book

Radio and Electronics Cookbook

by RSGB

November 2000

Intermediate to advanced

336 pages

7h 43m

English

Newnes

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Putting it together
The componentsPutting it togetherBox clever!
DescriptionBuilding it
Putting it togetherA simple ‘keyboard’Testing
ConstructionTestingUses of your circuit

The circuitMaking the prototypeCalibration
ResistorsThe colour code
Sensing thingsVisible wavesAll waves are described in the same wayThe basic formulaDivisions of unitsBands
ConstructionCalibrationUsing the BFOWhere to listen
Large and smallElectrolytics …… and the othersStoring energyVarying the capacitanceAC and DCFinally …
Getting weakerCarrying informationWider and widerWaves need aerialsMirrors in space
Assembly
The divisionsBandwidth againIt’s your choice!
Simple, but be careful!Types of switch
ConstructionIn practice…
The circuitPutting it together
There’s broadcast reception…… and there’s amateur DXA simple aerial ……and more complicated onesIndoor aerialsOutdoor aerials
DescriptionGet to it!TestingThe next part …
Details
The detailsSome useful varactor types
The circuitMore soundPutting it all togetherFinal touches…
The caseThe next part…
How it worksConstructionCommon types of transistor
What frequency?Keeping it goingA tiny spark transmitterHow it worksMake a tuned circuitMeasuring the resonant frequency
The direct conversion processBuilding the VFOThe mixer boardPutting it togetherSetting the VFOSetting the mixerTry listening!The next part …
A simple circuitIn useThe circuit boardThe key
Sensitivity and selectivityThe circuitAdjusting and testingIn conclusion …
Design and constructionAssemblyUse
The circuitConstructionCalibrationAccuracy
A basic descriptionThe circuit
Construction
How does it work?Calibration
ConstructionThe first testsIn action
Simple and quick to build
Charging NiCads – the ampère-hourConstant voltage to constant currentThe full circuit and its assemblyA quick test
The circuitUse a dummy load
The solar panelThe circuitThe prototype board
The circuit and its constructionTesting and tuning
Choose wisely!The series diodeThe parallel diodeThe diode bridgeDecoupling
The circuitConstructionSimple to use
How it’s doneConstructionWhat happens to the receiver?Warning
OperationConstruction
Basic factsThe practicalitiesHow It performsSafety
A short explanationThe photometer circuitIn use
The principlesConstructionTesting
DescriptionConstructionUsing the field strength meter
WarningDescriptionTesting
The designUsing itWarning
How it worksConstructionSetting upUsing the indicator
ConstructionUsing it
VHF aerialsThe dipole aerialThe long-wire aerialThe vertical aerialCable entry to the house
The circuitBuildingTesting and operating
A design of 7-element low-pass filterMaking the filter
Confused?RF mixers and beat frequenciesMultiplying togetherA mixer in every radio
The circuitConstructionTesting
WarningCircuit descriptionConstructionTesting
WarningBasic descriptionConstruction
Logic using switchesSwitches with no moving partsA taste of Boolean algebra
Sampling the RFConstructionIn use
The circuitConstruction
WarningDescriptionConstructionTesting and useFinishing touches
How it worksThe tuned circuit
The circuitCoilsConstructionCalibrationExtending the range
ConstructionTestingInstallation
Some detailsConstructionTestingMoving on …
Bearing the loadPouring the heat awaySwitching
The circuitThe caseAnother applicationWarning
The circuit and how it worksConstructionTestingUsing
Building the receiverAdjusting itListening!
The modificationsMore testing!The RSGB news broadcasts, GB2RS – Sunday mornings
The antenna (or aerial)The RF filterThe crystal oscillaterThe first mixerIntermediate frequency (IF) filterVariable-frequency oscillator (VFO)The second mixerThe audio preamplifierThe audio filterThe power amplifierHow does it work on 80 m?
How it worksThe circuitConstructionIn use
The circuitConstructionTestingCalibration
The circuitConstructionUseSafety notice
Theory (but only a little)ProblemsConstructionThe balunUsing the rhombic
Detecting waterConstruction
Putting the loop togetherConnecting to the radioUsing the delta loopExperimenting
ConstructionThe circuitThe last connections
The twin-TPutting it together
The designTools ready?AdjustmentPortable use
PlanningThe amplifierWhat power supply?
Circuit evolutionConstructionIn use
The circuitConstructionTestingFrequency tuning
The circuitConstruction
The circuitCalibrationThe GDO in useAerial resonance
The circuitConstructionIn useWarning
Longish wire aerialsFeed-point impedanceThe ATUA simple single-band ATUA multi-band ATUNotes

Content preview from Radio and Electronics Cookbook

A simple electronic organ

Introduction

This project has nothing to do with radio but, let’s admit it, any electronics project is good experience! Why not build this little organ – it will keep the children amused at least! It uses the popular NE555 integrated circuit, which contains a circuit which will periodically switch the voltage on the output pin between the supply voltage and zero. Just how frequently this switching occurs depends upon the components external to the integrated circuit. If this switching occurs several hundred or thousand times a second, the change in voltage produced will generate a musical note when connected to a small loudspeaker. The circuit is shown in Figure 1.

Figure 1 Circuit diagram