Alberto et.al. What do you think about this part? It is about $17 new.
http://www.cmac.com/mt/news/cfpt-125.html Thanks Eric2 -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Alberto I2PHD Sent: Saturday, November 26, 2005 10:58 AM To: FlexRadio@flex-radio.biz Subject: Re: [Flexradio] ebay 10MHz-OCXO- Ray J wrote: > with all the talk of frequency stuff lately.... found this on ebay while > looking around.. > don't know if its useful to any of the experimenters out there.... > > Isotemp model OCXO134-10 10.000000MHz OCXO $75 > > http://cgi.ebay.com/New-Isotemp-10MHz-OCXO-1PPB-EFC-For-GPS-Discipline-12V_W 0QQitemZ5833990844QQ Hmmm, I bought one of those OCXO three years ago. I paid 25 USD (one third of that price) and used it to build a GPSDO. It works, but you cannot do better than a few parts (2 or 3) over 10^11, which can be a superb result, depending on your goals... The problem with that OCXO is that its oven regulation has a periodic temperature change of about 0.2 degrees Celsius peak-to-peak, with a period of about 6 or 7 minutes. That period is too fast for the PI controller implemented in the Atmel AVR, which, after the initial transient period, has time constants in the order of more than one hour. So the frequency change caused by that variation in temperature goes almost uncorrected, causing that 2 or 3 part over 10^11 of frequency "pendulum" I have graphed it, you can see it here : http://sundry.i2phd.com/Lock3be.gif Of course, it could be that only my specific Isotemp OCXO had this problem, and other units work well. Anyway, my next GPSDO will make use of a double oven 10811... I found one brand new, still in its box...: 73 Alberto I2PHD _______________________________________________ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz
