Answer first: the CG1000 is a plug-and-play Band 20 + Band 8 commercial repeater for 1000 m² that repeats Band 20 at 800 MHz for O2, Vodafone and Three 4G data and Band 8 at 900 MHz for O2 and Vodafone 2G calls and SMS, with ≥70 dB uplink and ≥75 dB downlink gain roughly ten times the amplification of a 60/65 dB unit, a fixed ≥20 dBm output, a ≤5 dB noise figure, 1000 m² of indoor space and 100 active sessions, and a high-gain Yagi already inside the full kit. The basic job needs a drill, screwdriver, spirit level and clips, finishes in 10 to 15 minutes, and can grow to four indoor antennas through a splitter when the outside donor reads between -70 and -90 dBm. Follow the numbered steps, keep donor and server 10 m apart, apply power last, and survey the site before signing off a commercial lease or finalising a layout.

CG1000 Snapshot Before You Aim the Included Yagi

A short spec table keeps every number this guide relies on in one place. The CG1000 repeats Band 20 4G and Band 8 calls, recovers a faint rural or edge-of-town donor with ≥70 dB uplink and ≥75 dB downlink gain, and spreads a fixed ≥20 dBm field across the rated 1000 m² for 100 phones, with the Yagi included rather than ordered separately.

Step 1: Read the Outdoor 4G Signal in dBm Before Choosing Yagi or Omni

A commercial repeater can only amplify the signal the outdoor antenna actually receives; brick, reinforced concrete, solid stone, metal cladding and a pitched roof hide the tower from a handheld phone on a warehouse floor. The pre-mount survey happens outside the building, not behind the loading bay, and it decides whether the included Yagi gets aimed or the 5 dBi omni sits in open sky.

The dBm ranges the CG1000 expects at the outdoor antenna

A reading of -97 dBm on 4G reads as a healthy rooftop donor the ≥75 dB downlink gain and ≥20 dBm output turn into a usable indoor signal across several floors, rooms and a warehouse hall. -105 dBm sits at the edge of the recommended band and still produces a stable session once the Yagi clears the wall, rendered stone, cladding and pitched shelter; this is exactly the donor the included high-gain Yagi was supplied to recover, rather than a paid add-on. -112 dBm on 4G is the practical antenna near ceiling: below it the LTE receiver loses the control channel, the phone falls back to a slower service or shows no service, and no booster can pull a donor never received. The ≥70 dB uplink gain covers a weak outdoor antenna better than holding a phone to the glass, but it cannot invent a band the survey never picked up.

How to read dBm rather than bars in a commercial survey

Phone bars are subjective and differ between iPhone and Android; the dBm figure is the measurement the amplifier actually sees. On an iPhone, enter field-test mode from the dialer and watch the RSRP value while standing beside the building. On Android, use an engineering or network diagnostics menu, or a free field-test app that lists RSRP by band. Hold the phone away from your body, because a hand and head absorb 3 to 5 dB, and read on the side facing the nearest mast rather than the sheltered loading yard.

Where to survey: roadside, rear gable, yard corner, rooftop edge

Stand on the road-facing side, the open yard side at the rear, and the far corner beside the fence; record the reading for an O2, a Vodafone and a giffgaff SIM, because the strongest combined spot decides the Yagi bearing. On a rural industrial plot the open gable or ridge beside a hedge or barn; on a town office the hard street-facing wall beats the enclosed car park. Survey each floor inside too, because a strong roof donor can still fail a distant corner behind concrete columns; that gap decides where the four whips eventually mount. If Band 20 reads -112 dBm at every position beside the building, the CG1000 cannot manufacture that band inside, though it may still improve voice on the other network's service; re-check facing the proper mast rather than expecting the amplifier to close the gap.

Step 2: Aim the Included Yagi at One Clear Mast; Keep the Omni for Open Sky

The full kit ships both a 5 dBi omni and a high-gain Yagi, and choosing between them is the first mounting decision on a commercial roof. The omni gathers signal equally from all horizontal directions and suits a town office or retail unit where usable masts sit in several bearings; the Yagi focuses a narrow beam on one identified rural tower and recovers several decibels more where a single mast serves the valley or the industrial fringe.

When the included Yagi earns its place

Switch to the Yagi when the survey shows a single clearly identified mast, RSRP between -105 and -112 dBm on 4G, and no second useful tower nearby. Aim by walking the signal direction with the phone, peak the reading, then fix the boom at that compass bearing and a slight upward tilt for distance. Because the Yagi is already in the box, you do not pay for the aerial upgrade separately the way smaller models do; only the bracket and a short mast need fitting.

Ridge, gable or flat roof: clear sky line over 3 to 5 metres height

Fix the Yagi 3 to 5 metres up on the exposed ridge, gable or parapet, a metre clear of roof rails, satellite dishes, vent pipes, air-conditioning units and the TV aerial, so its beam is not blocked by roof metal or ductwork. On a tiled or slate roof the supplied bracket bolts to a chimney stack or fascia; on a flat commercial roof the weighted base settles in clear air. Keep the boom level in azimuth and tilt gently upward; never aim at a town centre several valleys away, because a closer weaker tower beats a distant strong one through a ridge.

When the 5dBi omni remains the better fit

Where two or more masts appear in different bearings and the donor sits between -97 and -105 dBm on every side, the omni's all-round pattern wastes nothing and avoids needing a rotation. Fit it vertically on the roof edge or gable, never tilt it, because tilting an omni cancels part of its circular pattern. The Yagi stays packed for a future rural move rather than forcing a narrow beam at a town donor.

Step 3: Run the 10 m Outdoor Cable to BS and the 5 m Indoor Cable to MS

The CG1000 ships two feeds for two jobs, and keeping them straight prevents feedback that shuts the amplifier down. The 10 m outdoor low-loss coax runs from the roof Yagi or omni down to the chassis BS (base station / donor) port; the 5 m indoor coax runs from the chassis MS (mobile station / server) port to the 3 dBi whip inside.

Clip the outdoor feed every 40 cm along the fascia, drop it through a purpose-made wall gland rather than a loose window gap, and seal the entry with exterior silicone so rain cannot chase the cable in. Keep bends gentle; a tight right-angle fold crushes the coax and costs decibels. The indoor 5 m feed reaches the central whip; a split system routed through the splitter uses extra runs to the second, third and fourth antennas, covered in Step 5.

Cable upgrades for a warehouse chassis set away from the roof

If the chassis lives in a server room or workshop at the edge of a large plot and the Yagi on the main roof sits beyond 10 m, replace the outdoor feed with the 20, 30, 40 or 50 m length rather than splicing two cables; every metre of coax costs signal, and joined sections invite water and mismatch. Keep the indoor whip feed short, because lengthening the server side also spends recovered power before it radiates.

Step 4: Match BS and MS Ports Before Any Power

The chassis labels BS and MS on their ports. BS stands for base station, the outdoor donor side facing the tower; MS stands for mobile station, the indoor server side facing the phones. Swapping the two creates a feedback loop between antennas that the automatic gain control treats as a dangerously loud signal and throttles back, leaving the building weaker than before.

Connect in this fixed order

First fit the roof Yagi or omni, second fix the whip indoors, third lay the 10 m outdoor coax from donor to BS, fourth lay the 5 m indoor coax from MS to whip, fifth confirm both labels match, and only then prepare power. A physical check before the adapter goes in avoids the common fault where the indoor whip feeds the donor port and the outdoor Yagi feeds the server port. On the split version, the splitter sits on the MS side after the chassis, never on the BS donor side, because splitting the faint incoming feed wastes recovery headroom.

Step 5: Hold the Two Antennas 10 m Apart and Split to Four Indoor Whips

Minimum isolation keeps the donor antenna from hearing the server antenna directly, which causes oscillation and automatic shutback. The CG1000 calls for a 10 m vertical separation: outdoor Yagi high on the ridge or parapet, indoor whip low in the central hall, with floors, columns and walls between rather than facing across a glass lobby.

10 m vertical isolation and the alternative horizontal gap

On a multi-floor office the ridge Yagi above and the ground-floor whip below already supplies the vertical gap; measure straight down through the floors rather than around the furniture. Where vertical separation falls short, place the Yagi at one end of the property and the whips at the far end on the same floor, giving roughly 10 m of horizontal distance with solid walls in between. Bringing a whip within 5 m of the Yagi, especially through a single glass pane, invites the AGC to mute the output.

Expanding to 4 indoor antennas through a splitter on a strong donor

The CG1000 states plainly that coverage expands by adding an indoor antenna, splitter and cable when the outside signal is strong. This expansion only works on a donor between -70 and -90 dBm, because a weak donor cannot spare extra split loss; on a strong donor, fit a two-way, three-way or four-way splitter on the MS side, run extra coax to a second whip in the far office, a third on the upper floor or hotel corridor, and a fourth in the warehouse annex or retail back-of-house, and let the ≥20 dBm output feed all four. Each split divides the radiated field, and the commercial recovery headroom of ≥70/75 dB absorbs that division so branches still hold a usable field; add antennas only where a single whip leaves a dead corner rather than blanketing every room by default.

Step 6: Power-On Sequence, LEDs and the 3 to 5 Minute AGC Lock

Apply power last and let the automatic gain control settle before judging the result. Rushing the LED readout within the first 30 seconds shows transient levels that change as the unit locks the donor.

The fixed power-on order

Connect both antennas and all split branches, confirm BS to outdoor and MS to indoor, then plug the 5 V DC UK adapter into the wall and last into the chassis. The LEDs light, the internal AGC listens for 3 to 5 minutes, backs off when the tower looms close and recovers when the donor fades, and only then holds a steady field. Never plug the adapter first and attach antennas live; the chassis can see an open port and push gain into nothing.

Reading the band LEDs after AGC settles

A steady green on the Band 20 channel means the 4G donor is recovered and repeating; a steady green on Band 8 means the 2G call layer is up. A blinking amber signals the AGC still balancing after a weather or traffic change; a red or unlit band means that layer is not being received at the Yagi, which points back to Step 1 rather than a chassis fault. Wait the full 5 minutes before concluding, because the rural donor swings between clouds and ridge reflection.

Step 7: Split 1000 m² into Zones and Test 100 Users Before Leaving

The final check proves the rating across the building rather than at the chassis. Divide 1000 m² into zones by use: central reception or hall, open-plan office or guest rooms, warehouse floor or production line, retail floor or back-of-house, and the far annex or upper floor. In each zone, place a phone on 4G, open a data session, and place or receive an ordinary O2 or Vodafone call.

Zone test for data, calls and concurrent users

Record the bar count and RSRP on each band in every zone, run a speed test on 4G, and keep a call open for 60 seconds to confirm no drop. To prove the 100-user rating, gather staff, guests or customers on a mix of O2, Vodafone, giffgaff, Sky Mobile and Tesco SIMs, hold a spread of calls and browser sessions at once, and check that none collapses into a drop when the busiest zone loads. A single perfect test at the whip position proves nothing; the far corner at floor level beside shelving, racks or a partition is the honest measurement.

Where a zone still falls short

If the far office or warehouse corner stays weak on a strong donor, add the next whip through the splitter; if the upper floor and hotel corridor both need a field, add another. If the donor itself reads -112 dBm everywhere, more indoor antennas cannot fix the missing layer, and the aimed Yagi or a larger commercial array becomes the honest answer.

The 10 to 15 Minute Basic Timeline and the Tools You Need

The single-whip setup finishes in 10 to 15 minutes with hand tools; the split-to-four-antenna version adds the cable runs and bracket mounts.

A 6 mm masonry bit for the ridge, gable or parapet bracket, a Phillips screwdriver, a spirit level, cable clips, exterior silicone for the gland, and a phone with a field-test or speed-test app cover the whole job. No soldering, no network configuration, and no account registration with the carrier; the unit works on the licensed bands in Ofcom's permitted class as supplied, and the Yagi arrives ready to aim rather than waiting on a separate aerial order.

Why ≥70/75dB Commercial Gain Drives 1000m²; It Is Not a Higher Output

On the CG1000 the commercial edge over a 60/65 dB unit is recovery gain, not transmit power. The fixed ≥20 dBm output stays the same as the flagship home model, but the ≥70 dB uplink and ≥75 dB downlink gain sit +10 dB higher, and a +10 dB step is roughly ten times the amplification factor. That extra recovery pulls a faint rural or industrial-fringe donor out of the noise before the fixed output spreads it, which is what lets one chassis serve 1000 m² and 100 sessions rather than 500 m² and 50.

What +10dB actually means in the field

Decibels are logarithmic: each +10 dB raises the recovered field tenfold. A 60/65 dB unit may stop recovering a donor that a 70/75 dB unit still hears through a hill, metal cladding or concrete slab. The output then distributes that recovered signal; raising gain does not raise output past the Ofcom-permitted ≥20 dBm ceiling, and the AGC balances recovered donor against fixed output as daytime traffic and weather change.

Commercial site survey tips before you commit

Survey at the busiest time of day, because donor levels dip when nearby cells load. Check the call layer on Band 8 separately from data on Band 20, since a warehouse may decode data but still miss a circuit call. Mark each dead corner on a floor plan before deciding where four whips go, and budget a short extra coax run per branch rather than overreaching one long feed. A rooftop feed exposed to lightning paths benefits from the optional in-line protector on the BS side; neither protection nor a long cable replaces a weak donor, they protect and carry what the survey found.

Honest Limits: What the CG1000 Does Not Fix at 1000m²

Four boundaries stay fixed no matter how high the recovery gain. The CG1000 tunes Band 20 and Band 8 only, so it does not repeat 3G Band 1 at 2100 MHz, does not repeat any 5G band, and does not convert 4G into 5G. EE 2G voice sits on Band 3 at 1800 MHz and is not carried, so an EE member gets boosted 4G data where reach applies but not a boosted EE circuit call. The rated space is 1000 m² for a large office, multi-floor SME, hotel, warehouse, retail unit or farm estate supporting 100 sessions; it does not blanket a separate outbuilding, a multi-building campus or an estate beyond the main footprint, and a permanently sited multi-building space calls for a dedicated commercial array rather than more home output.

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