## That will only work.... provided there is nobody within 6 khz of you.
In the example I used below, if you are listening on 3800..and switch to
USB, you will then hear everything from 3800 to 3803. If a 3rd fellow
happens
to be transmitting LSB on 3803, you will then hear the 3rd fellow full
bore.
Even if he is on 3806, transmitting LSB, you will still hear his
3806..down to
3803 LSB signal. So the opposite sideband RX works..but with caveats.
In any contest, you are very unlikely to have nobody within 7-10 khz above
your freq on 160, 75m or 40m. Or 7-10 khz below you on 20, 15, 10 m.
## Interesting enough, a bunch of us tried that on 75m, while using ESSB,
and 5.7
khz wide TX... using modified 1000-MP-MK-Vs. I cant hear anything on the
opposite
sideband of several friends identically modified MK-Vs. And they are
loud. But when the ICOM
756 Pro 2 and 3 folks start TXing, I can hear all sorts of crud on the ICOM
rigs..go figure. Its
to the point where I can usually tell what brand xcvr they are using..and
which model !
Hi Bob, how is your icom 756 Pro-3 working out for you ? How did you know
I was using a Pro-3 ?
Cuz it has a distinct sonic signature, a mixture of ....digital grunge and
unique imd products.
## IF you try and monitor your own signal, using a 2nd xcvr, switched to
the opposite sideband, only
a short 3 to 6 inch long pigtail is required for the RX ant. That plus
loads of RX padding employed,
RF gain control backed way down, RF pre-amp shut OFF, NB OFF etc, etc.
Jim VE7RF
-----Original Message-----
From: Gary Schafer
Sent: Wednesday, November 08, 2017 10:21 AM
To: 'Jim Thomson' ; amps@contesting.com
Subject: RE: [Amps] Alpha 87 (not 87A)
The easiest way to observe splatter is to switch your receiver to the
opposite side band and listen for the crud.
Intermod products are generated on both sides of the signal. By listening on
the opposite side band you eliminate your receivers filter bandwith from
causing you false indications.
On a good clean signal you will not hear anything on the opposite side band
from that station.
73
Gary K4FMX
-----Original Message-----
From: Amps [mailto:amps-bounces@contesting.com] On Behalf Of Jim Thomson
Sent: Wednesday, November 08, 2017 10:44 AM
To: amps@contesting.com
Subject: [Amps] Alpha 87 (not 87A)
Date: Tue, 7 Nov 2017 15:14:43 -0500
From: Larry <pacer99@aol.com>
To: jim@audiosystemsgroup.com, amps@contesting.com
Subject: Re: [Amps] Alpha 87 (not 87A)
<jim,
<i just finished the CQ WW SSB and except for a very few stations the
quality of signals was good. i am using an Icom IC-7800.
<i believe that if each of us take the time to contact the offending
station and explain, in a polite manner that they were "spattering".
try to help them correct the problem. the bands would clean up rapidly.
every time that i do it the problem is solved and the <offending station
is grateful. no one wants to be rude to others. it's a friendly hobby
after all.
<complaining does no good.
<73,
<larry
<n7dd
## For folks trying to measure the total BW of an SSB signal, remember
not to inadvertantly add the width of your RX filter...to the other
fellows TX bw. IE: say you are using a 3 khw wide RX filter..and are
on 3800 LSB. You will hear
everything from 3800...down to 3797. Meanwhile the offending station
is on 3797 LSB. Assume he is also TXing with a 3 khz filter. On
paper, he should be occupying 3797...down to 3794. You tune across
his signal, and you can hear
him from 3794....all the way up to 3800. You tell the fellow that
you can hear him.. 3 down...and 3 up from his TX freq of 3797. No the
fellow is not 6 khz wide, he is only 3 khz wide. You have added your
3 khz wide RX BW to his
3 khz TX BW to arrive at the 6 khz figure.... which is incorrect.
That mistake is done all the time. A better method would be to tune
across his ssb signal, using a pair of 500 hz cw filters..... sorta
like poor mans spectrum analyzer. In actual
practise, it works good. Then you will hear that he is only 3 khz
wide.
## I wouldnt put any stock in the Icom fish finders either. They will
easily show a dead cxr as being 2 khz wide, and other erroneous stuff.
Also make sure your NB is OFF, and dont have excess RF gain applied.
Shut the RF rx pre-amp off, NB
off, and back down on the RFor IF gain control a bit..and also switch in
some RX padding, like 6 or 12 db. Then use a pair of 500 hz filters
if using a xcvr that has switchable RX CW filters, or the dsp eq....
then carefully tune across his signal,
using your MAIN RX. Meanwhile you can simultaneously listen on 3797
LSB... on your SUB RX. Then you can correlate asap, any splatter
products, while listening on your Main RX..with a pair of 500 hz cw
filters in left ear... while listening to him on LSB... on your right
ear....using the sub RX.
Jim VE7RF
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