walkie talkie

[SRF]

16 hours ago, Heidi13 said:

Corre

Correct - due to limited availability of UHF frequencies, for our entire fleet we only had 1 inter-ship and 1 intra-ship frequency.

 

Therefore, all ships used the same intra-ship UHF frequency. To manage internal communications, each ship was assigned a specific tone. All radios assigned to a ship were programmed with the correct tone, so only those radios could access the repeater system. If we were alongside another company ship, their radios could not access our repeater system.

 

To talk to another ship, we could disable the tone feature, which reverted to a simplex transmission.

 

While I had a dual band radio, I could not Tx on multiple bands or frequencies with a single transmission. 

 

I am sure there are huge hoops to jump through for a frequency to be used in many countries. 🙂

 

I was not talking about transmitting directly from your hand held on two bands at the same time, but setting up a dual band repeater system to that a certain tone would be retransmitted on both bands at the same time to reach everyone.

 

In ham radio, there are some repeaters that are on both UHF and VHF.  Not matter if you transmit on UHF of VHF, it is transmitted on both.  Allowing people to communicate across bands.  Not that common, but it can be done.

[Heidi13]

6 hours ago, SRF said:

 

 

I was not talking about transmitting directly from your hand held on two bands at the same time, but setting up a dual band repeater system to that a certain tone would be retransmitted on both bands at the same time to reach everyone.

 

 

Ah!, apologies, didn't comprehend your response correctly. Don't believe our radios had the ability to monitor dual bands/ frequencies, as it would not be something I included in the purchase specs.

 

Our Bridge radios could monitor 2 or 3 channels (Ch 16, VTS  + another) and I always had Deck Officers monitoring the radios. When off the Bridge I only monitored the intra-ship channel, as if anyone needed to contact me, that is the channel they would call.

 

 

[SRF]

8 hours ago, Heidi13 said:

Ah!, apologies, didn't comprehend your response correctly. Don't believe our radios had the ability to monitor dual bands/ frequencies, as it would not be something I included in the purchase specs.

 

Our Bridge radios could monitor 2 or 3 channels (Ch 16, VTS  + another) and I always had Deck Officers monitoring the radios. When off the Bridge I only monitored the intra-ship channel, as if anyone needed to contact me, that is the channel they would call.

 

I mentioned that possibility based on comments about having some crew on VHF and some on UHF.  So, say in an emergency, you might want everyone to hear.

 

Similar in aircraft radios.  Military aircraft radios listen to the channel or frequency selected, plus a separate receiver just for Guard (emergency frequency).

 

Makes sense, let your bridge officers deal with inter-ship communications, unless they need to contact you.

[chengkp75]

1 hour ago, SRF said:

 

I mentioned that possibility based on comments about having some crew on VHF and some on UHF.  So, say in an emergency, you might want everyone to hear.

 

Similar in aircraft radios.  Military aircraft radios listen to the channel or frequency selected, plus a separate receiver just for Guard (emergency frequency).

 

Makes sense, let your bridge officers deal with inter-ship communications, unless they need to contact you.

For the most part, my experience is that inter ship is VHF, while intra ship is UHF.  Nearly all marine VHF radios have an automatic monitor of channel 16, the emergency channel.  VHF is mostly fixed radios, but some hand-helds for the deck officers when conditions warrant.

[SRF]

6 hours ago, chengkp75 said:

For the most part, my experience is that inter ship is VHF, while intra ship is UHF.  Nearly all marine VHF radios have an automatic monitor of channel 16, the emergency channel.  VHF is mostly fixed radios, but some hand-helds for the deck officers when conditions warrant.

 

That makes sense.

 

 

[Heidi13]

On 2/17/2019 at 7:42 AM, chengkp75 said:

For the most part, my experience is that inter ship is VHF, while intra ship is UHF.  Nearly all marine VHF radios have an automatic monitor of channel 16, the emergency channel.  VHF is mostly fixed radios, but some hand-helds for the deck officers when conditions warrant.

The availability of VHF channels on the portable was mainly to impress those reading the specs. You certainly couldn't use VHF inside the ship and we have so many radios on the Bridge for redundancy, about the only use for the portable would be in a survival craft.

 

Honestly can't remember ever using VHF on my portable

[chengkp75]

8 hours ago, Heidi13 said:

The availability of VHF channels on the portable was mainly to impress those reading the specs. You certainly couldn't use VHF inside the ship and we have so many radios on the Bridge for redundancy, about the only use for the portable would be in a survival craft.

 

Honestly can't remember ever using VHF on my portable

We mostly use them when communicating with an oil terminal during cargo operations, or with the bunker barge.

[SRF]

13 hours ago, Heidi13 said:

The availability of VHF channels on the portable was mainly to impress those reading the specs. You certainly couldn't use VHF inside the ship and we have so many radios on the Bridge for redundancy, about the only use for the portable would be in a survival craft.

 

Honestly can't remember ever using VHF on my portable

 

There is always that factor. 😄

 

But you COULD use VHF inside, if you had VHF repeaters.  But antennas tend to be longer, so UHF or even high makes a lot of sense inside the ship.