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Showing posts with label BATC Portsdown filters. Show all posts
Showing posts with label BATC Portsdown filters. Show all posts

Thursday, 20 July 2017

First On-Air Test Complete

Well,

Thanks to the help of Col, G4OHV I have tonight tested my Portsdown transmitter on air.


Here's the video Col captured of my TX - Thanks!

Good, egh?

Saturday, 3 June 2017

Filters Filters Filters

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.