SPECTRUM COMMUNICATIONS

Quality English products hand-crafted to order

GENERAL ACCESSORIES

26 May 2024

Proprietor;- Antony Nailer HNC BA G4CFY

12 WEATHERBURY WAY, DORCHESTER, DORSET, DT1 2EF, ENGLAND

Phone UK 01305 262250 International 0044 1305 262250. Email: g4cfy@talktalk.net

You can pay by card or to g4cfy@talktalk.net via Paypal, or direct to my bank Santander, Spectrum Communications, sort code 09-01-29, account 67273308. For multiple quantities or multiple items, please email for a quote or for a Paypal money request. You can also obtain many of my products from my Ebay shop https://ebay.co.uk/str/Spectrum-Comms

Understanding Radio Book 1 is a re-write of the Technical for the Terrified Book 1 published by Practical Wireless and compiled from 27 articles of that name previously published in PW Magazine between February 2005 and October 2008. The first chapter is a short revision for everyone who has not used algebra since leaving secondary or grammar school. It should also be useful to youngsters still at school and trying to get to grips with it. The articles have been reworked into chapters so there is now a natural progression of information through the book. All the circuits have been redone and a lot of wasted space and unnecessary comments removed. It runs to 112 pages, which is 10 less than the T4T Book 1 but there is a lot more in it. The writing style is aimed to be easy to read and should be of great value to readers of all technical levels. Subjects include; Algebra; Resistors & Ohm's Law; Diodes and Rectification; Transistors - FETs & Valves; Transistor biasing; Amplifier Classes of Operation; Reactance & Resonance; Parallel Tuned Circuits; Bandpass Coupled Pairs; Small Signal Bipolar RF/IF Amplifiers; Small signal FET & Mosfet RF/IF Amplifiers; Oscillators; Mixers; Decibels; Modulation Modes; TRF & Superhet; Filtering in HF & VHF Receivers; Modes & Demodulation; Choosing RF - IF & LO; Phase Locked Loop; PLL in CB & 10M rigs; Antennas & Feeders.

Understanding Radio Book 2 is a re-write of Technical for the Terrified Book 2 including all the articles 28-49 published in PW between October 2008 and April 2013 plus article 51 published in August 2013. The articles have been condensed into chapters and unnecessary duplication of information has been trimmed back and then the subjects further expanded. It runs to 114 pages and the subjects include Passive components, old and new; Equivalent circuits; Variable Frequency Oscillators; Crystal Controlled Oscillators; Feedback & Amplifier Stability; Singly Balanced Mixers; Analogue Low Pass Filters; Laying out Printed Circuit Boards; Measurements and Test Jigs; Receiving 100kHz - 30Mhz; Superhet Receivers; AGC of RF & IF Stages; Superhet with Tuneable IF; Coax & Twin Feeder; SWR/PWR Meters & the Noise Bridge; Aerial Impedance - Bandwidth & Gain; Aerials for Receive & Transmit; ATU's for Receive & Transmit.

To buy an individual book will cost £18.60 including P&P.

To buy both books will cost £32.10 including P&P.

CONTENTS

BNC Switch Boxes, 2 way, 3 way, & 4 way

Coax Cable Tester for BNC & PL259

Capacitance Meter, 1pF to 100nF

HF Wide Range Power Meter 10W, 100W, 500W

Morse Practice Oscillator

Two Tone Tester, for transmitter alignment

TVI Filters, high pass 450MHz and 550MHz

BNC SWITCH BOXES FOR VIDEO OR SMALL SIGNAL RF WORK

BNC 2 Way Switch. One receiver to two antennas, or two cameras to one video recorder. Isolation to 140MHz , >30dB. Box size 60x55x30mm. Ready built £31.20 UK, £40.40 EU, £48.50 World, including tracked carriage.

BNC 3 Way Switch. One receiver to three antennas, or 3 cameras to one video recorder. Isolation to 80MHz >30dB. Box size 80x55x25mm. Ready built £32.70 UK, £41.90 EU, £50.00 World, including tracked carriage.

BNC 4 Way Switch. One receiver to four antennas, or four cameras to one video recorder. Isolation between ports >36dB to 150MHz. Box size 115x63x30mm. Ready built £38.75 UK, £48.40 EU, £56.00 World, including tracked carriage.

COAX CABLE TESTER

This handy tester allows cables with PL - PL, or BNC - BNC, or PL - BNC to be tested inner to inner, outer to outer, inner to outer, and also a single end PL or BNC inner to outer. It should be intuitive, with a wanted connection showing the LED ON and the unwanted connection with the LED OFF. Price £30.00 UK, £38.50 EU, £42.30 World including tracked carriage.

CAPACITANCE METER

Direct linear reading in 5 ranges, 100pF, 1nF, 10nF, 100nF, and 1uF full scale. Supplied in an ABS box. 12/13.5V operation at 10mA. Accuracy within +/-2%. With 13cm (5") probe wires and connectors.

ABS box kit £47.50 UK, £56.00 EU tracked, £60.00 World. Ready built £62.50 UK, £71.50 EU, £76.00 World. Price include tracked carriage.

Cap meter tiny.jpg

HF WIDE RANGE POWER METER

1.8-52MHz in three power ranges 10, 100, and 500W with an accuracy of +/-5%. Thruline concept with a toroidal current transformer sampling element. Switched forward and reverse reading. SO239 connectors. Each unit is individually calibrated on each range. The picture is of the earlier 4 range version.

Ready Built and calibrated £76.00 UK, £86.50 EU, £91.75 World, including tracking.

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MORSE PRACTICE OSCILLATOR

A stand alone Morse Practice Oscillator supplied either as a kit of parts to build the board shown in the picture as well as a drilled and labelled box, and all associated hardware, or ready built. The boxed kit includes 1/4" jack socket for the Morse key, and 3.5mm jack socket for headphones, a SPST toggle switch, volume control, LED and holder, internal loudspeaker, PP3 battery holder and the necessary nuts and screws. The kit even includes various coloured hookup wire and four stick on feet. The battery shown in the pictures is NOT included.

PCB & Hardware kit £35.50 UK, £43.00 EU, £45.50 World. Ready Built £53.00 UK, £61.00 EU, £64.80 World.

TWO TONE TESTER

A vital test unit for power output, envelope, and carrier suppression testing of AM, DSB, and SSB transmitters. Either 1600Hz or 1850Hz tones or both. Diecast box size 102x84x40mm.

Box kit with all hardware £35.00 UK, £41.50 EU, £46.80 World, tracked. Ready built £51.50 UK, £59.50 EU, £63.30 World, including tracked carriage.

HPF small.jpg

TVI HIGH PASS FILTERS HPF450 & HPF550

The HPF450 has passband with a -6dB point at about 450MHz. It rejects signals from DC to 200MHz by 60dB. This includes HF, CB, 6m, 4m, 2m, marine, & taxi. Passband ripple 455-1000MHz 4dB. The HPF550 is a modified version to allow digital signals above 550MHz to pass and to reduce breakthrough by analogue signals at the bottom of the band. Price £15.50 UK, £17.50 EU, £18.50 World. Including P&P.