All posts by nicholas
Below are all of nicholas's postings, with the most recent are at the bottom of the page.Hi,the definition of ghosting is a secondary image attached to the video which can be from indifferent
reception on analogue,mismatch of input circuitery,noise, too many units in line,poor cable where the
signal gets reflected back and forth in the cable.On analogue,there were cases in London where the
ghosting wasn't fixed ,this was called multipath.
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As stated in my articles,mpeg 2 does suffer from stuttering or jerking effects particulary on fast motion
where there is insufficent bit rate to carry the video information but domestic equipment also has deliberate
noise added as per my previous articles and i have explained why.
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hi mike,as said,21-69 is for public use,however its been diluted,frankly the phone networks should been pushed up higher or lower,why should tv be pushed around but these are questions out of one's control, i think the reason why vhf band 3 wasn't reengineered for uk use is more political,many vested interests have
their fingers in the pie,it would just need wider channels,the frequency band makes no difference to the service concerned,405 required 5mhz channels,625 would need 8mhz, but as stated earlier,plenty of fingers,
ie transmitters and what goes with them,it seems the best solution is not available politically,and of course
other services also take away the available use.Channel 69 is used by wireless headphones and microphones,what will happen to secondary users remains in the hands of ofcom and the like.Most network
transmitters are fed by satellite these days,goodness knows what will happen if something drastic happened to the satellite service.
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HI, what you say is true but one is more interested in the technical side rather than the adminstrative side,my
feeling that band 3 was possibly the best option in ticking all the boxes but such is life the best isn't always
chosen.Band 1 had terrific range which worked against it,in swindon,one could view crystal palace on 1,holme
moss on 2,rowridge on 3,sometimes knocking out the swindon relay,4 was sutton coldfield and the most
troublesome from the fading was wenvoe on 5.Such memories.Perhaps it may have been better that UHf had never been allocated,perhaps an extended band3 would been best,who knows,really?If conference had
allocated 170-300mhz to band 3, it could have been utopia,one will never know.
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hI,Problems with signal cancellation by trains,it is suggested if the local field is high enough is to move
the aerial behind part of the building facing the track,this should modify the cancellation effects of the
trains,other suggestions require more technical knowledge unfortunately.Should there be another
transmitter in the opposite direction perhaps this might provide a solution.You could try inverting the
aerials upwards and see if that improves matters.
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All i can say,for good reception of broadcasting,the aerials and cable will need replacing from time to time,in
coastal regions perhaps more than inland,however, a lot of installations never get attention until the day when they fall off the roof.There are still Band 3 aerials on rooftops around the country,given a good clean,and new cable etc,they would be good in fringe locations for DAB,me, i prefer FM,really,but find lot of car radios have poor circuitry and go off tune when the signal weakens.
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StevensOnln1: I see your point but lot of the new aerials fall short in shallow or deep fringe areas,the pick
up of the double 6 was awesome.Still,its a shame to see these go to waste and you have an aerial for
pennies.I will be sad if the BBC was forced to leave FM,best quality,no drop outs,no stalling,stil everbody
has their opinion.
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Mark: Hi,when you scanned for channels,did you save them?,if the tv indicates same.Sometimes people
forget to save them or memories even i n new sets go faulty.
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Hi,i was just thinking,people who live very close to their local transmitter and yet have problems,is to use
the infill signal which is transmitted at a low height on the station mast but this is available only really
within one or two miles,anyhow its just a suggestion.An aerial could be put virtually at ground level and
pick up a stable signal,all these things are worth trying,aerial science sometimes is weird and wonderful.
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Sunday 16 October 2016 10:38PM
Hi,the uhf television used to be from channels 21-81,however ,channels 69-81 were withdrawn and given to
mobile phone companies,but as secondary users,various channels were allocated to tv translators and
pay tv,example is bfbs cyprus which uses 75/76 or whatever the licensing authority permits,say ofcom in
uk,there is a service called the c69 allocation for radio mikes and wireless headphones or audio.The general
tuning of the tv is determined by its target market,uk-uhf only,europe band 3 and uhf.In the african broadcas
ting area vhf channels 14 15 16 have been used,band 3 was channels 6-20,but 14-20 were withdrawn and
other services use these frequencies,Band 3 in my opinion was the best band for tv and it is such a shame that uhf was used,the problem of uhf was poor range which had to offset by high masts and tx power and
many relays or translator stations.