Well,
Following on from the success of last time; it was time to make some filters around the 146.5 MHz DATV frequency on the NoV allocated bit of spectrum we have above the 2M band.
I've also built up a kit I have had here for a while, it's a PGA144 from G4DDK.
So at the top we have the PGA144, middle is the LPF and bottom is the BPF. The designs are really quite simple - just ask if you need the details. Here's the spectrum from all three:
The yellow is the PGA144 - it has a 20dB attenuator at the input so the signals are actually 20dB higher than shown - the gain at 145MHz is exactly 20dB.
The purple is the LPF being swept and looks just fine.
The Blue is my BPF which I am very pleased with - it looks great.
So next will be a 60W "brick" amplifier for 146.5 MHz - waiting for the bits but I have to go work in foreign parts for a week or two so will pick this up on my return.
Local conditions.
Following on from the success of last time; it was time to make some filters around the 146.5 MHz DATV frequency on the NoV allocated bit of spectrum we have above the 2M band.
I've also built up a kit I have had here for a while, it's a PGA144 from G4DDK.
So at the top we have the PGA144, middle is the LPF and bottom is the BPF. The designs are really quite simple - just ask if you need the details. Here's the spectrum from all three:
The yellow is the PGA144 - it has a 20dB attenuator at the input so the signals are actually 20dB higher than shown - the gain at 145MHz is exactly 20dB.
The purple is the LPF being swept and looks just fine.
The Blue is my BPF which I am very pleased with - it looks great.
So next will be a 60W "brick" amplifier for 146.5 MHz - waiting for the bits but I have to go work in foreign parts for a week or two so will pick this up on my return.
Local conditions.
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