Hints & Kinks for the Radio Amateur - N5DUX

136 Pages·2010·7.14 MB·English

Hints & Kinks
for the Radio Amateur
Edited By
Stuart Leland, W1JEC
The American Radio Relay League, Inc.
Newington, CT 06111
Copyright © 1978by
TheAmerican RadioRelayleague, Inc.
Copyrightsecured underthePan-American
Convention
International Copyright secured
This work isPublicationNo.10ofthe Radio
Amateur's library,published bythe league.
All rights reserved.Nopartofthis workmay
bereproduced inanyformexcept bywritten
permission ofthe publisher. All rights of
translationarereserved.
Printed inUSA
Quedanreservadostoaos los derechos
Library ofCongress Catalog CardNumber:
33-14685
$4.00 InUSA
$4.50 elsewhere
Foreword
How can you find a solution to a tricky problem in your
amateur radio workshop or station? Has some other
amateur experienced a similar problem? Chances are
someone has already grappled with a like problem and
has devised a workable solution. It shouldn't be surpris
ing. Inventiveness has always been an outstanding quality
of the radio amateur.
This booklet contains a collection of such tricks of the
trade, written by several hundred amateurs. Many of their
ideas were published originally in 05T, the monthly jour
nal of the League.
A sincere effort has been made to touch upon a wide
area of interests with the Intention of offering something
for everyone. And should you find your own experiments
producing a handy answer to a common problem, send it
to 05T. You may be among the authors of the next
volume of Hints & Kinks for the Radio Amateur.
Richard L. Baldwin, W1RU
GeneralManager

Contents
1 Aids for the Station
and Shop
Page 7
2 Test Gear Ideas
Page 21
3 Transmitting and Receiving
Kinks
Page 36
4 Hints for the Power Supply
Page 56
5 Antenna Tidbits
Page 65
6 Thoughts for CW Operators
Page 76
7 Portable and Mobile Quickies
Page 95
8 VH F Band·aids and Tricks
Page 108
9 Notions for Various Modes
Page 118
10 Data for PC Boards
and Solid State
Page 126
Index
Page 133

- -------- --._...._.._--
Chapter 1
Aids
for the Station and Shop
SOME IDEAS ON STATION labeled for various pieces of equipment. grill cloth, and drill two more holes in
LAYOUT AND HELPFUL Wire such a unit with a three-wire system back, where you prefer, for hanging the
ACCESSORIES for maximum shock protection. The in speaker cabinet on the wall.
stallation might also include a voltage Doorstop/bookend: I just can't bring
Desk drawers with stops: "Second" or monitor meter, and the position would be myself to throw out that old transformer
"reject" doors, finishedand mounted on that burned out in my af amplifier. It
legs, with flaws'underneath, have come makes a fine bookend or doorstop. Be
into common use as desks. Two-drawer sure to put astrip offeltonthefeetsoyou
filingcabinetson each end, besidethe legs don't mar the bookshelf. - Harrison
Or in place of them, further extend the Leon Church, WeKXP
usefulnessof the gimmick. Thereisaneed
\
for more carpentry to make shallow
drawers for installation under the length
HOLDING LIGHTWEIGHT
ofthe frontof thedesk. Aneasytrick isto .l
EQUIPMENT IN PLACE
useshallow aluminum baking pans of the
type that are made with a rolled lip Yearsago, amateurequipmentwould stay
around the top. Strips of wood can be put by sheer weight alone. Today, light
grooved, then glued and screwed weight transceivers and the like willscoot
underneath the door. The pans are simply offthe desk with justa slight nudge.
slipped by the lip into the grooves. For a I have found that a piece of indoor
nice finishing touch, varnished strips of outdoorcarpetingwillhold them inplace.
wood are secured to the front side of the The equipment feet nestle down into the
"drawers." Both front and back slide nap of the carpet. The rubber backing
stops are made by placing a stick-on rub holds the carpet material firmly to the
ber foot on the undersideofthetable. For desk top or other surface.
the inside stop, simply reach inside the When stacking gear, put a piece of
open drawer at its intended maximum carpeting under the feet of the top unit.
pull, and stick the stop in place. This should not be used on a vented
Step-to-talk: For those who haven't cabinet of course, but is great for solid
discoveredthe easeof usinga foot switch, ones, such as speaker enclosures. ---:- Ed
here'saquick application for arelayfrom Thisoperating positionfeatures manyofthe Heubach, W9AO
hInts described,includingarelay forthefoot
thejunkbox.Selectonethatwillsitflat on
swncn, powerpanel,boommlc andKleenex
the floor, wire the push-to-talk circuit boxspeakercabinet85well asthecustom
through a length of line cord to the con crafted baking pandrawers underthetable. BEWAREOF PROTECTIVE
tacts, and place the assembly on the floor DIODES
under your operating table. A mic on a A word of caution regarding the use of
boom makes for hands-off operation in a good place to put your SWR meters. protectivediodes across the antennainput
the absence of VOX as wellas the profes Speakers the easy way: New poly terminals of solid-state receivers is in
sional studio look for the station. planar foam cone speakers are being order_If separate antennas are used for
Centralize your switches: A friend of marketed by Lafayette Radio Electronics transmittingand receiving, severeTVIcan
mine, K9KXP, told mehow hestops wor in a 5 x 8-inch(127 X 203mm) sizeand be created by the diodes rectifying the
ryingaboutwearing out theswitchesinhis willfit marvelously into a plastic Kleenex transmitted signals and reradiating them
various units. He has them wired through tissuebox, the oval openingservingasthe on many frequencies inthe rf spectrum. I
a master control panel which can be cabinet sound exit. Drill four holes in the discovered this while experimenting with
rigged to include master switch, fused cir front, spaced to fit the speaker mounts; my solid-state receiver. I was attempting
cuits and the individual circuit switches mount the speaker with a double layer of to see if the diodes really protected the
Aids 'or.he Station and Shop 7
front-end rftransistorstagebyleavingthe of work. Whilenot necessary,theendsof
receiver connected to its own antenna these pieceswere curved to improve the
while transmitting with a 3S0-watt rig appearance.
nearby. I wasimpolitely informed bythe 3) Place the 22-inch pieces (legs)over'
XYL that I was raising havoc with the thesehalf-moon cutsand markthelegsso
televisionset. Assoon asthe receiverwas starting holes can be made. Four a-inch
disconnected from its antenna, the No. 14wood screwsshould be sufficient
problemdisappeared. Ifthesameantenna to hold the legsin an upright, stationary
is used for transmitting and receiving, position.
sucha problem should not exist. - G/en 4) Next, place two 1 x e-incb pieces
Benskin, K6UH over the ends of the legs and drill four HOTE'LEHGTH OFSTRIPS
WILL VARYWITH BOX
starting holesatthe four positions. Secure LENGTH, THEY SHOULD
BEFLUSH WITH INNER
the two I X 6 pieceswith four No. 14
SURFACE.
GMT "HOURHAND" wood screws.Thiscompletesthe basefor
A homemade "hour hand" of thin sheet the table.
metal fixedto the sameshaft as the hour 5) Set a door or a sheet of plywood
hand ofyour clock, and setto theproper 112-or 3/4-inch (13to 19mm) thick on
number of hours ahead (or behind) will top. Drilltwo holesthrough the 1 X 6at Anorange-cratetransceiver stand.
show GMT, while the original hand will ,each end, so that they enter the top.
show local time. - Tom Chaudou, Securetotop with1-112inchNo. 14wood
ORANGE-CRATESTAND
WN9FLD screws.Thiscompletesthe table.
6) A 2 X 4isplaced on the backside, For those who have a small operating
about halfway down, to give the table table, awoodenorangecratemakesanex
HAM SHACK TABLE lateral stability and to support electric cellentstand for atransceiver. Oneofthe
For about $30,ahandsome deskthat will outlets and cabling. A piece of plywood' long'sidesof the crate isremoved to pro
support heavyequipment can be built by willdo verynicely,too. videasmallstorage spacebelow. Ihavea
following some simple steps. This infor 7) Alargeshelfon top givesadditional keyer, bug, and small lamp stored
mation is offered as a guide for any room for equipment. A 2 X 12wasused underneath with room to spare. If addi
amateur interested inconstructinghisown here. Theendsupports (alsomadefrom 2 tional support is desired, wooden strips
table (seedrawing). X 12 stock) for this shelf should be about I X 1 X 12inches(25 X 25 X 305
1) Two 4 X 4-inch, (102 X 102mm) centered overthe4 X 4legsofthe table. mm), attached as shown in the drawing,
8-foot (2.44 m) lengths are cut into the L-shapedbracketsholdtheshelftogether. should. do nicely. - Robert Zagorac,
will
following dimensions: four pieces 22 The overall dimensions used make WN9QYU
inches (558 mm) long, two pieces 33 the surface of the table about 28-1/4
inches(838mm) long. inches(717mm)high,whichisquitecom
LATCHING RELAY SOURCE
2) Half-moon shaped cuts are made fortable for myself.The heightcan bead
6-112 (615 mm) and 7-112 inches (190 justed by making the legs different For your latching relay requirements, I
mm) from each end of the 33-inch-long lengths.Thetable canbedisassembledin have found VWelectricalsystems.a good
pieces.These cuts should be 2inches(51 to its basic components, if necessary. sourceofsupply.Theyusealatchingrelay
mm)deep. Ajigsawishandy for thistype Mike Greenway,K4TBN to control high- and low-beam headlight
switchingwith a singlepulse button. My
last trip to the local junkyard netted me
four relaysfor two dollars. The quality is
USEWOOD SCREWS excellentand thesizeisabout l-inchcube.
ANDCOUNTERSiNK
OlderVWsare6Vand neweronesare 12
2,"012,"
V. - WalterLelioret, WA3VCY
12"
GROUNDING AC LINES
Howard M. Berlin's (K3NEZ) "Danger
Lurks!" article in February, 1976, QST
SCREWS GOIN ONUNDERSiDE was excellent. Because of Berlin's
TOHOLDDOOR DOWN
SUPPORTS familiarity with the subject, I think he
AREINSET
AfEW IN-;,";:;."27':;V may have overlooked supplying informa
'"""~ tion whichsomehams do not have.
'" BASE When a receptacleisproperly mounted
~'·'\. , 7 inawallbox,thepinholeGROUND isat
\2J BECURVED
DRILL ANDCOUNTERSINK HOLESATEACHEND 2'8" /f thebottom. Thelineground (NEUTRAL)
is at the left side of the two slots. It is
!:/
largerthan thehotsideslotinsomerecep
A2P'PLREOGXS. tacles.
® ):- The GROUND pin hole is frequently
connectedto the conduit or BXcableand
likemany other "pipe" conductors, does
not provide the most perfect ground. In
nonmetallic sheathed cable (Romex) in
t",e"-EXACTLENGTH
OFCOOR BEINGUSED stallations, the ground is simply a bare
wire.
Plansforahomemadetable that canbedisassembledeaSilyandIslargeenoughto handlemost Modern two-lead (two connections)
oftheequipment inone's shack.Thebuilder canmodify accordinglytosuit hisownneeds. wiring devices willshow different colors
8 Chapter 1
A ,10./Jf
Hi~
M'O>Ck
'NEUTRAL'"---+f '> Ir
LINE GAIN
GROUND
~2 ~
C
IO./Jf
GROWUIRNED,PTIHNIRD 5 zHU,E/P'<, • 6 ~,6,V <; GAAMIPNLIfiER
' 4
lN34A lN34A
Standardcircuit for 117·Vacreceptacle, +7 -i>
~~'"
'6V
ofmetalatconnections. Thenatural brass : 'M
is'the HOT side. The light-colored con
nection (tinned, nickel, cadmium, etc.) is S'M
theNEUTRAL (lineground) side.Ifthere
is a third connection, as in plug recep
tacles, it isthe ground connection, screw
head daubed bluish-green. ~~ +l6lVlr
Indeviceswithpigtails,thewhiteleadis
neutral ground. Inacpowerwiring,white
is almost always neutral ground. It must
Schematic diagram of te pre-ampforusewithdeskmicrophone.
neverbe broken withswitches,fuses,etc.
The hot lead isblack or anycolor except
white. - B. H. Hansen, W6HOZ
tothecarbon element.Removethecarbon power for the IC. A switchshould bein
element and install a dynamic element. stalledinthecircuittopreventrunningthe
One with approximately 500 ohms im batterydown whenthe preamplifierisnot
PUTIING YOUR BUGOR
pedance is satisfactory; however. I have in use. - Robert D. Shriner, WAIlUZO
PADDLE IN ITS PLACE
not found anyelement that won't work.
AND KEEPING IT THERE
Distribute the rest of the parts around
Ikeepmybuginplacebyapplyingasmall the inside of the microphone case. Prac DUAL-GATE MOSFET OFFERS
amount ofrubber cementon the feetand ticallyany pnp transistor willworkinthis AN UNUSUAL CRYSTAL·
pressingthe keydownon thedesiredspot circuit. Any of the' general replacement CONTROLLEDOSCILLATOR
on the table. When I wish to move the audio types should do. A drop or two of CONCEPT
key, Ijust pryitloosefrom thetable. The
cementorliquidrubber willholdtheparts This unusual crystal-controlled oscillator
old cement rubs off easily, leaving no
in place. Connect points Band D to the circuitoffers someinterestingpossibilities
marks on the table. - M. Crosby
dynamicelement. for application as the LO in vhf and uhf
Bartlett, K4EU
Foruseasadeskmic,addtheIecircuit converter design. No trimming or tuning
shown. Connect the output of the Ie isrequired to getthe overtone frequency.
points Band D to the input of the tran Should the fundamental frequency ofthe
DUAL.PURPOSE CARBON
sistercircuit, pointsBandD.Connectthe crystal be desiredas the output, raisethe
MICROPHONE REPLACEMENT
dynamic element to the input points A valueofRFCI to tOO~Hor replaceitwith
Some of the fm transceivers coming into and C. a 1000·ohmresistor.
servicein the vhf amateur band still use The output waveform isclipped bythe The stability of the oscillator is ex
carbon microphones. Avastimprovement 1N34Adiodestopreventovermodulation. cellent. Actually the circuit works well
inaudio qualitycanbeachievedbytheuse Careful adjustment of the input and out withaslittleasfour voltsappliedto it.
of a dynamic microphone replacement put potentiometers will result in a G. Tomassetti, I4BER
cartridge. distortion-free signal. Ifthe input levelis
(Editor's Note:The circuitissimilartothemodi~ed
Shownisasimpletransistorcircuitthat too high, severe clipping willoccur. Ad Pierceoscillator,whichusesthecrystalbetweengnd I
canbeusedtoadaptadynamicelementto just the input so that normal voicelevel andgrid2ofatetrodetube.Dependinguponthereso
nant frequency of the output network of the
a carbon circuit. The voltagerequiredJar willjust start clipping.
oscillator, overtone or fundamental crystal-mode
the transistor is derived from the same A small 6-volt battery supplies the operationcanbeobtained.]
sourcethat originallywasusedbythecar
bon element. To make the adaptation,
simplyopen upyourmicrophonecaseand 4100 '2k 1000
determine the positiveand negativeleads'
+~
T
m 15V
220
1000 OUTPUT
< _+-l"':>,-<>--1f-(---"1( 10mW
+ ~"V L ~42I.661ATMHZ
4'00 reo
,-
DYNAMIC 3300 NOTE:42.661.21-1152MHz
ELEMENT 0 '+ 1152+144·1296MHz
Schematic diagramofsimple transistoradapter
for dynamic element to carbon microphone ctr-
cult. Acrystal-controlledoscillatorwith Interesting possibilities.
Aids lor Ihe Slelion end Shop 9
ADJUSTMENT OF POLAR RELAYS to center, when moved manually. Slight
FORRTTY readjustment of the second pole piece
should help if needed here.
Almost nobody uses polar relays these
Now apply ac power. Look at the
days in connection with amateur RTTY
waveform on the scope, or use the
operation, but there are still hundreds of
voltmeter set on a low-value de range.
them available as surplus, and at com
You should seea symmetric signalon the
paratively low prices. They have many
scope. Itwillnot beaperfect squarewave,
possible uses besides RTTY. The most
because some time is required for the
common type is the Western Electric
armature contact to move from one side
2SSA, and there are several equivalents
to the other. During the travel time, you
manufactured by other companies. Ifyou
will sec a small part of the waveform
have one of these relaysthat you wishto
where the signal is neither positive nor
adjust. try this simple procedure. It isn't
negative. During contact, the signal
as precise as you could do with a polar
should be positive or negative 1.5 volts.
relay test set, but is plenty good enough
for most purposes. You will need an Any nonsymmetry can be corrected by a
veryslightreadjustmentofthepolepieces
oscilloscope for finest adjustment,
(notthecontacts).Ifyouareusingameter
although fair resultscanbeobtainedusing
forindication, themetershould readzero.
only a de voltmeter. A small nail or the
Slight pole-pieceadjustment should bring
pointed tip ofa soldering aid can be used
the reading'to zero, if needed. On the
for the adjustment tool. A feeler gauge
oscilloscope you may observe some
might also be helpful.
Thecircuit for testingtherelayisshown amount of contact bounce, as a broken
intheaccompanyingdiagram. Ifyou plan up portion of the square wave. A very
tocheck relayadjustments frequently, the slight readjustment of the contacts may
circuit can bebuilt into a3 x 4 X 5-inch mAepaonlasrorfeltahyesteuscthcairsctuhiitsshmoawynbebealodwju.sted by correct this. You won't be able to detect
(76 x 102 x 127mm) chassis box with any contact bounce using a meter only.
insulated binding posts provided forscope That's all there isto it. Just a word of
or meter connections. With SI closed, the caution: Onceyou apply the acand make
armature (moving contacts) of the relay Usethe demeterorwatchforashiftinthe readjustments, go veryslowlyand do not
will move back and forth between the position of the baseline on the scope. make adjustments of more than a small
fixedcontacts60timespersecond. That's After contact is made, back off thirty fraction of a turn. Usually with surplus
just a bit slowerthan you would get with degreesor 1/12 turnon the contactscrew. relays, if they can't be adjusted by very
an RTTY signalat 100wpm. The output This should give a .D02-inch clearance. slight trimming, something isdefective in
from pin I (through the lOO-ohm resistor) Then adjust the other contact inthe same the relay. Even if this is the case, com
willalternate insquare-wave fashion, go manner. You should end up with a sym promise settings can sometimes be found
ing from +1.5Vto -1.5 V. metric arrangement, with .002-inch which will give quite satisfactory relay
Beginthe adjustment by disconnecting clearance on either side of the armature operation. - KITD
the ac power. Back off the contacts and contacts.
the polepieces(those round-shapedthings Nowturnone polepieceuntilthearma
COLOR CODING CIRCUIT
belowthe contacts) and check to seethat ture just touches the opposite contact.
DIAGRAMS
the armature is centered inside the coil Then back off on the pole piece slightly
opening. Ifnot, loosening somescrewson lessthan a half turn and tighten the ten Numbered triangles showing connections
the bottom ofthe relay should allow you sion nut. Then adjust the second pole between parts of a schematic cleanup the
to position the coil for best alignment. piecesothat the armature stands midway diagram, but make it difficult to find the
After you getthe coilset so the armature betweenthetwopolepiecesandtighten its companionnumberofapair. Icolor them
iscentered, tighten allscrews. Adjustone tension nut. The armature should flip to aroundtheoutside,usingadifferentcolor
contact screw until it just makes contact. either contact and remain, or else return for each pair. - TempleNieter, W9YLD
(Editor's Note: Thisisahandyhintformatchingup
sectionsofmultifunction res.]
'00 OSCILLOSCOPE
,----"'-';----.,-----1
O.!5A
T1 5 TV BACKDROP
6' I With more amateurs usingSSTVand fast
11 an +
-'-----o-C'---J t±---~h>---I-o (regular) scan television, the need for a
.~. :4 6T2...l:" white backdrop becomes important for
'------'-i,-J the production of high-contrast pictures.
L .JI The installation of a white roll-type win
w.E.2!55A dow shade hanging from the ceiling,
mou~ted a few feet behind the subject,
provides a suitable background for this
purpose. - Robert W. Gervenack,
W7FEN
o
CATVTVI
Schematicdiagram foradjustingpolar relays. Resistances areInohms. This information should be ofinterest to
51 - Spst slide ortoggleswitch. shown with relayplugged In).
any ham operating in a community or
T1- Filamenttransformer,6.3Vat0.6 B'Tl,BT2- 1.5·Vpenlightcells. AKey-
A(Halldorson 21F21oreqvtv.). stone Electronicsno.140orequlv. condominium complex served by cable
X1- W.E.255ArelaysocketIclrcult battery holder maybeused. television.AfterbeinginformedthatIwas
10 Chep,er 1