Request for New and exciting CF feature.

Trev

The Dumb One
Background.
I have recently been changing/re-aligning my TV aerial, including optimising masthead amp gain etc.
Apart from the mechanical challenge of doing this, I found the process for checking signal strengths on the various MPXs a bit tiresom even when the Hummy/TVs are already tuned in, requiring a bit of tedious research.

1. Find the RF channels (MPXs) transmitted by the transmitter in question.
2. Find a suitable TV channel in each of the MPXs. (what do I call suitable? I don't know)

Then to check:
3. Tune the TV to one of the TV channels on the required MPX.
4. Check Sig/Qual for that channel
5. Repeat 3 and 4 for the other MPXs.

Of course, doing the latter on the Hummy/TV is the tedious bit, having to wade through multiple menu levels to get to the sig/qual readout; Exit; re-tune; wade through the menus again et. al.
Up onto the flat roof again. Make adjustment; back down to the TV; repeat 3-5 for new settings.

Request. If it's possible/doable.
Add a tablet/phone friendly function to the CF with the facilities to:

A. List the MPXs (by RF channel No.) to which the Hummy is currently tuned. (to cross check against the transmitter and to allow the across-band checks below)
B. Display an automatically updated (every few seconds or so) of the current sig/qual readings for the tuned TV channel (to give the MPX values).
C. Allow a one click ability to change TV channels to just one of the TV programmes in the aforementioned MPXs. (A single pre-programmed channel number per MPX?)

This would save a considerable amount of upping and downing of ladders and thumb work on the RC handset. :=)

Thoughts.
Are the various TV channels always/mostly on the same MPX. i.e. Is TV CH19 (Yesterday) always on MPX ArqB etc. (ref. C above)
Obviously, the research at points 1 and 2 above are still required.
 

prpr

Well-Known Member
A. List the MPXs (by RF channel No.) to which the Hummy is currently tuned. (to cross check against the transmitter and to allow the across-band checks below)
B. Display an automatically updated (every few seconds or so) of the current sig/qual readings for the tuned TV channel (to give the MPX values).
C. Allow a one click ability to change TV channels to just one of the TV programmes in the aforementioned MPXs. (A single pre-programmed channel number per MPX?)
You can do A and C already (Diagnostic, Channel Information and Remote page respectively). B is not possible as far as I'm aware.
Are the various TV channels always/mostly on the same MPX. i.e. Is TV CH19 (Yesterday) always on MPX ArqB etc. (ref. C above)
Do you mean in time or in geography? Everything is on the same muxes in England but there can be differences between England and the other nations on some.
Everything stays where it is unless it is moved for some reason (mostly the COM channels play this game), which means you need to do a retune.
 
OP
Trev

Trev

The Dumb One
Unless B can be done, the whole idea is dead in the water, as that's the main attraction, being able to see the values on a super portable device 'on the roof'.
As you are no doubt aware, what I would like is already available in the std I/F signal page, allowing you to change RF multiplex channel whilst looking at the sig strength all from the same diagnostic page. (I was using my TV during my 'on the roof'' escapades, which is nowhere near as convenient as the Hummy, but I didn't check how it was done on the Hummy first. Doh).

I meant TV channel vs. MPX for any given transmitter over time (will it still be on that MPX next week or whenever?). I know the MPX's RF channel number/polarisation changes depending on the transmitter in use.
 

prpr

Well-Known Member
Emu couldn't fly. Nor could Rod Hull. I doubt you can either. Get a man in with a proper meter.
 
OP
Trev

Trev

The Dumb One
Get a life. It's on an 8 foot high flat roof. I know that I can kill myself with a fall from that height, but I'm a bit careful. I have done a full gain vs. cost vs. risk analysis, which indicates that the gain is high, the cost is zero and the risk is minimal. So combining the probability of occurrence and impact, I decided that if I wore a high viz jacket (compulsory), a hard hat (to protect my head from seagull poo) and steel toecap boots (in case I should drop an 'F' connector), I would be OK provided I got HWMBO to hold the 7 rung step ladder to prevent it slipping on the dry paving blocks. If it were atop a pitched roof, I would "Get a man in with a proper meter".
 

grahamlthompson

Well-Known Member
Background.
I have recently been changing/re-aligning my TV aerial, including optimising masthead amp gain etc.
Apart from the mechanical challenge of doing this, I found the process for checking signal strengths on the various MPXs a bit tiresom even when the Hummy/TVs are already tuned in, requiring a bit of tedious research.

1. Find the RF channels (MPXs) transmitted by the transmitter in question.
2. Find a suitable TV channel in each of the MPXs. (what do I call suitable? I don't know)

Then to check:
3. Tune the TV to one of the TV channels on the required MPX.
4. Check Sig/Qual for that channel
5. Repeat 3 and 4 for the other MPXs.

Of course, doing the latter on the Hummy/TV is the tedious bit, having to wade through multiple menu levels to get to the sig/qual readout; Exit; re-tune; wade through the menus again et. al.
Up onto the flat roof again. Make adjustment; back down to the TV; repeat 3-5 for new settings.

Request. If it's possible/doable.
Add a tablet/phone friendly function to the CF with the facilities to:

A. List the MPXs (by RF channel No.) to which the Hummy is currently tuned. (to cross check against the transmitter and to allow the across-band checks below)
B. Display an automatically updated (every few seconds or so) of the current sig/qual readings for the tuned TV channel (to give the MPX values).
C. Allow a one click ability to change TV channels to just one of the TV programmes in the aforementioned MPXs. (A single pre-programmed channel number per MPX?)

This would save a considerable amount of upping and downing of ladders and thumb work on the RC handset. :=)

Thoughts.
Are the various TV channels always/mostly on the same MPX. i.e. Is TV CH19 (Yesterday) always on MPX ArqB etc. (ref. C above)
Obviously, the research at points 1 and 2 above are still required.

You can't compare signal strength and quality measured on items from a different make and model. You will nearly always get different values (often wildly different). Only a spectrum analyser will tell you the real numbers. They are only useful for comparisons using the same box. As all the channels in a multiplex use the same carrier, any one will give the measured quality and signal strength, if they are different something is radically wrong. Sortable list here (click on the column headings). If you click on the MUX it lists the channels in Mux order. Basically all you need is a list of one channel from each mux.

http://www.digitaluk.co.uk/industry/Channels/channel_listings
 

prpr

Well-Known Member
Get a life. It's on an 8 foot high flat roof. I know that I can kill myself with a fall from that height, but I'm a bit careful. I have done a full gain vs. cost vs. risk analysis, which indicates that the gain is high, the cost is zero and the risk is minimal. So combining the probability of occurrence and impact, I decided that if I wore a high viz jacket (compulsory), a hard hat (to protect my head from seagull poo) and steel toecap boots (in case I should drop an 'F' connector), I would be OK provided I got HWMBO to hold the 7 rung step ladder to prevent it slipping on the dry paving blocks. If it were atop a pitched roof, I would "Get a man in with a proper meter".
:poop::poop::poop::poop::poop::poop::poop::poop::poop::poop::poop::poop::poop::poop::poop::poop::poop::poop::poop::poop::poop:

If there was an emoticon for FU I'd have used it. Take the bl@@dy telly up there with you if you're that damned bothered then.
 

grahamlthompson

Well-Known Member
Get a life. It's on an 8 foot high flat roof. I know that I can kill myself with a fall from that height, but I'm a bit careful. I have done a full gain vs. cost vs. risk analysis, which indicates that the gain is high, the cost is zero and the risk is minimal. So combining the probability of occurrence and impact, I decided that if I wore a high viz jacket (compulsory), a hard hat (to protect my head from seagull poo) and steel toecap boots (in case I should drop an 'F' connector), I would be OK provided I got HWMBO to hold the 7 rung step ladder to prevent it slipping on the dry paving blocks. If it were atop a pitched roof, I would "Get a man in with a proper meter".

You forgot the crampons :roflmao:
 

grahamlthompson

Well-Known Member
:poop::poop::poop::poop::poop::poop::poop::poop::poop::poop::poop::poop::poop::poop::poop::poop::poop::poop::poop::poop::poop:

If there was an emoticon for FU I'd have used it. Take the bl@@dy telly up there with you if you're that damned bothered then.

Funnily enough when a I align a satellite dish I use a small fta satellite receiver and a portable DVD player with composite video input. But your post did assume that the kit was in a hard to access location, incorrectly it seems. Frankly your response is totally over the top.

In any case if a man was brought in, chances are that he wouldn't have a spectrum analyser nor the skills to use one.

Likely to be at the same level as Sky uses to install dishes. Most of them are merely trained to follow simple instructions and do not have a clue when something is a bit out of the ordinary. They are not engineers.
 
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MikeSh

Well-Known Member
You can't compare signal strength and quality measured on items from a different make and model.

All Trev is asking for (I think) is some way to know the signal strength while moving the aerial - using a commonly available handheld device rather than buying a meter for that once in 10 years occasion. It just needs to show the best position - comparison with other devices is irrelevant.
Sounds like a very sensible and reasonable suggestion/request and something I could use on occasion.
 

Black Hole

May contain traces of nut
If I might address post 1:

The only data the CF has access to regarding the signal strength and quality is that which gets stored in the tuning database. If you perform an auto-tune, the figures for all the tuned muxes get stored. If you perform a manual tune, only the mux most recently tuned gets stored (the others are zeroed). That's it. End of. And the stored figures are static records of what was current at the time of the retune.

The idea of bending the 'FOX as a tuning meter is pie in the sky. Get a tuning meter.

The Humax 0-100 strength figure is arbitrary, and cannot be compared with anything else. The quality figure however, I disagree with some of the content above - quality is a measure of the error correction required and is therefore objective.

Something to be aware of: the presence of a large bag of salty water near an antenna affects the polar diagram for the antenna. Therefore you can't stand right next to the antenna and adjust it while watching the signal meter, and expect it not to shift when you move away.
 
OP
Trev

Trev

The Dumb One
You can't compare signal strength and quality measured on items from a different make and model. You will nearly always get different values (often wildly different).
Yes, I know all that. But If I am looking at the sig strength on (say the TV) provided I keep on looking at the signal strength on the TV then surely this will give me an indication of relative signal strength when I waggle the aerial or twiddle the gain settings on the masthead amp.

As it happens, I used my Sammy TV to do the comparisons on, and only mentioned the Hummy, as I found out after the event that comparing signal strength across the MPXs is a damn site easier on the Hummy than on the Sammy, as you can change MPXs directly on the same screen as the sig strength is shown, unlike the Sammy on which you have to first switch to a channel that you know is on the MPX that you are measuring, then wade through the menus to get to the sig strength et. page.
The fact that the signal strength reads about 80 on the Sammy and 60 on the Hummy, I know, as you say, is irrelevant.
Basically all you need is a list of one channel from each mux
That's exactly what I did do.
You forgot the crampons :roflmao:
No I didn't, or the nylon rope and O2 cylinder, but couldn't be bothered to mention them.:D
Mike said:
All Trev is asking for (I think) is some way to know the signal strength while moving the aerial - using a commonly available handheld device rather than buying a meter for that once in 10 years occasion. It just needs to show the best position - comparison with other devices is irrelevant.
Sounds like a very sensible and reasonable suggestion/request and something I could use on occasion.
That's exactly right. At least someone understands. Thank you.:)
BH said:
And the stored figures are static records of what was current at the time of the retune.
Then why does it jump about a bit whilst watching it? I just idly wondered if it was possible to access the data from the CF
BH said:
The Humax 0-100 strength figure is arbitrary, and cannot be compared with anything else.
I know that
BH said:
The quality figure however, I disagree with some of the content above - quality is a measure of the error correction required and is therefore objective.
Presumably it reflects the actual error correction parameter which can be measured, otherwise how would the quality cctry know what the error correction is? If it can be measured, surely this is objective not subjective. (other than the relationship between bit error rate (BER) and %age quality). But I suppose that's what you meant, although my Sammy gives a reading for BER
 

Black Hole

May contain traces of nut
Then why does it jump about a bit whilst watching it?
While watching what? It doesn't jump about in the WebIF presentation, because, as I said above, the CF only has access to a static figure stored at the time of tuning (and even then only under certain circumstances).
 
OP
Trev

Trev

The Dumb One
Trev said:
But If I am looking at the sig strength on (say the TV) provided I keep on looking at the signal strength on the TV then surely this will give me an indication of relative signal strength when I waggle the aerial
The signal level on the TV. What do you think I was watching, Star Wars on the radio?:D
 

Black Hole

May contain traces of nut
'Scuse me, but I thought you were talking about using the Humax. If you are looking at the signal strength via the WebIF diagnostics, that's static. If you are looking at the Humax on-screen presentation via the Signal Detection menu option, then you get a real-time display - but the CF has no way to monitor the same.

Here's an idea for you: point a webcam at the TV, bring up the Signal Detection screen, and monitor the webcam via your WiFi on a smart-phone or tablet.
 
OP
Trev

Trev

The Dumb One
Thanks for that. I really didn't care whether it was the TV or the Hummy. But suspect that achieving it on the TV would take a miracle, but doing it on the Hummy would be just plain vanilla impossible. I appreciate the impossible takes a little longer, but knowing how a few people here seem to achieve the impossible with ease, I was just sort of thinking aloud. If it can't be done, then it can't be done. Oh well, I think I will retire to my hobbit hole for a while to work off my strop and who knows, I might come back a better and reformed character.:)
 

MikeSh

Well-Known Member
Something to be aware of: the presence of a large bag of salty water near an antenna affects the polar diagram for the antenna. Therefore you can't stand right next to the antenna and adjust it while watching the signal meter, and expect it not to shift when you move away.

Yes. There have been a few TV sketches involving that phenomena and (usually) a set top aerial.
I usually get the aerial all sorted out and firmly clamped, pointing in approximately the right direction, to the top of the pole, then loosen the clamps at the bottom and rotate the whole caboodle for the final tweak. This also has the advantage of putting me a few feet nearer the partner who is yelling "better, worse, even worse, .... " from the living room :) .
 

Owen Smith

Active Member
The Humax only gives signal quality after Viterbi error correction. It's always 100% on all my muxes, which is useless as I have no idea how close any of them are to dropping below 100%.

Last time I aligned aerials there was still analogue TV, and I took a 12" portable CRT TV with me into my loft and onto my parents's flat roof (for two different jobs). Watching snow or ghosting come and go on a screen was much easier than trying to watch digital qualities, though I was in both cases trying to improve digital reception (and I succeeded).

If there is a next time, I will try to use the signal screen on mine and my parents' 32" Sony TVs rather the Humax. These Sony TVs show the error rate pre Viterbi as well as post Viterbi. This means you can see how good the signal really is in the pre Viterbi figures rather than it saying 100% as the aerial is swung through a 10 degree arc.

Every Sony TV I've looked at for the last 7 years has this pre Viterbi error rate, though it's buried quite deep in the menu under advanced diagnostics or some such. I recommend a look to anyone with a Sony.

My other go to box is an old Nokia 221T set top box which has a great undocumented signal diags screen with multiplex encoding parameters, carrier strength, error rates etc. But it can't handle DVB-T2 and with COM7 and COM8 being the hardest to receive so needing the aerial to be optimised for them, I'm not sure how much more use I'll get out of it.
 
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