Return to KLUBNL.PL main page

rsgb_lf_group
[Top] [All Lists]

LF: RE: Ionospheric doppler ?

To: [email protected]
Subject: LF: RE: Ionospheric doppler ?
From: Alberto di Bene <[email protected]>
Date: Tue, 09 Mar 2004 16:29:59 +0100
In-reply-to: <[email protected]>
References: <[email protected]> <[email protected]>
Reply-to: [email protected]
Sender: [email protected]
User-agent: Mozilla/5.0 (Windows; U; Win98; en-US; rv:1.4) Gecko/20030624 Netscape/7.1 (ax)
Thanks all for your comments.

The clock has an analog part, the receiver, with a very small ferrite
antenna, and a large black wax blob on the PCB, with many traces
reaching it. Usually this is the low cost "packaging" of an IC, which
probably is a sort of simplified microcontroller.

But it turned out that Andy and Johan were right.  I did what I should
have done since the beginning, and what I usually do when building
an oscillator to test its stability : the "blow test".

I blowed for 20 seconds on the exposed components of the clock,
and the result was a change of more than one microsecond....
so the 1pps signal is not derived directly from each pulse of DCF-77,
but from the internal oscillator, corrected every now and then with
the received signal...

I think I can use it as a high sensitivity thermometer, to measure
fractional degree changes in the temperature of my shack  :-)

73  Alberto  I2PHD





<Prev in Thread] Current Thread [Next in Thread>