Radio intercom

[OptedOut]

Anyone know if it is possible to get a radio intercom suitable for lock use etc, would need to be 'phone type ear mounted?

[johnjo]

Anyone know if it is possible to get a radio intercom suitable for lock use etc, would need to be 'phone type ear mounted?

 

Decent set of rechargeable two way radio's?

[twocvbloke]

Anyone know if it is possible to get a radio intercom suitable for lock use etc, would need to be 'phone type ear mounted?

 

Well, there are handheld PMR radios, just pick a clear channel and set each radio to it and use at your will, you can get handsfree kits for them too so you can just talk without having to press buttons...

 

http://www.maplin.co.uk/Module.aspx?ModuleNo=224647

[johnjo]

http://www.maplin.co.uk/module.aspx?moduleno=224658

 

Bit more expensive, actually over twice as much, but come with re-chargeable batts and two chargers plus a case to keep them in when not in use.

 

Do you need earpieces for any particular reason?

 

John

[OptedOut]

Thanks gentlemen, I sometimes thought it would be handy to to be able to communicate with SWMBO at lock flights etc without shouting flapping arms etc.

Looks like the hands free option would be ideal.

 

Edit: The reason I wanted hands free was to use if cycling.

Edited December 3, 2008 by OptedOut

[Chris J W]

Thanks gentlemen, I sometimes thought it would be handy to to be able to communicate with SWMBO at lock flights etc without shouting flapping arms etc.

Looks like the hands free option would be ideal.

 

Edit: The reason I wanted hands free was to use if cycling.

 

And hands-free would be very useful if you're struggling with both-hands on a recalcitrant paddle gear and don't want to let go!

[OptedOut]

And hands-free would be very useful if you're struggling with both-hands on a recalcitrant paddle gear and don't want to let go!

 

Or if you're checking out the exit of Coseley Tunnel at school home time.

[chris w]

Well, there are handheld PMR radios, just pick a clear channel and set each radio to it and use at your will, you can get handsfree kits for them too so you can just talk without having to press buttons...

 

http://www.maplin.co.uk/Module.aspx?ModuleNo=224647

These ones don't mention having CTCSS. These are the codes that you can select to make it harder for someone to break into your conversation. They may have them but they're not mentioned in the blurb, and are a very useful facility.

 

Chris

[alan_fincher]

These ones don't mention having CTCSS. These are the codes that you can select to make it harder for someone to break into your conversation. They may have them but they're not mentioned in the blurb, and are a very useful facility.

 

Chris

I think generally when they don't mention it, they don't have it.

 

Sometimes 8 channels + CTCSS is (incorrectly) described as 304 channels, but these just say "8 channels".

 

I can't immediately see any evidence that they come with rechargeable batteries and charger, which also makes them a poor bet IMO, (those that use conventional batteries will trash them quite quickly).

 

It's often possible to find a pair of PMR446 radios offering both CTCSS and rechargeable batts for only around £20, so it's a case of keep looking. Maplin regularly bring particular items down by as much as 50%.

 

We bought what looked like some nice ones branded "Yeti". I can't recommend them - the range is poor, and the batteries do not seem to want to stay charged for very long. People have highly recommended some Binatone models on here, which seem to do better on range.

[OptedOut]

This set also mentions hands free?

 

 

http://www.maplin.co.uk/Module.aspx?Module...O&U=strat15

[churchward]

The little personal radios are great. we use them and find them excellent at locks or if one of us take the dog for a walk etc. There are several types some offer coverage up to 5km although that would be in perfect conditions. Ours are usually good for a 1-2Km occasionally more.

 

Rechargable types best for the boat. The ones we have can be recharged directly form a 12v supply (Oregan is the brand) so we can plug the charger base directly into the boats 12V system.

Edited December 3, 2008 by churchward

[alan_fincher]

This set also mentions hands free?

 

 

http://www.maplin.co.uk/Module.aspx?Module...O&U=strat15

Yeh looks pretty good, although I think you can find similar cheaper.

 

The "304 channel combinations" is a myth. PMR 446 only has a available frequencies I believe, but on these sets you can set a CSCSS "sub channel" to any of 38 possibilities. If two sets don't mach on both the channel used (one of 8) and the CTSS setting (one of 38) then no transmission is received.

 

However two groups of users nearby trying to use the same channel, but different CTCSS settings WILL cause interference to each other, often to the point of non usability.

 

It would certainly not be possible to have 304 pairs of users, each trying to use a different combination, and for none to experience problems. A little bit of marketing over fact!

 

Not an issue on canals though, where generally you will not conflict with anybody!

 

Alan

[Barry]

These ones don't mention having CTCSS. These are the codes that you can select to make it harder for someone to break into your conversation. They may have them but they're not mentioned in the blurb, and are a very useful facility.

 

Chris

 

What's CTCSS please?

 

I have a pair of walkie talkie radios that I bought from Argos a few years ago so you have piqued my curiosity

[chris w]

What's CTCSS please?

 

I have a pair of walkie talkie radios that I bought from Argos a few years ago so you have piqued my curiosity

CTCSS stands for Continuous Tone Coded Squelch System and is a way of creating artifiically more "channels" than the basic 8 channels you get with PMR radios.

 

Essentially what happens is that you choose a channel, say channel 3 and then you choose one of (usually) 38 codes by simply choosing 1- 38 on a menu. When you transmit, the other person's receiver first checks to ensure that the incoming message has the correct code (say code 7) appended to the beginning of the transmission. If it does, it allows the transmission through to their receiver but, if it doesn't have the correct code, it blocks the transmission. The codes are sent as a short burst of audio tone , different for each of the 38 CTCSS codes. So, to communicate with each other, you both need to be set to channel 3. code 7 in this example.

 

It is possible also to choose code 0, ie no code if you wish. The astute reader will then realise that if I sit listening on channel 3, code 0, then I WILL hear ALL transmissions on channel 3, whether coded or not, because my receiver is not listening for codes and ignores any codes that might be appended to the message.

 

HOWEVER, I can't reply and hence interfere in a conversation because, if I transmit on the wrong code (ie: in this example any code from 0-38 except code 7), YOUR receiver won't let my voice through. So CTCSS does NOT add security from the eavesdropping point of view but it does take away a lot of unwanted interference from other people who might wish to talk on the same channel. So with 38 codes to choose from, as an outsider, I'm unlikely to hit on the right one if I want to be a PITA on your conversation. Thus, with 8 "real" channels and 38 codes, it means there are 304 different transmitting modes. But remember that CTCSS adds NO eavesdropping security.

 

There is one drawback of using CTCSS though. It takes a very small but finite time for the receiver's processor to check the incoming code and give the thumbs up (or not). This means that if you push the PTT button and talk immediately the person to whom you are transmitting will miss the first couple of syllables of your message as their receiver processes the CTCSS code.

 

So, if you are using codes (and most people do) then push the PTT and pause for half a second before speaking.

 

Chris

Edited December 3, 2008 by chris w

[Barry]

Very comprehensive answer - thank you

[Keeping Up]

It's definitely worth getting CTCSS because your receiver doesn't keep jumping into life by picking up someone else's conversation (which causes your crew to call you back and ask "why did you just call me that" or similar - I know, it's happened to me).

 

Also it's worth making sure that your walkie-talkies have a "call" facility, which allows you to sound a loud tone in the other unit (like when a phone rings) because otherwise it can be impossible to attract their attention, especially if there's a lot of noise around them such as the sound of a lock filling.

[alan_fincher]

There is one drawback of using CTCSS though. It takes a very small but finite time for the receiver's processor to check the incoming code and give the thumbs up (or not). This means that if you push the PTT button and talk immediately the person to whom you are transmitting will miss the first couple of syllables of your message as their receiver processes the CTCSS code.

Ah!

 

I've just learned something.

 

I'm regularly accused of starting to speak before pressing the PTT switch, such that the start of what I say is lost.

 

I now understand that I'm not, but am not leaving the enforced pause you are suggesting.

 

I'll educate all my co-operators, who also often lose the start of their speech too.

 

Also it's worth making sure that your walkie-talkies have a "call" facility, which allows you to sound a loud tone in the other unit (like when a phone rings) because otherwise it can be impossible to attract their attention, especially if there's a lot of noise around them such as the sound of a lock filling.

We have more than 2 transceivers, and set each to give a different "ring tone". In that way we each carry our own personal sound, so it's obvious who is calling.

[Natalie Graham]

This means that if you push the PTT button and talk immediately the person to whom you are transmitting will miss the first couple of syllables of your message

 

As in when you have slipped from the boat in the lock and yell to your companion, 'HELP! Don't raise the paddles!"

 

Natalie.

[johnjo]

This set also mentions hands free?

 

 

http://www.maplin.co.uk/Module.aspx?Module...O&U=strat15

 

Q&A fom The Maplin site re: the above.

 

) On the Binatone Terrain 550 twin pack, please could you let me know what connector it utilises for mic / headset? - Chris Jones

A) A single 2.5mm jack connector

 

Q) can you fit a mic and earpiece to the radios - pete

A) yes you can (sadly we do not currently stock a compatible headset without the use of adapters etc)

[Peter R]

I've got a pair of these that do come in useful at times. From memory I think they are by binatone (although I can't be sure as I am at home and they are on the boat). Looking at the binatone website, I think they are the EK1000.

 

I've got a feeling that they were only about £20 new, but they may have been on special offer at the time.

 

Peter

[OptedOut]

Q&A fom The Maplin site re: the above.

 

) On the Binatone Terrain 550 twin pack, please could you let me know what connector it utilises for mic / headset? - Chris Jones

A) A single 2.5mm jack connector

 

Q) can you fit a mic and earpiece to the radios - pete

A) yes you can (sadly we do not currently stock a compatible headset without the use of adapters etc)

 

I had a bad feeling about that when there did not seem to be any mention of accessories.

[bottle]

And,

 

There are now 'digital' versions as opposed to the existing analogue that have even more 'codes' but both units have to be 'digital'.