Topics

TP 1 'Power.'

geojohnt@...
 

All,

I'm seeing + 1 dBm on my SR 1 Power reading this morning but no change in Es/No level, which remains 
at the usual morning clear sky level reading.

Mind you, I don't know what the 'Power' reading actually shows.

Regards,
John Tellick.




David J Taylor
 

All,

I'm seeing + 1 dBm on my SR 1 Power reading this morning but no change in Es/No level, which remains
at the usual morning clear sky level reading.

Mind you, I don't know what the 'Power' reading actually shows.

Regards,
John Tellick.
=====================================

John,

I asked this once, and the response was that this value was the level into the demodulator chip (with the Ayecka SR1). The scale on the Java program show -20 dBm as the maximum possible, so +1dBm sounds to be way out. What was the level before? Perhaps a typo?

As you know, the Es/No is determined almost exclusively by the LNB unless there is an excess of cable, so in principle adding a line amplifier would increase the level but not affect the SNR to any noticeable extent.

Cheers,
David
--
SatSignal Software - Quality software for you
Web: http://www.satsignal.eu
Email: david-taylor@...
Twitter: @gm8arv

geojohnt@...
 

David,

Thanks for your comments.

I see what you mean.

Well, my usual Power level is -25 dBm.
Today it's been -24 dBm all day.

So, that is an increase in Power level of 1 dBm? 

Regards,
John.

+++++++++++++++++++++

-----Original Message-----
From: David J Taylor via Groups.Io <david-taylor@...>
To: MSG-1 <MSG-1@groups.io>
Sent: Mon, 20 Jan 2020 16:01
Subject: Re: [MSG-1] TP 1 'Power.'

All,

I'm seeing + 1 dBm on my SR 1 Power reading this morning but no change in
Es/No level, which remains
at the usual morning clear sky level reading.

Mind you, I don't know what the 'Power' reading actually shows.

Regards,
John Tellick.
=====================================

John,


I asked this once, and the response was that this value was the level into
the demodulator chip (with the Ayecka SR1).  The scale on the Java program
show -20 dBm as the maximum possible, so +1dBm sounds to be way out.  What
was the level before?  Perhaps a typo?

As you know, the Es/No is determined almost exclusively by the LNB unless
there is an excess of cable, so in principle adding a line amplifier would
increase the level but not affect the SNR to any noticeable extent.

Cheers,
David
--
SatSignal Software - Quality software for you
Web: http://www.satsignal.eu
Email: david-taylor@...
Twitter: @gm8arv




Douglas Deans
 

On 20/01/2020 17:37, geojohnt via Groups.Io wrote:
David,
Thanks for your comments.
I see what you mean.
Well, my usual Power level is -25 dBm.
Today it's been -24 dBm all day.
So, that is an increase in Power level of 1 dBm?
Regards,
John.
========================================================

Hello John,

The thing that most affects the power level reading can be cable length. Decrease it and it will improve, increase the length and it will go up.
Maybe the long awaited drier weather (first this year) is drying something out and lowering the reading. It is a minor alteration and I see an occasional change in the evening if it is cold and dry.
My reading is -14dBm and during a cold dry evening often goes to -13dBm. I have a relatively short cable. Can't remember exact length but certainly less than 10 meters which explains my lower reading.

Regards,
Douglas.

geojohnt@...
 

Douglas,

Thanks for your comments.

This is my first winter with the new LNB - Inverto Black Ultra quad.
With the previous Inverto Black Ultra single used for many (many) years, the Power used to go up slightly 
during frosty periods if I recall correctly
And down slightly when the LNB baked in hot summer sun with high ambient temperatures.

Neither small steps cause any problems.

Regards,
John. 

++++++++++++++++

-----Original Message-----
From: Douglas Deans via Groups.Io <gm4vzy@...>
To: MSG-1 <MSG-1@groups.io>
Sent: Mon, 20 Jan 2020 17:54
Subject: Re: [MSG-1] TP 1 'Power.'

On 20/01/2020 17:37, geojohnt via Groups.Io wrote:
> David,
>
> Thanks for your comments.
>
> I see what you mean.
>
> Well, my usual Power level is -25 dBm.
> Today it's been -24 dBm all day.
>
> So, that is an increase in Power level of 1 dBm?
>
> Regards,
> John.

========================================================

Hello John,

The thing that most affects the power level reading can be cable length.
Decrease it and it will improve, increase the length and it will go up.
Maybe the long awaited drier weather (first this year) is drying
something out and lowering the reading. It is a minor alteration and I
see an occasional change in the evening if it is cold and dry.
My reading is -14dBm and during a cold dry evening often goes to -13dBm.
I have a relatively short cable. Can't remember exact length but
certainly less than 10 meters which explains my lower reading.

Regards,
Douglas.