Missing channel

RobH1

RobH1

Well-Known Member
Channel 23 (Caldbeck transmitter) will not tune on the FoxT2. I only noticed as Quest is missing, all the other channels on this mux I generally delete.
On a manual search, it shows strength 26%, quality 10%, however the Panasonic TV tunes this channel no problem.
It's not a problem in the sense that I have Quest+1, but it seems odd that the TV tunes ok but the Hummy doesn't.
 
So... let's start with the obvious: is the TV fed via the Humax or separately? If the latter, have you tried swapping the feeds? If the former, have you tried eliminating the amplification of the Humax by feeding the TV directly?

Assuming that all checks out, there is still no real mystery: it's just that the TV has a greater sensitivity. But nonetheless it seems your reception is iffy - is UHF23 out-of-band for your aerial?

[Reference] UHF Frequencies, Channel Numbers, & Aerial Groups, & How to Choose

(Sources: http://www.jimsaerials.co.uk/freeview/reception/aerials & coax/aerial.htm, https://www.aerialsandtv.com) Standard UHF broadcast frequencies for TV are 8MHz apart, spanning Channel 21 (474 MHz) to Channel 68 (850 MHz). The frequencies for intermediate channel numbers can be calculated...
hummy.tv hummy.tv
 
Thanks BH, the TV is fed via the Humax and I'll have a crack at your suggestion later. We have recently moved and haven't had opportunity to checkout the aerial which is communal and shared with two other apartments.
 
I'd be looking at what device is doing the sharing, as well as the cabling and the aerial.
What values do you get for the other muxes?
 
Ok,
Fed the TV separately and a manual search of channel 23 showed strength 30% quality 40% and I was able to see the programme ok. The remaining channels went as follows:

Ch25 36/100 to 48/100
Ch26 33/100 to 27/10 yes 10
Ch28 54/100 to 52/100
Ch30 48/100 to 42/100
Ch22 33/100 to 40/100 DVBT2

So a gain on ch23 and a loss of ch26

Suggests I may need a booster which I had at the last house, a half mile away, and shared with 8 other apts.
The sharing device and cabling ( state of the art property conversion) is very new and looks like this:

1574587818545.png
 

Looks like you have satellite and terrestrial on the same co-ax (different frequency bands), with individually selectable hi/lo and H/V (four satellite inputs provide all combinations from a quad LNB at the dish, the distribution box feeds you the right one according to the selector signals your sat box sends up the cable). Neat.

See if you can check reception in the other appts, maybe even switch cables around. If there is a difference you can localise the problem to a specific cable run or distribution box output. If there is no difference you will have isolated the problem to the cable from the aerial, the aerial itself, or reception conditions (aerial siting).

Can't say I'm very impressed with how neatly the distribution box is installed, so I wonder what that says about the cable runs etc that can't be seen. Tight bends in co-ax are a no-no.
 
Thanks BH, reception on the TV is ok, it is only via the FOXT2 on the one channel which is iffy.
Checking the other apts (whom I've not met yet) would probably not yield much if they haven't got a T2.
I'll have another play with the cables, may have to buy a splitter as one (of two) coax outputs on the room socket is used for the radio.
Line if sight to Caldbeck is pretty good, 17 miles.
 
You seem to be on the Cumbria side of the transmitter?

So you should be seeing:
Ch Mux Power Mode
22 PSB3 100kW DTG-6
23 COM4 50kW DTG-8
25 PSB1 100kW DTG-3
26 COM5 50kW DTG-8
28 PSB2 100kW DTG-3
30 COM6 50kW DTG-8
32 COM7 31.9kW DTG-6
35 COM8 35.8kW DTG-6

(DTG-6 = DVB-T2)

Looks like the communal aerial is a bit dodgy if the 1100' transmitter aerial is only 17 miles away. Try a portable aerial?
 
RobH1 said:
reception on the TV is ok
Click to expand...
But you don't know how "OK" the reception on the TV is - it might be (and probably is) only just OK. Can't you get any figures out of it? DF's post indicates UHF22 is being transmitted with twice the power of UHF23, and where are your UHF32 and UHF35?
 
RobH1 said:
The sharing device and cabling ( state of the art property conversion) is very new
Click to expand...
Unimpressed.
The TV installation is certainly not state-of-the-art. Is it really just plugged into a mains socket as the picture implies and hung on the wall?
There is no earth bonding either.
You should have no problems with signal levels from the TX as described, but yours seem to vary wildly, if I understand your figures correctly.
Have you got pictures of the dish/aerial installation and can you tell what the cable is?
I suspect physical damage (causes notch filter effect which kills certain muxes) and/or interference ingress.
I'm afraid you need to get whoever is responsible for this to start at the dish/aerial and work their way down the chain and check it all out properly.
RobH1 said:
one (of two) coax outputs on the room socket
Click to expand...
How is that split if there's only a single incoming cable? Picture of that too?
 
I appreciate the reply prpr, but life's too short to worry about one channel. As my original post the lack of one programme is not a problem.

I know some people are anal in regards getting to the root of all problems (not suggesting you are, of course), but I ain't one of them.
 
/df said:
You seem to be on the Cumbria side of the transmitter?

So you should be seeing:
Ch Mux Power Mode

32 COM7 31.9kW DTG-6
35 COM8 35.8kW DTG-6

(DTG-6 = DVB-T2)

Looks like the communal aerial is a bit dodgy if the 1100' transmitter aerial is only 17 miles away. Try a portable aerial?
Click to expand...

Yes we are. Com7/8 were removed a while ago, I remember being miffed and commenting on the loss of BBC NewsHD and QuestHD

See here
 
Last edited:
Let's hope one of your neighbours doesn't have a fault that causes the whole installation to become live then...
...otherwise life may be a bit shorter than you anticipated.
 
Black Hole said:
But you don't know how "OK" the reception on the TV is - it might be (and probably is) only just OK. Can't you get any figures out of it? DF's post indicates UHF22 is being transmitted with twice the power of UHF23, and where are your UHF32 and UHF35?
Click to expand...

See post #14 re COM7/8
 
You seem to have a blasé attitude to safety. It's also illegal. Perhaps you have a blasé to that as well.
You also seem to like being ripped off by shoddy tradesmen.
 
prpr said:
You seem to have a blasé attitude to safety. It's also illegal. Perhaps you have a blasé to that as well.
You also seem to like being ripped off by shoddy tradesmen.
Click to expand...
No I haven't but since I don't own the property (in between selling and buying) I tend not to worry. As to being ripped off by shoddy tradesmen well I guess most people are pussycats compared to me.
Anyway we're off the subject.
End of thread at this point. Thanks as usual to all who contributed.
 
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