[Lf] Re: Spectran

[Frank Gentges]

Alberto,

Good to hear your on the LF reflector.  Hope our chatter doesn't fill up 
your box too fast.  Further discussion and testing over here shows that 
Spectran has an error of 6 Hz on my IBM ThinkPad Notebook.  I suspect it 
is a sampling rate error.  An adjustment factor to compensate from 
computer to computer would be useful.  In the mode we use now that error 
is taken out with the receiver adjustments.

Frank K0BRA


On Sun, 9 Jan 2000, Alberto di Bene wrote:

> Frank,
>                   thanks for the suggestions. I have added them to my to-do list.
> In the meantime, I found a small bug that prevents Spectran (but this name will
> change, as it is trademarked...) from displaying frequencies with accuracy
> greater than 1 Hz, even when the resolution is set higher. The problem is
> that the horizontal frequency ruler, as it is coded now, wants to start at an
> integral value. That's no problem with normal resolutions, but when you go
> higher, it causes a slight misalignement between the spectrum and the ruler.
> I will try to fix it.
> 
> I have just subscribed to lf at amrad.org list, thanks for the invitation. Still
> have to read the past messages.
> 
> Waiting for the results of your trip to Nags Head,
> 
> 73
> Alberto    I2PHD
> -------------------------------------------------------
> 
> Frank Gentges wrote:
> 
> > Alberto,
> >
> > Your Spectran program is finding increased use on this side of the pond.
> > Several of us are using it with the TenTec RX320 receiver on LF with good
> > results.  You can see the latest at <www.amrad.org/projects/lf>.
> >
> > As you add changes we could find it useful to have a display option to
> > show 1 KHz on the frequency dial as zero hertz and frequencies above and
> > below as plus and minus from the zero at 1 kHz.  Thus, when the RX320
> > dial is set right on a frequency it will have a 1 kHz output and Spectran
> > would display it as being at zero.  Deviation would be displayed as
> > differences from that.
> >
> > We are doing that mentally now and it is not hard to do but the change
> > would be a "nice to have".  We can calibrate our systems to read frequency
> > using Spectran this way within 1 Hz with care and 10Hz over time and
> > temperature all the way from 10 kHz to 30 mHz.
> >
> > Also, as we change the "Resolution", the display dial shifts back and
> > forth.  If that could be changed to always start with 1 kHz centered it
> > would ease resolution changes.  In addition, the slider gets especially
> > sensitive when resolution is set at .125 Hz.  A desensitization would
> > make it easier to adjust.
> >
> > I tried your Hamview on my home machine and liked the filter function.
> > We are going to try some filtering below 100 Hz of bandwidth to see if it
> > is useful.  If so adding that at 1 kHz center frequency would be a help.
> >
> > We are going to have a trip next weekend to Nags Head North Carolina to
> > put abunch of our stuff (Spectran included) on the beach to see what we
> > can hear.  We may gain more experience and discuss our results and come
> > up with more ideas.
> >
> > I am CCing this email to our group.  If your mailbox can handle it I could
> > add you to our LF reflector.  You could see 10 messages on 24 hours on a
> > busy day.  You would be quite welcome to post to the group.
> >
> > Frank K0BRA
>