How to Keep Your PC Clock Accurate for FT8 and Other Digital Modes

Why Precise Time Matters

Digital modes such as FT8, JS8Call, and WSPR rely on tightly synchronized time slots. If your PC’s clock drifts by more than a couple of seconds, you may miss decodes, transmit outside the expected window, or introduce logging errors. Maintaining accurate UTC alignment is essential for reliable weak‑signal digital operation.

Windows includes a built‑in time synchronization service (Windows Time / W32Time) that uses Network Time Protocol (NTP) servers to keep the system clock aligned. However, on a typical standalone PC, its default behaviour synchronizes time only infrequently (often on the order of days), which is insufficient for time‑critical digital modes.

This guide shows how to configure Windows to synchronize time much more regularly using standard, reliable NTP servers—without installing third‑party software—ensuring your station remains accurately synchronized for digital mode operation.

Step-by-Step: Configure Hourly NTP Sync on Windows

Step 1: Enable Internet Time Sync

This guide applies to both Windows 10 and Windows 11. The layout may vary slightly between versions, but the settings and PowerShell commands are the same.

Open Settings > Time & Language > Date & Time
Ensure the following options are enabled:
- Set time automatically
- Set time zone automatically
Scroll down to Synchronize your clock and click Sync now

This confirms that Windows is actively synchronizing system time and that the Windows Time service (W32Time) is functioning correctly.

By default, standalone Windows systems synchronize time using Microsoft’s public NTP service, time.windows.com. In the next step, we’ll configure additional NTP servers to improve reliability and prepare Windows for more frequent synchronization.

Step 2: Set Regular Sync Interval via PowerShell

By default, standalone Windows systems synchronize time only infrequently (typically once every few days). For digital modes such as FT8, this is not precise enough—PC clocks can drift several seconds over that period, leading to missed decodes or mistimed transmissions.

To improve accuracy, we’ll configure Windows to synchronize time much more regularly using its built‑in Windows Time service (W32Time). This provides regular, predictable corrections without installing any third‑party software.

Don’t worry if you’re not familiar with PowerShell—this step is simple and only requires copying and pasting a command.

Open PowerShell as Administrator

Press Windows + X
Select Windows PowerShell (Admin) or Terminal (Admin)
(The name varies slightly depending on Windows version.)
When prompted, click Yes to accept the User Account Control (UAC) prompt

A blue PowerShell window similar to the one below will open.

Next, we’ll copy and paste six PowerShell commands into the PowerShell window. Each command performs a specific task; they are safe to run and can be entered one at a time.

1. Set how often Windows checks the time.

This command sets a shorter minimum update interval of around 64 seconds.
Windows will usually start by checking the time more frequently (around once per minute), then automatically increase the interval as the clock stabilises to reduce network traffic and improve efficiency.

Copy the entire command below, paste it into the PowerShell window, and press Enter:

Set-ItemProperty -Path "HKLM:\SYSTEM\CurrentControlSet\Services\W32Time\TimeProviders\NtpClient" -Name "SpecialPollInterval" -Value 64

2. Configure which internet time servers Windows uses

This command sets the time servers your computer will use and enables a more accurate way of keeping time.
Windows will start by checking the time more frequently, then automatically adjust how often it synchronises as the clock becomes stable. This helps improve accuracy while reducing unnecessary network traffic. Multiple servers are included so your computer can stay synchronised if one is temporarily unavailable.