Now fixed, i don't have a heartbeat coming from the module, but thats because the GPS module is too close to the U3 and also there is a lack of pull up resistors between the 3.3v and TX pins. both these issues I will fix this week
Another point and is based upon many questions i am getting about the module is what antenna am I running. Well its simple Im using my main shack antenna - this being the MQ26-SR. With the calculated output of the WSPR module(288mW) and the ERP figures of the antenna (6dB), the grand ERP will be about 1.1W-ERP
This 1.1W ERP would account for how well the little module is doing. I have since corrected the DDS instability, by adding a heatSink, only the clock update and calibration need sorting - these both will be corrected when I sort out the GPS module.
This map shows a 8 hour transmission period, transmitting once every 4 minutes. No calibration is done as the GPS module is disconnected. I manually set the Reference oscillator by transmitting a 14Mhz signal and measuring the output on the Oscilloscope. I made the change to the oscillator by making adding the difference to the Ref. Oscillator of how much it was off by. (in my case just 163Hz)
Anyway here is a quick tour around the unit. This video was taken and made before I realised i had the GPS wired up wrong, and before I corrected the instability of the DDS module.
No comments:
Post a Comment