[time-nuts] FMT 2006 results

John Ackermann N8UR jra at febo.com
Thu Jan 4 08:07:55 EST 2007


if it turns out that there really is an anomaly on 40M, we'll let ARRL 
know; last year they were off by about 0.4Hz on 160M so something like 
this isn't a first.

One problem is that they really don't aim the test at the time-nuts 
crowd, and frankly their measurement system isn't at the level some of 
us would like to see.  And the change of transmitter hardware this year 
didn't help.

I don't want to go into details on the list, but there is some activity 
going on to try to improve the situation next year.

John
-----

Rex wrote:
> John and others,
> 
> I didn't play in this game so I haven't been paying close attention to
> the contest or results. In my skimming of the messages I think I am
> hearing that several knowledgeable people came out with results close to
> each other but offset from the "winning" results.
> 
> If I am correct in my assessment, seems like the ARRL should be made
> aware that the process or the specification of the contest signal may be
> lacking in some details.
> 
> What do you think was the issue? Was it a modulated carrier on SSB with
> some residual rather than pure CW?
> 
> If there is some consensus of close mis-measured results in this group,
> seems like the ARRL needs to be informed about it so exactly what the
> signal is  is described or the contest is modified with a better pure CW
> carrier in the future.
> 
> Am I right, or am I completely missing the point in some way?
> 
> -Rex
> 
> On Thu, 4 Jan 2007 00:54:34 -0600, "Connie Marshall"
> <connie.marshall at suddenlink.net> wrote:
> 
>> Looks good John.... Our readdings are within .03Hz on 160, .1Hz on 80, and
>> .06Hz on 40 of each other.
>>
>> Connie
>>
>> -----Original Message-----
>> From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com]On
>> Behalf Of John Ackermann N8UR
>> Sent: Wednesday, January 03, 2007 9:33 AM
>> To: Discussion of precise time and frequency measurement
>> Subject: [time-nuts] FMT 2006 results
>>
>>
>> I've put my FMT results at http://www.febo.com/time-freq/fmt/fmt2006/
>> based on the preliminary numbers from ARRL that Connie posted here.
>>
>> As I noted earlier, I screwed up the math and ended up being off on all
>> three bands by 75 to 110 Hz -- double the delta between W1AW and my
>> marker, because I did USB math when the receivers were set to LSB.
>>
>> After correcting that error, I was -0.295 Hz on 160, -0.343 Hz on 40,
>> and -1.066 Hz on 40.  That's a bit more like it, though the error on 40
>> is interesting, and I see that a few other folks saw that problem, too.
>> We'll have to wait for the final results from W1AW to see if their 40M
>> frequency had a typo.
>>
>> I think a couple of other folks noted, as did I, that on 40M there
>> appeared to be two signals close to each other (I measured about 0.5
>> Hz).  An FFT with enough resolution to separate them lost any ability to
>> look for CW in the waterfall, so I had to guess which was the correct
>> signal.  I chose the sharper one, which was the higher frequency of the
>> two; had I picked the one that was more smeared out, I would have been
>> more like -0.5 Hz off.
>>
>> I've learned my lesson -- from now on, all measurements will be taken in
>> USB mode!
>>
>> John
>>
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