Digital Signal Meter

Souriau

Hi
Does anyone recommend a basic Digital Signal Meter for checking aerial alignment and signal quality?

St Senan

Have a look here http://www.boards.ie/vbulletin/showthread.php?t=2056168642

Souriau

Does anyone know what is a good software for Windows PC for checking digital signal from DTT landbase transmitter for checking aerial alignment and signal quality and so on?
I have hauppauge DTT tuner for my laptop

watty

Never seen it.
Also would not like a laptop on chimbly.

Oddly most software does just signal level which is meaningless.

Gerry Wicklow

@Souriau
The Hauppauge CD that came with your dongle includes a signal meter. AFAIK it is under MISC on the cd.
Look for HCWSIGMON.exe

watty

Very nice. probably only works Hauppauge cards. But no good for working at height.
http://www.hauppauge.com/site/support/support_digital_signal_monitor.html
(download link is dead)

WinTV version 7 has it built in (very recent version)
http://www.hauppauge.com/site/support/support_wintv7.html
Link works http://hauppauge.lightpath.net/software/install_cd/wintv7_cd_2.3a.exe
You need a Hauppauge CD ($10 to buy) or this will not install
Almost certainly only works with certain listed Hauppauge cards.

Souriau

I got a new sofware for my Hauppage Win TV Tuner
here is a scan of Cairn Hill

# 682000kHz, 8MHz bandwidth
# locked on 682000KHz, please wait for signal statistics...

# signal locked = Y, present = Y, strength = -64000, quality = 100%
# signal locked = Y, present = Y, strength = -63000, quality = 100%
# signal locked = Y, present = Y, strength = -63000, quality = 100%
# signal locked = Y, present = Y, strength = -63000, quality = 100%
# signal locked = Y, present = Y, strength = -63000, quality = 100%

# Average quality on 682000kHz = 100%


NETWORK INFORMATION

---

Network Name: RTENL
Network ID: 12801
ONID: 8564
SID: 1001

Frequency: 198500Khz
Bandwidth: 8Mhz
Modulation: 64QAM
Carrier: 8K
FEC HP: 2/3
FEC LP: 2/3
Guard: 1/32
#Alternate frequencies
#Network_6("RTENL", 177500, 8, 1)
#Network_6("RTENL", 184500, 8, 1)
#Network_6("RTENL", 191500, 8, 1)
#Network_6("RTENL", 198500, 8, 1)
#Network_6("RTENL", 205500, 8, 1)
#Network_6("RTENL", 212500, 8, 1)
#Network_6("RTENL", 219500, 8, 1)
#Network_6("RTENL", 474000, 8, 1)
#Network_6("RTENL", 546000, 8, 1)
#Network_6("RTENL", 666000, 8, 1)
#Network_6("RTENL", 682000, 8, 1)
#Network_6("RTENL", 690000, 8, 1)
#Network_6("RTENL", 730000, 8, 1)
#Network_6("RTENL", 738000, 8, 1)
#Network_6("RTENL", 746000, 8, 1)


CHANNEL NAME - - - - - - P-TYPE LCN SID PMT TXT AC3 PROVIDER

---

RTÉ One - - - - - - - - - - ASDTV , 1, 1101, 1901, Y, N, RTÉNL
RTÉ Two - - - - - - - - - - AHDTV , 2, 1102, 1902, Y, N, RTÉNL
TV3 - - - - - - - - - - - - - ASDTV , 3, 1103, 1903, Y, N, RTÉNL
TG4 - - - - - - - - - - - - - ASDTV , 4, 1104, 1904, Y, N, RTÉNL
RTÉ News Now - - - - - - ASDTV , 5, 1105, 1905, N, N, RTÉNL
3e - - - - - - - - - - - - - - ASDTV , 6, 1106, 1906, Y, N, RTÉNL
Temporary - - - - - - - - - ASDTV , 7, 1107, 1907, Y, N, RTÉNL
RTÉ Radio 1 - - - - - - - - RADIO , 200, 1226, 1921, N, N, RTÉNL
RTÉ 2FM - - - - - - - - - - RADIO , 202, 1227, 1922, N, N, RTÉNL
RTÉ Lyric FM - - - - - - - - RADIO , 203, 1228, 1923, N, N, RTÉNL
RTÉ Raidió na Gaeltachta, RADIO , 204, 1229, 1924, N, N, RTÉNL
RTÉ Radio 1 Extra - - - - - RADIO , 201, 1230, 1925, N, N, RTÉNL
RTÉ Pulse - - - - - - - - - - RADIO , 205, 1231, 1926, N, N, RTÉNL
RTÉ 2XM - - - - - - - - - - - RADIO , 206, 1232, 1927, N, N, RTÉNL
RTÉ Choice - - - - - - - - - RADIO , 207, 1233, 1928, N, N, RTÉNL
RTÉ Gold - - - - - - - - - - - RADIO , 208, 1234, 1929, N, N, RTÉNL
RTÉ Chill / RTÉ Junior - - - RADIO , 209, 1235, 1930, N, N, RTÉNL

===========================================

watty

Hmm

Frequency: 198500Khz

#Alternate frequencies
#Network_6("RTENL", 177500, 8, 1)
#Network_6("RTENL", 184500, 8, 1)
#Network_6("RTENL", 191500, 8, 1)
#Network_6("RTENL", 198500, 8, 1)
#Network_6("RTENL", 205500, 8, 1)
#Network_6("RTENL", 212500, 8, 1)
#Network_6("RTENL", 219500, 8, 1)
#Network_6("RTENL", 474000, 8, 1)
#Network_6("RTENL", 546000, 8, 1)
#Network_6("RTENL", 666000, 8, 1)
#Network_6("RTENL", 682000, 8, 1)
#Network_6("RTENL", 690000, 8, 1)
#Network_6("RTENL", 730000, 8, 1)
#Network_6("RTENL", 738000, 8, 1)
#Network_6("RTENL", 746000, 8, 1)

Souriau

Yes, I was also surprised :eek: to see VHF frequencies on it
and also was surprised to see Alternate UHF frequencies.

I must goto my brother's home and do a scan of Clermont Carn, Co Louth transmitter and see

I also did a scan of Divis, Belfast, and see they also got Alternate frequencies.
If anyone want to see it, I can paste it here if required :rolleyes:

watty

Should be same info on all Irish transmitters I think.

Souriau

Here is the full scan from my home outside Newry, getting Divis and Cairn Hill

fat-tony

Note the 166KHz offset from centre frequency on the NI transmitters. RTENL transmitters on centre frequency.

Souriau

Can anyone advise to what is the different between the Red and Blue DigiAir digital signal meter?

The Cush

Souriau wrote: »

Can anyone advise to what is the different between the Red and Blue DigiAir digital signal meter?

Digiair (Blue) = analogue terrestrial signals only
Digiair db (Red) = analogue & digital terrestrial (COFDM) signals

Souriau

The Cush wrote: »

Digiair (Blue) = analogue signal only
Digiair db (Red) = analogue & digital terrestrial (COFDM) signals

They are both digital but I will read into it further

The Cush

Souriau wrote: »

They are both digital but I will read into it further

Digital as in DVB-T (CODFM) terrestrial reception. The Digiair Blue doesn't do DVB-T.

This from the Digiair db manual

DIGIAIR dB is built for measurement on digital terrestrial (COFDM) signals. All specifications given for the precision of measurement refers to the Digital (COFDM) mode when measuring digital terrestrial signals. The instrument will give a higher value in dBμV when measuring analog terrestrial signals in the Digital (COFDM) mode. When measuring analog terrestrial signals in the Analog (CW) mode the instrument will give a lower value in dBμV than the actual one. However, when measuring on a non amplitude modulated analog signal in the Analog (CW) mode the instrument will give equally accurate values as specified for the COFDM mode measuring on digital terrestrial signals.

Souriau

One would think Digiair mean Digital terrestrial transmission
and of the Blue is just for analouge, would it not call it Anaair?

Anyway, thanks for helping me to know the different between the Red and Blue model

Have you or anyone else got experenice in using this Digiair db, Red and how does it perform?

Souriau

The Cush wrote: »

Digiair (Blue) = analogue terrestrial signals only
Digiair db (Red) = analogue & digital terrestrial (COFDM) signals

I contacted the company in Sweden to find out more and I received their reply


They are both suitable for digital and analogue
The difference is small, but vital.
Digiair shows a relative value.
Digiair dB is calibrated and shows an exact dB value.
Best Regards/Cordialement
Naima Wanisian
Sales Departement
www.emitor.se

Emitor AB
Sjöviksbacken 14
117 43 Stockholm
Phone : +46 8 7750001
Fax : +46 8 7750006

Souriau

I have decided to go for the Digiair db, the red one
Can anyone tell me where I can get one at cheapest price online?
the lowest I can find is £185

TIA

The Cush

Souriau wrote: »

I have decided to go for the Digiair db, the red one
Can anyone tell me where I can get one at cheapest price online?
the lowest I can find is £185

TIA

Got mine a few years ago from Wizard Satellites (trading now it seems as Wizmaster). They're charging £189 now, can't think of anyone cheaper.

Souriau

Thanks 'The Cush'
can you tell me how good is the Digiair db?
does it help align the aerial perfect?
what is the pro and con from your usage?

TIA

The Cush

Souriau wrote: »

Thanks 'The Cush'
can you tell me how good is the Digiair db?
does it help align the aerial perfect?
what is the pro and con from your usage?

I've never used a professional meter so I cannot compare the Digiair against one but it does what it says on the tin for the money.

I only use it to install aerials for friends, family etc. Once I point the aerial in the general direction I simply adjust until I get peak signal and job done.

Battery life is one downside, about 1 hr use before a very long recharge time. The menus can be a bit fiddly and the LCD screen can be a little difficult to read on a bright, sunny day.

Overall I'm happy with it, takes some of the guesswork out of a DIY install.

Souriau

The Cush wrote: »

Got mine a few years ago from Wizard Satellites (trading now it seems as Wizmaster). They're charging £189 now, can't think of anyone cheaper.

Got the new Digiair db today, am happy with it so far, just exploring and taking some reading of my aerial.
Bought it from Wizard for £169 over the phone with free P&P while online price showing £189.
Also came with Euro Schuko 2 pin connector

Souriau

what would be acceptable db level for a digital transmission?
Somewhere I saw the figure of 66db, would that be correct?
and is there a maximum db level for DTT? As I am sure too much power also break up the picture... Is that correct?

TIA

The Cush

Souriau wrote: »

what would be acceptable db level for a digital transmission?
Somewhere I saw the figure of 66db, would that be correct?
and is there a maximum db level for DTT? As I am sure too much power also break up the picture... Is that correct?

TIA

DTT Max Signal Level = 70dBμV
DTT Min Signal Level = 45dBμV

This according to the DTG - http://www.satmax.co.nz/Technical_Info/dgtspec.pdf

The 45 dBμV figure applies where the STB or idTV is the first item in the RF distribution chain. (This is the normal arrangement and is strongly recommended) A 5dB higher level is necessary to take into account the typical low gains and high noise figures for any satellite receiver or VCR (either operating or in standby mode) used ahead of the STB or idTV.

Ronnie Raygun

You're asking for it, posting something like that here.....

Do people pay you to do installs without a meter? How have you managed till now?

EDIT: This post was in reply to another which has since been deleted.

darth_maul

Ronnie Raygun wrote: »

You're asking for it, posting something like that here.....

Do people pay you to do installs without a meter? How have you managed till now?

Don't think anyone has mentioned professional installs,

Have a digiair for analogue installs and its fine, pretty useless for Digital installs as it lacks a quality/ber reading, have a promax TV hunter for that and its the dogs............

Believe me when you have the 2 peaking an aerial with the analogue meter and then putting the promax on you can see that the peak isn't always the best for Quality Ber/Mer, digital meter is essential especially for locating quality drops between aerial and receiver. A perfect analogue signal doesn't mean a glitch free Saorview

Ronnie Raygun

The post I replied to was an inquiry from someone who 'did a few installs' & wanted a meter to 'save time'.
I see it's since been deleted & I can't even remember the poster's name.

Galway

The Cush wrote: »

DTT Max Signal Level = 70dBμV
DTT Min Signal Level = 45dBμV

This according to the DTG - http://www.satmax.co.nz/Technical_Info/dgtspec.pdf

Whats the max and min signal levels for analogue?

The Cush

Galway wrote: »

Whats the max and min signal levels for analogue?

STB

I know the OP has bought the DB model.... but there is a pro one that is a little pricier.

Lacuna (mid price) also do one as do Promax (expensive).

The Cush

With signal quality being more important than signal strength with DTT I came across this interesting graphic



Anyone with a Sony TV may be familiar with pre-Viterbi (CH-BER / pre FEC) and post-Viterbi (aBER / post FEC) error correction information and their 5s averages e.g. 2.00 e-6 (2/1,000,000 or 0.000002 = 2 x 10-6 or 2.0E-06) - 2 bits out of the 1,000,000 bits received are errored.

Souriau

Just update my unit to Emitor DigiAir Pro for having BER and MER on it

When I done a spectrum scan, I see some activity at 450MHz

Can anyone tell me what is using this frequency?

Ronnie Raygun

Tetra?

Rippy

Ronnie Raygun wrote: »

Tetra?

Nope, Tetra is 380-40Mhz.

STB

Souriau wrote: »

Just update my unit to Emitor DigiAir Pro for having BER and MER on it

When I done a spectrum scan, I see some activity at 450MHz

Can anyone tell me what is using this frequency?

Do you have a wireless phone ?

Could also be HAM.

watty

PMR 446 walkie talkies?

There is also a Mobile Data licence around 450MHz, but I think nothing rolled out.

Tetra is indeed some place between 446 and 470MHz, but I forget where. It's buried on Comreg's site somewhere. Their site is a disgrace for searching.

"Ham" is 430 to 440 and not very active.

Lots and lots of 433MHz (Doorbells, Baby alarms, Remote channel on Video Senders, Wireless weather stations, wireless alarms etc)

STB

watty wrote: »

PMR 446 walkie talkies

"Ham" is 430 to 440 and not very active.

Lots and lots of 433MHz (Doorbells, Baby alarms, Remote channel on Video Senders, Wireless weather stations, wireless alarms etc)

I thought 70cm covered up to 450megs ? Well it seems it could be amateur radio. Fairly near is a repeater on 439.6mhz - digital just outside Newry.

Souriau

I have this meter a week now and been testing it and making adjustments to the aerial and amp distribution system

Firstly the signal reaching the TV was over power
BBC and UTV mux where breaking up

Now after the adjustment and now see rock steady pictures

First I check for aerial alignement to get peak reading,
The aerial was off by 10 deg
then I took reading and see chart 1
made adjustment with reducing signal strenght with 10db attenutor
took another reading and see chart 2

I am quite please with this meter as it help me to pin-point the problem quickly.

Ronnie Raygun

So the meter is at the tv & the attenuator is at the distribution input? What's the gain & maximum input signal level for the distribution amp? Those signal levels (especially considering the dist. amp. has applied its gain) shouldn't overload anything.

What is used to receive the Saorview signal & how is it combined with the others?

Peter Rhea

The readings for the analogue channels mightn't be accurate, probably should be higher.

Souriau

Peter Rhea wrote: »

The readings for the analogue channels mightn't be accurate, probably should be higher.

When set to digital mode, signal are, in dBµv.
21=72.8, 24=71.1, 27=72.2, 31=74.1, 37=55.3
from Divis and Black mountain for Ch.5

40=46.2, 43=52.1, 46=56.2, 50=43.5 from Cairn Hill

When set to analouge mode, signal are, in dBµv.
21=66.0, 24=67.1, 27=66.6, 31=67.8, 37=50.3
from Divis and Black mountain for Ch.5

40=38.8, 43=47.0, 46=50.2, 50=37.3 from Cairn Hill

Souriau

Ronnie Raygun wrote: »

So the meter is at the tv & the attenuator is at the distribution input? What's the gain & maximum input signal level for the distribution amp? Those signal levels (especially considering the dist. amp. has applied its gain) shouldn't overload anything.

What is used to receive the Saorview signal & how is it combined with the others?

Group B aerial with B amp at 14db gain
diplex into Group A to E
Group A from Divis and E from Cairn Hill
the attenutor is just on group A from Divis.
This is why 48 from Divis is weak as it is out of band with the diplexer, but that will change in October.

Ronnie Raygun

Souriau wrote: »

Group A from Divis and E from Cairn Hill
the attenutor is just on group A from Divis.

And the meter readings were taken at the tv point?

Is there also a masthead amp on the group A aerial?

What's the "power distribution in attic" referred to in the 2nd attachment?

It's misleading to state that the meter helped you find the problem if in reality you just got lucky with the attenuator.

Souriau

Without the meter, I would be working blind, not knowing is too much to too little.
The meter is a tool to help to see what is going on and help to make correct adjustment to gain good quality signal.
without it, I be spending a lot of time trying this and that.

The signal meter on the TV is not much help
one need to see the BER, Pre and Post to check the quality of incoming signal

Ronnie Raygun

Yes, but where in the system was the meter connected when you took those readings shown in the attachments? Simple question.

Souriau

At the end of the co-ax cable before plugging into the TV
taking into conderstion the cable db loss. the distrubition amp gain.
The final measurement was taken at the site where the TV is

Ronnie Raygun

The improvements in SNR & BER on mux 1 & mux B are plain to see, I suppose. Still doesn't explain why attenuating the signal led to an improvement.

Souriau

Ronnie Raygun wrote: »

The improvements in SNR & BER on mux 1 & mux B are plain to see, I suppose. Still doesn't explain why attenuating the signal led to an improvement.

I am not a qualified electronic engineer or have good understanding of the working of signal transmission or how the box decode the signal.
All I was showing is how the BER and SNR improved by reducing the strength of the incoming signal.
I took reading of before and after
What I did was to take the reading at the TV end of the co-ax lead, had a variable attenutor and adjust it till I see the highest reading I can get.
this was all done in the living room where the TV is
once I find the best SNR and BER, I then went to see the signal strength was, again with the variable attenutor and then without it,
this show me the different in dBµv. I subtract the lowest dBµv from the highest dBµv and was 10dB.
Then I went up to the attic and fit a 10dB attenutor at the distrubition unit

I came into this site a few years back with little knowledge of this
others members in here had help me and point me in the right direction
now I having more knowledge but still I am no expert
I am now just showing others of my finding and I also would like to thanks everyone for helping me to understand most of this.

Is this site not for seeking and sharing informations?

Ronnie Raygun

Souriau wrote: »

Is this site not for seeking and sharing informations?

It is indeed, but you have to get your story straight & explain exactly what you did & the layout of your system.

The reason I ask these questions is because I was interested to find out what was going on with your readings but I'm still mostly none the wiser as your replies regarding placement of the attenuator are confusing; is there a masthead amp on the aerial receiving from Divis?

The Cush

Souriau wrote: »

Just update my unit to Emitor DigiAir Pro for having BER and MER on it

Souriau wrote: »

I have this meter a week now and been testing it and making adjustments to the aerial and amp distribution system

Hi Souriau

Where did you purchase the meter and how much?