At 12:39 PM 6/2/2007 -0400, you wrote: >Asking for an opinion. Instead of using a OCXO, just leave the SDR1K >powered up 24/7. Isn't the stability just as good? OR, is even tighter >better? > >Phil
Hi Phil, I checked the stability of the SDR1K several times ... nothing scientific .... Here is how I did it: I tuned the the SDR1K to a frequency standard like WWV on 10mhz or 15mhz from a cold start (my shack is rather cool at just under 70 deg F) I also fired up MixW and clicked on the carrier while in PSK mode with an audio frequency of 1500hz with AFC engaged. The AFC in MixW will follow any drift with a direct readout in hz. I plotted the drift at 5 min intervals. The result is that there is fast drift (my SDR1K) up in frequency for the first 15 minutes ... in fact the drift is so fast that there is a perceptible 'lean' to the WWV carrier on the MixW waterfall trace. After 15 minutes the 'lean' in the trace is no longer perceptible .... the drift has slowed down to about 5 hz per minute to the 30minute mark. From the 30min mark to the 45min mark the drift still continues (in the same upward direction) at a decreasing rate. After 45 minutes there is no perceptible drift for any period of time. The total drift from cold start to complete stability (45 min later) is about 170 hz. For my general application (digital and CW) there is no drift after 45min. Knowing this I fire up and shut down according to my operating habits ... no need for 24/7. PS For general information .... I originally purchased the SDR1K barefoot (1w) and used it to drive the PA section of an old tube rig which worked fine. With the discontinuation of the SDR1K I broke down and purchased the 100w solid state amplifier and installed it .... I have to say it works wonderfully. I have it and the 35amp power supply installed in the closet in the spare bedroom behind the wall of our computer room. My desk looks exactly the same as the xyl's .... everything is controlled by the computer/sdr1k ... including antenna switching etc. (no fan noise hi hi) I did a stability run with the new arrangement and found it to be identical to previous stability test runs. Jim, VE3CI _______________________________________________ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Knowledge Base: http://kb.flex-radio.com/ FlexRadio Homepage: http://www.flex-radio.com/
