tag:blogger.com,1999:blog-7590176649168185428.post8686493844254771277..comments2024-03-29T07:34:28.586-04:00Comments on SolderSmoke Daily News: The Parasaki: DL3PB's Amazing All Diode TransceiverBill Mearahttp://www.blogger.com/profile/07662500663603350847noreply@blogger.comBlogger3125tag:blogger.com,1999:blog-7590176649168185428.post-31611454873373868182017-10-04T01:44:38.300-04:002017-10-04T01:44:38.300-04:00Mesmerized article written on this blog with other...Mesmerized article written on this blog with other relevant information. It is straight to the point that how we can improve our skills as well as how we can be represented to a new stream of professionalism.<br /><a href="http://www.ledinfinite.com/" rel="nofollow">หลอด led</a>Baker Axtonhttps://www.blogger.com/profile/15457450069709807860noreply@blogger.comtag:blogger.com,1999:blog-7590176649168185428.post-20092781442974817832012-02-10T13:08:56.251-05:002012-02-10T13:08:56.251-05:00Hello OM Bill,
thanks a lot for posting my story -...Hello OM Bill,<br />thanks a lot for posting my story -<br />only could you please correct my<br />callsign in the headline on occasion.(DL3PB)<br />Meanwhile received an mp3 file of our QSO from Chris - my signal was weak, but not too hard to copy.<br />Keep up your great blog/podcast.<br />73<br />Peter/DL3PBAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-7590176649168185428.post-5231809331720373532012-02-10T11:14:20.957-05:002012-02-10T11:14:20.957-05:00Bill,
I read about your problems with power ampli...Bill,<br /><br />I read about your problems with power amplifier stability in the blog and wanted to tell you a bit about parametric oscillation but it is not an easy topic to explain in a short comment. Fortunately this post contains a link to Mike, AA1TJ's article on the "Paraceiver". http://fhs-consulting.com/aa1tj/paraceiver.html In that link is the clearest and best explanation of the phenomenon that I have ever seen. Read Mike's article and visualize an RF power amplifier: the pump source is the RF drive to the PA, The time varying capacitive reactance is provided by the collector-base junction of the power transistor and the series tuned resonators (or idlers) are stray resonances in the output impedance matching and DC feed circuits.<br /><br />The DC feed choke and bypass capacitor can provide a low frequency idler, and stray resonances reflected from the output circuits can provide a higher frequency idler. If the sum of these two idler frequencies equals the pump frequency you can get parametric oscillation. It is hard to track down because it is not due to classic feedback and you have to think differently about it. Strategically placed ferrite beads can certainly help because they can "de-Q" the idlers.<br /><br />Thanks to Mike for a very readable explanation of parametric oscillation.<br /><br />Paul W2IOGAnonymousnoreply@blogger.com