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 with an upgrade to improve audio quality and provide a really effective noise squelch to give a quite background and excellent weak signal reception. RF output 5W or 25W presetable and switchable or can also be preset to 1W or 10W. Approved for use by M3 and M6 operators. Sensitivity better than 250hV for 20dB SINAD.  Audio output 500mW. Supply requirement 13.5V DC 4A on high TX, 1.5A on low TX, 130mA on RX.  Price £172.50 including delivery.   

Upgrade kit for previous customers to add a Noise squelch and improve the audio quality, NS1000F £20.00.

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 but without the toroids wound £29, with toroids pre-wound £39, ready built and tested £49.  Prices do NOT include the low pass filters.

DUAL PEAK/NOTCH FILTER with audio amplifier.  This unit plugs into the extension speaker socket of the HF receiver or transceiver and produces 1/2W 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 £35.75.  PCB kit and all the hardware with drilled and labelled box £73.00.  Ready built £112.00.

UPWEY AM/LSB Top Band Receiver  The receiver main board includes a TCA440 Mixer IF amplifier AGC IC, a junction FET product detector and a 0.5W audio amplifier. IF filtering is a LTW455HT 4 pole ceramic filter with a 40dB stopband at + - 9KHz and 60dB ultimate attenuation + - 100KHz. The BFO board is referenced to a two pole ceramic filter and has a drift not exceeding 50Hz from switch on.  The preselector is a bandpass coupled pair of coils tuned with a dual gang polyvaricon capacitor.  The VFO is a traditional type using a variable capacitor and has the oscillator section housed within an RFI proof plastic case, with the buffer board on the outside.  The main board, BFO board, preselector board, and VFO boards with VFO box in kit form is £92.50 inc P&P.  A box kit, including the PCB kits just detailed, and speaker, drilled and labelled box, slow motion drive, S meter, switches, volume control, knobs, connectors, nuts, screws and rubber feet £175.50 including carriage by Special Delivery.  Ready built and aligned receiver £241.00 inc Special Delivery.

CLASSIC 20/80m SSB RECEIVER This is a classic superhet receiver for 20 and 80m using a 9MHz IF and a 5.0-5.5MHz VFO.  It uses a 9 crystal ladder filter with near symmetrical passband a 2dB passband loss 1.8:1 shape factor and 70dB stopband.  The minimum discernable signal is 0.2uV.  There is a fixed tuned bandpass preselector on 20m and a tunable preselector on 80m.  The AGC and S meter are logarithmic.  Maximum RF signal handling is 1mV before the AGC runs out of range.  The audio output is 500mW to an internal 8 Ohm speaker.  Supply requirement is 13.5V at up to 250mA.  The VFO which is a development of the Portland VFO which featured in the March 2006 PW now uses a 3 terminal regulator supply and there is NO discernable drift from switch-on.  VFO kit with its drilled box, preselector, and main board PCB's and component kits including filter and carrier crystals £92.00.  Complete kit including box and all hardware £147.00. Ready built £240.00.

TOP BAND AM RECEIVER. Tuning 1.82 - 2.00MHz. Comprising a main board with receiver IC, 1W audio amplifier, a 4 pole IF filter, and S meter output.  Also a high stability VFO with oscillator board, buffer board and RFI screened VFO box.  Also a tunable preselector with diode switching for use together with a transmit strip. All three boards, all the components, and drilled VFO box, and 25pF C804 Jackson capacitor, total price £78.50.

LCR BRIDGE  with 5 resistance ranges, 100, 1K 10K 100K, & 1M.  3 capacitance ranges, 100pF, 1nF, 10nF, and 3 inductance ranges 1mH, 10mH, & 100mH, plus an external reference.  Scale calibrated 0.01 to 10 times reference value.  Optional drilled and labelled plastic or diecast box.  PCB & Parts with pot and switch £26.00.  With plastic box £39.00, with diecast box £44.00.

OFF-AIR FREQUENCY STANDARD This is a crystal calibration unit phase locked to Radio 4 on 198kHz using a two-loop system.  It includes a monitor receiver to ensure Radio 4 is being heard loud and clear.  Fixed outputs are 10MHz at 2V p-p, and 1kHz at 1V p-p as an oscilloscope CAL signal.  Switched outputs are 1MHz, 100kHz, 10kHz, and 1kHz at 6V p-p into 500 ohms.  Single board design as featured in July & September 2008 PW.   Background heterodyne whistle at 2kHz confirms lock condition.  12/13.5V DC operation at 65mA.  PCB kit with ferrite rod aerial £50.00.  PCB kit plus drilled box and hardware complete £86.00.  Ready Built £131.50.

TWO TONE TESTER, a useful test unit for power output, envelope, and carrier suppression testing of AM, DSB, and SSB transmitters. PW Feb 2005. Either 1600Hz or 1800Hz tones or both. Diecast box size 102 x 84 x 40mm. PCB kit £10.00.  PCB built £20.00.  Box kit with all hardware £28.00.  Ready built £52.50.

TRIBAND ACTIVE RECEIVE PREAMPLIFIER for 80,40, & 20m. Tuneable on 80m, fixed tuned on 40 and 20m. Can be configured for maximum gains of 16dB on 80m, 23dB on 40 and 20m, or 11dB on 80m 17dB on 40, and 18dB on 20m. Complete kit comprises amplifier and switch PCB's and components, 2 pole 3 way switch, polyvaricon, and 10K log gain pot. £20.50 inc P&P.

STATION RECEIVE PREAMPS 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 £20.00, PCB Built £30.00, PCB & hardware kit £35.00, Boxed Built £57.00.

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 to 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 £41.00, Ready Built £65.00.  Masthead fitting kit £6.00.

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 £42.50,  Ready built £65.00.  Masthead fitting kit £6.00.

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TRANSCEIVE CONVERTERS   Early commercial transceivers often had a transverter facility with low level output from the early transmit stages and a means of disabling the power amplifier stage.  This meant there were two connections for an outboard transverter, one from the low drive transmit port and the other for receive using the main antenna socket.  Some top of the range rigs still have this feature but most modern rigs don't have any transverter facility.   To use them you simply reduce the power output from the rig to as low as possible and use a single connection to the transverter from the antenna socket.  The RF sensing in the transverter then looks after RX/TX  switching.

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. Types TRC2-10, TRC4-10, TRC6-10, TRC6-2, TRC4-2. 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.

Transverters giving 0.5W output for use with 10 metre or 2metre rig with a   single connection and 0.5-10W drive. TRC2-10s, TRC4-10s, TRC6-10s, TRC4-2s, TRC6-2s.    Also Transverters giving 0.5W output for use with a 10 metre rig with  dual transverter connection and 1mW-500mW drive. TRC2-10d, TRC4-10d, TRC6-10d.  UK prices including P&P, PCB Kit £60.00, PCB built £92.50, Box kit £101.00, Boxed built £148.00.  Rest of Europe including P&P, PCB kit £62.50, PCB built £95.00, Box kit £106.00, Box built £153.00.                   

Transverters giving 25W output for use with 10 metre or 2 metre rig with  single connection and 0.5-10W drive, TRC2-10sL, TRC4-10sL, TRC6-10sL, TRC4-2sL, TRC6-2sL.   Also Transverters giving 25W output for use with a 10 metre rig with    dual transverter connection and 1mW-500mW drive, TRC2-10dL, TRC4-10dL, TRC6-10dL.                                        UK prices including P&P, PCB kit £141.00, PCB built £187.00, Box kit £179.00, Boxed built £266.00.                 Rest of Europe including P&P, PCB kit £144.50, PCB built £190.00, Box kit £184.00, Boxed built £271.00.       

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 is now available specially dedicated to 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.

The same transverter will most likely be compatible with IC701, IC735, IC740, IC751, IC751A, IC761, and IC765, though some of these will require the accessory plug to be a 24 pin Molex type.

The whole range is TRC2-10L/IC1, TRC4-10L/IC1, & TRC6-10L/IC1, and state if DIN or Molex connector are required.  Box kit £185 UK, £191 EU.   Boxed built £280 UK, £285 EU.

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.

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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. 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 £81.00, PCB Built £94.00.

TRANSMIT AMPLIFIER Single stage switched class AB linear amplifier suitable for CW, SSB, FM, RTTY, and PACKET. Versions for drive levels of 1W-5W and output levels of 8W-30W. 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 71 x 17mm. Diecast box size 127 x 102 x 38mm. Fitted with SO239 connectors. Types TA2SA, TA4SA, & TA6SA. PCB Kit £54.00, PCB built £65.00, PCB & hardware Kit £63.00, Ready Built £82.00.

TRANSMIT AMPLIFIER Single stage switched class AB linear amplifier suitable for CW, SSB, FM, RTTY, and PACKET. Versions for drive levels of 5W-20W and output levels of 22W-60W. 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 71 x 17mm. 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. PCB & hardware Kit £70.00, Ready Built £89.00.

TRANSMIT AMPLIFIER & PREAMP.  The amplifiers described above and a matching preamp from the RP2S series together in one box with independent switching. 1W-5W in 8W-30W out, together with 20/26dB gain preamp. Types TA/RP2SA, TA/RP4SA, TA/RP6SA. PCB & hardware Kit £89.00. Ready Built £123.00.

TRANSMIT AMPLIFIER & PREAMP.  The amplifiers described above and a matching preamp from the RP2S series together in one box with independent switching. 5W-20W in 22W-60W out, together with 20/26dB gain preamp. Types TA/RP2SB, TA/RP4SB, TA/RP6SB.  PCB & hardware Kit £92.00. Ready Built £126.00.

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. PCB & hardware kit £109, Ready built £130.00.

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MELLSTOCK 4 metre 1W AM TX, a two channel transmitter with integral speech processor. PW Sept & Oct 2005. PCB £16.00. Mod Transformer £9.50. Crystals £8 the pair. PCB & component kit with crystals & transformer but without hardware £57.50. 

MELLSTOCK 4 metre AM RX, a two channel receiver as a companion for the Mellstock TX. PW Nov 2005. PCB £10.00. Crystals £8 the pair. 100uA edgewise S meter £9.00.  Complete PCB kit, volume control,channel toggle switch, crystals, and meter £57.00.

RECEIVE CONVERTERS add 2 or 4 or 6 metres to a receiver tuning 28-30MHz,  Types RC2-10, RC4-10, RC6-10 are low noise and have 15dB gain. This is a brand new design productionised 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 £29.00, PCB built £42.50, PCB & hardware kit £44.00, Ready built £69.50.

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 Types RC4-2, RC6-2, RC10-2. PCB Kit £27.50, PCB Built £40.50, PCB & hardware kit £42.00, Boxed Built £67.50.

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PORTLAND VFO (1A), 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) delivers 1.6V p-p into 50 Ohm with second harmonic 40dB down. PCB and component kit with potentiometer £18.00. Drilled Box and PCB kit with potentiometer and feedthroughs £27.00.  Ready built units £50.00. State required frequency when ordering. 

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 £25.00. Ready built £35.00.

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 and component kit £60.00.  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 £2.50.

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.  Front End Board PCB & Parts including 2 panel pots £44.00.

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. PCB & hardware kit £42.50, Boxed Built £60.00.

LS AUDIO FILTER, a unit to plug into the speaker socket of any communications receiver or transceiver to filter the signal to within 300-2500Hz then re-amplify the audio and provide up to 1W output.  DiBD March 2006.  PCB size 60x48x15mm.  Box size 110x60x31mm. PCB Kit including LED and volume control £14.00, PCB built with pot £20, boxed kit £33, Ready built £50.50.  

PSK31 INTERFACE, as featured in February 2009 issue PW, now taking orders.  PCB on its own £5.00.  PCB and components £21.00.  Complete kit with box and hardware, cables and jack plugs £35.50.

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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 £5. PCB Built £7.50.

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 £8.00, PCB Built £12.00.

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 £11.50, PCB Built £18.00.

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 £26.50.       

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 £17.50, PCB Built £26.50.

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 2^nd IF filter but no first IF filter. 10.7MHz version available with 2 pole crystal filter at the input and 4 pole ceramic 455KHz 2^nd 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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