Summary: where exactly is the band edge?
W8JITom at aol.com
W8JITom at aol.com
Wed Nov 13 09:26:58 EST 1996
In a message dated 96-11-13 07:22:58 EST, you write:
>Principles 1 and 2:
>1- When you're on USB, your signal is above the indicated frequency.
>2- On LSB, your signal is below the indicated frequency.
>Theoretically is no energy between your center frequency and say 200 or 300
>hz or so ? All energy is between whatever the lower start "point" of your
>bandwidth is at 200 or 300 hz and goes up to 3khz or more (if you have a
>bad signal) from center.
My ICOM 751A (using the Mil Spec or commercial standards, not the ARRL's)
measures -25 dB for third and -28 for 5th order products. In addition it has
higher order products extending out for many kilohertz.
(I re-worked it and it is much better, now in the -35 dB range)
If my MODIFIED and IMPROVED rig is set within ten KHz of the band edge, its'
output would contain emissions outside the band. If S meter's were made and
calibrated correctly (they are not) and I was 40 dB over nine, my crud would
be about S-9 outside the band if I was parked on the edge.
If IMD isn't bad enough, turn to the page in the manual where the
manufacturer gives filter specs. Look at its' SSB filter attenuation.
This was always a problem on 160 and on other bands where weak signals and
strong SSB signals are mixed. Some operators look at their dials and think
(quite incorrectly) their signals extend in one direction 3 KHz, but in real
life they most certainly do not.
And this is all true both in theory and in practice. Operating on the edge of
a band or a few KHz from a weak signal area is Liddish.
>From seay at Alaska.NET (Del Seay) Wed Nov 13 23:11:02 1996
From: seay at Alaska.NET (Del Seay) (Del Seay)
Date: Wed, 13 Nov 1996 15:11:02 -0800
Subject: Summary: where exactly is the band edge?
References: <CMM.0.90.4.847863573.trey at scv-cse-4.cisco.com>
Message-ID: <328A5586.AE5 at alaska.net>
Trey Garlough wrote:
> Here is the summary of responses I received to my request asking for a
> pointer to the exact language that addressed the issue of out-of-band
> transmissions. The names of those who responded have been omitted for
> no particular reason. Personally, I liked the first answer the best. :-)
> --Trey, N5KO
> (All else snipped)
One Last Time:
The regs discuss 2 seperate types of emissions. That included in
the modulation envelope - and spurious emissions.
The various rates of attenuation in the regs are for spurious
emissions. This is rf that is not desired, nor necessary for
communications. It includes, but not limited to harmonic energy,
splatter, 2nd, 3rd etc IMD.
The signal within the modulated envelope - or wanted signal - is not
discussed in the R&Rs in an attenuated, out of band radiation. They
just say it has to stay within the band segment allowed to the
control operator. So - the conclusion?
>From HWDX09A at prodigy.com ( ROBERT REED) Wed Nov 13 15:07:27 1996
From: HWDX09A at prodigy.com ( ROBERT REED) ( ROBERT REED)
Date: Wed, 13 Nov 1996 10:07:27, -0500
Subject: REGISTERING E-MAIL ADDRESSES
Message-ID: <199611131507.KAA13268 at mime4.prodigy.com>
The QRZ Ham Radio site has available an input field for you Internet
e-mail address. Many DXers registered their address during the last
Easter Island DXpedition for the automatic QSL cards.
There are still many who have not registered or updated their
listings when changing Internet providers.
With the new Vanity call changes I am planning on a new CD for home
use later in the winter when the new editions are pressed. I have
decided on the QRZ so I can also have the Internet addresses handy
from the CD.
It would be nice if everyone inputed their Internet address into the
database before then.
Try http://www.qrz.com Look up your callsign and input your
73, Bob Reed, W2CE
1991 Route 37 West - Lot 109
Toms River, New Jersey 08757
Internet : hwdx09a at prodigy.com
Pager : (908) 288 - 6552
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