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swharden / FSKview

A high resolution spectrogram for viewing FSK signals in real time
https://swharden.com/software/FSKview
MIT License
13 stars 5 forks source link

FT4/FT8 audio frequency offset #32

Closed K4RCG closed 4 years ago

K4RCG commented 4 years ago

image

Scott, attached is a screenshot. The Callsigns are listed but unable to "link" them to a trace.

Bob K4RCG

swharden commented 4 years ago

Hey Bob! I took a closer look and think I figured it out. Let's use this log line as an example

191010_125753    14.080 Rx FT4    -10 -0.1 1730 AI2I KM4UJI -17
                 ^^^^^^                    ^^^^

The first frequency is the dial frequency in MHz. This is what FSKview is currently using for each FT4/8 frequency. However, the second frequency indicated is the audio frequency in Hz. For FT4/FT8 logs (as opposed to WSPR logs) the actual frequency should be:

14.080 MHz + 1730 Hz = 14,081,730 Hz

I updated FSKview to add these two numbers together and display the label at that frequency. Let's see if this works! 🤞 I made a new version of this program containing this change: https://swharden.com/software/FSKview/downloads/FSKview-1.0.9.zip

Let me know if this works for you!