[time-nuts] Temperature sensors and bridge amps
alan.melia at btinternet.com
Mon Nov 15 19:18:36 UTC 2010
Maybe the same things Harry ?? The advantage of latching relays is that they
maintain the position (EFC) if you lose the command link. You cant hear the
"clicks" in Space
----- Original Message -----
From: "Harry Brown" <harryhbrown at earthlink.net>
To: <richard at karlquist.com>; "Discussion of precise time and frequency
measurement" <time-nuts at febo.com>
Sent: Monday, November 15, 2010 7:00 PM
Subject: Re: [time-nuts] Temperature sensors and bridge amps
> Back in the early 80's I was working for a company making military
> communication satellites.
> The 5 MHz Oscillators used on the satellite were in a double oven keeping
> the oven temp within 0.001 Hz C.
> We could adjust the oscillator frequency for aging by ground commanding a
> bank of relays controlled a D/A converter to adjust the oscillator
> Lots of fun back then.
> Any idea what is used now?
> 73, Harry, W3IIT
> ----- Original Message -----
> From: "Richard Karlquist" <richard at karlquist.com>
> To: <time-nuts at febo.com>
> Sent: Saturday, November 13, 2010 10:48 AM
> Subject: Re: [time-nuts] Temperature sensors and bridge amps
> > The HP E9183A achieved 1 millidegree over -55 to +85C
> > in a single oven. The time lag was dealt with by adding
> > a double integrator to PID.
> > Rick Karlquist N6RK
> > On Fri 12/11/10 8:26 AM , "Bill Hawkins" wrote:
> > in the heater control loop. Of course, you can't get to a
> > millidegree from ambient with just one oven. And you can't
> > eliminate time lags if you have any thermal mass.
> > _______________________________________________
> > time-nuts mailing list -- time-nuts at 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 at febo.com
> To unsubscribe, go to
> and follow the instructions there.
More information about the time-nuts