tag:blogger.com,1999:blog-3380839830287420877.post2848757601889993631..comments2024-02-29T17:45:10.880-08:00Comments on VE7SL - Steve - Amateur Radio Blog: Summer SMT ProjectSteve McDonaldhttp://www.blogger.com/profile/06229640265009249231noreply@blogger.comBlogger2125tag:blogger.com,1999:blog-3380839830287420877.post-12710463099829227212016-08-28T11:25:19.801-07:002016-08-28T11:25:19.801-07:00Tnx for your input. I do agree with your comments ...Tnx for your input. I do agree with your comments and the need for more filtering. I will study your suggestions and add them to my growing list of notes regarding 'ways' to improve the outcome!Steve McDonaldhttps://www.blogger.com/profile/06229640265009249231noreply@blogger.comtag:blogger.com,1999:blog-3380839830287420877.post-10285472906040235232016-08-28T08:58:16.498-07:002016-08-28T08:58:16.498-07:00Hi Steve
Potentially lots of problems with that s...Hi Steve<br /><br />Potentially lots of problems with that schematic. A diode doubler better needs a higher output impedance -- usually an RFC to ground, then we'll often run an BJT amp with collector tuning to remove any extra frequencies. Also , after a diode ring, we would normally place a band-pass filter [although a low-pass can work depending on the frequency scheme ] , then an amp to drive the diode doubler.<br /><br />1 strategy is to mix your signal to 4X F, , then after the mixer, ply a band-pass filter and then drive a simple transistor switch set up for CMOS drive levels. Then drive a D-flip flop like the HC7474 to get a perfect 50 50 duty cycle square wave at half the input frequency. A Gilbert cell mixer seems perfect for what you are doing -- gives some conversion gain and cheap.<br /><br />My 2 cents<br /><br /><br /><br />Anonymousnoreply@blogger.com