[ARC5] Drift in BC-453 - more

[Kenneth G. Gordon]

On 12 Dec 2017 at 14:32, MICHAEL ST ANGELO wrote:

> Bill,
> 
> What is this millihertz spec for WSPR? I haven't tried it yet but I
> thought frequexcy stavility has to be a couple of hertz for the 2
> minute cycle: 
> 
> <https://groups.google.com/forum/#!topic/2-meter-wspr/-hDK071K1iM>
> 
> Mike N2MS

Hi again, Mike. That spec is for 2 meters: it becomes far, far more critical at HF and MF. 
Yes. Millhertz.

Since, "Many WSJT-X capabilities depend on signal-detection bandwidths no more than a 
few Hz. Frequency accuracy and stability are therefore unusually important."

See this for details:

http://www.physics.princeton.edu/pulsar/K1JT/wsjtx-doc/wsjtx-main-1.8.0.html#GENERAL

In fact, someone on one of our lists mentioned something like <0.5 Hz drift in 2 minutes or 
less. I can't remember the details now, but his post included the link above. As I remember 
it, he also told us that if the drift exceeded what I mentioned above, that would prevent 
decoding of the input.

I know that Bill Cromwell noted enough drift from the very slight drift in filament voltage by 
line-voltage drift to cause very noticable drift. As he says, he decided to simply forego 
attempts to use those modes.

Although I am inclined to agree with him, I am very curious to learn if it IS possible to use a 
BC-453 for these modes. I would guess not, but stranger things have happened.

Ken W7EKB

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