News items for tag dx - Koos van den Hout

Onderweg op de fiets zie ik nogal eens oude tv antennes op daken staan die duidelijk niet meer gebruikt worden (allemaal horizontaal gepolariseerd, terwijl alle dvb-t zenders in nederland verticaal gepolariseerd zijn). Misschien dat er daar nog eens eentje tussenzit die ik voor weinig kan meenemen voor meer DX experimenten. Of iemand moet een antenne weten? UHF / VHF band III.

Seeing another set of DVB-T DX pages by Hans makes me think I should have a look at parsing the vdr files from w_scan into an automatic DX logbook, noting when muxes are first found. I collected the output files since 3 January 2009. I started doing that after I saw the WDR program at 674 MHz so that was not logged in that format. Documentation: VDR file format.

In the dvb-t scan yesterday evening late:

TV Gelderland :642000:I999B8C999D999M999T999G999Y999:T:27500:7041:7042:7043:0:1104:0:0:0
Radio Gelderland:642000:I999B8C999D999M999T999G999Y999:T:27500:0:7112:0:0:1111:0:0:0

Part of Digitenne bouquet multiplex 1 at 642 MHz. The transmitter could be Oss or Veenendaal given distance and transmitter power. I only noticed it yesterday but now I see it in the w_scan output a few times. The reception is not error-free (I had to wait a bit for a chance of a screenshot with not too much distortion).

No extra foreign channels from the dvb-t scans.. yet. I keep an eye on the tropospheric ducting forecast for northwest europe. I also updated the DVB experiments page with the DX results.

Bouquet or Multiplex? It is described as bouquet at DVB-T zenders Digitenne Nederland but the mpeg standard term for multiple program streams in one transport stream is 'multiplex'. Bouquet in DVB terms means a set of 'programs' logically grouped together.

I caught the Omroep Brabant logo last night: after dark reception is a lot better! The Digitenne B1 bouquet at 546 MHz and Digitenne B2 at 786 Mhz scanned fine.

The log-periodical antenna has effect: a number of signals show workable data in w_scan. New:

490 MHz - Digitenne B3 from probably Lelystad
514 MHz - Digitenne B1 from Lelystad, including TV Flevoland / Radio Flevoland
682 MHz - Digitenne B4 from Lelystad

And with aiming and trying (3 windows with dvbsnoop for pid 0x00, 0x10 and 0x11, one window with tzap reading the signal strength):

546 MHz - Digitenne B1 including Omroep Brabant, source unknown

Updated the DVB experiments page with the latest findings. Time to take pictures of the antenna I built.

First success with the self-built antenna: I tried it in the 'home office', approximately 5 meters above ground, north-east direction. With the log-periodical antenna pointing outside through the window I was able to receive Digitenne bouquet 1 at 618 MHz UHF, which includes radio and TV Noord-Holland.

Several times when I scanned for DVB-T signals in the UHF band from home I saw some very weak signals on several frequencies. Too weak to make out anything other than that the signals are very probably DVB-T as the radio scanner does not pick up a thing there (for as far as I know FM receivers cannot pick up QAM signals). The DVB-T receiver I use has a small external antenna (simple half-wavelength wire), so to get more signals I will have to use a good antenna. Buying something is expensive and it is to me much more interesting to build something myself from scrap materials. Most promising seems to be Alan Yates' Laboratory - UHF Log-Periodic Array so I'm browsing my scrap electronics for materials to build this.

The empty slot I found before in a dvb service scan where BemBem used to be is now:

0x0000 0x0072: pmt_pid 0x0474 Digitenne -- 100%NL (running, scrambled)

As reported by radio-tv-nederland.nl.

Just heard on the scanner on one of the air traffic channels: "Request for sightseeing the Amsterdam Schiphol sector" describing (I think) the plane as a Cessna. It must be Sunday :)

So, the US is now also switched over to digital television. I found a nice compilation of analog shutdowns on youtube: 2009 DTV Transition: Analog TV Shutoffs in Los Angeles As They Happened and one particular WABCEndsAnalogShrtVrs061209 from ABC channel 7 New York. Some stations made a nice item out of it with a countdown and some just dropped their analog signal in the middle of a program. One big thing in the US is a lot of TV channels use their channel number in their branding (like ABC 7 for WABC above) and the US brother of DVB-T named ATSC has provisions for channels 'named' with a number which is not equal to the VHF/UHF frequency.
Update: Journal entry describing the end of analog tv broadcast: uneventful

The new scanner has been found: a Commtel COM225 scanner, which has a range from 25 MHz to 1300 Mhz and good scanning and receiving capabilities. A nice secondhand one, found via Marktplaats. Now I am programming lots of frequencies including Schiphol airport frequencies and other airport and eurocontrol frequencies. Commtel COM225 review at strongsignals.net.

I have been looking for a better radio scanner recently. For the amount of use it will get and what I want a second hand one is probably best. I also noticed the new ones on sale at the moment in the Netherlands are quite limited.
There are the simple ones with 50-100 channels which don't have the militairy air communications band that I want, and no 'tuning' option (tuning up and down the dial when looking for signals in a certain area).
Those are sometimes sold as 'church radio' in the Netherlands because somewhere in the years the rescue services moved to encrypted speech (C2000), frequencies 148.0125 to 149.0875 MHz and 153.0125 to 153.6875 MHz were opened especially for 'church radio': transmitting a church service (and nothing else). Most scanners will support this range. I really don't think the 'target audience' of church radio, people who want to hear a church service but are unable to go to church, usually elderly or sick people will be able to deal with all the little knobs and dials on the average radio scanner. I looked at the designs for church radio via Internet 'receivers' and those have a volume control and an on-off switch. The very advanced model has a 'channel' selector for choosing a church or gospel music.
The higher-end radio scanners sold new are really high-end with alphanumeric channel descriptions and trunk-tracking options. A bit too much for what I want, and too expensive.
So I'm browsing the secondhand scanner ads on a few websites. And everytime I see an offer that looks nice I look up the details of the offered scanner on the scanner reviews on the Strong Signals site which is a very good resource for finding out the options of scanners and comparing them.
I hope to find one for a reasonable price. In browsing the ads I learned about brands I haven't heard of before. There is Commtel which is actually from Uniden and GRE, making some Commtel models near copies of Uniden Bearcat models. There is also Realistic which seems to be the other name for Radio Shack scanners. Icom also makes receiver / scanners but those are out of my price range.

Interesting article The Great Brazilian Sat-Hack Crackdown in Wired on-line today. UHF-Satcom.com audio samples has some interesting samples of pirates using these frequencies and other interesting stuff (such as space shuttle audio). Time to dig up my radio scanner and see what I can find on these frequencies as listed at UHF Satellite reception - UHF-Satcom.
Update nothing, as this is outside the range of my trusty old Uniden Bearcat UBC120XLT, ranges 66-88, 108-174 and 406-512 MHz. Maybe time to find something better.

Oh and in Paris I did bring my laptop and the dvb-t stick. Tried a scan, and found 5 bouquets with in total 29 services (18 free-to-air). Some services with 'HD' in the name, which mplayer could not play. I also saw some multilingual services. Free-to-air services seen by w_scan: Canal 21(Multi-7), IDF1(Multi-7), NRJ Paris(Multi-7), CAP 24(Multi-7), M6(MULTI4), W9(MULTI4), NT1(MULTI4), PARIS PREMIERE(MULTI4), ARTE HD(Multi 4), CANAL+(CNH), TPS STAR(CNH), CANAL+ SPORT(CNH), TF1 HD(MR5), France 2 HD(MR5), M6HD(MR5), TF1(SMR6), NRJ12(SMR6), TMC(SMR6).

Another scan of the vhf/uhf spectrum in Brunssum, and this time I got lucky and found the VRT dvb-t bouquet at 506 MHz (UHF 25) from Genk. With scan:

scanning /usr/share/doc/dvb-utils/examples/scan/dvb-t/be-Genk
using '/dev/dvb/adapter0/frontend0' and '/dev/dvb/adapter0/demux0'
initial transponder 506000000 0 1 9 3 1 3 0
>>> tune to: 506000000:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_1_2:FEC_AUTO:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_4:HIERARCHY_NONE
0x0000 0x1090: pmt_pid 0x1090 VRT -- Klara continuo (running)
0x0000 0x1080: pmt_pid 0x1080 VRT -- MNM (running)
0x0000 0x1070: pmt_pid 0x1070 VRT -- Studio Brussel (running)
0x0000 0x1060: pmt_pid 0x1060 VRT -- Klara (running)
0x0000 0x1040: pmt_pid 0x1040 VRT -- Radio 1 (running)
0x0000 0x1050: pmt_pid 0x1050 VRT -- Radio 2 (running)
0x0000 0x1010: pmt_pid 0x1010 VRT -- EEN (running)
0x0000 0x1020: pmt_pid 0x1020 VRT -- Canvas/Ketnet (running)
0x0000 0x10b0: pmt_pid 0x10b0 VRT -- Canvas+/Ketnet+ (running)
0x0000 0x10a0: pmt_pid 0x10a0 VRT -- Sporza (running)
0x0000 0x10c0: pmt_pid 0x10c0 VRT -- Nieuws+ (running)
0x0000 0x10d0: pmt_pid 0x10d0 VRT -- MNM hits (running)
Network Name 'VRTmux1'
>>> tune to: 482000000:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_1_2:FEC_1_2:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_4:HIERARCHY_NONE
WARNING: >>> tuning failed!!!
>>> tune to: 482000000:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_1_2:FEC_1_2:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_4:HIERARCHY_NONE (tuning failed)
WARNING: >>> tuning failed!!!
dumping lists (12 services)
Klara continuo:506000000:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_1_2:FEC_AUTO:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_4:HIERARCHY_NONE:0:4241:4240
MNM:506000000:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_1_2:FEC_AUTO:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_4:HIERARCHY_NONE:0:4225:4224
Studio Brussel:506000000:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_1_2:FEC_AUTO:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_4:HIERARCHY_NONE:0:4209:4208
Klara:506000000:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_1_2:FEC_AUTO:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_4:HIERARCHY_NONE:0:4193:4192
Radio 1:506000000:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_1_2:FEC_AUTO:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_4:HIERARCHY_NONE:0:4161:4160
Radio 2:506000000:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_1_2:FEC_AUTO:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_4:HIERARCHY_NONE:0:4177:4176
EEN:506000000:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_1_2:FEC_AUTO:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_4:HIERARCHY_NONE:4113:4114:4112
Canvas/Ketnet:506000000:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_1_2:FEC_AUTO:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_4:HIERARCHY_NONE:4129:4130:4128
Canvas+/Ketnet+:506000000:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_1_2:FEC_AUTO:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_4:HIERARCHY_NONE:4273:4274:4272
Sporza:506000000:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_1_2:FEC_AUTO:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_4:HIERARCHY_NONE:0:4257:4256
Nieuws+:506000000:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_1_2:FEC_AUTO:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_4:HIERARCHY_NONE:0:4289:4288
MNM hits:506000000:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_1_2:FEC_AUTO:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_4:HIERARCHY_NONE:0:4305:4304

In the evening reception was ok, during the day lots of errors. I guess an outside antenna with preamp could make this usable. I updated the DVB experiments with the new data. This brings the total listing of free-to-air services found in this place to 24 television and 24 radio stations. The tuning to 482 MHz is because that is the other VRTmux1 frequency.

Interesting how conditions change, compared to the DX scan from yesterday Digitenne Bouquet 1 at 618 MHz (with Radio/TV Noord-Holland) is fine again and Mobile TV at 658 MHz is fine. Yesterday bouquet 1 had a very high error rate and 658 MHz did not show up at all. All with just w_scan. I think the location of the antenna is the key to these differences, centimeters movement make a lot of difference for certain frequencies.

Interesting DX conditions: A dvb-t scan using w_scan gives me Mobile-TV at 570 MHz and Digitenne bouquet 2 at 826 MHz easy (no tzap and dvbsnoop, just a simple scan).

New DX score: Digitenne bouquet 1 with Omroep Brabant at 546 MHz. Weak, but enough Service Descriptor Table was caught by dvbsnoop that I saw it. Transmitters of that bouquet are all over Brabant. I updated the DVB experiments overview with information on how I scan for signals and how I identify transmitters.

Good to very good radio conditions at the moment. I just picked the following out of the air in the attic:

tune to: 674000000:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_AUTO:FEC_AUTO:QAM_AUTO:TRANSMISSION_MODE_8K:GUARD_INTERVAL_AUTO:HIERARCHY_NONE
Network Name 'WDR D'
0x0000 0x0064: pmt_pid 0x1330 ARD -- MDR S-Anhalt (running)
0x0000 0x0081: pmt_pid 0x1320 ARD -- NDR FS NDS * (running)
0x0000 0x00e2: pmt_pid 0x1340 ARD -- SWR Fernsehen RP (running)
0x0000 0x0104: pmt_pid 0x1310 ARD -- WDR Düsseldorf (running)
0x0000 0x0109: pmt_pid 0x1350 ARD -- WDR Wuppertal * (running)
0x0000 0x010b: pmt_pid 0x1360 ARD -- WDR Duisburg (running)

Totally unviewable due to all the errors, but the service list is correct. This should be the transmitter in Wesel, Germany at 113 Kilometer distance. Later on I realized how special this was: several hours later there wasn't even a hint of signal on 674 MHz. This was probably due to tropopsheric ducting, I saw an active area forecasted on William Hepburn's tropospheric ducting forecasts from roughly the center of the Netherlands going to the east.

I also saw Dutch Mobile-TV at 522 MHz (Utrecht), 530 MHz (several locations, weak signal), 570 MHz (several locations), 658 MHz (Lelystad).

A complete scan at the highest point in the house gives me several more instances of Digitenne signals. As mentioned before, at 618 MHz Digitenne bouquet 1 with TV Noord-Holland, but also at 786 MHz and 826 MHz bouquet 2. These can come from a number of locations, I can only find out with a directional antenna. Due to the way several stations broadcast exactly the same program at the same frequency there is no way of knowing which station is transmitting it. The fact that the signals have to be exactly the same to avoid interference means there can be no identifying bits somewhere within the dvb datatream. I think it is way cool that transmitter technology is this far that we can transmit the same signal from different locations without interfering with eachother. It is probably the robustness against multipath interference that makes this possible: having more transmitters with the same signal is a form of multipath interference. DVB experiments page updated with these latest experiences.