Antenna Tuner
BOOST DX and reduce interference, IDEAL for HF150 etc or 10 W TX. 100kHz - 30 MHz in 6 overlapping ranges, BANDPASS design, not just usual highpass. DETECTOR output, connect voltmeter for free WAVEMETER, field strength meter etc. SO239 socket for receiver, single pole 3 mm for antenna and ground, 2.5 mm for detector. HIGH Q coils and expensive air dielectric capacitor, 4 x 7 x 14 cm, 350 g.
"certainly improved reception ... signals easily peaked up", Practical Wireless.
"performance outstanding", PJO'N in New Zealand.
"efficient and effective for DX reception ... small size", PB in Notts.
"effective with a short antenna at low frequencies ... gives excellent results", Practical Wireless.
Tunable Audio Notch Filter
RARE DX under QRM ? Dig it out with this filter between your receiver and extension speaker or headphones, BOOST your DX/QRM ratio, 40 dB notch, tunes 350 - 5000 Hz, built-in speaker amplifier sharpens the notch - resulting "hole" has little effect on speech, bypassed when off, needs 12 V at 50 mA, 4 x 7 x13 cm, 200 g.
"heterodyne disappeared completely", Practical Wireless.
"fully compares with other makes at much greater prices", HHA in Accrington.
"impressed at the ease with which I can tune out an annoying heterodyne", Practical Wireless.
VLF Receiver
Extend your coverage down to 10 kHz with this Very Low Frequency Receiver, direct conversion for morse, 50 k ohm input impedance for 15 m antenna, needs 12 V at 10 mA, 4 x 7 x 13 cm, 250 g.
"very interesting to hear stations on VLF", FR in High Wycombe, Bucks.
"excellent little set", THR in Worthing.
"neat and works very well", CGM in Jersey.

50 & 70 MHz Converter
BOTH VHF bands with one converter, switched 50-52 MHz or 70-72 MHz converted to 10-12 MHz, listen with your SW receiver, LOW NOISE FET input RF stage, approximately 20 dB gain, electronically switched 40/60 MHz oscillator and bandpass tuning for good image rejection, MOSFET mixer for strong signals, emitter follower IF, UHF sockets, needs 12 V at 30 mA, 4 x 7 x 13 cm, 250 g.
Low Frequency Converter
LONG WAVE DX ? Extend your coverage, tune the EXCITING low frequencies on your 3.5 - 4 or 4.1 - 4.6 MHz receiver, buitl-in antenna tuner, effective IF breakthrough folter, needs 12 V at 5 mA, 4 x 7 x 13 cm, 300 g.
"doing all you claim for it", CFP in Chipping Norton.
"still giving excellent service", ABGH in Daventry.
"very pleased", LWD in Warwickshire.

198 kHz Converter
Get BBC Radio 4 clear with this converter, suits any Medium Wave receiver, built-in antenna, 1000 km range, provision for external antenna beyond, covers 180 - 220 kHz (easily modified to 160 - 190 kHz band), coax and inductive (place near receiver) outputs, needs 12 V at 10 mA, 5 x 8 x 15 cm, 250 g.
"made up quite simply", PW in Leicester.
"yeoman servicee", DVD in Kings Lynn.

Crystal Calibrator
Can't find DX ? Get SPOT-ON with this calibrator between your antenna and receiver, switched equal-level 2 MHz, 200, 50 kHz MARKERS to VHF, no missing "even" ones, no unselected "ghosts", LED "on" indicator, bypassed when off, use it to align a receiver, needs 12 V at 70 mA, 4 x 7 x 13 cm, 250 g.
"very good value", BCH in Zimbabwe.
"very pleased the way the kit built up", LL in Kent.
"only circuit I have met which tackles the even harmonic problem", DFH in Stoke on Trent.

VLF ATU
Take the output from the emitter of T1 in the 100 - 600 kHz Converter, via a 100 nF capacitor. This works well with a short antenna. Add 33 mH in series with L3 to tune down to 15 kHz.