I find that occasionally around 17:30 to 19:00 I lose signal on BBC Yorkshire (101) I know this is trnmitted with vertical polarisation at 14V I beleive . I'm wondering if the mains voltage drops at those times as people cook Tea causing the LNB voltage to drop and losing signal lock.
Ive tried some of the other BBC1 regional stations and found some of those aren't available as well.

Ive tried swapping LNB cables round but it disappears on both my Freesat tv and the Humax.

Does my theory sound plausible?

^^^ nudge previous post to view

No it doesn't I am afraid. All modern electronic equipment use switch mode power supplies that maintain their output over very large input voltage variations. Most PC power supplies can work at 110v - 250V without the output voltages varying.

You might have a source of local interference that's time related, could even be a faulty street lamp outside your property

No its not the same problem as that. I can get BBC2, ITV etx. its just the ones on the vertical transponder that I get no signal.
Correct me if I'm wrong but the Humax switches the voltage from 18V to 14V when going from horizontal to Vertical. I just wondered what the max voltage was for satellite lock and if its dropping due to mains fluctuations at peak times.

Thanks, I even went outside to look and see if it was a big fat pigeon or something sat on the lnb arm.

This sounds possibly like some form of external interference. However, if you use another box (non-Humax) do you still see the same issues? If you don't then it's a Humax issue, if you do it's something external causing it - local taxi cab firm, domestic appliance, that type of thing.

It might be worth connecting the kit via good quality filtered mains block and so forth, and you could try clipping a ferrite choke to the incoming cables.

Next thing to try would be to replace the LNBs and downleads.

I sometimes get break-up on my satellite system - I've had the issue for a couple of years and I still haven't been able to fix it. I see break-up on the low h/v channels at pretty much the same time every night.

This will drive you crazy ....!


Clem

I will not tolerate nasty sly digs at BT..
which puzzled my aged mind..
How dare you? But as you are helpful to others ..
I'll helpfully explain the background..
I understand that all the major players..Branson et al..
have for a long time adopted the 7Pm change over time
and BT merely came into line as they.. the supposed Leaders ..
who are invisible in the Chilterns and such like places..
would not agree to adopt the liberal BT hours..
so Blame Maggie if you must blame anyone.
Down here i tune to OXFORD but BBC have been economising and using BBC SOUTH instead for some months..
There has been a court case i think which may have also accounted for the change..
Possibly something akin may have happened upNorth.
When i looked at the average bitrates recently.. under the guidance of Graham..
i saw large variations for the regional averages and from memory NI were best of the lot.. Strange that ?
Decades ago I was in charge of investigation of such matters in a Far-Off Land.
If you keep records of the interference i am sure that the new system will provide a free service
as we did as a function of the Licence fee..
I am reminded that in those halcyon days.. my chaps ..who were all Welsh..
had to explain to such complainers.. that it was
"The leaves falling off the trees" [sic] which made for Seasonal variation of the BBC Colour signal from Bristol across the channel..
Newly arrived English residents in South wales..who were usually in charge of large establishments..
regarded this as the welsh insulting their intelligence .
In those days the political PMG's office required me to visit such dignitaries and over a sherry or two..
persuade them of the reality of the situation..
Although Home Rule for Wales Activists did complicate the reality as well..

Clem thanks for advice. I have the same problem with my Freesat Panny TV as the Humax, so that rules out the boxes. One of the downleads is new and swapping them around doesnt change anything. S o it must be interference I reckon, will get a new filtered mains block & try that.

I dont know what stanandjan is on about!!!!

It's very unlikely to be mains borne interference, basically you are looking for a source of rf emissions at or near 1.0788GHz which is the BBC 1 transponder frequency.

If it's just the one transponder you should also be missing the following

952 BBC 1 E Mids
953 BBC 1 East (E)
955 BBC 1 N West
963 BBC 1 W Mids
966 BBC 1 Yorks
967 BBC 1 Eyrks*L

Typically this would be from a wifi router or cordless phone (it might be on a neighbours property). The timing of the problem might for instance be a wifi router thats only used in the evenings.

I think the Vertical polarisation is a red herring as presumably you can still get BBC HD which is also vertically polarised on 1.0847GHZ the specific frequency affected really rules out most things.

Long shot water in the coax cable can affect specific frequiencies more than others, but you have already ruled that one out.

I think you're right, difficult to over come though. I dont think any of the neighbours have freesat plus I cant tell them to get another Router. would changing channels on a Router solve it?

May be but it might then affect a different transponder. Simply shifting it even slightly may well afford a cure. If you are happy to get local news from BBC2 or ITV 1 you could move a different BBC 1 region to 101 from the following list or simply use the appropriate lcn when you have the problem.

956 BBC 1 NE & C
958 BBC 1 Oxford
959 BBC 1 S East
961 BBC 1 South
962 BBC 1 S West
965 BBC 1 West
951 BBC 1 CI
954 BBC 1 East (W)
950 BBC 1 London
957 BBC 1 NI
960 BBC 1 Scotland
964 BBC 1 Wales

You could check for a router in range by using a PC's Wireless Connection to view available wireless network connections and see if there is one specific one that causes the problem. (Right click the TV with brackets in the system tray)

If you want to see what WiFi is in operation in your area try NetStumbler, here is a link.

http://www.netstumbler.com/downloads/

It will leave a log showing when a system starts up and when it shuts back down to see if it coincides with your channels problem.

You will need Wifi on your computer but most lap tops have it built in.

I have found it best use with a USB extension lead with a WiFi dongle on the end, stuck in a window.

Thanks Skip Tracer I will give it a go see what I pick up.

There might be a problem if the wifi in the computer does not support N type routers like the BT Home Hub. If the offending source is a N type it won't recognise it.

Graham I don’t know what’s happening on this thread but your post which is shown as post number 13 (timed at 16.13) is shown on my computer as a post from Microvent ?.

To read your post I had to click on “find other post by grahamlthompson”

Strange.

Maybe when I post this post it will shake your post out into the open.

Now it's showing as post 14.

How Peculiar . Still as the Bard said "Alls Well That Ends Well"