SPECTRUM COMMUNICATIONS

Incorporating G2DYM Aerials & Garex Electronics

Radio Amateur & Listener Products - 16 June 2014

Please email or phone for a quote or to place an order by credit/debit card or for a Paypal money request. Purchase of several items is likely to make a saving on postage. Tel 01305 262250

Orders & quote requests to  jean@spectrumcomms.co.uk

Technical queries to  tony@spectrumcomms.co.uk

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2 NEW PRODUCT DESIGNS COMPLETED

5 Band filter.jpg 5 & 10 Band RX Front-end filter boards. Triple bandpass coupled filters, diode switched, with  5 bands to a board. Optimised for critical coupling with insertion loss below 4dB on any band.  Switching DC resistance only 1k Ohms, with any positive voltage 8V to 13.5V. Board size 92x84x15mm.  The two boards can be daisy chained for single pole 10 way switching and can be piggy backed with 20mm spacers to save space.  Kit 5A, 80/40/20/15/&10m.  Kit 5B, 160/60/30/17/&12m.  Single PCB Kit 37.75 UK & EU, 38.75 World.  Two PCB Kits 57.25 UK, 63.00 EU, 64.50 World.  Prices include tracking.

 

 PESKY RX101. A single band PSK receiver   as a further development of the RSGB Centenary Receiver and the Sudden Receiver, with new bandpass coupled front-end filter and bipolar RF stage. The full historical development of this receiver from its 1st version in 1989 to the present day is the subject of Doing It By Design in PW in July 2014.  The receiver connects between the aerial and the computer and should prove an ideal companion for the Raspberry Pi computer.  Pesky RX101 PCB & parts kit 23.50 UK, 25.50 EU, 26.50 World. Box & hardware and PCB kit 33.00 UK, 33.50 EU, 35.00 World.  Ready built Receiver 42.00 UK, 42.50 EU, 44.00 World. Pesky RX101.jpg

 

T4T little.jpg (13543 bytes) The first 27 articles of Technical for the Terrified, of which I am the author published in PW between February 2005 and August 2009 and have been compiled into a 124 page book of the same name. The writing style is aimed to be easy to read and should be of great value to readers of all technical levels.  Subjects include; a little maths, inductors & capacitors, DC circuits, transistor biasing, dB's, amplifiers, diodes & rectification, the superhet, SSB & CW, FM & AM, bandwidth, Q, antennas & feeders, band-pass circuits, RF/IF amplifiers, phase locked loops, HF transceivers, filtering in receivers, mixers, FET RF amplifiers.  Price is 12.00 plus 3.50 P&P.

Spectrum Communication purchased Garex Electronics on 1 December 2011 from Peter Longhurst.  The purchase included the sole manufacturing and selling rights to the 2001, 4001, 6001, & 7003 range of FM transceivers, preamps, wire aerials, flexi-whip handheld aerials, rigid mono-band and dual-band mobile whip aerials and interference filters.  Many of the products have been improved or completely re-designed.  

Contents

Target HF3 AM/SSB Communications Receiver Dual Peak/Notch Filter 7MHz DSB Receiver
RX Aerial Tuning Unit CW Audio Filter & AF Amp 7MHz DSB 1/4W Transmitter
HF Tuneable Preamp LS Audio Filter 5W Broadband HF Linear
4001 FM 4m Transceiver VHF Transmit Amplifiers Speech Processor
QRP TX Attenuator Receive Converters 1W IC Audio Amplifier
VHF Station Receive Preamps Portland VFO PSK31 Interface
VHF Switched Station Preamps Mixer - Osc for 4 metres CTCSS module
VHF Masthead Preamps Poundbury SSB TX & RX IF Toneburst Piptone & Kaytone
VHF Transverters Poundbury 70MHz Front-end UK CB to 10 FM conversion
Clara 2 Direct Conversion RX Top Band Receiver Frequency Demodulators

TARGET HF3 AM/SSB COMMUNICATIONS RECEIVER  This is a masterpiece of RF engineering, covering 30kHz to 30MHz, which is includes the traditional Long Wave, Medium Wave, and Shortwave bands.  There is a large tuning knob coupled to a flywheel to give easy smooth tuning.  When turned slowly the frequency changes in 1kHz steps.  When turned faster it goes in 10kHz steps and when spun faster still goes in 100kHz steps.  There is a clarifier control to fine tune the receive frequency and of particular use when receiving single sideband stations.

The radio automatically selects a 6kHz bandwidth filter when the mode is used to select AM. It uses a 3.8kHz filter when the mode switch is used to select Upper Sideband or Lower Sideband.  The MEM button can be pressed to store a frequency and while in memory mode the main tuning dial can be used to view each of the stored frequencies.  There is also a recall button which return the frequency to the last one stored.

The receiver uses a first intermediate frequency of 45MHz and has a high side synthesized local oscillator providing exceptional stability.  A large clear liquid crystal display shows the receive frequency to a resolution of 1kHz.  The audio amplifier can produce up to 500mW rms audio drive to the large internal loudspeaker.  There is also an audio output phono connector sampling detected audio, prior to the volume control, that can be connected to the sound card of a computer.

Target RX.jpg

Various Features.  Sensitivity: AM 30kHz - 15MHz 2.5uV, 15MHz - 30MHz 4uV.  SSB 30kHz - 15MHz 1.5uV, 15MHz - 30MHz 2.5uV.  Phono antenna connector.  DC connector with 2.4mm pin.  Power requirement DC 12/13.5V at up to 300mA.  Dimensions 185x65x190mm.  Weight 1.3kg. Supplied with a random wire antenna, a DC power cable with in-line fuse, a BNC to phono adapter, and a DC 2.4 to 2.1mm adapter.

Receiver 215.00.  Receiver & low noise PSU 12V 500mA 235.00.  Prices include tracking & insurance.   

RX AERIAL TUNING UNIT   For random wire end fed aerials.  Gives improved signal strength and lower receiver noise from 200kHz to at least 21MHz depending on wire length.  Diecast box 114x64x55mm. Fitted with terminals for aerial and earth inputs, and phono or BNC or SO239 coax output.  Includes a switch for tuner or bypass.  State required output connector when ordering.  Boxed kit 32.50 UK, 38.50 EU, 41.25 World.  Ready Built 43 UK, 49 EU, 51.75 World.  Including tracking & insurance.

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HF TUNEABLE PREAMP,   2-32MHz in 4 bands.  With highly selective tuneable filters, reduces overload from strong broadcast stations.  Gain 10dB at band edges and 25dB mid band, adjustable down to 20dB.  12/13.5V DC operation at 20mA.  SO239 in/out connectors. Two-part stove enamelled box 150x100x75mm.  Weight 410gms.  Box kit 52.50 UK, 60.25 EU, 64.25 World. Ready built 99 UK, 106.50 EU, 110.50 World, including tracking and insurance.

RF SWITCHED version, 100W through power handling.  Fail safe operation, straight through path if unpowered.  Box kit 69.50 UK, 77.75 EU, 81.75 World.  117.50 UK, 124.25 EU, 128.25 World, including tracking & insurance.

  HF Tuneable Preamp tiny.jpg

4001 FM 4m TRANSCEIVER 70.2500 to 70.4875MHz in 20 channels in 12.5kHz steps. Really easy to use, not menu driven.  Default channel at switch-on 70.450MHz. Now upgraded to give excellent audio quality on receive and transmit.  RF output 5W or 25W presetable and switchable. Sensitivity better than 0.25uV for 20dB SINAD.  Audio output 500mW rms. Supply requirement 13.5V DC 4A on high TX, 1.5A on low TX, 130mA on RX.  This product is now being custom built to a high quality standard rather than down to the cheapest price. Now with improved performance type 4001S 195.00 UK , 203.00 EU, inc. tracking & insurance.   Type 4001SN with a really effective noise squelch to give a quite background and excellent weak signal reception 215.00 UK, 223.00 EU, inc. tracking & insurance.

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UPGRADE KITS FOR 2001, 4001, 6001, & 7003

PIC module for 2001 to change to 12.5kHz channel spacing and add CTCSS. Supplied with replacement reference crystal, LED in-between channel indicator and handbook with new frequency listing. 22.50 excluding P&P.

New PIC for 4001 to change to 12.5kHz channel spacing. Supplied with replacement reference crystal and handbook with new frequency listing. 8.50 excluding P&P.

PIC module for 6001 to change to 10kHz channel spacing and add CTCSS. Supplied with handbook with new frequency listing. 20 excluding P&P.

Upgrade kit for improved IF amplifier, better RX filter matching and improved transmit audio. Supplied with replacement IF filters 10M07 and LTW455HT and complete circuit diagram & board component layout 14 excluding P&P.

Upgrade kit to add a Noise Squelch, NS1000F 20.00 excluding P&P.

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QRP TX ATTENUATOR, RF SWITCHED. This allows a rig running 5W output to achieve QRP output levels of 500mW, 250mW, 100mW, and 50mW, using just three switches.  Straight through path when off.  

Box kit 50.00 UK, 56.25 EU, 60.25 World. Built 71.50 UK, 79.75 EU, 83.75 World. Including tracking and insurance.

VHF RECEIVE-ONLY PREAMPS, low noise and custom made for various frequencies.  These replace the Garex Preamps, which had provision for a PP3 battery.  Narrow band types with typically 25dB gain, Amateur 50-52Mhz, 70-71MHz, 144-146MHz; Weather Satellite 137-138MHz; AIS 161-162MHz.  Wideband types with 9dB at band edge and up to 16dB mid-band, Airband 118-137MHz, Marine 156-162MHz.  HF-UHF 5-500MHz. PCB built 42x19x15mm 15.50.  Boxed version, stove enameled with choice of BNC, F, or SO239 connectors.  Supply requirement 12/13.5V at up to 10mA. Boxed built UK 32.50, EU 37, World 38.50, including tracking and insurance.  

Old Design

MP-3 Preamp small.jpg

New Design

VHF Preamp tiny.jpg

VHF PREAMP PCB BUILT, for inclusion into a receiver or transceiver.  It can be configured for any spot frequency in the range 40-200MHz.  Narrowband types have a typical gain in excess of 20dB.  Broadband versions have gain at the band edges of 9dB or more, and mid-band around 15dB. Supply 9-15V at 5-10mA. Size 42 x 19 x 14mm.  Stock frequencies 50-52, 70-71, 118-137, 137-138, 144-146, 156-162, 162-163MHz.  Price 15.50 UK & EU, 16.25 World including postage.

STATION PREAMPS RF Switched, for 2 or 4 or 6 or 10 metres. 100W through rated on transmit. RF & DC switched 0-20dB panel adjustable gain. 2m, 4m, & 6m types use BF964 with noise figure under 1.5dB. 10m type uses BFR84, with noise figure under 3dB. Over-voltage and reverse voltage protected.   Protected against transients and EMP at input and output ports. PCB size 68 x 46 x 28mm. Purpose made box 76 x 70 x 38mm. Fitted with SO239 connectors. DC supply 13.5V 80mA. Types RP2S, RP4S, RP6S, & RP10S. PCB Kit 23 UK, 23.50 EU, 24.75 World. PCB & hardware kit 43.50 UK, 49.75 EU, 55 World. Ready built 68 UK, 75 EU, 77.50 World. Tracking & insurance included.

RP-S front small.jpg

 

MASTHEAD RECEIVE PREAMPS for 2 or 4 or 6 metres. 100W through rated on transmit. RF & DC switched and DC fed via the coax. Gain 20dB, NF less than 1.5dB. Supplied with a DC/RF Station Box with SO239 connectors for the shack. Heavy duty waterproof plastic box fitted with SO239 connector for feed coax and 1 metre of coax for connection to the antenna. Box size 82 x 80 x 50mm. Types RP2SM, RP4SM, & RP6SM. PCB & hardware kit 55.00 UK, 61.75 EU, 66.50 World.  Ready Built 81.50 UK, 88.25 EU, 91.00 World, including tracking.  Masthead fitting kit 6.00 extra.

MASTHEAD RECEIVE PREAMPS for 2 or 4 or 6 metres.  400W through rated on transmit. RF switched. Supplied via separate wire DC feed.   Gain 20dB, NF less than 1.5dB.  Protected against reverse and over voltage and against EMC transients at input and output. Heavy duty waterproof box fitted with SO239 connector for feed line and 1 metre of coax to connect to antenna feed point. Box size 82 x 80 x 50mm. Types RP2SH, RP4SH, & RP6SH.  PCB & hardware kit 48.50 UK, 54.75 EU, 60.00 World.  Ready built 70 UK 76.75 EU, 79.50 World, including tracking.  Masthead fitting kit 6.00 extra.

Masthead Preamp.jpg

TRANSVERTERS Early commercial transceivers often had a transverter facility with a low level output from the transmit driver stage and a means of disabling the power output stage.  This meant there were two connections for an outboard transverter, one from the low power transmit port, the other for receive via the main antenna socket.  Some of the top of the range rigs still have this facility but most modern rigs don't have any transverter facility at all.  To use them with a transverter simply reduce the power to minimum and use a single connection to the transverter from the rig antenna socket.  The RF sensing of the transverter will work at drive levels down to 100mW.  Below that drive level, hard switching is required.

Add 2 or 4 or 6 metres Add 2 or 4 or 6 metres to a rig with 10 metres or 4 or 6 metres to a 2 metre rig.   The transverter main board contains an attenuator in the transmit path and can be configured for 1-500mW or 0.5-10W drive levels. Class AB linear operation gives all mode use.   The standard product includes a linear amplifier giving panel adjustable output 5 to 20W on 2m, or 5 to 25W on 4 or 6m.  All spurious and harmonic outputs better than 45dB below carrier.  Capable of withstanding long periods of transmit into bad SWR.  Receive side has panel adjustable gain 0-20dB gain and NF less than 1.5dB.   PCB size 150 x 93 x 18mm.     Box size 206 x 160 x 77mm. Suffix s is used for single IF drive arrangement, suffix d is used for dual IF drive version, the suffix L is for integral linear.

Transverter main board with 300mW output for use with 10 metre or 2metre 0.5-5W drive and single connection to the driving rig. Types TRC2-10s, TRC4-10s, TRC6-10s, TRC6-2s, & TRC4-2s.    Also  versions for use with a 10 metre rig with separate RX and TX connections and 1mW-500mW drive. Types TRC2-10d, TRC4-10d, TRC6-10d.   PCB Kit 62.50 UK, 69.25 EU, 70.50 World.  PCB built 95.50 UK, 100.25 EU, 101.75 World. Box kit 106 UK, 115.50 EU, 120.75 World. Ready Built 167.50 UK, 175.50 EU, 181.00 World. Prices including tracking & insurance. 

Transverters with two stage linear amplifier, 25W out for 4m or 6m version, 20W output for 2m version. Drive on 10m or 2m 0.5-5W with single connection to the driving rig. Types TRC2-10sL, TRC4-10sL, TRC6-10sL, TRC4-2sL, TRC6-2sL.   Also Transverters versions for use with a 10 metre rig with   dual transverter connection and 1mW-500mW drive.  Types TRC2-10dL, TRC4-10dL, TRC6-10dL.  PCB kits 163 UK, 168.50 EU, 171.00 World. PCB's built 201.50 UK, 207.50 EU, 210.00 World.  Box kit 204 UK, 215 EU, 224.50 World. Ready built 274 UK 282 EU, 291 World.  Prices include tracking & insurance.       

Transverters with repeater shift, types TRC2-10rs, TRC2-10rd, TRC2-10rsL, & TRC2-10rdL, add 8.50 to PCB kit or Box kit, 15 to PCB built or Boxed built.

ICOM COMPATIBLE TRANSVERTERS  A version of transverter specially dedicated to certain ICOM rigs, complete with 60cm long cables, ready to plug-and-play.  It is known to be suitable for the IC756Pro, 756Pro2, 756Pro3, 775, 781, 7600, & 7800, and any other rig not mentioned which requires just one TVTR IN/OUT RF lead plus a 7 pin DIN plug with a switching signal on pin 6.  Types TRC2-10L/IC1, TRC4-10L/IC1, & TRC6-10L/IC1.  Box kit 206 UK, 215 EU 224.50 World.  Ready built 281 UK, 290 EU, 299.50 World.

NOTE:  The following ICOM rigs are NOT plug and play compatible, but can be used with a standard transverter: 77, 78, 703, 706, 707, 718, 725, 726, 728, 729, 736, 737a, 738, 746, 746Pro, 756, 7000, 7400.

Clara 2 Direct Conversion Receiver.  Single band design, can be configured to work on 160m, or 80m, or 40m, or 20m.  High stability Hartley VFO.  12/13.5V DC operation.  PCB kit 28.50 anywhere.  Box kit 62.00 UK, 69.00EU, 73.00 World. Box built 85.00 UK, 93.25 EU, 97.25 World. Includes tracking and insurance.

DUAL PEAK/NOTCH FILTER with audio amplifier.  This unit plugs into an extension speaker socket of the HF receiver or transceiver and produces 500mW of audio to a front facing loudspeaker.  It can be used to notch out two unwanted heterodynes, or just one while enhancing the wanted audio frequency.  Similarly it can be used to sharpen otherwise dull audio or to dampen shrill audio.  PCB kit and all potentiometers 39.50 UK, 44.00 EU, 45.25 World.  PCB kit and all the hardware with drilled and labeled box 78 UK, 83.50 EU, 87.50 World, includes tracking.  Ready built 116 UK, 120.80 EU, 125.80 World.  Prices include tracking & insurance.

Peak Notch small.jpg

CW FILTER & AUDIO AMPLIFIER, uses a Wien Bridge as a peak filter with high Q to provide a narrow audio passband centred on 700Hz.  Plugs into an extension speaker socket of a receiver or transceiver and provides up to 0.5W into an 8 Ohm speaker. PCB kit 16.50, PCB built 28.50.  Boxed unit with loudspeaker and hardware in kit form 37.00, ready built 54.00.

LS AUDIO FILTER, a unit to plug into the speaker socket of any communications receiver or transceiver uses active high pass and low pass filters to limit the audio range to within 300-2500Hz then re-amplify the audio and provide up to 0.5W into an 8 Ohm extension speaker.  PCB size 60x48x15mm.  Box size 110x60x31mm. PCB Kit including LED and volume control 16.50, PCB built with pot 28.50, boxed kit 33, Ready built 50.50.  

ACTIVE AUDIO BANDPASS FILTER, uses active high pass and low filter filters to limit the audio range to within 300Hz to 3KHz for microphone or post demodulator filtering. Designed as an add-on board for existing equipment.  PCB Kit 7.00.

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TRANSMIT AMPLIFIER for use with Spectrum 0.5W Transverters. Two stage PTT switched class AB linear amplifiers for 2, or 4, or 6 metres giving a minimum of 20W out for the 2m version, and a maximum of 35W for the 6 metre version. Should not be run at more than 25W. Antenna relay with high speed TX/RX switching makes it suitable for all modes including data and RTTY and Packet. PCB size 125 x 57 x 28mm. Types TA2S4, TA4S4, TA6S4.   PCB kit 102.50 UK, 108 EU, 109.50 World.   PCB Built 112.50UK, 118 EU, 119 World.  Prices include tracking.

TRANSMIT AMPLIFIER Single stage switched class AB linear amplifier suitable for CW, SSB, FM, RTTY, and PACKET. 4m and 6m versions 1W in gives 8W and 5W in gives 30W output. 2m version 1W drive gives 6W out and 5W drive gives 25W out. Switching circuit senses RF & DC and uses a monostable relay driver giving VERY FAST attack and a hold time of 250ms to 2s for SSB use. For data modes the hold function can be disabled. PCB size 102 x 72 x 25mm. Diecast box size 171 x 120 x 55mm. Fitted with SO239 connectors. Types TA2SA, TA4SA, & TA6SA. Ready built 142.50 UK, 149.50 EU, 151 World. Prices include tracking.

TRANSMIT AMPLIFIER Single stage switched class AB linear amplifier suitable for CW, SSB, FM, RTTY, and PACKET. 4m and 6m versions 5W in 30W out, 10W in 50W out.  2m version 10W in 35W out. Switching circuit senses RF & DC and uses a monostable relay driver giving VERY FAST attack and a hold time of 250ms to 2s for SSB use. For data modes the hold function can be disabled. PCB size 102 x 72 x 55mm. Diecast box size 171 x 120 x 55mm with a heatsink on top 152 x 99 x 32mm. Fitted with SO239 connectors. Types TA2SB, TA4SB, & TA6SB. Ongoing development. Not presently available.

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TRANSMIT AMPLIFIER & PREAMP.  Linear amplifier and receive preamplifier together in one case with independent switching. Amplifier details as TA-SA above, together with 20/26dB gain preamp. Types TA/RP2SA, TA/RP4SA, TA/RP6SA. Ready built 166.50 UK, 173.50 EU, 175.00 World.  Prices include tracking.

TRANSMIT AMPLIFIER & PREAMPLinear amplifier and receive preamplifier together in one case with independent switching. Amplifier details as TA-SB above, together with 20/26dB gain preamp. Types TA/RP2SB, TA/RP4SB, TA/RP6SB.  Ongoing development. Not presently available.

TRANSMIT AMPLIFIER for 2, or 4, or 6metres. 250mW to 500mW input, 20w to 35W output, with RF & DC switching. Class AB operation gives clean output with intermod products 35dB down suitable for all modes CW, SSB, FM, & DATA. Designed as self contained amplifier as an add-on for 0.5W transverters such as MEON. Boxed size 127 x 102 x 38mm. Types TA2S2, TA4S2, & TA6S2. No longer available at previous price.  New price soon.

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RECEIVE CONVERTERS add 2 or 4 or 6 metres to a receiver tuning 28-30MHz,  Types RC2-10, RC4-10, RC6-10 have 15dB gain a noise figure about 1.5dB. This design was put into production in November 2001 incorporating a diode ring mixer together with an improved oscillator and multiplier circuit. The Boxed version has panel adjustable gain, on/off switch and power LED. Fitted with SO239 connectors and has 1metre of lead for 13.5V bench power input. PCB size 95 x 45 x 17mm, Box size 102 x 84 x 40mm.  Types RC2-10, RC4-10, & RC6-10. PCB kit 30 UK, 36.00 EU, 36.25 World. PCB built 43.00 UK, 49.00 EU, 49.25 World.  PCB & hardware kit 49.00 UK, 53.50 EU, 54.75 world.  Ready built 73 UK, 78.25 EU, 79.50 World.  Prices include insurance.

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RECEIVE CONVERTERS add 4, 6 or 10 metres receive to a 2 metre transceiver. These are low noise using a mosfet RF & mixer stage and have 15dB gain. The Boxed version has panel adjustable gain, on/off switch and power LED. Fitted with SO239 connectors and has 1metre of lead for 13.5V bench power input. PCB size 89 x 45 x 17mm, Box size 102 x 84 x 40mm. Types RC4-2, RC6-2, RC10-2. PCB kit 30 UK, 36.00 EU, 36.25 World. PCB built 43.00 UK, 49.00 EU, 49.25 World.  PCB & hardware kit 49.00 UK, 53.50 EU, 54.75 world.  Ready built 73 UK, 78.25 EU, 79.50 World.  Prices include insurance.

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PORTLAND VFO, a rock stable FET VFO for 6.995 - 7.205MHz for a direct conversion for the extended 40metre band, or 7.900 - 8.400MHz for use as part of a mixer VFO system as local oscillator on 70.000 - 70.500MHz band, or 5.0-5.5MHz for 20m and 80m rigs with a 9MHz IF.  Now includes upper band edge adjustment, and meets the requirement for the Intermediate Licence VFO project.  The Buffer (2A), mounted on the rear of the box, delivers 1.6V p-p into 50 Ohm with second harmonic 40dB down. Drilled Box and PCB kit with potentiometer and feedthroughs 34.75 UK, 39.50 EU, 40.75 World. Ready built 52.50 UK, 57.25 EU, 58.50 World. Prices include tracking.  State required frequency when ordering. 

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MIXER - OSCILLATOR, a module for use in conjunction with the Portland VFO to produce a very stable local oscillator signal for a 4 metre receiver or transmitter with a 9MHz or 10.7MHz IF. Uses either a 51.4MHz crystal for a 10.7MHz IF, and a 53.1MHz crystal for a 9MHz IF. Comprises an overtone oscillator, a 4 quadrant multiplier mixer, a filter and buffer amplifier. PCB kit including choice of crystal 23.50 UK. Ready built 32 UK.

POUNDBURY (2) 9/10.7MHZ SSB Generator and Receive IF. A traditional SSB generator incorporating a speech processor.  Carrier suppression typically in excess of 50dB. The board now connects directly to an external SSB filter which has a termination impedance of around 560 ohms and a few picofarads. Other termination impedances can be accommodated by the change of a single resistor. The circuit has provision for USB and LSB carrier crystals which are DC switched. Receive section uses Fet and Mosfet IF amplifiers and a singly balanced diode product detector and discrete audio derived AGC. Includes 1W audio amplifier. The crystal filter and carrier crystals are not included in the PCB kit.  PCB Kit 69.75. PCB built 99.50.  Optional extras, SSB filter 18.00. Carrier Crystals 3.00 each. Mic gain 4K7 log pot, Volume 100K log pot, 1.75 each.  Signal meter 9.00.  8 ohm Loudspeaker 2.00.  P&P on optional extras 3.50.

POUNDBURY 70MHz FRONT END.  A receive preamp and mixer together with a transmit mixer and three amplifier stages to give 250mW output on 4 metres.  Works in conjunction with the Poundbury Generator & Receive IF, the Portland VFO, and the Mixer-VFO board to give a complete 4metre transceiver.  Can also work with the TA4S4 amplifier to give 25W output.  PCB & Parts kit including 2 panel pots 45.00.  PCB built 65.

TOP BAND AM RECEIVER. Tuning 1.82 - 2.00MHz. The package includes a preselector PCB kit, a main board kit and a high stability boxed VFO. The main board has a receiver IC with S meter output, a 4 pole 455kHz IF filter, and a 500mW audio amplifier IC.  The VFO comprises an oscillator board, a buffer board, a 25pF C804 Jackson capacitor, and RFI screened VFO box.  Price for the complete kit package is 78.50.

7MHz DSB RECEIVER.  A double sideband direct conversion receiver requiring just the addition of a Portland VFO local oscillator.  DiBD January 2007.   Can be used with the 7MHz DSB 250mW Transmitter using just the one Portland VFO.   PCB and kit of parts including volume control and transformer, 27.75 UK, 30.75 EU, 31.50 World.  Including carriage.

7MHz DSB 250mW TRANSMITTER.  A double sideband transmitter comprising microphone amplifier, diode ring modulator driver and output stage. Works in conjunction with a Portland VFO and can be combined with the 7MHz DSB receiver to form a transceiver. The PCB kit of parts including a TO5 heatsink, a 10k log mic gain pot and wound toroids, price 30.75 UK, 33.25 EU, 34.00 World. Including carriage.

5W BROADBAND HF LINEAR AMPLIFIER   Push-pull transistor HF linear covering the range 1.8-29.7MHz with full out for input levels between 37 and 97mW drive.  Harmonics typically are 2nd -42dB, 3rd -18dB, 4th -49dB and 5th -29dB.  This amplifier needs to be used together with a double Pi type low pass filter, details of which are supplied with the kit. Full kit of parts with drilled heatsink. Without wound toroids 31.50 UK, 38.00 EU, 40.50 World.  With pre-wound toroids 39 UK, 45.00 EU, 47.50 World.  Ready built and tested 49 UK, 55.00 EU, 57.50 World.  Tracking included.  Prices do NOT include the low pass filters.

SPEECH PROCESSOR to increase the sideband power and hence communications effectiveness of SSB and AM transmissions. The unit includes filtering which enhances the higher voice tones which carry most of the intelligibility. The peak to mean ratio of the transmission is improved by 10dB which has the same effect as increasing the transmit power by 10 times. It sounds nice too. Panel controls are included for clip level and output level. PCB size 82 x 45 x 17mm.    Type SP1000. Box kit 44.50 UK, 45 EU, 47 World. Ready Built 62.50 UK, 70.50 EU, 73 World.  EU & World prices include tracking.

SP1000E small.jpg

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1W IC AUDIO AMPLIFIER, handy audio output stage with a gain up to 48dB, 0.5W into a 8 Ohm load, low quiescent current, and low noise.  Article in PW March 2006.  PCB Kit 9.00.

PSK31 INTERFACE, designed as an interface between a computer sound card and a transceiver.  PCB kit 21.00 UK, 22.50 EU, 23.50 world.  Box kit with cables and jack plugs 36 UK, 36.50 EU, 38.50 World.  Ready built 50 UK, 50.50 EU, 52.50 World.  EU & World tracking 5.50 extra.

CTCSS Module.  Designed originally by Ken Ginn G8NDL, then modified and a new PCB layout by Spectrum.  Produces all nine CTCSS tones that can be selected by a link or using a 9 way rotary switch. The unit is triggered by the microphone PTT and in turn provides a PTT output to the rig via an opto-isolator. The module includes a trimpot to set the tone level output to accommodate different microphone impedances.  PCB size 67x55x10mm.  PCB kit 21.00 UK.  PCB built & tested 28.00.  Including P&P.

AUTO TONEBURST stable RC oscillator to provide a 500mS burst of 1750Hz audio for repeater access. The board has option for 7-10V or 10-16V operation. PCB size 29 x 27 x 15mm. Type AT1750. PCB Kit 6 UK & EU, 6.50 World. PCB Built 9 UK & EU, 9.50 World. Including carriage.

PIPTONE end of message tone for 250mS for weak signal SSB use. The unit provides 50mV across a 600 ohm microphone. The tone and amplitude are presetable. A relay is included for receive and PTT switching. PCB size 44 x 25 x 17mm. Type PT1000S. PCB Kit 9.50 UK & EU, 9.50 World. PCB Built 13 anywhere. Prices include carriage.

KAYTONE (a name coined by Spectrum) this unit is the successor to the original Kaytone sold in 1979. End of message Morse K particularly useful for weak signal or QRM situations. Adjustable pitch, speed, and level. A relay is included for receive and PTT switching. PCB size 58 x 39 x 15mm. Type KT1000. PCB Kit 14.00 UK, 14.50 EU, 15.25 World. PCB Built 21.00 UK, 21.50 EU, 22.25 World. Price include carriage.

SYNTHESIZER CONVERSION CB to 10FM suitable for UK CB rigs with LC7136/7 or TC9119P PLL IC’s. Puts the rig onto 29.31-29.70 MHz. State rig type when ordering. PCB size 64 x 40 x 17mm. Type SC29. PCB Built & aligned 28.50 UK & EU, 29.00 World.       

FREQUENCY DEMODULATOR and noise squelch. Adds FM detection and squelch to receivers such as FRG7, FRG7000, R600, & R1000 that use a 455KHz IF. Sensitivity 33uV for 3dB quieting. Produces 500mV AF output for fully quieting signal with + - 2.5KHz deviation. PCB size 69 x 49 x 17mm. Type FD455NS.   PCB kit 19.75 UK, 20.50 EU, 21.25 World. PCB Built 29.75 UK, 34.74 EU, 35.50 World. Prices include carriage.

FREQUENCY DEMODULATOR adds FM second conversion, amplification and detection to receivers with a first IF between 3 and 11MHz. Includes carrier level squelch with preset on the PCB. Sensitivity 2uV typical for 20dB S/N. Normal version has a 4 pole ceramic 455KHz 2nd IF filter but no first IF filter. 10.7MHz version available with 2 pole crystal filter at the input and 4 pole ceramic 455KHz 2nd IF filter.    Type FD3-11, PCB Kit 18.50, PCB Built 27.50. Type FD3-11F, PCB Kit 21.50, PCB Built 30.50.

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