tag:blogger.com,1999:blog-7396057548824140336.post1931875051144126866..comments2023-07-31T22:42:16.719-07:00Comments on WA0UWH - Electronics & HAM Radio Blog: AutoDyne Receiver ProjectEldon R. Brown SRhttp://www.blogger.com/profile/16271671761017534867noreply@blogger.comBlogger4125tag:blogger.com,1999:blog-7396057548824140336.post-5655007285731840672016-05-27T09:12:01.128-07:002016-05-27T09:12:01.128-07:00Thanks Greg, for the interesting updates of your p...Thanks Greg, for the interesting updates of your project and the use with the counter. I may revisit this circuit to do something similar. Eldon R. Brown SRhttps://www.blogger.com/profile/16271671761017534867noreply@blogger.comtag:blogger.com,1999:blog-7396057548824140336.post-88702100901251873942016-05-27T09:06:05.001-07:002016-05-27T09:06:05.001-07:00Thanks Greg, for the interesting updates of your p...Thanks Greg, for the interesting updates of your project and the use with the counter. I may revisit this circuit to do something similar. Eldon R. Brown SRhttps://www.blogger.com/profile/16271671761017534867noreply@blogger.comtag:blogger.com,1999:blog-7396057548824140336.post-27285113253920527652016-05-27T07:29:06.082-07:002016-05-27T07:29:06.082-07:00Greg Morris here again (as unknown, above).
I cont...Greg Morris here again (as unknown, above).<br />I continued tweaking the circuit, using an air-variable cap for C6, and using one of the Radio Shack 9V pocket amplifiers (based on the LM386) at the output of the on-board LM386 to really boost the audio. One possible improvement would be to use the leftover transistor in the CA3146E (or equiv.) as a preamp, so the unit doesn’t require an external amplifier.<br />I am getting much better results. The LO output *does* track the received station, as described by Nick (see link in article). I can usually hear WWV or WWVH, sometimes both at the same time. I was able to use the LO output to also tweak my home-built ARRL frequency counter (needed more localized supply filtering) and so now I have achieved the goals I set out to accomplish with this unit. I more than doubled the sensitivity of the frequency counter 10 MHz front-end, improved the stability of the 550 MHz front-end, and got it calibrated within a Hertz or two.Unknownhttps://www.blogger.com/profile/04123001715702917691noreply@blogger.comtag:blogger.com,1999:blog-7396057548824140336.post-70215713858246583362016-05-18T21:21:01.639-07:002016-05-18T21:21:01.639-07:00I found this autodyne circuit a couple of weeks ag...I found this autodyne circuit a couple of weeks ago. I've been looking for a reasonably-accurate frequency reference to calibrate my frequency counter. I had a PCB made, and put it together. My circuit uses a CA3146E which I found on eBay. I am using the original design by K7QO & VE3DNL, which can be found on the Brainwagon site.<br />I used a different L1 at first, and the oscillator would not run. Reducing the value of R1/10K fixed that, but I ended up adding a regulated 12V supply instead.<br />I can hear some beats at certain settings, but no modulation at all. This is with a 1/2 wavelength dipole through a commercial 300-75 ohm balun. Amplified LO output is 150mV-PP, not enough to trigger my 1989 ARRL Handbook frequency counter. So thus far it has been a total waste of time. If anyone else has suggestions for improvements, I'd love to hear 'em.Unknownhttps://www.blogger.com/profile/04123001715702917691noreply@blogger.com