Decodium 4 · DecoPort

Decometer

Decodium's RF front panel, on your phone. Every reading the radio takes, fetched from the PC across your home network — with none of them invented.

0 WFORWARD POWER100 W
5
pages on one dial
9
readings taken from the radio
+8
quantities derived on board
1
vector antenna analyser
The dial

Five pages, one single instrument

The same front panel as on the computer, not a cut-down version: same geometry, same colours, same needle ballistics. You swipe from one page to the next; the radio stays the same.

PowerPAG 01

How much goes out, and how much comes back.

Forward powerW The watts leaving for the antenna. It is the number the main needle chases.
Reflected powerW The watts coming back because the antenna will not take them all. Zero is the dream; anything more says there is a mismatch.
SWRSWR The standing wave ratio: how well the antenna answers the radio. 1.0 is perfect, above 2 is worth a look.
MatchPAG 02

The mismatch, translated into decibels and into watts lost.

Return lossdB The SWR said in decibels: how many dB below the forward wave the bounced one sits. The bigger the number, the better.
Mismatch lossdB The share of power the mismatch eats before the antenna even gets it.
Net powerW Forward minus reflected: the watts that really go on the air.
DrivePAG 03

How hard you are pushing the transmitter.

ALC% Automatic level control. If it climbs, the radio is telling you that you are overdriving: turn the gain down, do not insist.
PEPW Peak envelope power — the value that counts on voice, where average power misleads.
AverageW Power averaged over time, to read a steady carrier without the peaks.
SignalPAG 04

On receive: how strong, and where.

S-meterS units The strength of the received signal on the scale every operator knows, from S1 to S9 and beyond.
LeveldBm The same strength in dBm, for those who prefer the absolute number to the S unit.
FrequencyMHz Where you are tuned, down to the hertz.
Bandm The matching amateur band, recognised on its own.
Final  ·  the power amplifierPAG 05

The telemetry of the final stage, for the radios that report it.

Drain voltageVd · V The supply voltage of the power stage.
Drain currentId · A The current the final draws: it rises with power, and together with the voltage it says how hard the stage is working.
Temperature°C The heat of the final, on the radios that have the sensor. Where there is none, the app does not fake it.
CompressiondB How much speech compression the transmitter is applying.
Power knob% Where the power control sits, so you know the level you start from.
Efficiency η% Derived: the watts out against the watts the final consumes. An honest solid-state final sits around forty per cent — and the app only shows it when the arithmetic holds up.
The active side

The antenna analyser

It gathers frequency and SWR pairs while you operate — or with a sweep that drives the radio — and works out the curve of your antenna, band by band. This is the vector part: no longer just «how much», but «which way».

measured SWR two compatible antennas
Resonant frequencyMHz Where the SWR touches its minimum: the point at which the antenna agrees with the radio.
BandwidthkHz How wide the bell around resonance is — how far you can move before the SWR gets worse.
Reactance XΩ  ± The vector quantity that gets determined, with its sign: it tells you whether the antenna should be shortened or lengthened. This is the thing a plain SWR meter cannot give you.
Resistance RΩ  ×2 Two values, not one: from SWR alone the two possibilities give identical curves (their product is always 2500), and picking one would be inventing. The app declares both.
Q factor×2 The steepness of the resonance, for the two candidates consistent with the resistance.
Reflection coefficient |Γ|0–1 The magnitude of the reflection, the radius of the circle on the Smith chart.
The sweep transmits. It is the only function of the app that goes on the air: it moves the radio in frequency and at every step sends a tone that brings the carrier out, to measure faster. It only starts if you start it, with the power you choose, and it puts the radio back where it was.
House rule

Numbers are never invented

An instrument that shows a plausible but false value is worse than one that says nothing. Decometer always prefers silence to invention.

— —

When the radio does not know

If a meter is not available, two dashes appear and the status line says why. No convenient number in place of data that is not there.

At rest, it stays quiet

With the transmitter idle the transmit meters do not read zero: a zero would say «no power, perfect SWR», which looks like a station working beautifully. Better nothing.

Freeze frame

The HOLD key freezes what you see: handy on the phone, where you look at the instrument after releasing the PTT, not during.

How it connects

No address to remember

1

On Decodium 4, on the PC, switch on the DecoPort gateway and choose a password.

2

The computer announces itself on the network: the radio appears in a list inside the app.

3

You tap it, type the same password, and from then on it reconnects by itself at every start.

Authenticated, never in the clear. The link is signed with a key derived from the password, which never travels. Nothing crosses the internet: without the password there is no connection, and on a port that exposes a radio that is no detail.
Become a tester on Telegram Get Decolink for the PC
Brochure

Download the brochure

Four panels: the meter face, the antenna analyser and every reading explained. PDF, ready to print.

Download the brochure (PDF)

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