Hi All,
I've just completed my 30M QCX and I have to pass my complements on a most excellent kit! I documented the build on my blog here:?
I am curious over the output power measurements and I have uploaded a Photo into the album "G0MGX" in the photos section.
The screen grab from my 'scope shows the following:
Yellow - pin 3 of IC3; this is the input to the PA transistors and measures 7.2Vpp of a bit less (6.5Vpp) with 'scope bandwidth limited to 20MHz
Light Blue - this is the input to the LPF and measures 56.8Vpp but obviously includes lots of harmonics and unwanted products
Purple - this is the output from the LPF and measures 35.6Vpp which is about 3.2W (ish)
Dark Blue - this is the output measured at my 50R termination; very close to the Purple above.
If I look on my Spectrum Analyser then there is no loss in the 10MHz signal through the LPF, the higher readings on the input are due to other rejected products.
Are these in the correct ball park or am I low on power out?
Thanks
Mark
G0MGX
Mark