Hi Willi: Thanks for that very nice detailed description. I am not quite sure if the thermistor is the problem, but your description should help me to track down the culprit that causes the short term drifting between TX and RX
Thanks Again Brian K7RE Willi Reppel wrote: > Peter, > > You wrote: > >> I am not sure where the power for the heater on the 200MHz oscillator >> come from >> > > I bought a new 1 W SDR1000 last month before the announcement about > the 100 W-only version came. > I disassembled the unit to have a look at the termistor. It is a small > disk of approx 8 mm diameter and 2 mm thickness which is soldered or > glued with a conductive compound on to the case of oscillator QG1. A > wire is soldered to the top of the disk which is connected directly to > the terminal strip and + 13.8 V dc. The grounded case of the crystal > oscillator serves as return pass and minus. It seems to be a combined > heater / termistor with approx 50 ohm att room temp. and 150 ohm at > operation temp. > Hope this sheds some light upon how the preheater / termistor is fed. > > groeten van > > SM6OMH Willi > > ----- Original Message ----- From: <[EMAIL PROTECTED]> > To: "Brian Kassel" <[EMAIL PROTECTED]>; <flexradio@flex-radio.biz> > Sent: Saturday, January 06, 2007 11:09 PM > Subject: Re: [Flexradio] More Strange Frequency Drift Problem > > >> I am not sure where the power for the heater on the 200MHz oscilator >> come from >> >> power to the 200MHz oscilator: >> PIOboard [AVDD] IC9(TPS76833) pin5+6 to interconnect pin 10 >> TRXboard power to 200MHz oscilator pin14 [AVDD] J7pin10 (interconnect) >> interconnect J7 is a 12 pin connector >> >> I hope it helps you >> 73 peter pa0pvn >> >> groeten Peter >> petervn(a)hetnet.nl <mailto:[EMAIL PROTECTED]> ; pa0pvn(a)hetnet.nl >> <mailto:[EMAIL PROTECTED]> ; >> pa0pvn(a)gmail.com ; pa0pvn(a)amsat.org . >> >> >> ________________________________ >> >> Van: [EMAIL PROTECTED] namens Brian Kassel >> Verzonden: za 6-1-2007 22:16 >> Aan: flexradio@flex-radio.biz >> Onderwerp: Re: [Flexradio] More Strange Frequency Drift Problem >> >> >> >> Folks: >> >> Can someone tell me where the regulated voltage for the 200 MHz. >> oscillator comes from? It isn't clear to me in the schematic. I am >> investigating a 22 HZ oscillator frequency change from TX to RX that >> occurs in the first 10 seconds, then stabilizes to less than 1 Hz >> change. . Temperature doesn't seem to be the culprit, and as far as I >> can see, there is no switching or changing of loading on the >> oscillator between TX and RX. >> Still fighting the uphill battle to determine my frequency shift >> problem. >> >> Brian K7RE >> >> >> >> _______________________________________________ >> 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 Homepage: http://www.flex-radio.com/ >> >> FlexRadio Knowledge Base: http://kb.flex-radio.com/ >> >> >> -------------- next part -------------- >> An HTML attachment was scrubbed... >> URL: >> http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/attachments/20070106/87177bc4/attachment.html >> >> >> _______________________________________________ >> 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 Homepage: http://www.flex-radio.com/ >> >> FlexRadio Knowledge Base: http://kb.flex-radio.com/ >> > > > > _______________________________________________ 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 Homepage: http://www.flex-radio.com/ FlexRadio Knowledge Base: http://kb.flex-radio.com/
