Full Spectrum kit: instructions

Your kit arrives programmed, set up for your area and tested as one rig. Set it up on a table at home first, which takes about twenty minutes and proves every part works. Then, if it is going in a vehicle, follow the installation steps in order. No soldering and no software to install on the kit.

Printable version (PDF) · Applies to Full Spectrum ($499). Going in a vehicle? Read the power section before you buy anything.

In the box

The two RTL-SDRs are labelled A and B. Each has its own antenna; do not swap them.

What you need

• A USB-C power supply that delivers 5 V at 5 A. It is not in the box, because the right one depends on where you use the kit. See the next section before you buy or reuse one.
• A phone or tablet with the Wavelens app: Android 8 or later, or an iPhone or iPad on iOS 17 or later. Get the app.
• Wi-Fi at home, for the first setup and for updates. The kit does not need Wi-Fi or mobile data to scan.
• For a vehicle: a 12 V to 5 V converter rated 5 A, a powered USB hub, an add-a-fuse tap with a 5 A fuse, and a little wire. Sizes and prices are in step 2 below.

Power: 5 V at 5 A

A note on fast chargers: a USB-C car charger's big wattage number is for 9 to 20 volts, which the Scanner does not use. Read the small print for the 5 V line. If it says 5 V 3 A, it is a 15 watt supply as far as this kit is concerned, whatever is printed on the front.

Part 1: set up at home

Do this on a table before anything goes in a vehicle. If a part was damaged in the post, you find out here, not after an afternoon of routing cables.

1. Check the parts

   Lay everything out against the list above. The memory card is already inside the Scanner; leave it there.

2. Fit the antennas

   Screw the short 433 MHz whip's lead onto RTL-SDR A and the roof whip's 3 m lead onto RTL-SDR B. Finger-tight is enough; do not use pliers. Stand each antenna upright, on something steel if you have it (a baking tray works).

   If an antenna needs an adapter, use one adapter, not a chain of them. Leave the lead slack where it meets the RTL-SDR, so the lead is not what holds the RTL-SDR up.

3. Connect the two RTL-SDRs

   Plug each RTL-SDR into one of the USB extension cables (6 inches or longer), and each extension into a USB port on the Scanner. Keep the two a hand's width apart: side by side they interfere with each other.

   Use the extension cables from the box. If you ever replace one, buy a data cable, 6 inches or longer: a charge-only cable lights the RTL-SDR up and the Scanner never sees it. It does not matter which USB port each one goes in; it does matter that each stays on its own antenna.

4. Power the Spotter

   Plug the Spotter's cable into any USB charger, or into a spare USB port on the Scanner. Its antenna goes flat against a window if one is near.

5. Power the Scanner and wait two minutes

   Plug in the 5 V / 5 A supply. A red light comes on, a green one flickers while it starts, and the fan may run. There is no switch and no screen. Give it two full minutes the first time.

   The green light settles to an occasional flicker once it has started. The scanner software starts by itself every time the Scanner gets power; there is nothing to log into and nothing to shut down.

6. Pair the Scanner

   In the Wavelens app: More → Companion radio → Find. The Scanner appears as Wavelens- followed by four characters. Tap Pair. From now on it reconnects by itself whenever it has power and the app is open.

   Stand within a few metres for this first pairing. The Scanner becomes the main companion: it carries the scanner audio and the sensor decoder.

7. Pair the Spotter

   If the Spotter is on its own charger, tap Find again, choose it and tap Pair; it becomes the second companion. If it is plugged into the Scanner, skip this step: it shows up on the Scanner's hardware line within a few seconds.

8. Check the radios and the area

   On the Companion radio screen, the hardware line should read 2 RTL-SDR. The kit is set up for the postcode you gave when you ordered. If you will use it somewhere else, change it on the admin page (step 10) under Area: a two-letter country and a postcode.

9. Scan

   Open the Scanner tab and tap SCAN. The first lock takes 30 to 90 seconds while it finds your area's control channel; after that it is remembered. You should hear dispatch traffic. If your area's system is encrypted you will see talkgroups and their names and hear nothing, which is correct. Indoors, reception is weaker than it will be with the antenna on a roof.

10. Open the admin page once

    The Scanner joins the Wi-Fi network you gave at checkout. On a phone or computer on that network, open http://wavelens.local:8080 and set a password. That page is for updates, Wi-Fi, area, settings and logs. Nothing on it is needed day to day.

    If that name does not open (some Android phones cannot look up .local names), use the address shown on the Companion radio screen's hardware line, followed by :8080. Part 4 of this guide goes through every page. The Scanner needs Wi-Fi only to update, never to scan: on the road it talks to your phone over Bluetooth and nothing else.

What normal looks like

• One RTL-SDR is hot and the other is cool. The one that is sweeping works all the time and is hot to the touch; the other only warms up while it is playing a channel. Both are fine.
• The fan runs on and off. Keep the case's vents clear.
• Nothing is heard for a while. Radio traffic comes in bursts. A quiet minute on a quiet night is not a fault.
• The app says "connected" within two minutes of power. If it takes longer every time, see the table further down.

Part 2: install in a vehicle, step by step

Plan on an afternoon. Work in this order: power first, because every power problem looks like a radio problem; antennas second; cables and tidying last. Each step has more detail in the vehicle installation guide.

How to read the diagram

• Two separate 5 V feeds come off one switched 12 V wire: one converter for the Scanner, and the hub's own supply. The hub is never powered from the Scanner.
• Everything USB goes into the hub, and one short cable takes the hub to a blue USB 3 port on the Scanner. Nothing else plugs into the Scanner.
• Each radio has its own antenna. Do not join two radios to one antenna with a splitter: it costs signal and lets each radio's noise into the other.
• The phone has no wire. It talks to the Scanner over Bluetooth from anywhere in the vehicle.

1. Lay it all out loose

   Before fixing anything: Scanner and hub under a seat or in the glovebox, out of the sun; roof antenna where its 3 m lead reaches the cabin without an extension; the small antenna on the rear deck or dash; Spotter high on the dash. Check you can still reach the Scanner's ports.

   Under the front passenger seat is the usual place for the Scanner and hub: cool, out of sight, and close to both the fuse box and the rear door where the roof lead comes in. RTL-SDR B goes where the roof lead ends (rear-seat floor or parcel shelf is typical) and USB runs from there. Your phone can be anywhere in the vehicle.

2. Buy the power parts

   A 12 V to 5 V converter rated 5 A continuous with a USB-C plug ($12 to $25); a powered USB 3.0 hub with its own supply ($20 to $30); an add-a-fuse tap for your fuse size with a 5 A fuse ($6 to $10); a ring terminal and two metres of 16 to 18 AWG wire. Never an unpowered hub, and never a 2.4 A lighter plug.

   If you buy extra USB cables, check they are data cables. Charge-only cables are the most common reason a kit that worked on the table does not work in the car.

3. Find an ignition-switched fuse

   In the cabin fuse box, with a test light or multimeter, find a fuse that is dead with the key off and live in Accessory or Run: the 12 V socket and the radio are good candidates. Avoid airbag, ABS, engine-control and lighting circuits, and anything rated under 10 A. The kit should switch off with the ignition, so it cannot flatten the battery.

   The fuse box is usually in the driver's footwell or behind a panel at the end of the dash; the owner's manual has the map. Test on the small exposed metal points on top of each fuse. Do not use a fuse that is live all the time.

4. Fit the add-a-fuse

   Pull that fuse and seat it in the tap's lower slot, so the original circuit keeps its own fuse. Put the 5 A fuse in the upper slot and plug the tap in. Check with the meter: the tap's wire is dead with the key off and shows 12 V with it on. If it is live with the key off, turn the tap around.

   Which way round the tap sits matters: its wire must be on the side of the slot that is live with the key on.

5. Ground the converter

   Fix the converter's negative wire, with the ring terminal, under a bare-metal chassis bolt near the fuse box. Scrape paint if you have to. A poor ground is the usual reason a converter gives 5 V on the bench and 4.6 V in the car.

6. Run the converter to the Scanner with a short cable

   Connect the converter's positive wire to the tap, and its USB-C plug to the Scanner. Keep that USB-C run short: 30 cm is ideal and 1 m is the limit. A long, thin cable loses a quarter of a volt at full load, and the Scanner notices.

   If your converter has a bare 5 V output and you are fitting the plug yourself, set it to 5.1 V under load.

7. Power the hub from its own supply

   Feed the powered hub from the same switched circuit through its own supply. The hub must never draw its power from the Scanner. Plug the hub into one of the Scanner's blue USB 3 ports with a cable under half a metre.

   A hub that takes 12 V goes straight onto the same add-a-fuse wire and the same ground. A hub that takes 5 V gets a second converter of its own. Then check the order things start in: turn the key to Accessory, and the hub's light should come on with, or before, the Scanner's red light. On the same switched circuit this happens by itself.

8. Fix the Scanner and hub in place

   Under a seat or in the glovebox, with hook-and-loop tape or a cable tie through the case. Keep the fan vents clear and slide the seat through its full travel to make sure nothing is pinched.

   A glovebox suits small cars; leave the fan intake clear and do not pack the RTL-SDRs in beside it. If the floor ever gets wet, tie the Scanner to the seat frame so it sits a few centimetres up.

9. Put the scanner antenna on the roof

   Set the magnetic mount near the centre of the roof on clean paint. Bring the lead in through the top of a rear door seal, with a small downward loop outside so rain drips off before the seal. Do not extend the lead. Screw it onto RTL-SDR B, finger-tight.

   The section after these steps, Roof antenna: mounting and keeping water out, goes through this job in full. Between the rear doors, or just ahead of the rear glass, is nearly as good as the centre and keeps the lead short. A magnetic mount will not hold on an aluminium or composite roof: use a hatch-lip or boot-lid mount there. Do not let a door close hard on the lead; it is thin, and a crushed section is a dead antenna. One adapter at most between the lead and the RTL-SDR.

10. Place the sensor antenna inside

    Stand the small 433 MHz whip on flat steel inside the cabin (rear deck or dash), half a metre from the other radios, and connect it to RTL-SDR A.

    Your own wheels are two metres away and loud, so this antenna does not need to be outside. If the rear deck is plastic, a steel washer under the carpet gives the magnet something to hold.

11. Connect the RTL-SDRs to the hub

    Each RTL-SDR on its own USB extension, 6 inches or longer, into the hub, 15 cm or more apart, hanging free, not taped to the Scanner or to each other.

12. Mount the Spotter

    High and forward: top of the dash or an A-pillar, antenna flat against glass that has no metallic tint. Power it from the hub or from its own USB socket.

    Not behind the dotted black band around the mirror, and not on heated glass if you have a choice. There are two ways to run it, and you can change your mind later. On its own power (a car charger or power bank), it pairs to your phone as the second companion and keeps working with the phone outside the car; use this with an iPhone or iPad. Plugged into the hub, there is no pairing: the Scanner runs it and your phone holds one Bluetooth link, which helps when the phone is already busy with earbuds, a watch or the car.

13. Tie everything down, with slack

    Leave 10 cm of slack at every plug, then tie cables so nothing swings or sits under a foot. A plug that works loose looks exactly like a radio fault.

    Each RTL-SDR should hang free on its cable, not pressed into carpet or against the other one. A loop of hook-and-loop tape to the seat frame keeps a cable from being kicked.

14. Turn the key and test

    Key to Accessory, wait two minutes. The hub lights, the Scanner starts, and the app reconnects by itself. The hardware line should still read 2 RTL-SDR. Tap SCAN.

15. Check the power under load

    With the engine running, the scanner playing and the headlights and fan on, open the admin page (at home, on Wi-Fi) or watch the app for ten minutes. No under-voltage warning, no restarts, both radios still listed. If the Scanner restarts when you start the engine or hit a bump, go back to steps 2 to 6: it is the supply, the ground, or the cable.

16. Switch off and on again, then drive

    Turn the ignition off, wait ten seconds, and on again: the Scanner should be back in the app within two minutes without you touching it. Then take a short drive. Part 3 checks each radio in turn.

Roof antenna: mounting and keeping water out

The roof antenna is the only part of the kit that lives outside. The whip, its magnetic base and the lead are made for weather. Nothing else is: the RTL-SDRs, the hub, the Scanner and the Spotter must stay inside and dry. The job has two halves: put the antenna where it hears best and stays put, and make sure the lead does not carry water into the cabin.

Mounting

1. Pick the spot

   The centre of the roof is best: the steel roof works as part of the antenna, and the centre gives an even view in every direction. Between the rear doors or just ahead of the rear glass is nearly as good and keeps the lead short. Stay a hand's length or more from a sunroof, roof rails, a roof box and other antennas.

2. Check the magnet will hold

   Try a fridge magnet on the spot. If it does not stick, the panel is aluminium, glass or composite and a magnetic mount will not hold: use a hatch-lip or boot-lid mount instead. Do not put the base on a glass sunroof panel.

3. Clean the paint and the base

   Wash and dry the spot, and wipe the underside of the magnetic base. Grit trapped under the magnet is what scratches paint, not the magnet itself.

4. Set it straight down

   Lower the base flat onto the roof with the lead pointing toward the door you will bring it in through. To move it later, lift it off; do not slide it. Check that the whip is screwed firmly into the base and stands vertical.

5. Lay the lead across the roof

   Run it straight back to the top corner of a rear door, lying flat, with no loop standing up for the wind to catch. On a long run, a small piece of clear paint-protection tape every 30 cm stops the lead buzzing against the roof at speed. Do not drill the roof; the kit never needs it.

6. Check it after the first fast drive

   After the first motorway trip, check that the base has not moved and the whip is still tight. Check again after strong wind, and lift the antenna off before a brush car wash, a low car park or fitting a roof load.

Keeping water out

1. Bring the lead in at the top of a rear door seal

   Open the rear door and lay the lead across the rubber seal at its top corner, where the seal is soft and the door closes gently. Close the door slowly the first time and feel for resistance. The lead should be gripped, not flattened: a crushed lead is a dead antenna and a path for water. A rear hatch with a rubber grommet for wiring is a good second choice.

2. Make a drip loop outside

   Just before the lead meets the seal, let it dip a few centimetres below the point where it enters, then rise to the seal. Rain running along the lead drips off at the bottom of that loop and never reaches the seal. This one loop does more than any sealant.

3. Make a second low point inside

   Inside the cabin, let the lead drop below the RTL-SDR before it rises to it, and keep the RTL-SDR and its connector off the floor. If a drop ever does get past the seal, it stops at the low point and not in the connector.

4. Seal the crossing if the seal no longer sits flat

   If you can see a gap either side of the lead, put a small bead of neutral-cure silicone where the lead crosses the seal and let it set with the door closed. If your order included the roof antenna kit, the sealant in the box is for this. Do not fill the door's own drain holes.

5. Protect the whip's joint

   Where the whip screws into the base, a turn of self-amalgamating (self-fusing) rubber tape stretched over the joint keeps water and road salt out of the thread. Ordinary electrical tape lets go in the sun.

6. Test with water before you trust it

   With the doors shut, pour a watering can over the roof above the door for a minute, or use a hose on a gentle setting. Open the door and feel the inside of the seal and the carpet below it. Dry means done. Damp means the lead is sitting in a fold of the seal: move it a few centimetres toward the corner and test again.

• In winter and by the sea, lift the base off every month or two, wipe the paint and the base, and put it back. Salt and grit collect under the magnet.
• If the seal ever leaks after months of use, the lead has usually worked its way down the door. Move it back to the top corner and remake the drip loop.

Part 3: prove the install, then drive

Ten minutes in the driveway, one radio at a time. Each check tests one part, so a failure tells you exactly what to move.

The first drive

• Keep the phone in a dash mount with the screen on for the first trip, so you can watch what each radio adds. Scanning with the screen off works afterwards.
• The sensor radio will be the busiest in traffic: every car around you has tyre sensors. What matters is the ones that stay with you.
• The Spotter shows far more Wi-Fi than your phone did on its own. That is its antenna doing its job, not a fault.
• Follow mode on the Scanner tab holds your area's system through a drive. If you cross into another system's area, it locks on again in about a minute.

Part 4: the Scanner's web page

The Scanner has a small web page for looking after it. Nothing on it is needed day to day. It is there for Wi-Fi, updates, the area, settings, and a look at what the Scanner is doing when something seems wrong.

1. Be on the same Wi-Fi as the Scanner

   Use a phone or computer on your home network, with the Scanner powered and in range of that network. In a vehicle, that means parked at home.

2. Open the address

   In a web browser, type http://wavelens.local:8080. If it does not open, use the numbers shown on the app's Companion radio screen hardware line instead, for example http://192.168.1.20:8080, or look for "wavelens" in your router's list of devices.

3. Choose a password, the first time

   The first visit asks you to choose an admin password of 8 characters or more. Later visits ask for it; a login lasts 12 hours on that device. Write it in the table on this page. You can change it on the Account page.

4. Read the Status page first

   It is the page you land on. If anything is wrong, a red box at the top says what, in plain words, with the fix as a button.

Your Scanner's details

Fill this in the first time you set the Scanner up, and keep it with the kit.

Advanced: logging in to the Scanner itself

You never need this to use the kit. It is for people who want a command line on the Scanner, and for support when we ask you to run a command. The Scanner is a small Linux computer and accepts a remote login (SSH) from your home network.

1. Open a terminal on a computer on the same Wi-Fi

   On Windows open PowerShell; on a Mac or Linux open Terminal.

2. Log in

   Type ssh wavelens@wavelens.local and press Enter. The first time, answer yes to the question about the host. The user is wavelens and the password, as shipped, is wavelens. Nothing shows on screen while you type a password.

3. Change the password straight away

   Type passwd, enter wavelens as the current password, then a new one of your own, twice. Every kit ships with the same login, so until you change it anyone on your Wi-Fi who has read this page can log in to your Scanner. Write the new one in the table above.

4. Log out

   Type exit. The scanner software keeps running whether or not anyone is logged in.

This login and the web page password are two separate things: changing one does not change the other. If you forget the web page password, log in this way and email support for the reset command. If you forget both, email wavelensapp@gmail.com.

If the Status page shows a red box

Every red box also has Download log for support. Email that file to wavelensapp@gmail.com. If an update does not start, the Scanner puts the last working version back by itself and the Status page says so; there is nothing for you to do.

If something is wrong

Updates and care

• Updates arrive when the Scanner is on your home Wi-Fi. The app's Companion radio screen shows when one is waiting and installs it with one tap; so does the admin page.
• Moving house or travelling: change the area on the admin page so signals are named for where you are.
• Every start is automatic. Key on, two minutes, and the Scanner is back in the app. Key off and it is gone. There is no shutdown routine; the memory card is built for it.
• Moving it between vehicles: unplug the hub's power and the roof lead and lift the Scanner, hub and radios out together. The add-a-fuse and converter stay with the car.
• Washing the car: lift the magnetic mount off first, or hand-wash around it. A brush wash will take it.
• Heat: keep the Scanner out of direct sun. A black case on a dashboard in summer gets hot enough to make the radios drift.
• The law: the kit only receives. Rules on scanner radios in vehicles differ between countries and between US states; check yours.

Help

Email wavelensapp@gmail.com with what you see on the Companion radio screen's hardware line. That one line tells us most of what we need. More answers are on the support page.

Checklist

• Ignition-switched fuse found: tap wire dead with the key off, 12 V with it on
• Add-a-fuse fitted with a 5 A fuse; ground on bare chassis metal
• Converter (5 A) to the Scanner's USB-C, cable under 1 m
• Powered hub on its own supply, same switched circuit, lights with or before the Scanner
• Scanner and hub fixed under a seat or in the glovebox; fan vents clear; seat travel checked
• Hub to a blue USB 3 port on the Scanner, cable under 0.5 m
• Roof whip near the roof centre; lead through the rear door seal with a drip loop; finger-tight on RTL-SDR B
• Small 433 MHz whip on steel inside, on RTL-SDR A, half a metre from everything else
• Each RTL-SDR on its own USB extension (6 inches or longer), 15 cm apart, hanging free
• Spotter high on the dash, antenna flat on plain glass, powered
• 10 cm of slack at every plug; everything tied so nothing swings
• Scanner paired as the main companion; Spotter as the second, or plugged into the hub
• Hardware line reads 2 RTL-SDR; SCAN locks and plays
• Own tyre sensors in the journal; hotspot seen by the Spotter; Rule hits from all three
• Ignition cycle: Scanner back in the app by itself within two minutes
• Admin password set on home Wi-Fi; automatic updates on

More detail

The vehicle installation guide goes further on every step of Part 2: the layout drawing, antenna placement with measured differences, noise and heat fixes, and adding radios later. A copy of this page for printing: Full Spectrum kit instructions (PDF).