Monthly Archives: January 2014

Making a crystal filter

A few weeks ago, I was given some hand-matched crystals at the radio club. My mission: to make a crystal filter for a Belthorn IF-module I’m going to build. Once again, something I’ve never done before. Let’s dive in with both feet.

To make a filter, there exist many software packages. I used Dishal from dj6ev, a windows program that luckily runs just fine under wine on Linux.

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N2PK Vector Network Analyzer

N2PK VNA under construction
This is a very interesting build. If I were to make it again, I would go for a dual detector and the fast ADC, but even with its slow measuring rate (7 measurements per second), it’s still a very interesting piece of equipment to have. It can be used to measure complex impedances of all kinds of circuits. Using a bridge (I still have to build mine), you can also check antennas, something I’m looking forward to measure. You can find N2PK’s project page for this instrument here.
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