Answer first: fix the omni outdoor aerial high and clear on the roof ridge, chimney stack, gable wall or rear elevation facing the serving mast, keep it at least 10 m vertically separated from the indoor whip, run the 10 m coax to the BS donor port, plug the interior whip into the MS server port, leave the 5V adapter unplugged until both antennas are connected, then power on and read the LED. Test voice calls and 3G data across the main room, second room and furthest corner for up to 10 handsets before relying on the system. The DW100 suits EE-family households who need reliable voice calls plus an all-network 3G fallback; it cannot create signal where the phone already reads zero bars outside, carries no Band 20 rural 4G on 800 MHz, carries no Band 8 on 900 MHz, and does not carry 5G.

What Comes in the DW100 Kit Before You Start

Open the box on a clean table before running any cable. The standard DW100 kit contains the booster chassis, the omni outdoor antenna, the indoor whip antenna, the UK Type power adapter, the 10 m outdoor coax and the fixing hardware; no drilling, crimping or soldering is required for the core three-step install.

Kit element, spec and install role

Checks before the aerial leaves the table

Confirm the phone already reads one or two bars outside the property on the target EE, BT, ASDA, Virgin, O2, Vodafone or Three SIM; the repeater amplifies an existing weak donor and cannot manufacture a block the mast does not transmit. Check the omni base seals flat to the bracket, the coax connectors screw firmly, and the indoor whip has its own base and lead. Automatic gain control inside the chassis balances the level as handsets move around the flat, so clean antenna separation matters more than manual tuning. The DW100 covers up to 100 m² with 10 simultaneous users; a studio, one-bedroom flat or small home office fits that footprint naturally, while a larger terraced house should consider splitting carefully or choosing a higher coverage tier.

Step 1: Outdoor Omni Placement and the 10 m Vertical Isolation Rule

The omni outdoor antenna picks up the donor mast through the roof or wall; because it sits outside the masonry it sees a stronger block than the phone behind the double glazing alone can. Mounting high and clear beats mounting low and hidden, and the separation between donor aerial and indoor whip stops the amplified field feeding straight back into the chassis.

High and clear beats hidden and low

On a detached or terraced home, fix the omni to the roof ridge, chimney stack, gable wall or rear elevation with a clear sky view toward the serving mast; on a flat block of flats, use the communal balcony railing, a stairwell roof bulkhead or an approved shared landing position rather than poking the aerial through a bedroom window. Brick walls, concrete floors, foil-backed insulation and metal window frames all absorb 1800 MHz and 2100 MHz energy, so the donor aerial should clear the roofline, neighbouring chimney stacks and tall hedges that could shade the bearing. The omni picks up signals broadly rather than in one narrow beam, which suits a flat where the mast direction cannot be fixed precisely; a directional Yagi is the upgrade when the donor reads only one bar outside.

10 m vertical separation between donor and whip

The two antennas must sit at least 10 m vertically apart wherever the property geometry allows: the omni on the roof or upper wall, the whip on the ground-floor room or living area below. That gap prevents the indoor field from reaching the donor aerial directly, which is the physical root of oscillation. In a single-storey bungalow or a flat without a 10 m fall, place the two antennas on opposite external walls, route the leads on separate sides of the property, and accept that usable gain will be lower than the 10 m separation design; clustering both antennas near the same window is the most common cause of a flickering, unstable LED after power-on.

Step 2: Route the 10 m Feed and Choose a Longer Cable Upgrade

The 10 m low-loss coax runs from the omni aerial to the chassis indoors; tidy routing preserves the signal that the omni collected and keeps the property looking finished. Keep the bend gentle, avoid crushing the coax under floor trim, and keep the lead away from mains wiring, TV aerial coax and equipment power bricks to prevent electrical interference on both Band 3 and Band 1.

Sealed entry and tidy routing

Run the feed down a gutter channel or roof edge, enter the property through an existing drilled masonry grommet, a window frame gap or a dedicated sealed wall entry with a weatherproof gland. Leave a drip loop where the cable exits the wall so rainwater runs away rather than down the lead, then tuck the wire behind skirting, door architrave or wall trunking on its way to the chassis position. Do not run the coax alongside mains electrical cable for long sections; cross the mains run at a right angle rather than parallel, and clip the lead every 30 to 40 cm so it does not hang loose behind furniture.

When the 20/30/40/50 m upgrade applies

The fixed 10 m lead reaches a roof-mounted donor down to a living-room chassis in a typical two-storey home; if the strongest donor point sits beyond that distance — a distant chimney stack on a large plot, a shared roof bulkhead on a tall block, or a rear annex separate from the main house — order a 20 m, 30 m, 40 m or 50 m low-loss upgrade. Longer coax adds signal loss at the donor stage, so a stretched cable on a weak donor reads worse than a short cable on a strong one; check the outside bar count first, then match the cable length to the distance rather than assuming more cable always helps. Splices in a self-routed coax should be avoided: a poorly joined run adds loss and moisture risk that the 45/50 dB gain cannot fully recover.

Step 3: Chassis Placement and the BS versus MS Ports

The compact chassis fits on a shelf, inside a cupboard, behind a TV unit, in a hallway recess or under a desk in the home office; it needs ventilation, must sit away from direct heat, radiators and kitchen ovens, and should stay reachable for the LED check. The two ports are labelled, and swapping them inverts the amplifier loop and causes oscillation.

Why a port swap causes a loop

The BS port faces the donor mast; the MS port faces the interior users. Connecting the omni to MS and the whip to BS lets the interior field repeat through the donor aerial back toward the mast, feeding the stage a second loop that the automatic gain control cannot balance. Match the labels before applying power, and do not swap leads while the adapter is live.

Where the whip radiates best

Place the interior whip in the main usage area — living room centre, hallway between two rooms, home-office desk corner — upright and clear of metal cabinets, filing racks and thick concrete partitions. Keep it one to two metres from the chassis and away from the donor coax route, so the cabin field does not couple onto the external lead. In a split living and bedroom layout, the whip should sit central to both spaces before a second whip is added through the splitter. Lay the interior lead behind furniture rather than across a walkway, and keep the whip upright rather than folded behind a bookshelf.

Where the chassis sits in each space

In a flat, tuck the chassis on a kitchen or hallway shelf with the vents clear; in a cottage, inside the under-stair cupboard beside the mains supply; in a home office, on the desk recess behind the monitor; in a small shop, on the stockroom shelf away from the point-of-sale till. The chassis should remain visible enough to read the LED during the 10-user test but hidden from visitor knees and stored stock.

Step 4: 5V DC Power, Power-On Order and the LEDs

The booster runs on the included UK adapter, input AC 100–240 V 50/60 Hz, output DC 5V. The installation order protects the radio stage: antennas first, power last, so the chassis never wakes into an open or self-fed loop.

Correct power-on sequence

First the omni is fixed and the 10 m coax reaches the BS port; second the interior whip connects to the MS port and is spaced away from the donor; only then the 5V adapter is plugged into the mains socket. Powering the booster before the MS side is connected lets the chassis radiate into an open port and can trigger oscillation in a confined room. Once power is applied, wait ten seconds for the LED to settle, then compare phone readings near the whip against the outside donor count before stepping back to the installation review.

Reading the status LEDs

The 18 KA surge protector on the roof run

On a detached house with the aerial on the roof ridge or chimney, fit the optional 18 KA lightning surge protector in the 10 m coax run near the building entry, bonded to the house earth where available. The surge protector drains a lightning-induced voltage spike before it reaches the chassis or the room network; it does not make the property lightning-proof, and regular earth bonding and roof protection remain separate electrical jobs. On a flat block with an internal landing bracket the protector is less critical, but it is the recommended upgrade on any elevated external mount.

When to Add the Yagi Directional Aerial for Weak Signal

The DW100 standard kit ships with the omni aerial; the higher-gain Yagi is an upgrade option rather than an included item, recommended when the outdoor phone reading holds only one bar on the target network and the omni result indoors is weak at the far corner.

Donor readings that trigger the Yagi

Before ordering the Yagi, walk the outside of the property with the target SIM and note the bar count and data speed at the front, rear and roof positions. If the strongest donor site still reads one bar, the omni's broad but moderate gain may not lift the room field enough; a Yagi concentrates the receiver toward that single mast bearing, squeezing a stronger block through the chassis on both Band 3 and Band 1. The Yagi also suits a rural cottage where the serving mast sits behind a hill ridge or a treeline that the omni cannot see around.

Do not over-aim a town property

In an urban street with several nearby masts, aiming a Yagi too tightly can lock onto a distant stronger mast that does not serve the flat's own local area; the omni's broad pick-up often performs better in town. Test the Yagi bearing against the actual phone reading at the window before tightening the bracket, and recheck after fitment that both Band 3 EE-family calls and Band 1 3G data improve rather than one band at the expense of the other.

Splitter Expansion: Two Indoor Antennas When the Outside Signal Is Strong

The DW100 supports up to two indoor antennas through a 2-way splitter, the same entry-tier expansion class as the small-house boosters, for a second room, bedroom or hallway beyond the main living area.

How the 2-way splitter adds a second room

The source guidance states, verbatim, "Expandable coverage by adding indoor antenna, splitter, cable if the outside signal is strong." After the main whip serves the living area, fit the 2-way splitter on the MS side, run an extra coax to a second whip in the bedroom or rear room, and space that second whip away from the donor omni and its own lead. The split divides the amplified field between two whips, which lowers the field at each point compared with one whip alone; that trade is acceptable when the outdoor donor is strong, because the chassis has headroom to share, but it should not be attempted where the outside phone already reads one bar or less.

When not to split

On a weak donor, a splitter just splits a faint signal across two rooms and leaves both spaces weaker than a single well-placed whip. Do not daisy-chain multiple splitters beyond the 2-way arrangement on this entry-tier chassis, and do not add a second whip into a concrete-partitioned room that the Band 3 and Band 1 signals cannot reach from the main chassis; a separate repeater in that room is the correct route. The 10-user limit is shared across both whips, so a household or small office with more than ten active handsets should move to a higher coverage tier rather than overloading the splitter.

The 10-User Test: Voice Calls and 3G Data Across 100 m²

The DW100 supports up to 10 simultaneous handsets sharing the boosted field; in a flat that means the household family members, a hotspot tablet and a home-office laptop, while a small shop spreads the load across staff phones, a till terminal and a customer hotspot.

How to run the test before relying on it

Park the test where the outside phone reads one to two bars. Place mixed EE, BT, ASDA, Virgin, O2, Vodafone and Three SIM phones near the main whip, then move one handset to the bedroom, hallway and furthest corner. Start a Band 3 voice call on an EE-family SIM and a Band 1 3G data session on an O2, Vodafone or Three SIM at the same time, hold both for a minute, and walk the reading around the main room and any second room covered by the splitter. Record the bar count before the booster, after fitting near the whip, and at the furthest point; compare against the outdoor donor so the test reflects amplification rather than a strong mast that would have worked anyway. Stagger hotspot sessions so the gain stage balances ten handsets rather than piling every device on the whip at once.

Expected coverage by space

DW100 Against the Entry Range: Why Band 3+1 Adds EE Voice and 3G

The Boost4U entry dual-band range splits by tuned band; the DW100 is the only vehicle in this group pairing Band 3 1800 MHz with Band 1 2100 MHz, so choosing the wrong combo leaves either the EE voice call layer or the all-network 3G data layer unboosted.

Pick the DW100 for an EE, BT, ASDA or Virgin household that needs voice calls to hold through the living room and bedroom, while O2, Vodafone and Three family members still get 3G data and voice on Band 1. Choose the CD100 where the priority is EE, O2 and Vodafone 4G data on an 800 MHz rural layer with no call band requirement; choose the CW100 for O2/Vodafone rural 4G plus 3G on every network but without EE voice; choose the D250 single-band unit when the household runs EE-family SIMs only and has no need for an all-network 3G fallback. The DW100 fills the voice-plus-3G gap between those three approaches on the 100 m² entry tier.

Troubleshooting: Oscillation, No Voice, No 3G and the LED Read-Out

Oscillation: feedback loop and flickering LED

The symptom is a flickering LED, a reading strong beside the whip but fading a metre away, and dropped sessions despite power. Causes are a BS/MS port swap, the interior whip mounted too close to the omni or its coax, or the chassis sited beside the donor aerial where the interior field feeds the donor directly. Swap the ports if reversed, move the whip one to two metres away, keep the leads on opposite sides of the room, and let automatic gain control settle before retesting on a parked install.

No voice on the EE-family SIM

If an EE, BT, ASDA or Virgin handset cannot call indoors but 3G data works on another SIM, check the Band 3 layer first: the omni may face an O2 or Vodafone mast bearing that does not serve the EE 1800 MHz band, the donor reading outside may be too weak for Band 3 alone, or the Yagi upgrade has been aimed at the wrong mast. Walk the property outside with the EE SIM, find the strongest 1800 MHz bearing, re-aim the omni or Yagi toward it, and verify the Band 3 voice call holds after refit. A phone that has disabled network mode, or a legacy handset stepped off the 4G packet layer, should be checked in the handset settings rather than blamed on the chassis.

No 3G on an O2, Vodafone or Three SIM

If the Band 1 3G data session will not connect on a non-EE SIM while EE-family calls hold, confirm that the local mast still transmits 3G in that street, reseat the MS whip lead, and check that the donor outside reads at least one bar on that carrier's SIM. A host network that has retired 3G in a local area shows its own fallback behaviour; the chassis amplifies what the mast transmits, it cannot create a missing 3G layer. A weak reading that strengthens after shifting the omni a few centimetres confirms the aerial placement was the limiting factor rather than the chassis gain.

Weak far corner, dead valley and mains noise

A far corner that drops while the main room holds is a coverage footprint issue: move the whip toward that corner, add the second splitter whip if the donor is strong, or accept the entry-tier limit and consider a higher coverage tier for a larger home. In a dead valley with zero external bars on every SIM, no indoor kit can manufacture the donor; route plan against host coverage maps before installing. Hiss, clicks or data dropout that track the kettle or washing machine point to mains coupling: separate the coax from the power lead, check the adapter fuse, and keep the chassis away from the fuse board.

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