VHF/UHF AC Radios

[The Dog's]

Are the most modern still half duplex ie press to transmit, or are they full duplex?

 

[docbombhead]

Who gives a duplex ?

 

[Searchwatergeek]

Voice Procedure

PTR

DT_Xtremez_28:

Well with most voice comm's, only one person should be speaking at one time, the rest should be listening.

 

[PTR Hoar]

mmm PTR's!

 

[PD TC]

Are the most modern still half duplex ie press to transmit, or are they full duplex?

Never come across a full duplex VHF either in service or in marine radio

 

[The Dog's]

http://en.wikipedia.org/wiki/Voice_procedureWell with most voice comm's, only one person should be speaking at one time, the rest should be listening.

True, but you can still operate VP using full duplex. It does offer advantages over half duplex such as being able to transmit quickly in an emergency whilst receiving.

So is the Typhoon's radios still half duplex does anybody know?

 

[Searchwatergeek]

Avionic stuff on typoon

Don't know the answer to your Q matey, might find it in here.......DT_Xtremez_14:

 

[Ex-Bay]

Never come across a full duplex VHF either in service or in marine radio

Many marine channels are semi-duplex (two channels are used).
Never seen anything other than simplex for RAF radios.

DT_Xtremez_15:

 

[The Dog's]

Thinking about it full duplex isn't a practical proposition I think. Full duplex uses a different tx and rx freq for each channel, so it would not be compatible with existing half duplex V/UHF systems which use a single freq for each channel. Replacing all radios with a full duplex system isn't practical either because the HF, VHF and UHF bands are crowded as it is and a full duplex sysem would at least double the bandwidth requirement methinks?

 

[Ex-Bay]

Thinking about it full duplex isn't a practical proposition I think. Full duplex uses a different tx and rx freq for each channel, so it would not be compatible with existing half duplex V/UHF systems which use a single freq for each channel. Replacing all radios with a full duplex system isn't practical either because the HF, VHF and UHF bands are crowded as it is and a full duplex sysem would at least double the bandwidth requirement methinks?

True.
Use of duplex is not worth the effort or bandwidth. Duplex is usually reserved for data transmission (requiring ACK every now & again). The human cannot listen and talk at the same time, so it's a bit pointless as well as being heavy.


"Ground Control to Major Tom. . . . ."



DT_Xtremez_28:


PS. Anyone heard of a TWT being used below 1000MHz?

 

[The Dog's]

The human cannot listen and talk at the same time

Unless youre female of course!DT_Xtremez_35:

PS. Anyone heard of a TWT being used below 1000MHz?

No, but can we use SI old boy. That should read 1GHz!

 

[monobrow]

PS. Anyone heard of a TWT being used below 1000MHz?

Theres plenty of tw@ts where I work, but I don't think they are measured in Hz........

 

[Ex-Bay]

Unless youre female of course! DT_Xtremez_35:

No, but can we use SI old boy. That should read 1GHz!

Didn't want to get too technical. I should have said 30-odd cms. . . . . . . .



DT_Xtremez_14:

 

[kerrang]

Avionic stuff on typoon

Don't know the answer to your Q matey, might find it in here.......DT_Xtremez_14:

Reading from that article about the Typhoon Fly by wire computer processor uses 4 x 68020 processors. The same processor used in an Applemac II in 1987 and Commodore Amiga 1200 computer from around 1992.

Nice to see that BAe invested heavily in the latest technology for the money the RAF are spending on these jets.DT_Xtremez_25:

 

[Shugster]

Reading from that article about the Typhoon Fly by wire computer processor uses 4 x 68020 processors. The same processor used in an Applemac II in 1987 and Commodore Amiga 1200 computer from around 1992.

Nice to see that BAe invested heavily in the latest technology for the money the RAF are spending on these jets.DT_Xtremez_25:

Don't be too quick to judge.

Components have to be approved for use in various enviroments including radiation.

The older components were tested to such standards until it wasn't really deemed necessary for your average desktop.

Radiation can wipe eproms and destroy memory locations.

So although a pentium quadcore could outpace the 68020 easily, it might not stand up to the effects of jamming etc.

So, "Bulletproof", technology is used as opposed to fast but not made for stressfull enviroments technology.

Besides, as the 68020's won't have to run all the crap that windows does they'll probably still be more than fast enough to do the tasks required.

 

[T93]

A mechanism known as VAD (Voice Activation Detection) is used in your handsets (2G&3G) + Compressed Mode is is an algorithm that is enabled via the RNC.

To save time/power on your handset. During quiet moments during a CS call the UE will "drop out" and monitor all other frequencies (inc:GSM) to enable it to be ready to initiate a handover.

Very basic, but can pad out when I have the time.

fyi: I have been on a NSN course (Nokia Flexi BTS) this week in Munich for the next generation Base Stations (Nokia). This course basically covers the Installation/Commissioning/Integration/O&M.

These Flexi BTS are small, I mean you can fit a couple in an estate car & One person could easily do the install/comm within a few hrs (dependent upon local conditions)

These are the 1st BTS (any vendor) that has no backplane & there is no rectifiers located on the BTS, The -48v DC feed comes directly into the unit.

The course was not much use to me, but hey, I get the cert and it was a freebie.

 

[planesailing]

VHF/UHF AC Radios

PS. Anyone heard of a TWT being used below 1000MHz?[/quote]

Don`t know of any applications, never came across them much except in a certain maritime ecm.

but see link


http://en.wikipedia.org/wiki/Traveling_wave_tube