Radios

[Caradhras]

I just thought I would ask a brief idea from your greater experiences of these things.

I am running a T2K group but have little actual military experience (just some basic Territorial Army). My players always are asking questions that I have to wing-it with at times but this one is a bit of a niggle for me.

Radios - hand held, portable things like walkie-talkies. With their small unit actions they use these a lot - the FO to the mortar, the recon guy etc. But what range do these things realistically have (2-3 k?)? Next is the backpack style radio, presumably a considerable range compared to the others?

Power sources for these also (the battery thread prompted this thread!) - I assumed that rechargable batteries would be available but how would it really be?

Thanks for reading

[Twilight2000v3MM]

I can only give you input from a civilian poitn of view.

Our police radios (800 mhtz), now digital, have great reception and range IF you have a repeater closeby. If it's radio to radio (no repeater), even in a flat city, at BEST you may get 8-10 blocks with bad reception. I can only imagine that with big structures, hills, ect, this range would be cut in half easy. We used a specific channel for SWAT ops which is radio to radio and the range is no that great - like I said at best 8 blocks.

FYI - Battery life is probably good for 12 hours with "average" usage (I would say 70% standby and 30% transmitting and receiving). New batteries life woudl be longer and older batteries less.

[Marc]

Bon dia!

I will give my opinion without entering much in technical details, trying only to give some useful information at the level of game play. Take in to account that my direct experience about the matter is from 8 years ago...
About the walkie-talkies, you need to know that, in general terms, their range of available frequencies and their limited power output can provide a maximum distance of communication of about the range of sight in open terrain (between 4.5 and 5Km). This distance can be drastically shortened in an urban area and (in general terms) in any terrain with important obstacles cutting the line you can trace between the two communicators. Perhaps the effective range could be reduced to 1 to 2 Km. In that conditions, a good way to simplify the things would be: If there's an interrupted line of sight between us, we can communicate easily. If not, it's not an automatic task and you would need a roll to determine success.


I've got much more experience about backpack radios. I will suppose that you're talking about a VHF radios, the typical at platoon level. Their lower frequency and greater in power output usually makes them less vulnerable to the physical obstacles than the walkie-talkies. You could consider about 8 Km of effective range with the normal whip antenna and 4Km with the metallic-flexible antenna. Sorry, I do not know the correct English term for this type. Again, you can reduce the distance if there's a lot of obstacles, but, even in the worst conditions, you could consider that at 4km with the whip antenna and 2km with the flexible antenna, all communications attempts would be nearly an automatic success. Finally, this type of radio usually could be used with a 12m mast antenna (in a separate bag, of about 20Kg in weight) that can extend the maximum distance at about 30Km in optimum conditions. The task to deploy the mast usually implies two persons and can take about 5 to 10minutes depending of the training level of the operators. Again, a high position will help.

I hope it will be useful.

[pmulcahy11b]

Here's an interesting T2K idea -- major units that become disrupted due a breakdown in the radio nets of frequency-hopping radios. I don't know if it's classified anymore (it was when I was in), so I won't say how the frequency "hopsets" are distributed, but if the hopsets for FH radios aren't synchronized, you won't be able to talk to each other any more -- and you won't even know it's happening until you notice the rest of the formerly-chatty net has become silent. That can really disrupt unit cohesion. Are they on a different hopset? Have they been wiped out? Was there a hopset error at higher HQ that screwed up the works (easily fixed, but not if higher HQ has been destroyed)? If you need help, are you going to get it?

Eventually, everyone will be talking in the clear as hopsets and scrambling modules can no longer be synched except between small units, but in between during the Twilight War, there will be a lot of confusion.

[Twilight2000v3MM]

Makes for great plot devices Paul!! :-)

[Tegyrius]

Originally Posted by pmulcahy11b

Here's an interesting T2K idea -- major units that become disrupted due a breakdown in the radio nets of frequency-hopping radios. I don't know if it's classified anymore (it was when I was in), so I won't say how the frequency "hopsets" are distributed, but if the hopsets for FH radios aren't synchronized, you won't be able to talk to each other any more -- and you won't even know it's happening until you notice the rest of the formerly-chatty net has become silent. That can really disrupt unit cohesion. Are they on a different hopset? Have they been wiped out? Was there a hopset error at higher HQ that screwed up the works (easily fixed, but not if higher HQ has been destroyed)? If you need help, are you going to get it?

If you can say, Paul, could physical damage (or EMP, per the other current thread) compromise that synchronization without totally breaking the radio?

- C.

[pmulcahy11b]

Originally Posted by Tegyrius

If you can say, Paul, could physical damage (or EMP, per the other current thread) compromise that synchronization without totally breaking the radio?

- C.

Well...let's just say they are EMP-hardened, but EMP is still very much an unpredictable element in small electronics. EMP can literally push just a few a few atoms around in an electronic device and do something unpredictable.

The interior of a SINGCARS radio, though, doesn't look the inside of like a PRC-77 -- The old PRC has a lot of gizmos and components that look like they have no rhyme or reason to my un-commo-MOS. The inside of a SINGCARS is smaller and looks basically like layered circuit boards -- even a grunt like me can fix one with the right parts.

So yeah, you could probably break the hop module without ruining the radio -- but there are features to prevent it from transmitting if the hop module itself is compromised.

[chico20854]

Years back, somebody developed a set of pretty workable radio range rules - take a look at http://www.reocities.com/david_km/table.htm

[Nowhere Man 1966]

Originally Posted by pmulcahy11b

Here's an interesting T2K idea -- major units that become disrupted due a breakdown in the radio nets of frequency-hopping radios. I don't know if it's classified anymore (it was when I was in), so I won't say how the frequency "hopsets" are distributed, but if the hopsets for FH radios aren't synchronized, you won't be able to talk to each other any more -- and you won't even know it's happening until you notice the rest of the formerly-chatty net has become silent. That can really disrupt unit cohesion. Are they on a different hopset? Have they been wiped out? Was there a hopset error at higher HQ that screwed up the works (easily fixed, but not if higher HQ has been destroyed)? If you need help, are you going to get it?

Eventually, everyone will be talking in the clear as hopsets and scrambling modules can no longer be synched except between small units, but in between during the Twilight War, there will be a lot of confusion.

Plus it takes less energy to transmit and receive in the clear than it would with frequency hopping and/or digital radios because the computer in the radio would use energy for the synchronization and/or digital to analogue and analogue to digital conversion. I know when the batteries get low in some of those radios, they resort to "in the clear" transmissions.

Myself, on VHF, it is line of sight dependent as well as depending on height. I can hit ham radio repeaters 10 miles away on one watt with the rubber ducky antenna and once talked about 80 miles across Lake Erie and into Canada with the same setup. I think HT to HT, you can get a half mile to several miles depending on terrain.