The original batch of high quality twin feeder was all sold and a new quantity has been made.  The new cable unfortunately has increased in price by 25% and my price is also then increased by the same proportion.

The price of the flanged coupling box and u-bolts has now been taking into account and the price of the Regular Inverted-L has unfortunately been increased to £84 and the Strong Inverted-L to £99, with immediate effect.

The Inverted-L aerial has a new type of connection box with two U-bolts to clamp it to a ground stake.  The pricing was checked and found to be too cheap so the price has had to be increased for the regular version to £80, and the stronger version £95.   Including carriage.  The Trapped dipole has also been re-costed and I am pleased to report that I have not been underselling them, nor will the price need to increase, unless carriage costs increase.

On 30th October 2006 Spectrum Communications acquired G2DYM Aerials.  That business had run for exactly 30 years selling Trap Dipoles mainly to the Amateur Radio fraternity.  Richard Benham-Holman G2DYM the previous owner had just had his 84th birthday and due to failing eyesight so was unable to continue running the business. 

The G2DYM Trap Dipole.  This was based on the W3DZZ trap dipole design using a 7MHz dipole comprising two inner sections of 32 feet each, with 7MHz traps then a further 21 feet 7 inches beyond each trap.  As standard it was supplied with 70 feet of 75 ohm twin feeder.  A 1:1 balun was then used to convert to the unbalanced feed of the transceiver.

Full size Trap dipole, how it works

On 80 metres, the off-frequency trap acts as inductive loading and extends the effective length of the outer sections to 132 feet, the half wavelength resonance for 80 metres.

On 40 metres, the traps isolate the end sections so it works as a half wave centre fed dipole. 

On 10 metres it functions as a seven half wave centre fed dipole.

G4CFY Full size Trap Dipole, 106 feet overall length, for 80, 40, 20, 15, & 10m parallel fed, also 160m as T configuration.  It comprising two inner sections of 33 feet and two outer sections of 19 feet 7 inches, two 7.1MHz traps, a centrepiece, two dog-bone end insulators, and 20 metres of high quality 100 ohm twin feeder.  All the wires used in a complete dipole are terminated either by wrapping back round and soldering, or by crimped and soldered lugs.  All termination ends are properly finished with heatshrink and PVC sleeves.  Connections to traps and the centrepiece are made using M6 nuts and bolts.  The power rating is 600W continuous for all versions.  Must be used in conjunction with a 1:1 Balun in the shack.

Regular duty, for normal environment.  2.5sq.mm stranded PVC covered top wires, insulators, centre-piece, traps, and 20m of feeder.   £146.50, carriage £18.00.

Regular duty, for normal environment.  2.5sq.mm stranded PVC covered top wires, insulators, centre-piece, traps, and 16m of feeder.   £142.00, Special delivery £10.00.

Strong duty, for inland exposed site.  6sq.mm stranded PVC covered top wires, insulators, centre-piece, traps, and 16m of feeder.   £157.50, Special Delivery £10.00.

Twin Feeder, 65 Ohm, 150W rated, 65 ohm twin single strand cores, 60p metre, postage at cost. 100m drum £62.50 including postage, while stocks last. Making off to lugs and with heatshrink £12. 

Twin Feeder, 100 Ohm 2kW rated. 24/0.2 cores individually polyethylene sleeved with an overall sheath of polyethylene. Loss only 0.04dB/m at 10MHz.  £1/metre, postage at cost.  100m drum £90.00 including carriage. Making off to lugs with heatshrink £7.50. Replacement 20m length for full size dipole, with ends made-off £27.50, plus £3.50 P&P.  Replacement 16m length with ends made-off £23.50, plus £3.50 P&P.

Balun 1:1 ratio, 160 - 10 metres, air cored, 1KW rated. Low impedance in and out. £40.00, carriage £3.00.

Switched Balun, 160-10m air cored, 1KW rated.  Low impedance balanced to unbalanced, plus high impedance in Marconi-T mode.  It includes switching to join the twin feedline wires so the aerial can be tuned against ground as a Marconi T.  This means the 80 to 10m trapped dipole can be loaded up on 160m, and the 40 to 10m trapped dipole can be loaded up on 80m. Ready built £50.00 carriage £3.00.

3.5MHz G4CFY traps.  Under development.

7.1MHz G4CFY traps.  Coax wound and potted in polyurethane compound.  Connection are made using nickel-plated M6 nuts and bolts. £30.00 each, post £3.00 singly, or £3.50 pair.

14.15MHz G4CFY traps. Cox wound and potted in polyurethane compound.  Connections are made using nickel-plated M6 nuts and bolts. £30.00 each, post £3.00 singly, or £3.50 pair.

TRAPPED INVERTED-L AERIAL, this aerial is half a trap dipole with the feedpoint at ground level.  It operates on 80 - 10 metres and is only 2dB down on a full quarterwave 80 metre inverted L.  With a total wire length of just 53 feet this can be accomodated in a very small garden, with say 20 feet vertical and just 33 feet back to a support on the gutter or chimney of the house.  This type of aerial is unbalanced and must be fed with coax. The complete aerial, top wire, two insulators, trap, and coupling box with two U-bolts to clamp it to the earth stake. Aerial with 2.5sq.mm stranded PVC covered top wires £84.00 including Special Delivery.   Aerial with 6sq.mm stranded PVC covered top wires £99.00 including Special Delivery.