RS Yesterday


John Quarmby
 

One thing I noted in yesterday evening's good RS opening was the way that dog-leg paths that normally don't seem to work were possible. I heard DJ5BV (JO30) consistently on a heading of about 165 degrees, he would have been beaming south of West so the path had a near right angle reflection, similarly F6APE in IN97 (west south west of the scatter point) was worked on the same heading. I also had a good backscatter contact with Neil G4BRK. Signals were not huge, indicating that the losses were higher than on the more direct paths, but it demonstrates that RS will work over significant distances in any direction if the storm is sufficiently intense, regardless of the path geometry.

73

John G3XDY


SAM JEWELL
 

I tried my technique of level measurement on DJ5BVs strong RS signal. He measured up to -112dBm, although a little peak energy will have been lost in the Doppler sidebands.
This is interesting as Gerd was getting so many 59s reports. This equates to about 19dB below an IARU definition of S9!

I'm not raising this as any sort of issue but merely illustrating how misleading the current 'S' system can be!

2 new squares on 3cm. I love the rain!

And 2 new squares (and initials) on 13cm EME this morning.

73 de Sam














Not sent from my PC!

On 26 May 2009, at 12:35, "G3XDY" <g3xdy@...> wrote:

One thing I noted in yesterday evening's good RS opening was the way that
dog-leg paths that normally don't seem to work were possible. I heard DJ5BV
(JO30) consistently on a heading of about 165 degrees, he would have been
beaming south of West so the path had a near right angle reflection,
similarly F6APE in IN97 (west south west of the scatter point) was worked on
the same heading. I also had a good backscatter contact with Neil G4BRK.
Signals were not huge, indicating that the losses were higher than on the
more direct paths, but it demonstrates that RS will work over significant
distances in any direction if the storm is sufficiently intense, regardless
of the path geometry.

73

John G3XDY



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Arie Dogterom <pa0ez@...>
 


Hello Sam,
It is not the s-scale but the people giving reports out of their black hat. I am always worrying about my rx when reveiving s9 from stations I cannot give more than s4
regards
Arie
 

----- Original Message -----
From: Sam
Sent: Tuesday, May 26, 2009 2:48 PM
Subject: Re: [ukmicrowaves] RS Yesterday


I tried my technique of level measurement on DJ5BVs strong RS signal. He measured up to -112dBm, although a little peak energy will have been lost in the Doppler sidebands.
This is interesting as Gerd was getting so many 59s reports. This equates to about 19dB below an IARU definition of S9!

I'm not raising this as any sort of issue but merely illustrating how misleading the current 'S' system can be!

2 new squares on 3cm. I love the rain!

And 2 new squares (and initials) on 13cm EME this morning.

73 de Sam

Not sent from my PC!

On 26 May 2009, at 12:35, "G3XDY" <g3xdy@btinternet.com> wrote:

One thing I noted in yesterday evening's good RS opening was the way that
dog-leg paths that normally don't seem to work were possible. I heard DJ5BV
(JO30) consistently on a heading of about 165 degrees, he would have been
beaming south of West so the path had a near right angle reflection,
similarly F6APE in IN97 (west south west of the scatter point) was worked on
the same heading. I also had a good backscatter contact with Neil G4BRK.
Signals were not huge, indicating that the losses were higher than on the
more direct paths, but it demonstrates that RS will work over significant
distances in any direction if the storm is sufficiently intense, regardless
of the path geometry.

73

John G3XDY

------------------------------------

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F6DRO
 

Hi all ,

it is also possible that there was some " ping pong " effect between
scatterers , so the 90deg offset was not real... During my latest xped in
JO10 I noticed a qso between F6DKW/JN18 and F5BUU/JN03. F6DKW turned to
JN38 scaterer and F5BUU to JN05 , looking like there was some chordal link
between JN38 and JN05.....

73
Dom/F6DRO


Richard Newstead <g3cwi@...>
 

--- In ukmicrowaves@..., Sam <jewell@...> wrote:

This is interesting as Gerd was getting so many 59s reports. This >equates to about 19dB below an IARU definition of S9!

I'm not raising this as any sort of issue but merely illustrating >how misleading the current 'S' system can be!
Sam

That is surely faulty logic. How can you possibly be sure that he was the same level with everyone else that he was with you?

(I fully accept the S meter point though!).

73

Richard
G3CWI


SAM JEWELL
 

I know Ari. You have long campaigned for a sensible system.
But I think the definition of VHF/Microwave S9 is set far too high for the reasons I gave in my column and DUBUS.

By any current, common, usage Gerd was 59S here yesterday. Yet by IARU definition he was considerably short of S9? I don't think I am wrong to send S9 if I believe that to be correct and what is expected, but the existing system is clearly unreliable as any sort of meaningful measurement of levels. A range of maybe 20 to 30dB is outrageous.
It was created  based on equipment standards of too many years ago. They need updating, IMHO.
System noise figures of 10 and 20dB, at VHF, belong in the past! A system based on those sorts of equipment sensitivities needs looking at again, surely?

73 de Sam, G4DDK

Flack jacket on.....................



From: Arie Dogterom
To: ukmicrowaves@...
Sent: Tuesday, 26 May, 2009 1:58:23 PM
Subject: Re: [ukmicrowaves] RS Yesterday



Hello Sam,
It is not the s-scale but the people giving reports out of their black hat. I am always worrying about my rx when reveiving s9 from stations I cannot give more than s4
regards
Arie
 
----- Original Message -----
From: Sam
Cc:
Sent: Tuesday, May 26, 2009 2:48 PM
Subject: Re: [ukmicrowaves] RS Yesterday


I tried my technique of level measurement on DJ5BVs strong RS signal. He measured up to -112dBm, although a little peak energy will have been lost in the Doppler sidebands.
This is interesting as Gerd was getting so many 59s reports. This equates to about 19dB below an IARU definition of S9!

I'm not raising this as any sort of issue but merely illustrating how misleading the current 'S' system can be!

2 new squares on 3cm. I love the rain!

And 2 new squares (and initials) on 13cm EME this morning.

73 de Sam

Not sent from my PC!

On 26 May 2009, at 12:35, "G3XDY" <g3xdy@btinternet. com> wrote:

One thing I noted in yesterday evening's good RS opening was the way that
dog-leg paths that normally don't seem to work were possible. I heard DJ5BV
(JO30) consistently on a heading of about 165 degrees, he would have been
beaming south of West so the path had a near right angle reflection,
similarly F6APE in IN97 (west south west of the scatter point) was worked on
the same heading. I also had a good backscatter contact with Neil G4BRK.
Signals were not huge, indicating that the losses were higher than on the
more direct paths, but it demonstrates that RS will work over significant
distances in any direction if the storm is sufficiently intense, regardless
of the path geometry.

73

John G3XDY

------------ --------- --------- ------

Yahoo! Groups Links




SAM JEWELL
 

I'm not Richard. I was merely saying I would have given him an S9 (I did) yet he was measured at nearly 20dB lower. I have no idea how strong he was with others but I doubt he was any stronger than with me yet he received a number of S9 reports that I heard. That's all. No need to read anything more into it than that! I'm trying to raise some support for a more accurate reporting system as the current one is clearly flawed.

Sam




From: Richard Newstead
To: ukmicrowaves@...
Sent: Tuesday, 26 May, 2009 2:03:07 PM
Subject: [ukmicrowaves] Re: RS Yesterday

--- In ukmicrowaves@..., Sam wrote:

> This is interesting as Gerd was getting so many 59s reports. This >equates to about 19dB below an IARU definition of S9!
>
> I'm not raising this as any sort of issue but merely illustrating >how misleading the current 'S' system can be!

Sam

That is surely faulty logic. How can you possibly be sure that he was the same level with everyone else that he was with you?

(I fully accept the S meter point though!).

73

Richard
G3CWI



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Christopher Bartram <cbartram@...>
 

Hello Sam

I was thinking about signal reporting during the 1.3GHz contest last week. One
problem which seems as though it needs addressing is the increased complexity
of the proposed system: a report in the dBm scale format requires four
characters eg. 123S. That's one more than the RST format...

If the dBm reporting scheme were to be slightly modified by rounding the
observed level to the nearest 10dB point, that would simplify matters. OK, the
accuracy would suffer, but it would then be possible to make reasonably
meaningful reports by ear.

A second way of condensing the report, I think unambiguously, without loosing
resolution, would be to remove the 'hundreds' character, so a report of eg.
23s would be most unlikely to be -23dBm or (at least with current technology
:-) ) -223dBm!

It would be a good idea to include a qualifier in the report which denotes that
the report is given aurally. An 'A' in place of the 'ones' character would do
nothing to reduce accuracy! So an report of a moderately strong RS signal
would perhaps be '2AS'. It wouldn't be very difficult to construct a series of
signal descriptions, like those used for the existing RST system, which would
probably result in more meaningful aural reports.

I agree completely with your and Arie's observations on current reporting
schemes. The reports given on the VHF/UHF/microwave bands are currently only
very slightly more meaningful than those given on HF!

Vy 73

Chris
GW4DGU


SAM JEWELL
 

Hi Chris,
I agree that the extra digit of the proposed system may be an encumbrance. I don't have any personal attachment to it so if a better system can be found, it has my acceptance.
I certainly don't have any problem with the nearest 10dB. That's still miles better than what we have today and anyway, the fading characteristics of most long haul VHF and above means that the signal is possibly changing over at least that amount, short term. We certainly don't want to get into statistical averaging or any-such.


I would have thought that a system that has a POSSIBLE 100dB range would be enough for all practical purposes, so that a single digit that denotes the 10dB block would be enough? The anomaly would be the change at the -100dBm point, so maybe we start with -140 and below as '0' and work up by 10dB to 9 (that has a nice comfortable feel) this would be -60 to -500dBm. Above -50 most (weak signal mode) signals would be so loud who needs  a reporting system? The suffix still represents the perceived propagation mode, e.g. A, R, S and maybe N. The DJ5BV signal would then have been 4S (-120 to -110dBm and S for rain scatter). An optimistic report would have been 5S!

Looking at this it is not such a big change from what we currently have, but the reference is reset and any argument that the increments are now 10dB whereas they were a finer 6dB before is already totally discredited. This system is at least meaningful.

I wonder what others think about the current system and possible changes to it? I haven't had much feedback to my column or DUBUS. Maybe most don't care? Keep on as we are?


73 de Sam, G4DDK






From: Christopher Bartram
To: ukmicrowaves@...
Sent: Tuesday, 26 May, 2009 2:49:27 PM
Subject: Re: [ukmicrowaves] RS Yesterday

Hello Sam

I was thinking about signal reporting during the 1.3GHz contest last week. One
problem which seems as though it needs addressing is the increased complexity
of the proposed system: a report in the dBm scale format requires four
characters eg. 123S. That's one more than the RST format...

If the dBm reporting scheme were to be slightly modified by rounding the
observed level to the nearest 10dB point, that would simplify matters. OK, the
accuracy would suffer, but it would then be possible to make reasonably
meaningful reports by ear.

A second way of condensing the report, I think unambiguously, without loosing
resolution, would be to remove the 'hundreds' character, so a report of eg.
23s would be most unlikely to be -23dBm or (at least with current technology
:-) ) -223dBm!

It would be a good idea to include a qualifier in the report which denotes that
the report is given aurally. An 'A' in place of the 'ones' character would do
nothing to reduce accuracy! So an report of a moderately strong RS signal
would perhaps be '2AS'. It wouldn't be very difficult to construct a series of
signal descriptions, like those used for the existing RST system, which would
probably result in more meaningful aural reports.

I agree completely with your and Arie's observations on current reporting
schemes. The reports given on the VHF/UHF/microwave bands are currently only
very slightly more meaningful than those given on HF!

Vy 73

Chris
GW4DGU




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Arie Dogterom <pa0ez@...>
 

Hello Sam,
I have been involved in that IARU R1 definition ( it was accepted at the Brighton conference almost 40 years ago) and the text is based on a proposal from PA0MS and me.
At that time there were no commercial VHF-up receivers. The standard was a convertor in front of a 28 of even 4 MHz RX. That is the pure reason for the 20 dB difference between the HF and the VHF-up reference.
One can fight about an S-point being 6dB or something else. If people are using a reasonably calibrated meter than it is worth contemplating. At the time we tought that the dBm values and the 6 dB were a reasonable approach to the existing (ARRL?) system with terms as "very strong" etc. I do not think many people do in fact know what the "non-dBm" definition of S-points are.
I can agree to any deviation of the -93 dBm reference and/or 6 dB step, if that could result in real reporting. But I am rather pessimistic.
Regards
Arie
 

----- Original Message -----
From: SAM JEWELL
Sent: Tuesday, May 26, 2009 3:15 PM
Subject: Re: [ukmicrowaves] RS Yesterday

I know Ari. You have long campaigned for a sensible system.
But I think the definition of VHF/Microwave S9 is set far too high for the reasons I gave in my column and DUBUS.

By any current, common, usage Gerd was 59S here yesterday. Yet by IARU definition he was considerably short of S9? I don't think I am wrong to send S9 if I believe that to be correct and what is expected, but the existing system is clearly unreliable as any sort of meaningful measurement of levels. A range of maybe 20 to 30dB is outrageous.
It was created  based on equipment standards of too many years ago. They need updating, IMHO.
System noise figures of 10 and 20dB, at VHF, belong in the past! A system based on those sorts of equipment sensitivities needs looking at again, surely?

73 de Sam, G4DDK

Flack jacket on.....................



From: Arie Dogterom nl>
To: ukmicrowaves@yahoogroups.com
Sent: Tuesday, 26 May, 2009 1:58:23 PM
Subject: Re: [ukmicrowaves] RS Yesterday



Hello Sam,
It is not the s-scale but the people giving reports out of their black hat. I am always worrying about my rx when reveiving s9 from stations I cannot give more than s4
regards
Arie
 
----- Original Message -----
From: Sam
Sent: Tuesday, May 26, 2009 2:48 PM
Subject: Re: [ukmicrowaves] RS Yesterday


I tried my technique of level measurement on DJ5BVs strong RS signal. He measured up to -112dBm, although a little peak energy will have been lost in the Doppler sidebands.
This is interesting as Gerd was getting so many 59s reports. This equates to about 19dB below an IARU definition of S9!

I'm not raising this as any sort of issue but merely illustrating how misleading the current 'S' system can be!

2 new squares on 3cm. I love the rain!

And 2 new squares (and initials) on 13cm EME this morning.

73 de Sam

Not sent from my PC!

On 26 May 2009, at 12:35, "G3XDY" <g3xdy@btinternet. com> wrote:

One thing I noted in yesterday evening's good RS opening was the way that
dog-leg paths that normally don't seem to work were possible. I heard DJ5BV
(JO30) consistently on a heading of about 165 degrees, he would have been
beaming south of West so the path had a near right angle reflection,
similarly F6APE in IN97 (west south west of the scatter point) was worked on
the same heading. I also had a good backscatter contact with Neil G4BRK.
Signals were not huge, indicating that the losses were higher than on the
more direct paths, but it demonstrates that RS will work over significant
distances in any direction if the storm is sufficiently intense, regardless
of the path geometry.

73

John G3XDY

------------ --------- --------- ------

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