Quality English products hand-crafted to order












8 February 2024

Proprietor;- Antony Nailer HNC BA G4CFY. 


Tel: 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


SPECTRA FLEX950 Coax cable with foam dielectric, 9mm diameter, fit perfectly into a screw-on PL259/9.  Lower loss than RG213 by 0.6dB at 70cm. Velocity factor 0.77. Pure copper inner and screen wires. £2.40 per metre. P&P at cost.


Coax cables, Flex 950, RG213, RG58U, & URM76 Balun 1-42MHz Air cored (RX & TX) Active Wire Aerial HF (RX)
Noise Cancelling 95 Ohm Twin Feeder Balun, 20m 95R feeder, & centrepiece Nomad VHF/UHF (RX)
G4CFY Traps 80m, 60m, 40m, 20m  Slim-G 2m, 4m, Air, & Marine (RX & TX) Active Nomad VHF/UHF (RX)
G4CFY HF Trap dipoles (RX& TX) Flexi-whips 2m, 4m, Air, & Marine (RX & TX) Compact Coil HF Active Aerial (RX)
Inverted-L HF (RX & TX )  Mobile Whip Aerials VHF/UHF (RX/TX) Long Wire HF portable aerial (RX)


Spectra Flex950, 50 Ohm. A new foam dielectric coax cable 9.5mm diameter, so it fits standard PL259 and N connectors.  Incredibly tight weave bare copper screen and foam dielectric with a 77% velocity factor for lower loss than RG213. At 70cms this cable is 0.6dB lower loss than RG213. Also it has 19 strands of 26swg for the inner core giving a much smoother characteristic across DC to 1000MHz, much better than the uncut grass look of the RG213 characteristic with 7 strand inner core. With its foam dielectric insulator it weighs 130g per metre. The Flex950 is at the top of the picture and it is noticeably smaller in diameter than the RG213. In the right hand picture the PL259 is a perfect fit.  Price £2.40/metre + P&P at cost.

RG213, 50 Ohm. Cabnex RG213 cable from Nevada with 7 strands of 20swg (0.035") plain copper centre core and copper coated aluminium braid with estimated 85% coverage.  Solid polyethylene dielectric with a 66% velocity factor.  It weighs 143g per metre and has an outside diameter 10.5mm.  It will not fit the standard PL259 unless you cut back 35mm of the outer cover, then add 10mm of 9.5mm diameter adhesive heatshrink and shrink it down tight against the PVC cover, then bend the braid back and crop it to 8mm and it will just about fit the PL259.  In the right hand picture it shows that in the conventional manner a PL259 just won't fit on it.  Price £1.80/metre + P&P at cost.

RG58C/U; 50 Ohm. High quality Webro cable with 19/0.18mm (36swg) tinned copper centre core and tinned copper braid with 90% coverage. Solid polyethylene dielectric with a 66% velocity factor. 100pF/metre, outside diameter 5mm. 80p/metre + P&P at cost. 

URM76; 50 Ohm. High quality Webro with 7/0.32 plain copper centre core and plain copper braid 87% coverage.   Solid polyethylene dielectric with a 66% velocity factor. 100pF/metre, outside diameter 5mm. 75p/metre + P&P.

RG174A/U; 50 Ohm. High quality with 7/0.16mm tinned centre core and heavy braided tinned copper screen.  98pF/metre, 2.8mm diameter.  75p/metre + P&P at cost. 4 metre length £3.00 + £3.10 P&P.


TWIN FEEDER, 95 Ohm, 2kW rated. 24/0.2mm cores individually polyethylene sleeved with an overall sheath of polyethylene. Cancels near field so doesn't emit an electromagnetic field and won't cause TVI.  Both cores pick up the same noise so there is no noise differential between them and is so much quieter than coax.  Loss is much lower than RG58 because the insulation between the cores is so small. Price £1/metre, postage at cost.  Replacement 20m length for full size G4CFY/G2DYM dipole, with ends made-off £25.00, plus £5.70 P&P. 



 CABLE Length Plugs Weight Price P&P              CABLE Length Plugs Weight Price P&P
URM76 0.3m BNC-PL 39g £6.00 £3.10   RG58U 10m BNC-PL 396g £14.25 £5.70
URM76 0.6m BNC-PL 49g £6.25 £3.10   RG58U 20m BNC-PL 766g £22.60 £5.70
URM76 0.9m BNC-PL 63g


£3.10   RG58U 10m PL-PL 406g £14.75 £5.70
URM76 1.2m BNC-PL 76g £6.75 £3.10   RG58U 20m PL-PL 776g £23.10 £5.70
URM76 0.3m PL-PL 49g £6.55 £3.10   RG213 10m PL-PL 1474g


URM76 0.6m PL-PL 59g £6.80 £3.10   RG213 20m PL-PL 2904g £45.15 £9.65
URM76 0.9m PL-PL 73g £7.00 £3.10   Flex950 10m PL-PL 1344g £31.50 £5.70
URM76 1.2m PL-PL 86g £7.25 £3.10   Flex950 20m PL-PL 2644g £56.70 £9.65


Traps small.jpg


NEW LITE TRAPS for 10m, 20m, 40m, 60m, & 80m.

Produced to satisfy the requirement for lighter weight traps.  Probably the lightest traps on the market weighing just 40gm (1.1oz), 51gm (1.5oz), 72gm (2.0oz), and 90gm (2.6oz)respectively.  The new design concept has made it possible to produce the long awaited 80m traps.  The maximum power rating is the legal limit of 250W continuous 400W unprocessed peak power.

Prices each 20m & 30m £25.00 each, 40m & 60m £27.50 each, 80m £30.00. Tracked 24 Royal Mail £5.70.



The picture opposite is the G4CFY 80/40M Trap dipole with 6sqmm top wires, the new Lite Traps and 21m of 95 Ohm twin feeder.  The feeder must be used with a 1:1 balun or balanced ATU in the shack.


The low impedance twin feeder allows differential mode signals on receive and transmit to travel along the feeder without a measurable emitted electromagnetic field.  On receive identical noise is picked up on both cores giving almost no differential feeder noise at the rig.  It is so quiet using this feeder that at first you might think the aerial system is faulty.   

If you want the bands 80, 40, & 20m then the best aerial will be the LTD80/40/20m, and 2.52mm wire will do just fine.

Prices below give a choice of 2.52mm or 62mm top wires.  Not including packing and postage by Royal Mail.


2 TRAP TYPE                   BANDS LENGTH 2.52mm  LENGTH 62mm
LTD40/20m  40 20m 52ft 7" £124.50 - -
LTD60/40m 60 40 15m  79ft 8" £136.75 - -
LTD80/40m 80 40 15m 103ft 3" £142.80 102ft  £179.60
LTD80/60m 80 60m 113ft 6"  £145.50 112ft 6" £186.15
LTD160/80m 160 80m - - 193ft 6" £241.90
LTD80/40/20m 80 40 20m 89ft 11" £195.95 88ft £227.50
LTD80/60/40 80 60 40 15m 105ft 2" £197.00 103ft 6" £247.50
LTD160/80/40 160 80 40 15m - - 168ft 2" £287.85



These Spectrum Lite Trap Inverted-L Aerials are essentially half a trap dipole with the feedpoint at ground level.   Another way of understanding its operation is as a loaded quarterwave Marconi vertical with the radiating element bent over.

The aerial is fed via coax to a coupling box secured to an earth stake at the far end of the garden. There is then a near vertical section, as high as you choose, and the remainder is near horizontal back towards the house.   Because it is coax fed it is much noisier than the twin fed trap dipole.  To work efficiently it requires a good ground.  Supplied in 2.52mm or 62mm PVC covered wire and with the coupling box and U-bolts.

LIL 80/40m 80 40 15m 51ft 3" £80.40 49ft 10" £98.75
LIL160/80 160 80, 30, 17m 98ft 4" £95.25 95ft 10" £130.50
TWIN TRAP          
LIL 80/40/20 80 40 15m 44ft 3" £106.90 43ft 5" £122.50
LIL 160/80/40 160 80 40 15m 85ft 6" £122.80 83ft 3" £153.00

Prices not including packing or postage by Royal Mail.

Inv L Drg small.jpg

L aerial small.png


BALUN 1:1 RATIO, Low Impedance 50R or 95R

This air cored balun is only a slight variation on that of Richard Holman G2DYM and 2 of them back-to-back give a flat response between -1dB points from 1.8-42MHz.  Experiments using toroidal cored designs by well known authors in Rad Com, such as the late Peter Dodd G3LDO, fail to produce anything like such a low loss flat response over such a wide range.  

The screen shot opposite of the back-to-back test has 0dB three divisions down from the top and each vertical division is 10dB.  The horizontal scale is 5MHz per division and you can just see that the response rises up near the white line on the left at about 1/5th of the first division (1MHz) and has dropped again to -2dB at the right of the 6th division across, that is 30MHz.  It continues at -2dB and rolls off again about 1/5th across the 9th division (42MHz).  That is for two Baluns back-to-back.

G2DYM rated the balun at 1kW but I had one fail at less due to thin enamel insulation so I switched to 3 different types of coloured enamel  It looks much nicer too. It might now survive 1kW again but I conservatively rate it at full legal power of 400W on SSB and 200W continuous.  It is to be used in the shack between the end of the 95 Ohm twin feeder and an ATU/RIG. Price £40.00, carriage £5.70





Here is a useful pack to help you make your own dipole or trap dipole. It includes the 1:1 Balun and 20 metres of 95R noise cancelling twin feeder and a centre piece.

Price £66.00 + £6.50 Tracked 24.


G4CFY Aerial Development History  Link

SLIM G TX & RX AERIAL. This is ¾ of a wavelength long at the manufactured frequency and achieves a gain of 1.8dBd, which is 12dBd (15 times) better than a 15cm rubber duck. The main element is fabricated using 300 Ohm twin feeder with a matching stub in a watertight housing 4" (10cm) long. There is 4m of coax cable with a choice of BNC, or PL259 connectors. Available for 2m (145MHz), or 4m (70.5MHz), or Air Band (118-137), or Marine Band (156-162MHz).  

This is a portable version of the Slim Jim described by G2BCX in PW April 1978. Actually the aerial described as a J pole is really a misnomer as it really is a squashed letter G, hence the new name.   The 156MHz version is 1.3m long, the 2m version is 1.4m long and the 127.5MHz version 1.6m long, and the 4m version 2.87m long. All fold down to 20cm. Weight is just 250g (9oz).Price for 2m, Airband and Marine Band, £20.00, 4m version £22.50, UK P&P £5.70, Tracked 24.

Slim-G small.jpg


   Flexiwhip small.jpg







FLEXIWHIP FOR HANDHELDS   These are made using a nylon tube and are fully waterproof and rugged. Solutions have been developed to allow the aerial to be supplied with a wide variety of plug or socket connectors.  The maximum production length is 50cm, so for frequencies below 140MHz they are made as loaded quarter-wave aerials, and above that frequency they are full quarter wavelengths.

Flexi-whips can be custom manufactured for any frequency in the range 68-418MHz, and the 2m (144MHz)version is normally made and trimmed as a dual band, quarter wave on 144MHz and three quarter wave on 433MHz.

A loaded 4 metre Flexiwhip can be made 50cms long and is -6dB relative to a full length 1/4 wave whip. The loaded 4m Flexiwhip will give 12dB more gain (that's 2 S-points) than a 12.5cm rubber duck. Connector options are BNC plug, SMA plug, SMA socket, TNC plug, PL259.

Frequency band Length cm UK inc P&P
70.5MHz 4m 1/4 wave loaded           47             £28.50    
118-137MHz airband 1/4 wave loaded 49       £28.50      
144/433MHz 1/4 & 3/4 wave, unloaded 50 £24.50
156-162MHz marine band 1/4 wave, unoaded 47 £24.50

2m/70cm DUAL BAND MOBILE WHIP.  This is a centre loaded whip with antiphase coil so the full 46cm length corresponds to 1/4 wave on 144MHz giving 0dBd (2.15dBi) gain.  The antiphase coil allows the top section to be in-phase with the bottom section on 70cm to provide 3dBd (5.15dBi) gain.  Robust and reliable ferrules connect the 17/7PH whips to the antiphase coil and the assembly is solid moulded in nylon. The aerial is supplied with a 3/8" UNF stud, or with a PL259 and includes a protective plastic tip.   Price £26.50 including carriage.

Whips small.jpg

QUARTER WAVE WHIPS.  These are cut from 2.54mm diameter 17/7PH stainless steel to suit any centre frequency in the range 68 to 450MHz.  They are supplied with a hinge adapter, or a 3/8" UNF stud, or even with a PL259 and all include a protective plastic tip. 1/4 wave whips in the range 68-90MHz are two sections which screw together. Priced at £16.50 each including carriage.   1/4 wave whips 90-450MHz are single section and are £12.50 including carriage.


NOMAD WIDEBAND PORTABLE SCANNER AERIAL 25-500MHz.The aerial element is made from 300 Ohm feeder configured like a Slim Jim, with modified stub matching to give greater operational bandwidth. It is intended to be portable but can be used as a permanent aerial in places where conventional wire aerials cannot be used. The overall length is 1.4metres with a matching stub housing 6" (15cm) long and folds down to just 25cm (10").  It is fitted with 4m of 50 Ohm coax cable with a BNC male connector as standard, but can be supplied with PL259.  For better reception of Air-band, 2m Amateur band or Marine-band use the Slim-G detailed above. Price £25.70 including UK P&P.  

<Slim-G small.jpg

ACTIVE NOMAD WIDEBAND SCANNER AERIAL 25-500MHz. Uses a monolithic microwave integrated circuit (MMIC) giving a flat gain of 10dB from 100MHz to 450MHz. Overall length 1.4m. Ideal for loft or portable use. Includes 4m of coax cable.  0.6m patch lead with choice of phono, BNC, or PL259 connector for receiver. DC/RF combiner box for external 12V supply. Price £50.00 including UK P&P. 

Version with Mains Adaptor £73.00 incxluding UK P&P.

Active Nomad tiny.jpg

COMPACT COIL ACTIVE HF AERIAL.  500kHz to 30MHz. Ideally suited to permanent installation in marine environments and where other wire aerials would be unacceptable. The Antenna is a 420mm PVC cylinder with saddle type mounting bracket and 7 metres of high quality RG58 cable terminated with an RCA Phono plug.  The end caps are force fitted and the cable entry is through a waterproof gland.  The aerial is a further evolution of the original Compact HFAA sold by Garex Electronics and NASA Marine and as standard gave a gain of 20dB up to 14MHz then falling steadily to 0dB at 28MHz.  The Compact Coil Aerial contains an amplifier with 20dB gain at band edges of 500kHz and 30MHz with 24dB in the middle of the band.   The DC version works in conjunction with a DC/HF combiner (sometimes referred to as a bias-T) that has a BNC socket for connection to the receiver and a DC 2.1mm chassis plug for connection to an external 12/13.5V supply.  It comes with an 0.6m red/black DC cable to connect between the adapter and a supply of 12/13.5V with a current of up to 20mA and also a 0.6m BNC to PL259 cable to the receiver.  The Mains version works in conjunction with a Mains/HF combiner (sometimes referred to as a bias-T) and has a BNC socket for connection to the receiver and a 1 metre cable with UK mains plug.   It also comes with a 0.6m BNC to PL259 cable to the receiver.  

Compact Coil DC, £54.00 including tracked UK carriage.   Compact Coil Mains, £78.75 including UK trascked carriage.


ACTIVE WIRE AERIAL. An active aerial for VLF to 30MHz and ideal for locations where an outdoor aerial is prohibited. The aerial is wire 5 metres long with 4 washers to allow it to be pinned to the wall or ceiling.  It comes with a mains powered wideband amplifier with 15dB gain, flat across the band. Also included is a 1.2m BNC to BNC, or BNC to PL259 patch lead.  It is so much better than the Active Antenna with 60cm whips as it picks up a lot more signal but mot a lot more noise. Price £58.95 including tracked UK carriage. 

Active wire aerial.jpg


LONG WIRE PORTABLE AERIAL. This thin wire aerial is ideal for discrete outdoor and indoor use.  It comprises 10m (32ft 10") of PVC covered wire together with a 1.8m length of thicker PVC wire with a crocodile clip to provide an earth. The two wires are joined to a short length of coax cable with a PL259, BNC or SMA connector. Your choice. The main element length has a natural 1/4 wave resonance on 40m (7MHz) so would benefit from the use of the RX SPC ATU to improve reception efficiency over the whole of the HF band.  Price £14.60 including UK P&P.

<Long wire tiny.jpg<