Scout. However young, however old, you made a promise. Live up to it!
Three things to remember:
1
2
3
Picture: Bob Bailey
Alone and busy
TOGETHERTogether, when we’re all together,
we know how lucky we are.The world around us is ev’rything,
the sound of music, the songs we singAnd even in the coldest winter the warmest summer arrives.
We’ll share together, when we’re together, the best years of our lives.
(and repeat, but a bit faster!)
Don’t let this song fade from your mind. It connects you to your friends and to our marvelous world in an
optimistic celebration of youth.Sing it in the shower!
3
Ways to do a good turn
Phone your friends. Phone your relatives
Do more for those who care for you than you usually do
Make something for someone
Mend something for someone
Entertain the family (Song, poem, reading, conjuring trick, joke)
Brew up a pot of tea when it is most needed
As a Scout, you are obliged to do at least one good turn every day (B.-P.)
Lock-down Scout
A REMINDER
Something to surprise youou might already have some cosmetic glitter
Ydust in your house that you can use for this activity. (Biodegradable glitter if possible!)
Put a small dab of hand-cream in your palm and rub it over all your hands. Now rub in some glitter dust over the lot. Let it go between the fingers and over your nails.
Shake someone’s hand and open a door. Does the glitter transfer?
Now go wash your hands as you normally do. Don’t do anything different to what you usually do. When you are done, see if you can find ONE glitter speck.
The rest is for your imagination. A virus is so small that millions could fit on to a glitter speck and so easily hide in the features of your hand.
We touch and touch and touch all day long dabbing our finger tips everywhere! And then we touch our lips and eyes– and everything transfers.
eBayIf you don’t have glitter at home:
Search for biodegradableglitter that is very fine.
A few gramsis all you need and it is
very low cost.
Gold glitter5g pot£2.99
4
BeaversBeaversLock-down Scout
A home for insects
You will need:Plastic bottle withthe bottom cut off.... ....and some twigs...
...to make
A home for insects
his simple home for insects is a
Tsafe, dry place in the garden for insects to live. Some insects fly
and want a home off the ground. Other insects crawl and want to be close to the soil.
This plastic bottle-home can be hung up in the dense foliage of a tree. (Use string or wire around the bottle-top to hang it). Force lots of twigs into the bottle so they cannot fall out.
Or it can be laid on the soil, hidden in a shady flower bed or under bushes. If this is what you do, tilt the bottle on stones to ensure rain cannot run in.
Be sure to keep the bottle-top on. Once placed you must not disturb it.
Many of our garden mini-beastswill thrive among the sheltered twigsof this ultra simple bottle-home.
Hang it in a tree
String orwire around the neck
5
What to do:Take a piece of Blu-Tack (about the size of a two-pence coin) and roll it into a thick sausage, wrapping it around the rim of a bottle-cap.
Use the Blu-Tack to stick the cap over the central hole of the CD, ensuring that the disc is printed side up.
Blow up the balloon and place it over the sports bottle-cap, making sure that the cap is closed. Let go– the balloon should stay inflated. If it doesn’t, make sure your Blu-Tack is making an effective seal.
Place your hovercraft on the floor and carefully open the sports bottle-cap. Give the CD a little push. It should then glide across the surface as the balloon deflates.
Take a picture !
1
2
3
4
5
You will need:BalloonOld CDPack of Blu-TackPlastic sports bottle topSmooth floor
Hovercraft
Add straws to
steady the balloon
Lock-down Scout
CubsCubs
Fact
Fact
Fact
Cubs started as ‘Wolf Cubs’ in
1918
There are 137,500 Cub
Scouts in the UK today
There are 7 Cub Challenge Awards, 53 activity badges
and many other badges
6
SCOUTSSCOUTS
Lock-down Scout
Hooey stickMake a
A Hooey Stick (or Hui) is a brilliant and fascinating toy. You hold it in one hand and with the other, you run the rubbing stick up and
down the no tches and the propellor spins like crazy. But
the remarkable thing is, it has a secret– a special power: when all your audience stamp their
f e e t , t h e p r o p e l l o r c h a n g e s direction.
The trick is to hold the rubbing
stick so that you have your index finger one side
of the Hooey stick and your thumb on the other. If you want to
have it turn one way, you press your thumb on the Hooey stick. To make the
propellor turn the other way you press your finger on the Hooey stick. Which you press is
totally invisible to the audience so when you get them to stamp their feet and the propellor changes direction, it really looks like magic.
ConstructionNothing is very critical. The size can vary a lot and the Hooey Stick will still perform. Aim for a square stick that is about 12mm x 12mm and 250mm to 300mm long. The rubbing stick could be a pencil or something similar.
The notches do not have to be perfect or regular but the rubbing stick should fall into the notches as it passes back and forth. A junior hacksaw is probably the safest way to cut the notches finishing with a file and sandpaper.
Drill a hole in the end for a screw. (Or a nail).
The propellor, about 80mm long, can be made from any light wood or plastic. Ensure the centre hole is in the exact middle and a loose, sloppy fit on its fixing screw. The propellor must rattle on the screw.
Ensure there are no splinters anywhere, And it is ready to go!
Visit YouTubeEnter ‘Hooey Stick’ in the search field
Another way to perform: instead of
getting your audience to stamp their feet,
you can shout HOOEY! and (secretly)
swap the finger/ thumb pressure to
change the propellor direction. Every
time you shout HOOEY! it magically
changes direction.
You have some entertaining to do!
7
Aerial terminal
Earthterminal
Tuning capacitor(2 foil covered cards)
Gemanium diode
Aerial co
uplin
gco
il, 25 turn
s
Tunin
g c
oil
25 +
25 turn
s
(Tap)
Earth
Head-phones
10nF to 100nFcapacitor
Aerial
Lin
k
Terminalblock
(Slides overtuning coil)
EXPLORERSEXPLORERS
Lock-down Scout
Frequency kW Service
909 kHz 150 Radio 5 Live
1089 kHz 400 talkSPORT
1215 kHz 125 Absolute Radio
1458 kHz 125 Lyca Radio 1458
Build the simplestradio possible:A crystal set
There are still a few high power Medium Wave transmitters operating and so the historic crystal set remains a practical radio. These transmitters are bound to fall silent soon and so here is perhaps a last chance to be part of the first radio technology. The only component that is critical is the germanium diode (the crystal). But any germanium diode will work. They are available from eBay at low cost.
All the instructions are annexed at the end of this issue of Lock-down Scout.
wo cardboard tubes,
Tsome wire, a few
components and kitchen
foil is all you need to make a
crystal set. The transmitter
provides the power to make it
work. You will need to rig up an
aerial and an earth.
A bit of can-do determination
and some creativity will have
music or sports news coming
out of the headphones.
AM services still available
See back of magazine for full details
8
The Round Table Collection for the needy
Lock-down Scout
Listen for the music
This is a really important initiative for the most vulnerable in our community.
Please support in any way you can, and share with your young people's parents and carers so that we can make their efforts as successful as possible.
Russhttps://glympse.com/!HarpendenFoodBanks
8
District Commissioner
9
On the way to the Cape, at the time of the South African War, the liner Donolly Castle, converted into a troopship, put into Saint Helena, anchoring
off the harbour of Jamestown.Officers and NCO's are allowed ashore for a few hours and a chum and I took advantage of the privilege. We were anxious to see Napoleon's tomb and the Boer prisoners already in captivity there. And we trekked off on foot to find them.
The island was sparsely populated, very little being known of it. After a good deal of wandering, we found both the tomb and the prisoner’s camp, of which we saw all we wished.
Suddenly we realised that our sight-seeing had taken much longer than we intended. Unless we hurried, we had a very good chance of being left behind with a court martial for desertions into the bargain.
So we attempted what we thought was a shortcut— a foolish thing to do, as we knew nothing of the island beyond the small portion we had already traversed.
Apart from the roughness of the roads which tried our feet and legs after the slack time spent on board during the voyage, all went well for the first hour. This brought us to the top of a very steep donga or gully, the sloping surface of which was composed mainly a flat stones and loose shingle.“Doesn't look very promising, does it?” I remarked to my chum.
“ I don't care for it at all,” he replied. “I've been down these shaly slopes at home. Jolly uncomfortable travelling they are. It means we'll slide pretty well all the way down, if we tackle it. Can't we get down anywhere else? Let's dodge the place altogether if possible.” “You know as much about it as I do, old chap,” I said. “But anyhow, we've no time to go chasing round. If we retrace our steps, we'll miss the boat for a dead cert, and you know what that will mean. I daresay the stuff will hold together enough for our fairy weights. What about making a move?”
“Oh, I'm ready when you are.”
“Well, here goes, then.
As I stepped onto the stones, they gave way beneath my weight and I slid several yards, when I managed to catch hold of a small projecting spur of rock with which I pulled myself up.
“I don't think much of this,” I said, striving to keep a foothold.“Didn't suppose you would,” interjected my chum.
The more I struggled, the farther I slipped, great stones and little stones all sliding away from me. Eventually my arms became so strained that I had to let go and down I slivered several more yards.
My chum was a few yards away slipping and sliding just as I was and looking the picture of misery. We seemed to loosen the rubble for each other.
It certainly wasn't a pleasant position to be in; but there was no escape from it. We should have to go to the bottom now— pretty well a couple of hundred feet— even
if we slid all the way. It would be a waste of time trying to get up again.
We had started the descent with our faces to the side of the slope, but as we slid so much we decided that it might be more comfortable (or less uncomfortable) to go down on our backs.
So we slithered along bringing great streams of shale with us, our arms extended on either side to steady ourselves as far as possible.
We dug our heels into the mass of litter, and until it started sliding it gave us momentary support. Stones of all sizes came clattering about our heads— you know the way loose stones have of sliding when supplied with the necessary
impetus. We comforted ourselves with the reflection that we were lucky to be going down rather than up this awful slope. We could never have climbed it.
Slip—slither— clatter— slide—slither—slip! That was how we continued our journey to the bottom, where we landed knee-deep in litter, and more dead than alive. It really is a helpless feeling when one goes sliding down, down, quite unable to put on the brake.
We dare not rest for more than a few minutes as time was precious, and we had not the least idea where we were or how long it would take us to reach the boat.
At the foot of the gully it was fairly flat, and we wondered on hoping to encounter someone who might help us out of our difficulty. But the precious moments passed and so far as meeting anyone was concerned St. Helena might have been a desert island.
And worse than that, we could not perceive the faintest sign of a path, or even a track leading in any direction. We had lost ourselves with a vengeance. “We've done it now, old man,” said my chum despondently “Not much use trudging any farther along here. Better turn back and see if there's any better the other way.”
I must confess that I was beginning to feel a bit hopeless myself. It was not being lost that worried me so much as
Lock-down Scout
Lost in St Helena
Without any warning, we slid
down the stony slope
The plight of two British officersin their race against time
By Major G. W. King, DSO, MC (and Bar.)
Reprinted from the ‘Scout’ 27th Feb 1921
10
the possibility of being unable to re-join the Donolly Castle. But I didn't intend to show my feelings.
“Oh, buck-up!” I said cheerily, “There's sure to be a way out somewhere. Come on, we'll have a look in the other direction.”
But this was no more promising than where we had already been. Still no sign of a proper exit from the gully.
On the opposite side of the donga to that down which we had slithered was a similar slope of loose stones and shale. It looked as if we should have to climb that. My chum laughed at the idea when I suggested it.
“Can't be done, old chap. You know how we came down the other slope, and how the dickens do you suppose we shall reach the top of this one by taking one step up and two down, licks me.”
“But we've got to get out of this hole somehow.” I said. “Have you any better suggestion to make?”“Couldn't make a worse,” he growled. “Don't care if I stay here for ever. I'm not going up that beastly slope unless you carry me.”
“Oh, pull yourself together, man. We're not on holiday now. There's a war in South Africa waiting to be won, and we must get back before the ship leaves”.
Eventually I persuaded him that as our only possible means of exit from the gully seemed to be up the stony steep, we should have to tackle the climb.
“Very well, then.” he said, resignedly, “If we must, we must, I suppose.”
And it was a climb! Far worse than the descent. All the time we were wondering what we should see at the top. Would it be the harbour of Jamestown, with the Donolly Castle riding steadily at anchor, or would it be another desolate tract of country? If the latter, we should be marked down as deserters, without a doubt.
I am sure there was never such a loose bed of shale as this. We climbed a few paces, then the stones would give way, and we slithered and slid to the point where we had started. By dint of much hard work, we had got about a quarter of the way up the slope and were congratulating ourselves on our progress, when without warning we slid almost to the bottom. It was disheartening! All that ground to be covered again, just as we thought we were getting on nicely.
After what seemed like hours of sliding and slithering and climbing and slipping, we had got almost within sight of the top, when my chum said he simply couldn't move another inch. And he sank down where he stood, ankle-deep in the shale, too exhausted to care what happened to him.
This put me in a nice predicament. I couldn't leave him where he was, to slide down the hill again, and I didn't see how I was going to get him up the few remaining yards between ourselves and the top.
“Come on, man,” I cajoled him. “we're nearly up.” But he was done.
“Can't move another yard,” a weary voice replied, and with that he started to slide away from my side.
“Flinging out my arm, I just managed to catch his tunic
with my hand. Happily I was in a fairly secure position myself, so the extra weight did not shift me, and I stopped his descent.
But what was I to do next?
He implored me to leave him and look after myself; but of course, that was out of the question.
“If you hold on to me, do you think you could get along?” I asked.“I'll try” he said weakly.
He put a hand on my belt, and I gripped the shoulder of his tunic with one of my hands. And in this way we struggled— and it was a struggle!— to the top, where we sank exhausted together.
Leaving him safe on a piece of flat ground, I went off to try to find out where we were.
A little higher up, I got a commanding view and instead of the desolate country which I half expected to see, there nestling below us, was the port of Jamestown. You may imagine my surprise and relief at the sight.
Hastening back to my chum, I told him the good news, and in a few minutes he was on his feet, as anxious as I was to get back to the boat.
It was a downhill path this time— and no shale! So the going was quite easy— at least compared with what we had just been through.
As we neared the quay, we could see that one of the Donolly Castle's boats were still alongside. So we were in time, alright.
But were we? As we watched, we could see that she was loading up, and a shrill warning whistle rang out bidding the late comers hasten.
We were too far away to shout loudly enough to be heard, but we started running, or rather stumbling along at sort of jog-trot, expecting to pitch over at every step. It would be cruel if we were too late, after all the efforts we had made.
Again that warning whistle sent forth its shrill note. We were still a quarter of a mile away, but we shouted now and waved out arms, in the meantime continuing our poor efforts at speed.
But there was no sign from the boat that we were noticed, and I could see that they were preparing to cast off from the quay.
We redoubled our shouts and jesticulations, and just as the last mooring rope was about to be hauled aboard, we were noticed and in another few minutes we stumbled on board.
This was, I think, the longest day I ever spent— every hour of that awful journey seemed a lifetime. And both my chum and I have registered a vow never again to take a short-cut in a strange country.
Lock-down Scout
11
Lock-down Scout
Amazing Knots
A
B
C
Single Cat’s Paw
Many knots when heavily loaded will need extra time to untie.
Not so the Single Cat’s Paw. This little-known knot is easy
to tie, will take strong loads, and will fall apart when untied.
Create two bights as at A. Wind 6 to 8 turns around the
middle (wind the main rope, not the end) as at B then slip the
two loops over the anchor.
The loops should be adjusted to bring the knot close to the
anchor as at C.
Friendshe joy of having friends is that they unlock a special part of our being. When we are without
Tfriends for any length of time we shrink. When we reconnect, that part of us comes alive turning
us back into who we really are.
We know friendship is about trust and loyalty, companionship and fun, but also it is about this extra bit:
that each is equally lifted to become greater than their lonely selves. Only through friendship do we reach
all the best experiences. Surely, this is a key insight— we grow through friendship.
And if you are someone's friend it means that you are far more than just a playmate. Our friends affect us,
and we affect them.
If you call yourself a Scout, be adventurous and bold, but be clean, honest and true, for our choices also
shape the lives of our closest friends.
Dec 2018
g
The Cat’s Paw is slipped over an open picket whereas for heavily loaded ropes, the picket is usually tethered at the top. This limits the Cat’s Paw’s use.
But also, the Cat’s Paw fixes the rope as an anchor point; it can’t be used for tying off a tensioned rope. This also limits its use.
However, its merit is in its speed of tying and untying and should there be a tree-stump at the far-end of an aerial run-way, a Cat’s Paw is the perfect knot, because at break-down it falls apart without fuss. rv
12
Lock-down Scout
13
1
3 45
6
7
8
9 10
Lock-down Scout
What’s wrongwith these pictures?
2
Answers page 15
HOW QUEER
“I can’t go straight,” wailed the corkscrew.“I’m an awful bore,” drawled the gimlet.“I smooth matters down,” said the plane.“Life’s all ups and downs for me,” grumbled the lift.“I’m always being sat on,” groused the chair.“Well, I’m going on strike,” chimed the clock.“Ditto,” cried the match.“What stirring times I live in,” exclaimed the spoon.
CLEVER
Smart: “Without moving from the table I will show you something you have never seen before, that I have never seen before, that nobody has ever seen before, and that nobody will ever see again.”
Duller: “Impossible!”
Smart (taking up a nut, cracking it, and showing the kernel): “There you are, I’ve never seen it before, you haven’t, and (swallowing it) nobody will ever see it again.”
How smart is your right foot?
While sitting, lift your right foot
and make clockwise circles.
Now, while doing this, draw the
number '6' in the air with your
right hand. Your foot will change
direction.
Apparently, no one can defeat this.
Our brains are wired in such a way
that independent control in this
manouevre is impossible.
14
Lock-down Scout
Scout?Can you name
six trees?
There are hundreds of different trees and they are all important. To help care for them
Scouts learn the names of the commonest trees. But, of course, it’s not just conservation that interests Scouts– we play among trees and we rely on them constantly, just as the wildlife does.Recognising them and naming them is traditional to Scouts because woodland lore was so valued by the first Scouts. They made trees part of their Scout life and we keep the skill going.
12
3
4
5
6 Answerson page 15
15
Lock-down Scout
Remove six matches from the six squares so as to leave two perfect squares and no odd matches.
10
What’s wrong with the pictures? (P14)
1 Tiger has lion’s main2 Post box has no slot3 Handle on wrong side of bucket4 Impossible date5 Beech nuts should be acorns6 Bi-plane has no wheels7 Head should be tails8 Far wheel wrong position9 Hen doesn’t cock-a-doodle-do10 Salute should be right hand
Arrange five coins so that every coin touches every
other coin
Matchstick puzzle No. 9
(Iss 6 p13)
Area puzzle: (Issue 6, p13)Ans: 3 (Count the touching areas)
Puzzles
Can you name six trees? (P14)
1 Holly2 Ash3 Maple4 Oak5 Horse chestnut6 Birch
Can you name this place?
(Issue 6, p13)
Ans: Empire State Building, USA
A N S W E R
A N S W E R
A N S W E R
A N S W E R
A N S W E R
16
Lock-down Scout
Scout artNorman Rockwell
(3rd Feb, 1894 – 8th Nov, 1978)
orman Rockwell must have influenced
NAmerican Scouting and youth culture
through his 5 decades of illustration
for the popular Scout magazine, Boy's Life.
Over his lifetime he produced more than 4,000
original works for a range of clients. One work
recently sold for $46 million.
His Scout pictures always depict Scouts as
serious, patriotic, dutiful and charged with
mission. Critics claim his work is sentimental.
I think his work shows Scouting rather too
close to militarism and the playfulness of
boyhood (there were no girl Scouts in his day)
is rarely seen.
17
In lock-downHarpenden and Wheathampstead Scout District
https://www.scouts.org.uk/the-great-indoors/
Extra activities available from Scouts.org
Find out more at:
Lock-down Scout
18
Build a simple
Crystal Set
An activity suitable for part of the Creative Challenge badge
Ray Vassie(First outing at 4th Harpenden
family Camp, August 2014)
Lock-down
ScoutOur Magazine for Isolated Scouts
Issue No. 7
For as long as it takes
Project supplement: Crystal set radio
rystal sets are simple to build but require a little care with the coils and tuning capacitor. There are no
Cbatteries since all the energy comes out of the sky from the transmitter. There is considerable latitude in construction but stick to the tuning coil as described or experiment to see what works. The wiring must be
as shown in the diagram.
Definite requirements for crystal sets to work
There must be a strong medium-wave transmission in the area.
Space to erect a horizontal aerial, as long as possible. (15-20 metres would be great).
There must be an earth: a metal water pipe is ideal but a metal rod in the ground will serve. For safety, do not use earth terminals on mains sockets.
A germanium diode (the crystal) is available via ebay and other internet sources. (Modern silicon diodes will not work in crystal sets).
Headphones: many small earphones commonly used with i-pods, etc., will serve well. (The bigger hi-fi speaker-phones will definitely not work).
Quiet. The power of the crystal set is very small and cannot be heard in noisy settings (eg cars, crowds, music, etc.)
1
19
Safety and Risk Assessment
There are three areas of risk:
1 Hand-tools will include craft knives and cutters, etc.
2 Putting up aerials may involve climbing. (See ‘Ways to stay on the ground’ in the section on aerial masts.)
3 In storms, aerials can be favoured pathways for lightning. Lower the aerial to ground in stormy conditions.
The Crystal Set circuit diagram
Aerial terminal
Earthterminal
Tuning capacitor(2 foil covered cards separated by shopping-bag plastic)
OA91 diode (The crystal)(Must be Germanium, not Silicon)[Connect either way round]
Ae
ria
l co
up
ling
coil,
2
5 t
urn
s
Tu
nin
g c
oil
25
+ 2
5 t
urn
s
(Tap)
Earth
Head-phones
10nF to 100nFcapacitor
Aerial
Lin
k
Terminalblock
(Slides overtuning coil)
Suitable diodes
OA7OA47OA81OA90OA91OA951N341N60
1N270CV7 130GEX23D113(If it is
germanium it will work)
The build planThe crystal set is build in 4 parts: the base board, the coils, the capacitor, and the diode block. There is a further stage of rigging an aerial and proving an earth. Then the whole is brought together.
The picture shows a rock. This provides gentle pressure on the tuning plate and any comparable weight will serve.
The cost depends on what is to hand but expect £5 for wire and £3 for other components via eBay.
You will need to be creative and find solutions to many wrinkles.
Lock-down Scout
2
20
Making the aerial coupling coil
Making the diode block
The aerial coupling coil is wound on the bigger diameter former prepared as shown on P10.
Anchor a wire end by looping it through two holes close together (see tuning coil details); then wind 25 turns and anchor the finish end in the same way as the start.
The coil is shown layered but it can be a single layer or even pile wound (i.e. untidy) but keep to 25 turns.
Cut each wire to 300mm to allow the coupling coil to slide along the tuning coil former.
Finally, twist the two wires together (not shown).
Aerial coupling
coil
The capacitor shown in the picture is but one type of capacitor; there are many shapes and sizes but providing it has a value between 10nF and 100nF (nanoFarad) and has two wires it will work. Ignore the voltage rating of the capacitor since any will be suitable. 10nF might also be expressed as 0.01 F, and 100nF as 0.1 F (microFarad). µ µ
The diode is a bit fragile so avoid bending the wires close to its body. Normally it matters which way round a diode is connected but for crystal sets, you can connect it either way round.
Finally, add the short link-wire.
Fix the block with two short screws to the base board.
Diode
CapacitorLink
Making the tuning coil
Tuning coil:50 turns tapped at 25
The tuning coil is wound on the long, smaller diameter card tube prepared as shown on page 10.
Start by anchoring a wire end to the former (nearest the middle) by looping it through two holes close together. Leave a tail of wire to reach the earth terminal. Wind 50 turns but stop at 25 to create a tap: use the holes in the middle to secure the wire. The picture shows the two 25 turn sections in different colours just to illustrate the construction but one colour is fine. Twist the tap wires together and make them long enough to reach the diode. Anchor the wire at the 50th turn and cut the tail 300mm long.
Anchor the wire by looping it through 2 holes in the former
Lock-down Scout
3
21
Making the tuning capacitor
Cut two stiff cards each about 100mm x 150mm and then two aluminium foils 150mm x 200mm. Try to keep the cards perfectly flat and the edges free from burrs. A craft knife or guillotine is usually best for card and scissors for the foil.
On each card, apply double-sided sticky tape along each side, on one side.
Cut the corners off the foil as shown in the picture. Working on a flat surface, place one card centrally on the foil. Lift and crease one edge of the foil. Remove the backing from the adjacent sticky tape and press the foil flap on to it. Repeat with the remaining 3 sides being careful to keep the underside clean, flat and tight to the card.Do exactly the same with the second card.
The finished tuning capacitor plates. Keep them safe from harm until you are ready to add connections.(One shown up, the other down).
Making connections to the tuning capacitor
Strip 20mm off the end of a connection wire and fan out the strands as shown in the picture.
(This may need a little practice so try a few times on scrap pieces of wire).
Lay the wire with the spread strands onto a
piece of gaffa tape. 20mm x 50mm is about right. (Other
kinds of tape may also serve).
Take care to keep the strands nicely spread.
NOTE: Each plate requires its own separate wire .
Lay the tuning plate face down on a flat surface and align the gaffa tape nicely over the foil that is fixed by double sided tape, then press down firmly.
Press the gaffa tape around the features of the wire strands so that its impression shows. See the picture.
Do this for each plate but be careful to attach the correct wire to each: one to earth, the other to the coil.
Lock-down Scout
4
22
Making the base board
Making connections to headphones
2-way terminal blockfor aerial and earth
2 supports for the tuning coil former.(Woodscrews with cork spacers)
4-way terminal block for the diode blockFix with one or two screws
Base boardxxmm x ssmm
The base board can be any convenient size but the one illustrated is 300mm x 250mm. The position of the supports for the tuning coil should be marked by placing the coil in position and using a pencil to mark through the holes in the former.
The cork spacers (bottle-tops might serve as well) should be about 10mm thick and the woodscrews short enough so they do not penetrate the board.
Phones with a 3.5mm jack (the commonest in use) can be connected by attaching wires as shown in the picture.
However, the jack plug may be cut off old headphones, the wires stripped and connected.
Historic war-time headphones (if available) may have jacks that dismantle enabling simple wiring to the block
Simple wire connections toa 3.5mm jack.Only one phone is connected
These wires needonly be 60mm longto reach the terminalblock
Bringing it all together
Connect tuning coil tap to the diode (the crystal)
Connect the phones across the capacitor
Connect a wire from earthto the capacitor(outer lead)
Connect the tuningcoil to earth
Use gaffa tape to
secure the phones
Connect the aerialto the terminal block
Connect the aerialcoupling coil.(One wirein eachterminal)
Connect the earth wire to the terminal block
Connect the top of the tuning coil to the aluminium
foil (see text).
Insulator:Cut a piece of heavy polythene (perhaps from a shopping bag) big enough to cover the bottom capacitor plate. Secure it with tape. (It isshown folded back for illustration).
Place the tuning capacitorplate face up (attached wire underneath). Usea piece of double-sidedsticky tape to secure itto the base-board.Connect the wire to theearth terminal.
Find a weight ofabout 100gto rest on the topplate. (A stone works well)
Refer to the circuit diagram
on Page 4
Lock-down Scout
5
23
Fixing hole each end
Twin holes toanchor wires
200mm
50mm
35mm
55m
m
20mm
20mm
70m
m
300mm
250m
m
Base board
Coil formers
Cards for thetuning capacitor
100m
m
150mm
Dimensions
These are the sizes of the illustrated crystal set but other sizes will work as well. The one dimension that should be as close as possible is the tuning coil diameter, 55mm. If the diameter increases, reduce the turns and vice versa. Experiment will decide what works.
The completed crystal set shown working in a field. The earth is a metal rod driven 500mm into grassy soil. Connection is made by crocodile clip.
The aerial (the red wire) is the end of a 30 metre wire held between two structures to lift it off the ground.
Put the headphone to the ear, slide the coupling coil over the tuning coil, then tune for a radio signal by sliding the top capacitor plate over the plastic insulator.
Good luck!
It’s finished! Test it out!
Lock-down Scout
6
24
33nF
capacitor
Extra pictures
Looking inside
the tubes
The earth rodand aerial connection
OA91 diode
The arial and earth
terminal block
The aerial coupling coil
over the tuning coil
MaterialsBase board (Prototype used whiteboard 300mm x 250mm. )Former for tuning coil (200mm tube, 55mm outer dia, cardboard)* Use nearest plastic bottle
Former for aerial coupling coil (50mm tube, 70mm outer dia, cardboard)* Use nearest plastic bottle
*Avoid tubes with metalised surfaces (e.g. Pringles). Plastic tubes (e.g from bottles) may be used.
Terminal blocks, 4 way and 2 wayEarth rod, (if no metal water pipe available). 300mm metal rod driven into lawn. Connection required.Aerial wire. 30 metres (ish). (Green garden wire will serve). Wire to wind coils and general wiring, 20 metres. (Eg 7/0.2mm stranded wire, pvc). (eBay).Cork (to make spacers for tuning tube).2 wood screws, 25mm, pozidrive3 smaller screws to secure terminal blocksCapacitor: any value between 10nF and 100nF. (eBay)Germanium diode (the crystal): OA91 or equivalent. (See list by diagram) (eBay)Headphones: i-pod earphones will work, war-time 2,000 ohm phones are better.Plastic sheet for tuning capacitor insulator (plastic shopping bag will do)Aluminium kitchen foil. (Keep it smooth)Strong cardboard, A5 minimum size. (E.g. back of writing pads serve well)Crocodile clip (to attach to earth rod). (eBay)Double-sided sticky tape.Gaffa tape (duct tape). (100mm will be more than enough)A weight of around 100g. (A clean stone will serve)
ToolsScissors; Craft knife; Wire cutters; Small long nose pliers; Small pozidrive screwdriverSmall flat screwdriver; Paper guillotine to cut card (Optional)Drill to make holes in cardboard (but could use small screwdriver instead)
Other possible itemsPoles (for aerial masts)Ropes for guys and lashing etc.Clamp or clip to connect to water pipe)Gazebo (to work in the rain or out of sun)
Lock-down Scout
7
25
Getting the aerial up
Fieldwork
The aerial is fundamental to success but so too is staying safe. The task is to get the aerial high off the ground and for it to be easily raised and lowered – without breaking bones! Scouting’s pioneering skills make the task safe and easy.
How to use branches too high to reach.Basic idea: Take a rope twice as long as the height of the branch. At the middle tie a Manharness knot (or an alpine butterfly knot) to make a small loop. Tie a stick to one end of the rope and throw it over the out-of-reach branch. Untie the stick and pass the rope end through the middle loop and hoist the loop up to the branch; pull on the other rope to bring it back down. The loop is now available to raise or lower the aerial (anything) up to the branch.
Arrangement at the tree (or mast) by the crystal set.Bring the loop down from the branch. Tie the aerial to it making sure that the aerial end still reaches the crystal set when it is hoisted. Hoist the aerial up to the branch and secure the hoisting rope to the tree trunk.
Arrangement at the far end of the aerialDuplicate the arrangement for the far end. Bring the loop down to ground and pass a second rope through the loop. Hoist the loop back up to the out-of-reach branch and secure it to the tree trunk. The second rope is now available to hoist the aerial. Tie the end of the aerial wire to the second rope and hoist the aerial up. Pull just tight enough to lift the aerial clear of a Scout’s reach. Then secure the rope to the tree trunk.
In the event of a storm, simply unfasten the hoisting ropes and lower the aerial to ground.
Ways to avoid climbing
Aerial
Aerial
To loweraerial
To hoistaerial
To hoistaerial
Tightenaerial
Manharness knotto make the loops
Tie 3 loops in a rope then bind to the top of the mast-head to anchor guys and aerial
Sheerlashing
2 poles
3 guys
Outdoor Challenge Badge(Build a simple pioneering project)
Using a high branch
Making a mast
Lock-down Scout
8
26
At the transmitter an electrical wave is sent to its aerial which is able to pass into the air – part electric, part magnetic and it travels through space. If a wire is suspended at some distance from the transmitter, the electric part of the wave induces small voltages across it. Such a wire can be a receiving aerial and those small voltages can provide enough power to operate a crystal set.
It is not possible for the low frequencies of speech and music to leave an aerial and so transmitters must use high frequencies far, far above our hearing. In the medium wave band, transmitters use frequencies of around 1MHz (megahertz) which means the wave goes up and down 1 million time a second. (As it travels, each wave is 300metres long). Because it leaves the aerial it is called a carrier wave and this is what the crystal set actually receives.
The low frequencies of speech or music are called audio and these too are waves but they cannot escape the wires; they are typically 1kHz, i.e. rising and falling at around one thousand times per second.
The trick of radio is to make the carrier wave rise and fall with the audio wave. So a musical note at 1kHz makes the carrier wave get bigger and smaller at 1kHz. This is called modulation and because it affects size or height of the carrier wave it is called amplitude modulation or AM for short.
This modulated carrier leaves the transmitter and finds its way to the receiving aerial where the small induced voltages have exactly the same musical note impressed on it.
The aerial signal is still a carrier wave and the audio signal has to be extracted. The carrier wave swings positive and negative and the modulation makes both sides rise and fall equally and, in effect, they cancel each other out. But by chopping the carrier wave in half and allowing, say, only the positive half through, no cancelling occurs. This leaves a carrier wave (at 1MHz) going from zero to positive values determined by the audio signal.
The next clever bit: a small capacitor is used to store the voltage at the top of the carrier wave for a short time. The carrier can no longer rise and fall at 1MHz because the charge on the capacitor holds it up. But the charge leaks away (through the phones) so that as the carrier rises and falls by audio modulation, the voltage on the capacitor follows it. In this way, the carrier disappears and the audio remains. The diode and capacitor together are called the demodulator. In the crystal set, the audio signal across the capacitor is fed to the headphones directly. The signal is small but providing the world around is quiet, whatever sound is aimed at the transmitter microphone, the very same sound will be heard in the crystal set’s headphones.
Selecting a particular transmitter
Any high frequency can be used as a carrier wave and so transmitter stations can choose which frequency they use. And then, if the receiver has some means of responding to different frequencies, various stations can be selected. Crystal sets use a coil and tuning capacitor to do this. Just as a pendulum has a definite swing rate as it exchanges energy from height but no movement (top of swing) to movement but no height (bottom of swing), so the coil and capacitor exchange energy and do so at a definite rate determined by their size.
The coil creates a magnetic field when current flows, the capacitor holds an electric field when there is a voltage across it. When connected together they transfer their energy backwards and forwards like the pendulum; one moment it is all magnetic, the next it is all electric. The big difference is the speed: the coil and capacitor can exchange energy at millions of times a second.
Like the swing of a pendulum is determined by its length and gravity, so the coil and capacitor’s speed is determined by the magnetic and electrical properties. If either the coil or capacitance is made bigger, the speed slows down.
In the crystal set the coil is fixed and so its magnetic properties don’t change. But the capacitor (the two aluminium foil plates) is variable. When they completely overlap, the capacitance is at maximum; when pulled apart, the capacitance falls. The ‘swing rate’ changes accordingly.
An aerial will pick up energy from many radio stations, all with different frequencies. The only one that will get through the circuit is the one that matches the swing rate of the coil and tuning capacitor; all other frequencies are rejected. By adjusting the tuning capacitor, the one desired station can be received.
Using the aerial coupling coilThe electric energy from the many transmitters travelling through the sky would like to go to earth so we give it a helping hand by connecting the aerial to earth via the coupling coil. As the signals on the aerial shoot through the coupling coil they create a small current which in turns creates a magnetic field which can be coupled to the tuning circuit. By making the coupling coil slide nearer to or further from the tuning coil, the selectivity of the tuning circuit can be controlled. Too much coupling is louder but causes two or more stations to be received together; too little coupling gives excellent selectivity but weaker reception. The user slides the coupling coil towards or away from the tuning coil for best results in any given situation. rv
How the crystal set works
Chopped in halfby the diode
Crests held by the charge onthe capacitor
The recovered audio signal
(Carrier disappears)
Modulated radiosignal
Lock-down Scout
9
27
In lock-downHarpenden and Wheathampstead Scout District
10