It’s been along time since my last update, but I’ve managed to measure the magnetron spectrum output using a Signalhound. I sent an email to Signalhound and this was their reply:
For quick hoppers (FHSS), you will probably need to turn image rejection off to catch the signal. This will speed up the sweep but will also pass the image frequency (21.4 MHz below frequency of interest). If you turn video bandwidth down to 6.5 KHz and RBW to 25 KHz, Power Average mode, then turn on Max Hold, you should be able to capture and measure the signal.
These suggestions pointed me in the right direction to get the Signalhound working the way I wanted. Unfortunately I think the signal is very rapidly changing frequency so the max hold suggestion is the only way to see the signal.
A friend stopped by this weekend and dropped off some fun toys.
He needs a frequency locked 1000W 2.45GHz signal based on a microwave magnetron. I like the magnetron solution because it’s a cheap way to generate such a high power RF signal but they wander between 2.42GHz and 2.48GHz which is a problem for his application. I have volunteered to help him figure out a method to lock the output frequency. I think it will make a great writeup for the blog since I expect it will take a significant amount of reverse engineering and experimentation to make it work.
Here are pictures of some the cards I worked on for the Scuba2 telescope. These cards were part of the electronics package used to measure the telescope sensor array. Both of them are based around the now ancient Altera Stratix FPGAs. The card below was the controller for the whole package. This card has 2 FPGA configuration memories to make sure it could still boot if a remote update failed.