[1000mp] 1000-Field Review ... Notice what's MISSING?

[Hare,Ed, W1RFI]

> >The numbers are there.
> 
> Not full use of them ... they even noted that they used the 
> 20 kHz unless
> otherwise stated at the bottom of the chart. 

The file is updated now.  If you try to download it and the 5-kHz number
don't appear to be in the test-result table, hit the reload button.  The old
file could be in your cache.

>Look at ALL the "numbers" found in the text, are 20 kHz data, 
>NOT 5 kHz, but again ... this is going to be revised ASAP. 

The only change we could make at this time is to the table. The text will
not be changed. Sorry; it is the best that could be done. This was literally
corrected at the printer, by making new plates for that page.  A few hours
longer and it would have been too late.  Leaving off the 5-kHz numbers was
an error on the ARRL Lab's part, plain and simple.  Unfortunately, as Joe
Bottiglieri was passing the Product Review editor baton to the new guy,
Brennan Price, the error did not get caught before it was sent to the
printer.

In general, you can probably expect the 20-kHz spacing numbers to receive
the most text attention.  At the time this was started, 20 kHz made a lot of
sense wrt most receiver architectures.  In today's receivers, 100-kHz would
probably make more sense, considering the way that dynamic range varies with
the spacing of the tones. With test tones spaced 100- and 200-kHz above or
below the desired channel, the intermod is occuring early in the receiver
chain. At closer spacing, at some point, it also starts occuring at a lower
input level later in the receiver.  Naturally, with "roofing" and IF
filtering coming into play, the two tones are not necessarily at an equal
amplitude at the intermod point, so the response of that receiver becomes a
bit less "classic."

QEX just ran a nice article on intermod and testing in receivers; I will try
to get that posted somewhere on the ARRL Web page relatively soon.

> Again TU to those at HQ who have taken the steps to ensure
> this form of information is both valid and accurate for our usage.

I just wish we could do more.  It is a very tough balance between all the
testing that COULD be done, and the staff-time costs and calendar-time
delays to do it. We can relatively easily add a test here and there, such as
doing the DR tests at 5 kHz spacing, but some of the things that would be
nice to do can take a lot of time, and each day at the front end of the
review cycle adds to the delays in the review. 

Any and all suggestions for ways to do this all better are appreciated!

73, 
Ed Hare, W1RFI
ARRL Lab
225 Main St
Newington, CT 06111
Tel: 860-594-0318
Internet: w1rfi@arrl.org
Web: http://www.arrl.org/tis



> -----Original Message-----
> From: Billy Cox [mailto:aa4nu@ix.netcom.com]
> Sent: Thursday, June 27, 2002 4:59 PM
> To: 1000mp@mailman.qth.net
> Subject: Re: [1000mp] 1000-Field Review ... Notice what's MISSING?
> 
> 
> >>The ARRL had stated they were moving from the 20 kHz to the
> >>more useful (and accurate) 5 kHz spacing measurements ...
> >
> >The numbers are there.
> 
> Not full use of them ... they even noted that they used the 
> 20 kHz unless
> otherwise stated at the bottom of the chart. 
> 
> I understand this will now be updated with the web data and corrected
> prior to the actual QST printing.
> 
> And for that I say ... THANK YOU ... Way to go ARRL ! 
> 
> For where they listed the two sets of numbers (20 kHz and 5 kHz) it 
> really shows how the closer measurements can define what is or is 
> not a 'good receiver'.  Which is what many of us had asked for.
> 
> Look at ALL the "numbers" found in the text, are 20 kHz data, 
> NOT 5 kHz, but again ... this is going to be revised ASAP. 
> 
> Again TU to those at HQ who have taken the steps to ensure
> this form of information is both valid and accurate for our usage.
> 
> 73 Billy AA4NU
> 
> 
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