It would be interesting to have the details of the frequency measuring
setup for the stations measuring with the 1 Hz error. Is there a
common factor?
DaveB, ZL3FJ
----- Original Message -----
From: "Gary - G4WGT" <[email protected]>
To: <[email protected]>
Sent: Thursday, June 08, 2006 8:46 AM
Subject: LF: RE: Re: RE: BBC 198kHz
Hi Peter,
I have carried out the same comparisons again ie. 60KHz, 75KHz &
77.5KHz
against 198KHz & BBC 198KHz is 1Hz high, tested at 2035z. Could
there be an
error in respect of the frequency difference in the receivers band
set up
although I believe the range is in the same band on my JRC NRD-345.
When
compared with DFC39 (accuracy of this station not known to me) there
is a
difference of 0.5Hz. Is there another accurate signal nearer 198KHz
with
which to compare?
73,
Gary - G4WGT
-----Original Message-----
From: [email protected]
[mailto:[email protected]]On Behalf Of Peter
Martinez
Sent: 07 June 2006 21:20
To: [email protected]
Subject: LF: Re: RE: BBC 198kHz
From G3PLX:
On seeing the report of Droitwich being off frequency, I connected
up my
Clicklock set-up, which enables me to measure off-air signal phase
relative
to GPS.
I have to run the system with no antenna in order to get Droitwich
low
enough in level, and that makes the measurement a little sensitive
to
disturbances in the shack, but this is a disturbance in both
amplitude and
phase, and it's quite easy to see that the few degrees wobble I am
seeing in
the phase is the same as the wobble in amplitude, and is not due to
a
systematic drift in phase. A random distrbance results in a blob on
the
vectorscope. A frequency error shows as an arc around the origen.
If it had been 1Hz off, I would have expected to see a change of 360
degrees
PER SECOND, i.e. a full circle rotating once/sec. All I can see is
a
circular blob about 2% amplitude, and that's over the last 20
minutes.
I would say Droitwich is spot-on. Has anyone who saw it off
frequency
checked it again (since 20:00 utc) to see if it's back on frequency?
Was it
off frequency and it's back again, or maybe it was never off.
73
Peter
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