Cold \ Frost - better signal

[Manikm909]

i've noticed when its very cold, my reception gets stronger on weaker sats and TP's - why is that? whats the science behind it.

 

[Channel Hopper]

Better (lower ) background noise, both in the atmosphere and within the electronics.

Noise Temperature - an overview | ScienceDirect Topics

www.sciencedirect.com

 

[moonbase]

i've noticed when its very cold, my reception gets stronger on weaker sats and TP's - why is that? whats the science behind it.

Less people out and about polluting the airwaves with mobile phone 5G and wifi guff, they all indoors keeping warm.

It's a lovely clear morning 'ere in Surrey, you are not far from me, signal reception should be decent at the moment.
Some satellites with fringe reception have better signal levels in the evening, cold evenings with clear skies might be the best time to lock some of those elusive frequencies.

 

[PaulR]

Cold weather has less water vapour in the atmosphere which means the signal isn't absorbed as much. In addition, cooling down an LNB is a well known way of reducing noise in the circuitry. See this thread from a few years ago. Cooling the LNB

 

[PaulR]

Professional radio astronomy uses extreme cooling to produce low noise figures in LNAs. Liquid nitrogen and even liquid helium are used. See Low Noise Amplifiers - Pushing the limits of low noise — Science Website and How do the Cryogenic Cooling Systems Work on the VLA Receiving Systems? - National Radio Astronomy Observatory

 

[Terryl]

It could be that the crystal oscillator in the LNB is moving closer to the correct frequency needed for the down conversion, most LNB's use a Phase Locked Loop circuit to derive the correct down conversion frequency (the LO frequency) of the satellite transponders, the PLL circuit relies on a crystal to keep it on a set frequency, if the crystal is off a bit (too high or low) so is your down-conversion frequency.

The cold weather is causing the crystal to move up or down, thus moving the PLL frequency closer to the correct down conversion frequency.

Professional quality LNB's use a Temperature Controlled crystal oscillator circuit (TCXO) to keep things on the right frequency.



Sorry, too much coffee...

 

[Manikm909]

It could be that the crystal oscillator in the LNB is moving closer to the correct frequency needed for the down conversion, most LNB's use a Phase Locked Loop circuit to derive the correct down conversion frequency (the LO frequency) of the satellite transponders, the PLL circuit relies on a crystal to keep it on a set frequency, if the crystal is off a bit (too high or low) so is your down-conversion frequency.

The cold weather is causing the crystal to move up or down, thus moving the PLL frequency closer to the correct down conversion frequency.

Professional quality LNB's use a Temperature Controlled crystal oscillator circuit (TCXO) to keep things on the right frequency.



Sorry, too much coffee...

Lol

I bow down to your knowledge sir.

Nice one