For many years, I’ve been looking for a spectrum analyzer. These devices are usually very expensive, but recently I was lucky on ebay and won a fantastic device - the HP 8561B.
The HP 8561B is a professional spectrum analyzer which sold at around 50k Swiss Francs about 20 years ago. It can measure signals from 50 Hz to 6.5 GHz. My unit includes the option 003, called the “10 MHz precision frequency reference”, and the HP 85620A “mass memory module”. The device is in great shape. It shows no errors and the picture tube is still brilliant.
There are many spectrum analyzers on ebay at affordable prices at the moment, even more so as the USD is now relatively cheap compared to the Swiss Franc. Many of them are HP 8560 and 8590 series analyzers, while there are more of the 8590’s around and they seem to be more recent. However, after reading web sites and forum entries for a few weeks, I’ve decided to go for an 8560 series device. They may be older, but their frequency stability seems to be better.
My Spectrum Analyzer
I didn’t have much time to test the device yet, but what I already tried was the integrated FM demodulator. In the video below, see how it demodulates a radio frequency at around 101 MHz.
Of course, the next step is to check the output of my 1P24B transmitter.