Little bit of playing around with the IF stage today, finished the C++ code for the IF Shift feature – here is a short video listening to a QSO on 40 meters. A second video listening to Volmet on 5.450 and 5.505MHz, no BPF or preamp just random wire straight into first mixer.
Great to see the value being noted in the power of Amateur Radio, a quote from the article below; “People tend to think of (amateur radio) as a dying hobby. In fact, we’ve never had more (hams),” Gallagher said putting the number at 750,000 with an additional 30,000 every year.” https://www.nbcnews.com/news/latino/puerto-rico-amateur-radio-operators-are-playing-key-role-puerto-n805426 Great work guys.
Having noticed some serious performance issues with the first and second mixer filter stages, I identified the problem to be poor design choices and a lack of gain in the first IF stage. I have split the first IF mixer and filter and added a dual gate mosfet variable gain amplifier on the output side… Read More »
Guys, please don’t waste your time posting spam’ish comments about viagra, dodgy money deals and communist political campaigns – they will never appear on this site as each and every comment is moderated and requires my personal approval. 🙂
I have added a new domain to my web server host, this is more inline with the function of this website. Thew new address is: http://www.homebrewradio.uk however all the old links from http://vhfdx.org.uk should still work and will be redirected.
Recently I was drawn in the direction of a simulation software package called LT Spice, Pete Juliano N6QW uses it in several of his articles so I gave it a shot and not having used it before it was surprisingly easy to use. I modelled my original IF amplifier based on the Hybrid Cascode design… Read More »