Message	Date	From	Subject
101	2006-08-22 14:21:55	jim.scott@scottel...	RF Design Procedures Step by Step?
** Reply to note from Russell Shaw <rjshaw@netspace.net.au> Sat, 19 Aug 2006 10:03:05 +1000 I've been experimenting with the BFR-90 (5GHz-ft) used as a CC Colpitts osc. I thought I could build a free running oscillator and pull it to frequency using a crystal in the feedback path - Emitter to center of the series cap network. Well, it works to a degree, but ends up off frequency, and I apparently need a tutorial on just what I'm doing. IN addition, it may not start, I thought that if the fundamental osc frequency was at 217-218 MHz, I could use a crystal with a 3rd overtone at 72 MHz, won't odd multipliers work? Then double to get to 440MHz I have a couple of books that I have referenced, but not spent time doing all the exercises - so I guess I'm at that dangerous stage. Operative word above is experimenting. My background is not RF design, but low frequency design, and I'm just becoming familiar with this stuff. I do need the basic arm waving pointers, to help me simplify my life. Perhaps there is a procedure outline with example to do basic RF design? Any help? Thanks in advance. Jim Scott WB0IYC Joplin, MO

** Reply to note from Russell Shaw <rjshaw@netspace.net.au> Sat, 19 Aug 2006 10:03:05 +1000

I've been experimenting with the BFR-90 (5GHz-ft) used as a CC Colpitts osc. I thought I
could build a free running oscillator and pull it to frequency using a crystal in the feedback
path - Emitter to center of the series cap network.

Well, it works to a degree, but ends up off frequency, and I apparently need a tutorial on
just what I'm doing. IN addition, it may not start,

I thought that if the fundamental osc frequency was at 217-218 MHz, I could use a crystal with
a 3rd overtone at 72 MHz, won't odd multipliers work? Then double to get to 440MHz

I have a couple of books that I have referenced, but not spent time doing all the exercises -
so I guess I'm at that dangerous stage.

Operative word above is experimenting. My background is not RF design, but low frequency
design, and I'm just becoming familiar with this stuff. I do need the basic arm waving
pointers, to help me simplify my life.

Perhaps there is a procedure outline with example to do basic RF design? Any help?

Thanks in advance.

Jim Scott
WB0IYC
Joplin, MO