Freeview loft aerial?

[John Rumm]

Yup, sounds like it should be fine - at least for Muxes in channels that are in-band on the aerial.

I take it he was not using it?

I have my aerial pointed at Sudbury, since I could not get a clean feed from CP (but that was over a decade ago when I set it up). I am using a group B that I modified to Mr Wright's recipe to munge into being a Group E (i.e. not quite wideband, but from B to the top of the (then) frequency range allocated to terrestrial TV. Now that CP is running at full power on the DTV output, I do also receive duplicates of the main muxes from there - even though its probably 90 degrees off axis for my setup - so there is a fair chance I would get all of them if I were to repoint it at CP.

Yup, its been a good meter - paid for itself several times over as well :-)

Yup, also I note that while there are a few devices in the "low hundreds" price range, many claim to be analysers for DVB-S, DVB-T, CCTV and a host of other things - so possibly somewhat less "focussed" than Terry.

Yup, sometimes one has the override the technical challenge of "because I can", and ask the more basic question, do I actually want it?

With your signal strength, chances are you could swap the aerial for a wideband (or probably even a log periodic), and pull them all in.

I was going to ask how you were getting on with that. Sounds like you are making good progress.

Where are you storing the recordings?

Do you even need a specific plex client? If you ran the server on the Pi, you could use the web interface from any browser?

Ah, did not know about the xbox tuners - you can't argue with the price!

Glad its doing what you wanted. It sounds like you have come up with a somewhat different solution to mine - might be worth doing that wiki article on setting up a DTTV PVR since we seem to have covered a fair bit of the landscape between us.

[Chris Green]

As I understand it they're simply squeezing more in on the other MUXs and losing a few channels as well.

[T i m]

Ah, thanks Chris.

Cheers, T i m

[Mark Carver]

As an aside, COM 8 (UHF Ch 56) ceases transmissions on Monday (30th June)

This week most of its channels closed, others (notably BBC 4 HD) transferred to COM 7

COM 7 will struggle on, but its days are numbered (possibly only a year or two more), so don't spend a huge amount of money to try and receive it

[T i m]

Ok ...

OK, thanks.

Understood, but I'm guessing if I can get the 20kW Mux from here at

60%, I should be able to get the other 2(1) at ~40kW easily, given an aerial with a good enough bandwidth (even if it's only for the S&G's for the next couple of years)?

As mentioned previously, I may have such an aerial in the loft already and they may just need swapping over (I think I put sockets on them on a short flying leads so I could do so easily) and could that be all it takes (to get Com7)?

Cheers, T i m

[Mark Carver]

All things being equal, yes. However at Ch 55, loss through obstructions, (trees, buildings and not least your own roof/gable end) are significantly more than at Ch 20s/30s, as are the downlead losses, and (particularly) any cheap and cheerful fly leads (and silly gold plated crap on Amazon/ebay). Some of them have horrendous attenuation in the 50s/60s

[charles]

that takes me back to when Hutton came on air with BBC2 on Ch 66. The flylead supplied with someone'sVCR was losing some 20dB at that channel.

[Andrew]

I have actually seen one of those aerials on a hotel in Cumbria, near Beetham, called the Wheatsheaf. It doesn't show up on Google Earth, where the image is dated 2011. I was there in feb 2019.

Cumbria is a bit of a problem area for freeview, AFAIK.

William will know.

[T i m]

<snip>

Ah, ok, well I guess that's where a half decent way of measuring the signal strength could be handy, maybe starting at the higher end of the frequencies I can see currently?

And for ease and speed, daughter picked up some Poundshop flyleads for me to experiment with before I made up some suitable patch cables.

For my current tests I've been taking the signal from my house distribution amp and feeding it into a 4 way splitter and then to (say) 4 of my tuners on my test rig.

The 200KW muxes are *all* 80+% sig strength and the 20kW is 60+% but as you say, they may all still be within the 'good' frequency range of all the kit (from aerial, CT100 cable, distribution amp [1], splitter, patch leads etc).

So, if we are currently good between 482Mhz and 689Mhz, do you think such dropoff could happen over another 60Mhz (746Mhz), and going by the worse case of 20Kw being 60% and the 700M muxes are twice the power and can't be tuned at all (but may be 'seen' during, unless that's just because they are pre-subscribe when you select CP as your TX)? I could try a 'raw' scan and see what it actually thinks is out there?

Cheers, T i m

[1] I'll try to access the DA and see what make / model it is and if it mentions any frequency range. I believe it was there from the analogue days.

p.s. Given I might want 7 individual tuners and doubt I'll want the final NAS / PVR / TV backend / tuner solution in the main bedroom (where the DA happens to be as it's central to the house and where I stick the PC during testing), and given I seem to currently have reasonable signal, do I try to get away with a passive 8 way splitter or would I be better off with another DA, running off the first?

[Paul]

The typical TV band receiver, works over six orders of magnitude, and uses AGC (automatic gain control).

The signal strength indicator could be just about anything, like a log scale. But probably isn't. The signal strength indication changes too much, for it to just be hooked to the AGC control signal.

The decoding behavior has a sharp knee, going from "a few pixels the wrong color", then when the signal is 2dB lower "screen goes black". This is unlike the old analog TV, where the signal goes gradually into the soup, the picture is fuzzy, eventually there isn't enough signal for flyback synchronization, and after that the audio fades out. In the country, many a newscast was "watched" in audio only, while being 100 or 150 miles from the transmitter, with only a basic set top antenna.

*******

The quality indicator, is related to decoding errors. One kind of error characteristic for multipath, perhaps another for a faded signal situation. I have one tuner that must have an extra stage of error correction enabled, because it's excellent compared to a second tuner. And both of them fed from a 1:2 splitter, so they're seeing the same signal. The fancy error correction is the equivalent of a few more dB of gain in a sense.

Paul

[Brian Reay]

That looks, more or less, the same as mine. I bought mine, perhaps, 5 years back. The display failed- I think due to my dropping it- but I was able to get a replacement for about a tenner. Then I left it out over night in the rain but it survived. Certainly when setting up sat dishes they are excellent. Typically, I use an app to get the rough direction and elevation, then with the gizmo I can have it aligned in a couple of minutes and know how good reception is - it has a tv screen and tuner built in. Remember, the signal isn?t as strong as it could be in parts of Europe- where I often use it- so it isn?t like lining up a dish in the UK.