This antenna is based on the 80/40M trap dipole design found in the ARRL Handbook. The W2AU balun is used with a pair of 40M traps to create a multiband dipole antenna capable of operating on 80, 40, 20, 15 and 10 meters. It is approximately 110 feet in length and provides a relatively low SWR on these bands.

Use Unadilla’s W2VS high performance traps to convert your single dipole into a tuned, multiband wire antenna. You can also use these traps to design HF vertical multiband antennas using either wire or aluminum tubing. Traps for different bands can be combined onto one dipole to create a single antenna tuned for maximum gain on all your favorite bands, from 160 to 10.

W2VS traps are available for 80 meters and up in two versions. A FREE trap design guide is provided to aid multiband dipole construction. Rated for 2KW PEP. Built from stainless steel and aluminum hardware to resist corrosion, these rugged traps have a pull strength of over 600 lbs. Trap coils are waterproofed and condensers are epoxy-sealed.

Model#	Description (multi-band pairs):	MSRP(US)
KW-10	10 Meter (28.675 MHz) Reyco™ Coils	$45.00
KW-12	12 Meter (24.950 MHz) Reyco Coils	$45.00
KW-15	15 Meter (21.275 MHz) Reyco Coils	$45.00
KW-17	17 Meter (18.118 MHz) Reyco Coils	$46.00
KW-20	20 Meter (14.175 MHz) Reyco Coils	$46.00
KW-30	30 Meter (10.125 MHz) Reyco Coils	$47.00
KW-40	40 Meter (7.1500 MHz) Reyco Coils	$47.00
KW-60	60 Meter ( MHz) Reyco Coils	$52.00
KW-80F	80F Meter (Phone Band) (3.875 MHz) Reyco Coils	$52.00
KW-80CW	80CW Meter (CW Band) (3.625 MHz) Reyco Coils	$52.00
KW-CUSTOM	Special Frequency Traps/M.A.R.S./C.A.P./Comm/Gov (3.000 to 30 MHz)	$75.00
KW 40 EURO	set at 7.05 MHz	$49.00
W2AU 4:1-B	Beam Version (Transformer Type)	$27.50
W2DU INLINE (HF ISOLATOR)	with SO-239 at each end.	$29.50
W2DU INLINE (VHF ISOLATOR)	with SO-239 at each end.	$29.50
Other frequency bands available on special order – call us 2 traps to a pair

hi-voltage, UV-inhibited, antenna insulators!

W2DU End-sulators Unadilla’s shatterproof End-sulators are made from the same tough plastic as their Baluns. An unbreakable alternative to ceramic insulator they’re lightweight with a long leakage path. Sold in pairs.

2 & 3 Position InLine Wired & Wireless Coaxial Relays

Unadilla’s 2 and 3 position InLine coaxial relays are available from Unadilla, the W2AU/W2DU Balun company. Relays are available in either a Wired type or an Wireless type.  The Wired versions require DC power to be brought to the relay. The Wireless versions can decouple DC power injected into your coax cable through the use of a Power Coupler (refer to the next page).

All relays are weatherproofed for mounting outside.  With the Wireless Relays you can inject the DC power required by the relay in the shack and have the relay operate at a remote location.  These Wireless relays separate the RF signal from the DC voltage off the same coax line.  Wireless relays are therefore ideal for switching antennas at tower tops or locations far from the station where the required DC power is unavailable. Two and three position require 0 & +12 vdc and -12vdc & 0 & +12vdc, respectively.

Power Couplers

Unadilla’s InLine Power Couplers are for use with 2 & 3 Position Wireless Relays.  These Couplers have a built-in switch to disconnect the power to the remote relay without effecting other items connected to your dc supply.

2 & 3 Position Wired & Wireless Relays

Related Couplers for Relays

also referred to as line isolators, these choke off RF currents on the shield!

These In-Line Baluns have an SO-239 UHF type connector on both the input and output side.  In-Line baluns provide similar performance to their respective wire balun counterparts.  Applications for In-line baluns include line isolation anywhere along the coax transmission system and use on Quad and Yagi antennas.  The W2DU’s RF choke design can be used anywhere along your coaxial transmission path to help eliminate RF feedback and TVI.  While the RF currents flowing along the coax shield are “choked” out by the balun/isolator, the internal 50 ohm signal is completely unaffected.  Some users have noted a reduction in interference with the use of line isolator between their transmitters (transceivers) and linear amplifiers.  Another use is placing one at the vertical, beam, or quad antenna to augment the antenna’s matching system to coax.

NOTE: All baluns are available with “N’ connectors, or double S0-239’s when requested.
- Additional charge of $2.00 per connector –

The W2AU is the preferred Balun of Amateurs worldwide. W2AU’s operate at a low VSWR from 1.8 to 40 mHz, and handle powers up to 2 KW PEP (at SWRs of less than 3:1). W2AU Baluns are transformer designs with ferrite cores to provide 95% minimum coupling efficiency. Each has a built-in lightning arrestor, hang up hook, and 600 lbs of pull-apart strength in a weatherized, rugged package using only stainless steel hardware and quality materials. Two models are available. The 1:1 matches 50(75) ohms unbalanced coax to 50(75) balanced dipoles. The 4:1 matches 50(75) ohm unbalanced coax to 200(300) ohm folded dipoles.

Model#	Description	MSRP(US)
W2AU™ 1:1	50 ohm-50 ohm or 75 ohm-75 ohm (Transformer Type 1.8 – 40 MHz)	$26.50
W2AU 4:1	200 ohm-50 ohm or 300 ohm-75 ohm (Transformer Type 1.8 – 40MHz)	$26.50
W2AU 4:1 LL	Ladder line / Coax Transition 4:1 Balun	$28.00

The W2DU Maxi-Baluns owe their extremely high power capability to the fact that they contain no ferrite cores to saturate. Even at high SWR levels, the W2DU Baluns won’t generate harmonic radiation. The internal feed line passes through ferrite beads which prevent RF current from flowing on the coax shield.

Two 50 ohm 1:1 models are available; HF (1.8-30 mHz) and VHF (30-300 mHz).

• At 10 mHz, the HF model handles over 10 KW PEP at VSWRs up to 2:1.
• At 200 mHz, the VHF model handles over 3.2 KW PEP at VSWR’s up to 2:1.

Each W2DU Balun has a built-in lightning arrestor, hang up hook, and 600 lbs of pull-apart strength in a weatherized, rugged package using only stainless steel hardware.

For matching yagi or quad elements select the Beam models of the famous W2AU or W2DU Baluns. These models are designed to be mounted horizontally to a beam’s boom. Pigtail wires are provided in lieu of the hooks on the wire models to connect these Baluns to the driven element. Specs for beam models are the same as their respective wire models with the exception that the W2AU and W2DU HF beam models only operate from 40 to 10 meters.

NOTE: All baluns are available with “N’ connectors, or double S0-239’s when requested.
- Additional charge of $2.00 per connector –