开云体育

ctrl + shift + ? for shortcuts
© 2025 开云体育
  1. HABalloon
  2. Messages
Single Messages Topics Expanded Polls

Re: Unable to Decode WSPR Generated by SI5351 Project

 

Hello Jeff.
About the TX frequency, you must set it somewhere between 14097000 and 14097200, in these 200 Hz bandwidth reserved for WSPR transmissions.

The one who could mislead you is the so-called "dial frequency" that is 14095600 for WSPR on the 20 meters band.
But, what does it mean "dial frequency" ?
It means the frequency you set on your radio display, so that is the frequency "where the USB zero starts".
Let me explain: when you set your radio to receive digital signals in the USB (Upper Side Band) the radio itself set the receiving band of 3000 Hz from "dial frequency"? ?to? ?"dial frequency?+ 3000 Hz".

So, if you set dial frequency to 14095600, as per my suggestion, your radio will have a bandpass from? 14095600? to? 14098600 Hz.
Well, the center of this range (14095600? to? 14098600) is exactly in the middle, or rather 14097100.? So, the WSPR range is exactly 14097100?+/- 100 Hz, meaning? 14097000 to 14097200.
This last range (14097000 to 14097200) is EXACTLY where the software WSJT-X (or another wspr decoder if any) will look at to find any wspr signal!

Hope this helps.
Enjoy your balloons!

73 de IZ7VHF
Roberto

?



Il giorno mar 30 mar 2021 alle ore 23:54 <groups.io@...> ha scritto:
Hi Mikael,

Thanks for your time.? I think the xo speed was a good hint.? I'm doing a mock-up using the Adafruit SI5351 breakout board.? The board has a 25MHz TXCO, but I noticed that the HABalloon code was set for 27 MHz.? So I made that correction.? Also, someone mentioned that my signal seemed off target frequency, so I looked through the code and found WSPR_FREQ set for 14000000 MHZ, so I adjusted that to be 14095600.? Now I get a signal that seems to be in the filter frequency path.? I believe it may be WSPR, but not sure as I can't seem to find a good Waterfall diagram of a WSPR signal, online.

Still not decoding in WSJTX, however.? Looking at the waterfall, it appears to me that I may be overdriving the receiver, particularly considering the receiver and SI5351 are directly connnected, no antennas.? I'm going to try an attenuator and see what happens.

In the mean time, here are some updated pics of waterfalls.? Thanks for your time.

TY,
Jeff

Join [email protected] to automatically receive all group messages.