Esa, I am back home now and can't access the amigazone files from my home IP. Can you provide access?
Thanks, Joe -----Original Message----- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Esa Heikkinen Sent: Monday, March 09, 2009 4:51 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] About HP10544A > Since retrofitting an improved oscillator circuit isn't really an option > you will need to filter the output to reduce the harmonic content. > Try a bandpass filter driven by the buffer and terminated in 50 ohms. Well I have to decide what to do, get another oscillator or try the filtering. The difference to another oscillators (like tbolt ocxo or LPRO) is so huge that I do not know how hard it would filter the 10544A to the same level, which parts to use and how much it will cost. > Should you retrofit an improved oscillator circuit you may as well > replace the oven controller to eliminate the oven switching frequency > related sidebands. Infact the switcher sidebands are now gone: http://www.amigazone.fi/files/gpsdo/544-13.png http://www.amigazone.fi/files/gpsdo/544-14.png It was like thios earlier: http://www.amigazone.fi/files/gpsdo/544-1.PNG http://www.amigazone.fi/files/gpsdo/544-2.PNG It was easier than I expected... When I took the output directly from OSC pins without using the coax connector like you suggested the switcher peaks was gone! So I had a closer look to the PCB today and noticed that it has only 2 layers and the ground net is too thin and goes around PCB totally wrong way so that switcher current seems to flow via the signal flow. It's PCB layout design fault, I think that with correct layout design this could be done even with 2-layer PCB correctly. But this is not a problem of course because I will design my own PCB for the final system anyway, having SMA connectors for 10 MHz and EFC. I'll also create separate power supply for ovens and signalling stages. -- 73s! Esa OH4KJU _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.