Dopravni Podnik Radiosystem (foreign language topic)

[Kočí]

I wish that i could speak Czech so i could work and live in Czech Republic!

Thanks That´s not problem, you need only the time to learn Czech (but Czech is more difficult than Swedish, you know...)

Pro XSC: Jak se dá provést to odblokování?

[Bearen]

In MHz?

Yes in MHZ. I now i am in Sweden again after some great days with my friends in Prague!
Prague is a lovely capitol! And it´s cheap to buy food etc there to.

I wish that i could speak Czech so i could work and live in Czech Republic!

[Kočí]

In MHz?

[KGX1]

In Prague:
169,5500
169,6000
169,6750
169,7750
169,9250
170,0000
170,1250
170,2500
170,3000
170,4000

Underground:
156,5250
156,6750

In Brno:
77,2500
77,7500
82,0500
82,5500
460,8300
461,0300
461,0500
461,2300
461,6900
466,4100

[XSC]

CTU neni Telecom, ale Cesky telekomunikacni urad.

Jo jasne, ale to je jen urad, k cemu by asi potreboval komunikovat v radiopasmu. Navic ta tabulka je asi starsi nez CTU.

[Rapid]

CTU neni Telecom, ale Cesky telekomunikacni urad.

[XSC]

Than i know where i shall "scan"

Anyone who can translate?

Thanks, Björn

Marek wrote, that he scanned 67-87MHz band with standard FM receiver without succes. But it was old receiver for FM radio - Czechoslovakia used OIRT band (66-73MHz) for FM broadcasting. This receiver use wide band FM (250kHz), so there may be problem with receiving FM 25kHz wide channel.
The channel table is rather old.
Translation: ČTÚ-Czech telecomunications (Telecom), mo-Army, zdravotnictví-Health service.

Pro Marka:
To co popisuješ je běžný jev zaviněný nedostatečnou selektivitou přijímače. Stanice samozřejmě nevysílají na 2 kmitočtech. Při příjmu se ale signál zpracovává tím způsobem, že se vstupní signál slučuje se signálem místního oscilátoru a vznikající rozdílový kmitočet standardně 10,7MHz se pak dále zesiluje a zpracovává. V tvém případě kmitá oscilátor o 10,7MHz výše než je přijímaný signál. Takže při správném příjmu platí, že Fmf=10,7MHz=fosc-fvstupní. Pokud je vstup nedostatečně selektivní, povede se i příjem 10,7MHz=fvstupní-fosc, což je tvůj případ. Tesla prostě nepředpokládala, že by v západní normě někdy vysílalo tolik stanic - v té době se v této normě jednalo skoro vždy o dálkový příjem pár stanic. Ten rozsah 66-104 je u těchto přijímačů normální, dříve se horní konec pásma nepoužíval. Platilo 66-73 OIRT (východní norma), v tom se u nás vysílalo do konce 80. let. 87-108 CCIR (západní norma), do té se začaly některé stanice přesouvat někdy okolo 88 roku. To pásmo mezi bývalo u spousty přijímačů zatlumené, nebo se při ladění přeskočilo, ale dalo se jednoduše odblokovat.

[Björn]

Than i know where i shall "scan"

Anyone who can translate?

Thanks, Björn

[Marek]

Doufám, že se na mě nebudete zlobit za česky psaný příspěvek.

Mám takový pocit, že jsem kdesi slyšel, že DP používá několik kanálů - nějaký pro přenos dat, třeba informace o vyhlášení zastávky, jiný pro hovory, další samostatný pro tísňové volání... Ty hovorové kanály by snad měly být analogové, takže by mělo být technicky možné je chytit.

Na internetu jsem našel zajímavou frekvenční tabulku

Kód: Vybrat vše

pásmo | MHz | druh provozu | rozestup kanálů | použití
45     44-46  simplex        25 kHz            ZD,LS
80     67-73  duplex+3MHz    12,5 kHz          čtú,mo,ZD
80     73-87  simplex        25 kHz 	        čtú,policie,mo,zdravotnictví,DP,atd.

Mimochodem, směrem nahoru (od 87,5 do 108 MHz) hned navazuje pásmo, ve kterém vysílají veřejná (VKV, FM) rádia. Tabulka je to asi starší, zdravotnictví a policie dnes už určitě vysílá jinak a jinde.

Shodou okolností jsem se dostal ke staršímu přijímači (zase tak starý nebyl - už žádné elektronky, ale samotné rádio bez zeslilovače bylo velké jako gramofon) se zajímavým rozsahem 66 až 104 MHz. A jak to dopadlo? Překvapivě se mezi 66 a 87 MHz nepodařilo naladit nic speciálního, ale jen veřejné rozhlasové stanice, stejné a ve stejném pořadí jako v 87,5 - 108 MHz.

Zatím mě nenapadá vůbec žádné vysvětlení.
- Že by veřejná rádia vysílala ještě jednou o cca 20 MHz níže, na frekvencích, kde je nikdo neposlouchá je asi nesmysl,
- že by byl rozsah přijímače se stupnicí 66 - 104 MHz (jediný rozsah, jediný proměnný kondenzátor (či co), žádné přepínání) ve skutečnosti 2x 87 - 104 MHz se mi taky moc nezá
- a že by třeba odrazem signálu došlo k posunu signálu o cca 20 MHz podle mě nejde.
Napadá vás něco?

Ještě malá odbočka k právní otázce poslechu na neveřejných frekvencích: Není to dovoleno, ale určitě to není trestné.

Zdroj: http://www.mujweb.atlas.cz/zabava/amtero

[Kočí]

Thats good!

Yes the calling-tone is so long because it´s "open" all the radios on the trams and busses. When you get the message in the in the drivers cab you only hear the calling-tone for about 1/2 second.

Yes i can guess so But is Czech Republic still the richer of these two?

Hmm, I think in the radio of Prague´s DP you hear complete melody so I expect it´s digital also from these point of view, you know. But maybe it depends on the range of transmission and power of signal


I hope we´re richer than Slovaks Now I´m not sure because Slovaks after entry to EU have bigger GDP... The truth is that in the past (between twenty´s and thirty´s of last century) we (like Czech firms or with our help) built there many fabrics and some infrastructure too and they´ve still been having it. Nowadays is a fact they have better "conditions" for foreign investors so we´ll see who is richer in the future

[Návštěvník]

For Björn: My energy is good if it´s interesting and your photos and sounds are But I was shocked when I herad your calling tones, I think we have more agreeable melodies

And "war" between you and Danes is like between Czechs and Slovaks, mostly in fun, not seriously, you know

Thats good!

Yes the calling-tone is so long because it´s "open" all the radios on the trams and busses. When you get the message in the in the drivers cab you only hear the calling-tone for about 1/2 second.

Yes i can guess so But is Czech Republic still the richer of these two?

[Kočí]

Hmm, thanks XSC, that´s interesting... I think it´s hard to call by analogue to specific tram (I don´t mean it´s not true) because in this case the others must listen also to this message. All of analogue receiver must be on the same frequency than it´s not possible to talk directly without listening for others. Or maybe there is possibility to have this station on this frequency, other on the other frequency but it blocks many frequencies... I can´t imagine how the dispatcher could call to (for example) twenty two trams on other frequencies...

For Björn: My energy is good if it´s interesting and your photos and sounds are But I was shocked when I herad your calling tones, I think we have more agreeable melodies

And "war" between you and Danes is like between Czechs and Slovaks, mostly in fun, not seriously, you know

[XSC]

Of course... I think this system used by DP Prague is digital because the dispatching centre can call to one tram on this line and on this order, so analogue can´t do... But if someone of you can explain me how does it work on analogue I´ll be very suprised and thankful

I don't know if DPP use digital or analog system now. But there is no problem to call specific tram in analog system. It use DTMF or other system - works like tone dialing on analog phone line. In this case specific sequence unmute receiver. On normal receiver you here series of tones and then speach. So it's like phone - "digital" selection and then analog communication.

[Návštěvník]

But here in Gothenburg the system still is analogue but the radiocentral here in Gothenburg called TLX can call on to all trams at the same time, when there is for example a crash or trouble with starting the tram etc.
But they can also call a specific tram.

Please read my last message one´s more I actualizated it

How they do a specific calling? Can they also call to all trams on some lines? Do you have also in Gothenburg the detectors for actual position and time accuracy on the stations?

haha, i guess it´s an old story, but some of the danish people and ofcourse some of the Swedish people don´t like eachother. I don´t care so mutch, but some danish-people are self-assured and many of them are extremly proud of their country and that irritare the Swedish and Norwegian people a lot!

Every tram here in gothenburg got it´s own number, 741 or 338 for exampel. For some years ago they checked with the computer, line numer 9 train number 4 car numer 522+812. But now the tram are operateing on maybe 3 lines on one day, so now the tram have a special "circulation-number" for exampel 7211. But this radiosystem called R5 is from 1973 so soon the DP here in Gothenburg will start use a digital radio system. The busses of DP Gothenburg already use this system, and they are on their way install the digital radios in the tram.

We got a system for switching ways, signals, loudspeakers in the tram, for TLX to see where the tram is. The system is called KomFram, and you can read about it here:
http://www.thoreb.se/Mainframe/KomFram-sidan.htm

Yeah the Mustangs are quite funny, i like them!
If there is any swedish text you want me to translate it´s no problem!

http://www.ss.se/forum/ is the Swedish "version" of this site

Of course i will visit the museum

Here are som pics from Gothenburg if you want to see!



The drivers place. this is our newest tram in trafic, built beetween 1984-1992

One of the old trams, built 1970

Outside Vozovna Rantorget

One of the two test-trams from Ansaldo in Italia!

And if you are intrested to hear how the radiosystem sounds here in gothenburg

http://bear.starchannel.nu/request.mp3
This is a message to all drivers of busses and trams saying that TLX will use the ordinary radiosystem again, this message is from January, it was a hard storm over Sweden and the "electricity get down" so TLX used a
reserve radiosystem, so thats because of the bad quality on the message

http://bear.starchannel.nu/vasttrafik.mp3
This is a message from the TLX to the passengers waiting on the trams on the stops. It says that line number 11 is late because of an earlier stop.

Hope you have the energy to read all this

[Kočí]

But here in Gothenburg the system still is analogue but the radiocentral here in Gothenburg called TLX can call on to all trams at the same time, when there is for example a crash or trouble with starting the tram etc.
But they can also call a specific tram.

Please read my last message one´s more I actualizated it

How they do a specific calling? Can they also call to all trams on some lines? Do you have also in Gothenburg the detectors for actual position and time accuracy on the stations?