Strong Signal == Wide Signal??

Strong Signal == Wide Signal??

Post by Marty Tipp » Fri, 09 Oct 1998 04:00:00

I was listening to a guy calling CQ on 10m yesterday afternoon who had
a 20 over signal, and I could hear splatter about 8 kHz either side of
him - to the point that he was drowning out QSOs 4 to KHz above and
below him.  So I let him know I thought he had a rather wide signal,
and his reply was that any time you have a strong signal like that,
you're going to hear splatter.  He also said I was 40 over 9 and he
could hear me all over the place too (which I doubt as I was running
100w into a half-square about 15 ft off the ground...)

I didn't press it too much as I'm still fairly new to HF and didn't
know for sure.  But it seems to me that I frequently hear 20-over
signals that seldom splatter like that.

So, should I expect to hear that kind of mess any time I'm picking up
a strong signal? Maybe it's a defect in my FT-920, I dunno - but I
still think he just had a poor signal or was driving his amp too hard
or something...

-Marty KI0LO

 
 
 

Strong Signal == Wide Signal??

Post by STEVEN L UMBAC » Fri, 09 Oct 1998 04:00:00


Marty - Was this a guy from Florida who was calling cq for the far
east/asia? If so I heard the same guy and you are exactly right about him.
The guy I heard was about 28.49 and he was very wide on my FT1000MP and my
TS850, both rigs with noise blankers off. I also saw his signal on my SM220
scope and he was very wide. I heard another station down the band with the
same signal strenght who DID NOT exhibit the same annoying problem.
Unfortuneately you just can't convince some of these idiots that they don't
know how to operate an hf rig.  Another problem are guys using "glorified
cbs" on ten meters. They can sound ok if adjusted right, but I heard a guy
on one (Ranger or etc.) that was splattering all over the place. Some of
these guys go in the radio and jack the power way up and think nothing of
it. Don't worry about your rig and ignore these poor operators.  --- Steve
KK9ZZ

>I was listening to a guy calling CQ on 10m yesterday afternoon who had
>a 20 over signal, and I could hear splatter about 8 kHz either side of
>him - to the point that he was drowning out QSOs 4 to KHz above and
>below him.  So I let him know I thought he had a rather wide signal,
>and his reply was that any time you have a strong signal like that,
>you're going to hear splatter.  He also said I was 40 over 9 and he
>could hear me all over the place too (which I doubt as I was running
>100w into a half-square about 15 ft off the ground...)

>I didn't press it too much as I'm still fairly new to HF and didn't
>know for sure.  But it seems to me that I frequently hear 20-over
>signals that seldom splatter like that.

>So, should I expect to hear that kind of mess any time I'm picking up
>a strong signal? Maybe it's a defect in my FT-920, I dunno - but I
>still think he just had a poor signal or was driving his amp too hard
>or something...

>-Marty KI0LO


 
 
 

Strong Signal == Wide Signal??

Post by Gary Coffm » Fri, 09 Oct 1998 04:00:00


>I was listening to a guy calling CQ on 10m yesterday afternoon who had
>a 20 over signal, and I could hear splatter about 8 kHz either side of
>him - to the point that he was drowning out QSOs 4 to KHz above and
>below him.  So I let him know I thought he had a rather wide signal,
>and his reply was that any time you have a strong signal like that,
>you're going to hear splatter.  He also said I was 40 over 9 and he
>could hear me all over the place too (which I doubt as I was running
>100w into a half-square about 15 ft off the ground...)

>I didn't press it too much as I'm still fairly new to HF and didn't
>know for sure.  But it seems to me that I frequently hear 20-over
>signals that seldom splatter like that.

>So, should I expect to hear that kind of mess any time I'm picking up
>a strong signal? Maybe it's a defect in my FT-920, I dunno - but I
>still think he just had a poor signal or was driving his amp too hard
>or something...

A lot of so-called splatter is really IMD in someone's receiver.
A quick test is to switch in 20 db of attenuation. If the spatter
goes down 20 db, then it is probably real. If it goes down more
than 20 db, or disappears completely, it is your receiver.

Gary

534 Shannon Way     | We break it  |
Lawrenceville, GA   | Guaranteed   |

 
 
 

Strong Signal == Wide Signal??

Post by Doug Smi » Fri, 09 Oct 1998 04:00:00



Quote:>So, should I expect to hear that kind of mess any time I'm picking up
>a strong signal? Maybe it's a defect in my FT-920, I dunno - but I
>still think he just had a poor signal or was driving his amp too hard
>or something...

Some of each...  There are some rather questionable signals on the
band from time to time.  But receiver overload is also a reality.  

One quick check is to use the attenuator on your receiver.  If the
splatter is generated in your receiver, its strength should drop by
considerably more than the amount of attenuation you kicked in - in
fact, there's a pretty good chance the splatter will disappear
altogether.  If it's still there, just weaker by the amount of
attenuation you used, then it probably is in the guy's transmitter.

Still, don't be too quick to judgement - don't demand that he back it
off. Psychologically, it doesn't work.  Tell the guy you think he
might be too wide & suggest he double-check things with a local.

73 Doug

Doug Smith (ham call W9WI) - EM66 nr. Nashville, TN, USA
real email address is:

 
 
 

Strong Signal == Wide Signal??

Post by Doran Plat » Sun, 11 Oct 1998 04:00:00

Crank in 10dB or so of front-end attenuation.  If the signal is no
longer "wide", its your receiver being overloaded.  In many of the
"modern" imported solid-state radios, this is a grevious problem.  Sure,
they claim extreme dynamic ranges, but only with the use of attenuation
at the high end!!!

> Marty - Was this a guy from Florida who was calling cq for the far
> east/asia? If so I heard the same guy and you are exactly right about
> him.
> The guy I heard was about 28.49 and he was very wide on my FT1000MP
> and my
> TS850, both rigs with noise blankers off. I also saw his signal on my
> SM220
> scope and he was very wide. I heard another station down the band with
> the
> same signal strenght who DID NOT exhibit the same annoying problem.
> Unfortuneately you just can't convince some of these idiots that they
> don't
> know how to operate an hf rig.  Another problem are guys using
> "glorified
> cbs" on ten meters. They can sound ok if adjusted right, but I heard a
> guy
> on one (Ranger or etc.) that was splattering all over the place. Some
> of
> these guys go in the radio and jack the power way up and think nothing
> of
> it. Don't worry about your rig and ignore these poor operators.  ---
> Steve
> KK9ZZ

> >I was listening to a guy calling CQ on 10m yesterday afternoon who
> had
> >a 20 over signal, and I could hear splatter about 8 kHz either side
> of
> >him - to the point that he was drowning out QSOs 4 to KHz above and
> >below him.  So I let him know I thought he had a rather wide signal,
> >and his reply was that any time you have a strong signal like that,
> >you're going to hear splatter.  He also said I was 40 over 9 and he
> >could hear me all over the place too (which I doubt as I was running
> >100w into a half-square about 15 ft off the ground...)

> >I didn't press it too much as I'm still fairly new to HF and didn't
> >know for sure.  But it seems to me that I frequently hear 20-over
> >signals that seldom splatter like that.

> >So, should I expect to hear that kind of mess any time I'm picking up

> >a strong signal? Maybe it's a defect in my FT-920, I dunno - but I
> >still think he just had a poor signal or was driving his amp too hard

> >or something...

> >-Marty KI0LO