Radios

[sam.henderson]

Hi All,

 

Just wondering if there was a set of radios that could do the following. Basically I want to give radios to each of the crew and me and then put each of the different depts. (sound, lx, stage management) on a different channel so they can only here there own dept. however I want one where I can hear all the channels and talk to which ever one I want but only that one or do a message that goes to all of them.

 

I hope that thats clear, I know nothing about radios so any help would be great.

 

Many Thanks,

 

Sam

[richard]

Most motorolas can do this (GP300, 350 etc) You would just program the different radios with different frequencies, but one radio could have all the frequencies. As the motorolas can each hold up to 16 I think frequencies, you may be best to just put them all in each radio, then just tell people to use the channel you specify.

 

Someone like Mike Weaver or National radio Bank would be the best to talk to, and they are both nice companies

[sam.henderson]

OK, Cheers Richard, will have a look round the motorola site and give Mike Weaver a call tomorrow.

 

Cheers,

 

Sam

[Brian]

I can also recommend K2 Radio Communications who were at ABTT and whom I've bought gear for pro use off before.

 

[EDIT]

hmm, website seems to be playing up at the moment so 01353 669708

 

[EDIT AGAIN]

added some www and it now works (thanks DSA)

[Freddie]

If you don't mind straying from Motorola, there's TTI. High quality kit and fabulous customer support. (The MD (Dale) also posts on 446User.) On the subject of which, the guys on 446user know their stuff, so you could try asking there. PMR446 (The focus of that site) is the licencefree one, the one where anyone can buy a handset (Prices start at £20). You'd probably want the licenced frequencies, shared with the GP300s others have mentioned, so be sure to ask in the right place (General Radio Forum)

 

Your plan for channels is easy, as long as your chosen radio(s) have a "Dual Watch" feature (Most do). Dual watch is where a radio "watches" 2 channels; it's "home channel, which in your case would be the department, and a second channel, which in your case would be the "call all"

 

EG:

Ch1: LX

Ch2: Noise

Ch3: FOH Manager

Ch4: Master (Call All)

 

Set the Dual Watch channel on each radio to be the call all channel.

Set the Home channel on each to the relavent channel for that dept.

To talk to one dept.:Move to their channel

To talk to all: Move to "call all" channel

 

 

HTH

[paulears]

There are two different concepts here. The common method of using CTCSS (continuous tone controlled squelch system) allows the receivers to remain muted if a signal with the wrong CTCSS tone appears. This means that sound talks to sound, and lx and stage don't hear anything. You could have a rado programmed to send CTCSS tones, but ignor them when receiving. You would hear everyone, and could have the radio programmed with 3 different tx tones in the first 3 channels - so you could selectively talk to any of the groups. Problem are that only a single frequency is in use. So when sound is talking to sound, LX can't use the radio. On better equipment, the transmit button is locked out when receiving a 'wrong' CTCSS tone. On cheap equipment, there isn't a lockout, and lx could 'talk-over' a conversation in progress, making a mess of it. Not good for reliable comms. You could use three separate channels, and as said up the thread a bit, you could have a scan programmed in, so that your radio monitors all three, then stops on the busy one. What you can't do is transmit to every group.

 

All this is using standard pmr kit on a simplex system - i.e. radio to radio.

 

It is possible to do what you want if you use a base station, and use talkthrough. For those who don't get involved with comms - this means everyone transmits on freq A, this is received by a base station, and re-transmitted on freq B. Everyones portable radios then receive ch B (but TX on A) The base station is fitted with logic that allows it to detect what the incoming signal wants to do. This way, you could have a system designed so that you could 'selcall' one radio, or a group, or all. Downside is that only one conversation can take place at a time. It is quite possible to run multiple base stations - one for each group of users, and cross connect using the logic controller.

 

The cost of base stations of this type is very high, plus the portables have hefty price tags attached too - so in practice, it is usually cheaper to just gear up with portables that have 3 channels (I.e 3 frequencies) in each. If you forgo the talk to everyone facility, then a simple scanning radio for you may well do.

 

Sorry it was such a long post, but not the easiest thing to explain

paul

[Freddie]

Apologies in advance if I have misunderstood you,

You could use three separate channels, and as said up the thread a bit, you could have a scan programmed in, so that your radio monitors all three, then stops on the busy one. What you can't do is transmit to every group.

 

<snip>

so in practice, it is usually cheaper to just gear up with portables that have 3 channels (I.e 3 frequencies) in each. If you forgo the talk to everyone facility, then a simple scanning radio for you may well do.

<{POST_SNAPBACK}>

 

I was not referring to having the "master" scanning, but rather the "slaves" watching 2 channels ("Dual Watch", Where a radio flicks between 2 channels twice a second). Some sample instructions for the is type of thing would be:

 

Ensure all radios are programmed with the same memories, (eg Memory 1: Ch1 CTCSS12; Mem2: Ch2 CTCSS36 etc)

 

Programme all slave radios to "Dual Watch" the call all channel (eg, Mem 16)

 

****ON A "BLACK-BOX" TYPE RADIO (NO SCREEN) THE ABOVE STEPS ARE DONE USING A PC INTERFACE CABLE NORMALLY****

 

For LX: Twist the channel selector to mem1

For Noise: " " " " " mem2

 

In this system, sound can talk to sound and LX can talk to LX at the same time. If you want to speak to LX, twist your channel selector to 1. If you want to talk to sound, twist to ch2. If you want to talk to both, twist to the channel you programmed as Dual Watch (16).

 

I hope that this has made what I am trying to say clearer. In conclusion, you can have a call-all channel as long as you use relatively high end (But still quite cheap ~£50+) equipment. An example of a PMR446 that would be suitable would be the Entel Eurowave, although for interference (People messing about/channel overcrowding) reasons, I would advise talking to a dealer (As Richard and Brian have said) about a Licenced system.