Find safe windows and coordinate channels

A safe window is a stretch of spectrum with nothing in it: no TV channel, no cellular block, no guard band, and — once you have imported a scan — nothing above the noise threshold. The packer then places your channels inside those windows.

Find the windows

1. Set the Region and pin a Manufacturer / Band overlay. Until you do, the windows panel shows Pick your hardware to see safe windows; you can still print the regional whitespace on its own.
2. In Safe Coordination Windows, set Min width (MHz) to the smallest gap worth your time. If nothing is left, the panel says No windows ≥ X MHz — lower the minimum width.
3. Sort Widest first (default) or Frequency ↑.
4. Each card shows the width, a Safe badge and ≤ n ch @ … kHz — the channel count at the packer's spacing. Click a card to highlight the window on the spectrum.
5. Press ↓ CSV to export the window list.

Windows only exist inside the ranges a region declares legal for PMSE. Where the tool has no data it suggests nothing, rather than offering a cellular band as free.

Coordinate the channels

1. In Coordinate N Channels, set N (channels) and the Channel spacing.
2. Press Coordinate. The status line reads X of Y placed. If it reads … try a larger spacing, the band ran out of room; widen the spacing or reduce N.
3. Edit rows by hand if you must — type a Frequency, then press Recompute to re-check intermod and ACR. + Add row appends a channel; the toast Band full means there is no room at this spacing.
4. Fill Talent, Role and Power (dBm) for each row. The power feeds the intermod estimate.

The packer rejects placements that fall on 3rd-order intermod products of the channels already placed. 5th-order products and TX-on-RX hits (a 3rd-order product landing on one of your receive frequencies) are drawn as flags on the spectrum, not excluded — read them and decide.

Check intermod by hand

The Intermod Calculator takes any list of frequencies and TX powers:

• Enter at least two frequencies (in MHz) and a power per source (in dBm). Press + Add for more rows, Clear to start again.
• 3rd-order products are always computed, including the three-transmitter A+B−C family. Tick Include 5th-order to add the 2A+B−2C and 3A−2B families.
• Hide products below −90 dBm trims the list to products that could plausibly reach a receiver.
• Products are marked with an arrow on the spectrum; the header says how many.