Winter is approaching ladies and gentlemen, and it is time to think about radio projects. Bob N7SUR suggested a direct conversion receiver project. I think this is a great idea. As a kid, I had fallen victim to the idea that building receivers was "too hard" for radio amateurs. Not true! DC receivers to the rescue! Carry on with the DC revolution first launched by Wes W7ZOI in 1968.
Pete N6QW is providing guidance and tribal knowledge via his blog. For those of you who want to join the ranks of those who have defied the conventional wisdom and have broken through the "receivers are too hard" barrier. I say build yourself a DC receiver. Build it from scratch. Many of you already got your feet wet in homebrewing with the Michigan Mighty Mite project. Now it is time to jump into a DC receiver project.
You folks already know what kind of VFO Pete will prefer: It will be an Si5351. That's fine. But I will try to keep the banner of discrete component analog ludite-ism flying high. This morning I ordered a batch of 7.37 MHz ceramic resonators. I hope to pull them down into a significant portion of the 40 meter phone band. If this works, I will share the batch with anyone who wants to joining my Analog Army (remember the CBLA?). Note (above) that Pete has magnanimously left open the possibility of using a non-digital VFO. What a guy!
Check out Pete's project here:
http://n6qw.blogspot.com/2017/08/a-new-line-of-transceivers-difx_19.html
Arrow.com has 7.200MHz and 7.159MHz ceramic resonators too! I bought a handhful each.
ReplyDeletehttps://www.arrow.com/en/products/cstls7m20g53-a0/murata-manufacturing
https://www.arrow.com/en/products/cstls7m16g53-a0/murata-manufacturing
SOme other hamband ceramic resonatrs they stock are:
https://www.arrow.com/en/products/cstls7m37g53-b0/murata-manufacturing
https://www.arrow.com/en/products/hwzt-3.58md/abracon
https://www.arrow.com/en/products/cstls3m58g53-b0/murata-manufacturing
Apparently at 20usd you get free overnight shipping. And it worked for me across the pond, took two day tho.
de OH2FTG
Bill, you're not suggesting us Si5351 fan boys use a VXO? Almost sounds like sacrilege. Oh, alright, maybe we could try something a little more analog like...Hey Pete, how about using PWM on an Arduino to generate an analog voltage to tune a VXO. We might be able to get precise tuning steps and some kind of feedback to keep the frequency stable. We could still claim that it is analog tuned!!!
ReplyDelete73's
Dean AC9JQ
Of course, it probably wouldn't work because there would only be 256 tuning combinations....not very continuous..
DeleteBill,
ReplyDeleteFYI. Cecil K5NWA (The Parts Place) has come lower freq. ceramic resonators at 7.16, 7.2, 7.28 MHz to get lower in the band. These have a bit more delta freq. using a capacitor vs. varactor diode. I bought some a few weeks ago for a (currently unfinished) DSB rig.
73 Walt/K3ASW