Results 1 to 14 of 14

Thread: Reception at night

  1. #1
    Junior Member
    Join Date
    May 2012
    Location
    Melbourne
    Posts
    140
    Thanks
    39
    Thanked 46 Times in 23 Posts
    Rep Power
    159
    Reputation
    505

    Default Reception at night

    Why is that that some transponders (mainly C band) can be received perfectly each night but either no lock or bad break up during the day?
    What is it that causes this issue?

    Weather? Local interference ?



Look Here ->
  • #2
    Junior Member
    Join Date
    Aug 2016
    Posts
    168
    Thanks
    0
    Thanked 10 Times in 9 Posts
    Rep Power
    102
    Reputation
    210

    Default

    I think it's a bit of both plus there's always solar fade and stuff. Sky is normally clearer at night as well.

  • #3
    Senior Member

    Join Date
    May 2011
    Location
    Perth
    Age
    64
    Posts
    732
    Thanks
    934
    Thanked 246 Times in 141 Posts
    Rep Power
    271
    Reputation
    4545

    Default

    I have found over the years that early morning around sunrise can be better for C band reception. With my 3.7m mesh dish - some of the weaker transponders in the evening have some picture break up but are quite often better in the early morning.

    Cheers.

  • #4
    Junior Member
    Join Date
    Feb 2008
    Location
    eastern N Z
    Posts
    143
    Thanks
    0
    Thanked 33 Times in 21 Posts
    Rep Power
    213
    Reputation
    640

    Default

    Never noticed much of a difference on c band
    remember aurora back in the day used to get abc @55 7pm, by 11 pm down to 38 almost every day

  • #5
    Administrator
    mtv's Avatar
    Join Date
    Jan 2008
    Posts
    19,893
    Thanks
    7,508
    Thanked 15,066 Times in 6,761 Posts
    Rep Power
    5647
    Reputation
    239305

    Default

    Basically, it's atmospheric conditions.

    Signals vary all the time, but those which may be fairly low are more noticeable when they fluctuate as they can drop below the minimum threshold for reliable reception.

    The same thing happens with terrestrial signals.

  • The Following 2 Users Say Thank You to mtv For This Useful Post:

    backer (10-06-18),OSIRUS (20-05-18)

  • #6
    Premium Member

    Join Date
    Jan 2008
    Location
    Central Tablelands of NSW
    Age
    81
    Posts
    13,824
    Thanks
    1,242
    Thanked 3,806 Times in 2,525 Posts
    Rep Power
    1797
    Reputation
    56986

    Default

    Read up on receiving Short Wave Radio etc regarding how the atmosphere and its layers are affected by the Sun.
    In the USA, they had AM radio stations that only broadcast during the daylight hours because the coverage area increased after dark.
    I believe we had Radio stations here that increased their Power during the Day to maintain coverage of their license area.
    My own local AM station had all sorts of problems when they did a major upgrade, new more powerful transmitter, antenna and a frequency change by almost drowning out a similar frequency station 200 kms away once the nights cooled off.
    Eventually it was decided to change the transmission frequency to an unoccupied spot on the dial.
    TV skip was a big thing in the years past but now rare as Hens Teeth.

    The Sun is the prime generator of 'Noise' along with heating of the atmosphere that causes all sorts of disturbances.
    I stand unequivicably behind everything I say , I just dont ever remember saying it !!

  • #7
    Administrator
    mtv's Avatar
    Join Date
    Jan 2008
    Posts
    19,893
    Thanks
    7,508
    Thanked 15,066 Times in 6,761 Posts
    Rep Power
    5647
    Reputation
    239305

    Default

    Gordon, the ionosphere is certainly relevant to HF frequencies but is has virtually no effect on satellite frequencies.

  • #8
    Premium Member

    Join Date
    Jan 2008
    Location
    Central Tablelands of NSW
    Age
    81
    Posts
    13,824
    Thanks
    1,242
    Thanked 3,806 Times in 2,525 Posts
    Rep Power
    1797
    Reputation
    56986

    Default

    Which is fortunate because if it did, we would not have Satellites or be able to send probes into the depths of Space.
    I stand unequivicably behind everything I say , I just dont ever remember saying it !!

  • #9
    Senior Member

    Join Date
    May 2011
    Location
    Perth
    Age
    64
    Posts
    732
    Thanks
    934
    Thanked 246 Times in 141 Posts
    Rep Power
    271
    Reputation
    4545

    Default

    I have found that the Insat satellites providing reception to India have been (fringe reception) viewable to Perth under certain conditions over a number of years.

    I also find that Intelsat 20 into the west coast of oz varies. The tp's close to and showing break up or non-existent tp's at night on some mornings show up quite well. My experience is over the last eight years!!!

    David.

  • #10
    Junior Member
    Join Date
    May 2012
    Location
    Melbourne
    Posts
    140
    Thanks
    39
    Thanked 46 Times in 23 Posts
    Rep Power
    159
    Reputation
    505

    Default

    Have you ever found yourself getting a bit obsessed about tweaking the dish then after spending hrs it's better or worse or some TP's are improved while others are worse. Then having to stop yourself and say the signal strength is just too low or my equipment isn't good enough?

    Sometimes I feel like I am chasing signal ghosts.
    Last edited by backer; 10-06-18 at 01:00 AM.

  • #11
    Senior Member

    Join Date
    Jul 2012
    Posts
    1,433
    Thanks
    934
    Thanked 1,661 Times in 724 Posts
    Rep Power
    836
    Reputation
    32307

    Default

    Quote Originally Posted by backer View Post
    Why is that that some transponders (mainly C band) can be received perfectly each night but either no lock or bad break up during the day?
    What is it that causes this issue?

    Weather? Local interference ?
    Satellite Communications and Space Weather

    Satellite communication is normally thought of as a robust means of communication, not sensitive to environmental impacts. This perception is not totally accurate. Satellite communication can be and is affected by the environment in which it operates.



    Satellite signal propagation

    Summary
    Although satellites generally operate at frequencies that may be thought to be immune from tropospheric and ionospheric disturbance, these regions still have a significant effect and this needs to be taken into account when designing satellite systems. As a result satellite propagation, i.e. the radio signal propagation to and from the satellites of great importance.



    Note that many of these phenomena are influenced by the level of ionospheric ionisation, which is generally much higher during hours of daylight........this could explain the loss of some signals during the day.

    Such a loss, or significant signal degradation during daylight hours, has also been my experience.

  • The Following User Says Thank You to Thala Dan For This Useful Post:

    tristen (10-06-18)

  • #12
    Premium Member

    Join Date
    Jan 2008
    Location
    Central Tablelands of NSW
    Age
    81
    Posts
    13,824
    Thanks
    1,242
    Thanked 3,806 Times in 2,525 Posts
    Rep Power
    1797
    Reputation
    56986

    Default

    The Sun is the prime generator of much atmospheric 'Noise'.
    Its at first and Last light where you are with the Sun at the time, causes some odd phenomena briefly.
    After the Sun has passed more than 3 hours, the night ambient temperature has dropped and so does the 'Noise' level.
    There are numerous other factors that play a part as well.

    During Daylight hours where you are is being bombarded with all sorts of energy from the Sun with Sunspots creating disturbances across the bands and its them that are responsible for HF Radio (27Mhz CB) using just 5 watts to travel almost anywhere (Skip) around the World.
    It was the 'Rule' that 3 to 30 Mhz was prone to atmospheric 'Skip', 30 to 300 Mhz less affected with 300 Mhz and above virtually unheard of, but like all Rules, they have been broken.
    They dont often say much about it but every now and again there is a warning issued of the possibility of intensive Solar Flare activity that doesnt just affect the radio bands but could even 'Nuke' satellites by their intensity.
    I stand unequivicably behind everything I say , I just dont ever remember saying it !!

  • #13
    Senior Member

    Join Date
    Oct 2010
    Posts
    1,384
    Thanks
    46
    Thanked 980 Times in 500 Posts
    Rep Power
    503
    Reputation
    14661

    Default

    Don't forget that what we consider to be geostationary satellite do wobble a move a little out of position throughout the day. Hence minor variations in signal. Also local temperature can effect your lnbf, high heat or freezing conditions.

  • #14
    Premium Member

    Join Date
    Jan 2008
    Location
    Central Tablelands of NSW
    Age
    81
    Posts
    13,824
    Thanks
    1,242
    Thanked 3,806 Times in 2,525 Posts
    Rep Power
    1797
    Reputation
    56986

    Default

    Its really fascinating when you get right into it and were chasing Skip or SW stations ( before they were closed down) for those elusive QSL cards.
    I know of a friend whose Austar LNB became heat affected and the palaver he went through to get it replaced.
    I felt during specific times of the year, the LNB on my Ipstar LNB reacted to the Sun hitting the full flat face of the LNB during the afternoon.
    Electronics have improved markedly and with many forms of Communications going into the higher bands and being located closer because of that, its not until you get out into the lesser covered areas do you experience these almost forgotten reception problems.
    I stand unequivicably behind everything I say , I just dont ever remember saying it !!

  • Bookmarks

    Posting Permissions

    • You may not post new threads
    • You may not post replies
    • You may not post attachments
    • You may not edit your posts
    •