Filmmaker's Newbie Question

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gong123321

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I'm an independent filmmaker working on a script. There is a scene where two private investigators are trying to listen in on an individual's cell phone conversation but the scanner is having problems and is unable to pick up a signal prompting one of the investigators to take the scanner and sneak closer to the individual such that the scanner can receive the signal - The idea here being that the scanner is malfunctioning and will only pick up the signal if it is closer (signal is stronger) to signal. As of right now, I have one of the investigators saying something along the lines of "i think the damn thing's receiver is dying on me" to explain the malfunction. I want the problem to be realistic so my question is this:

Is the "receiver...dying" a legitimate problem, is there even a part called a "receiver" in a scanner or is the whole scanner a "receiver"?

What would be some realistic hardware problems that would cause a scanner to have trouble receiving all signals but the very strongest ones?
 

scanfan03

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You could say that the antenna is broken or along the lines of that. A scanner is a receiver, but call it a receiver instead of a scanner anyways because if the movie is based in this day in age, you can't pick up cell phones with scanners.
 

Garymaxon1234

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Scanfan03 beat me to part of my answer, Drop the scanner and the antenna connection inside the scanner breaks. The connection inside the scanner breaking happens in real life I've had to fix mine a couple of times and so have others.

Better make the phone a cordless phone if you could actually receive the cell phone you would have to move closer to the tower.

GT
 

zz0468

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gong123321 said:
Is the "receiver...dying" a legitimate problem, is there even a part called a "receiver" in a scanner or is the whole scanner a "receiver"?
Yes, a receiver can "die" in a manner that causes it to lose sensitivity and one presumably could have to get closer to the signal source to hear it.

gong123321 said:
What would be some realistic hardware problems that would cause a scanner to have trouble receiving all signals but the very strongest ones?
Failure of any one of several stages of gain inside the receiver could cause this.

Something else for you to be aware of... Receiving cellphones on a scanner is now a near impossibility due to the digital nature of the phones, and a law passed by congress prohibiting the manufacture of scanners capable of receiving the older style analog phones. Your scenario could have taken place a decade ago, but is highly unlikely today. The average viewer might not care, but to people like us, we'd notice!
 

Airdorn

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Sounds like you are trying to justify a plot device so that one of the investigators, in trying to get a better signal, gets into harms way. That seems a little campy, really.

Is it possible for a scanner to malfunction in such a way that one would have to get real close to the cell phone? Yes. Is that probable? NO.

And in that lies the improbable (campy) nature of that idea. See if you can get your character into trouble some other way.
 
D

DaveNF2G

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Cell phones operate via high-powered repeater stations on mountaintops and tall buildings. There is no need to get close to any particular cellphone to monitor it.

However, as others have pointed out, you're already in technological trouble because no scanner model can demodulate the multiplexed digital transmissions made by most cellphones today.
 

af5rn

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DaveNF2G said:
Cell phones operate via high-powered repeater stations on mountaintops and tall buildings. There is no need to get close to any particular cellphone to monitor it.
Yeah, that was my immediate thought. The whole premise of listening to a cell convo by getting close to the cellphone is not accurate. You wouldn't be monitoring the transmission from the cellphone itself. Doing that would only get you one side of the conversation. And the $15 thousand-dollar, government grade receivers that could actually monitor cellphone conversations are not something you can carry around in your hands. They'd be bolted into a vehicle. And they would be monitoring the conversation by listening to the repeated transmission from a cell tower somewhere nearby, not the cellphone itself.

Perhaps a better premise would be the failure of video surveillance equipment (intensifier in the night vision scope burns out), forcing the hero to sneak down for a closer look. Or alternately, if instead of a cellphone, they were listening to a bug whose battery was getting low, then your premise of needing to get closer with a scanner would work out.

Good luck! Be sure to get back with us when this hits the screen!
 

wa6ube

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gong123321 said:
I'm an independent filmmaker working on a script. There is a scene where two private investigators are trying to listen in on an individual's cell phone conversation but the scanner is having problems and is unable to pick up a signal prompting one of the investigators to take the scanner and sneak closer to the individual such that the scanner can receive the signal - The idea here being that the scanner is malfunctioning and will only pick up the signal if it is closer (signal is stronger) to signal. As of right now, I have one of the investigators saying something along the lines of "i think the damn thing's receiver is dying on me" to explain the malfunction. I want the problem to be realistic so my question is this:

Is the "receiver...dying" a legitimate problem, is there even a part called a "receiver" in a scanner or is the whole scanner a "receiver"?

What would be some realistic hardware problems that would cause a scanner to have trouble receiving all signals but the very strongest ones?

How about something like "We have a poor signal path... have to get closer" ..

It is more likely that a cellular phone that is close to a cell site will automatically transmit with lower power settings .. this is more likely in real life than the scanner being messed up ..

You may need to dummy something up that is supposed to be decoding the GSM digital format since even scanners that can tune in cellphone calls cannot decode the digital phone modulation .. that would make the scene more realistic.. especially to the tech geeks in the audience ..

and yes , refer to the scanner as a receiver and not a scanner ...
 
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slicerwizard

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af5rn said:
The whole premise of listening to a cell convo by getting close to the cellphone is not accurate. You wouldn't be monitoring the transmission from the cellphone itself. Doing that would only get you one side of the conversation.
Back in the analog days, that's exactly how we did it. Removing the scanner's antenna and sweeping the input frequencies always got you locked on to the guy using his phone across the room from you or in the car next to you. There was enough of the landline audio being retransmitted by the user's handset to hear both sides of the conversation. And the difference in levels always made it clear who was talking. Sometimes, we'd tune a second scanner 45 MHz up and get proper stereo. It blew away onlookers every time.
 

af5rn

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slicerwizard said:
Back in the analog days, that's exactly how we did it. Removing the scanner's antenna and sweeping the input frequencies always got you locked on to the guy using his phone across the room from you or in the car next to you. There was enough of the landline audio being retransmitted by the user's handset to hear both sides of the conversation. And the difference in levels always made it clear who was talking. Sometimes, we'd tune a second scanner 45 MHz up and get proper stereo. It blew away onlookers every time.
I miss the good old days.

:tear: :(
 

StaticLine

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Batteries weak?,He could drop it.Heck is fantasy land anything could happen.My best bud from school wound up in some intel, they used unblocked Icoms back in the days of analog rock tablets.
 

hoser147

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Besides the reasons all posted above we really dont need the uninformed public thinking we can listen in on their cellphone conversations. Good luck with your film............Hoser
 

gong123321

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wow so many replies! thanks for all the info. I liked the idea about there being a bug instead. So if it was a bug that was planted and is malfunctioning would the battery running out be the only explanation for a weak broadcast signal? what type of portable receivers would one use to listen to the bug? Would it look just like a portable scanner or what?
 

af5rn

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gong123321 said:
wow so many replies! thanks for all the info. I liked the idea about there being a bug instead. So if it was a bug that was planted and is malfunctioning would the battery running out be the only explanation for a weak broadcast signal? what type of portable receivers would one use to listen to the bug? Would it look just like a portable scanner or what?
A low battery would be the most logical explanation. Your heroes could argue over whose responsibility it was to check the batteries before planting the bug, lol.

"Dammit! We're losing the signal! You did put new batteries in there before you planted it, didn't you?"

"Me?" I thought YOU did it!"

"Geeze, do I have to do ALL the work here?"

"Where are you going"

"I'm going to TRY and get close enough to listen to your DEAD BUG!"

And yes, you can listen to simple bugs with just a regular handheld scanner. In this scenario, they'd probably be using headphones on it though.
 

Don_Burke

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gong123321 said:
wow so many replies! thanks for all the info. I liked the idea about there being a bug instead. So if it was a bug that was planted and is malfunctioning would the battery running out be the only explanation for a weak broadcast signal? what type of portable receivers would one use to listen to the bug? Would it look just like a portable scanner or what?
You could have an interfering signal come in and your character would need to get closer to the bug and further from the interfering signal.

The interfering signal could be many things. The first one that comes to mind would be a wireless microphone being used in an aerobics class. They tend to come out of nowhere.

Many off-the-shelf scanners could be used. Heck, someone here might loan you one. :)
 

af5rn

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Don_Burke said:
The interfering signal could be many things. The first one that comes to mind would be a wireless microphone being used in an aerobics class. They tend to come out of nowhere.
ROFL! That's funny right there! I can just picture that.

I sure hope this film is going to be a comedy, lol! I'm picturing something like "Sneakers" or "True Lies", which were two of the best movies ever!
 

slicerwizard

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gong123321 said:
So if it was a bug that was planted and is malfunctioning would the battery running out be the only explanation for a weak broadcast signal?
There are lots of possibilities:

- the bug sustained damage (it was stuck on the back of a couch and got slammed against the wall when the target sat down)

- it fell into a floor air duct (metal blocks signals)

- a vehicle with a lot of sheet metal (like a van) got parked up against the window that the signal was funneling through

- the target fired up some electrical device that's causing interference (DC motors can throw off tons of hash, so it could be a poorly maintained elevator motor, a water pump for an outdoor fountain, or an electronic control for a non-incandescent outside light fixture (flourescent, high pressure sodium), a triac lamp dimmer, you name it)

- etc., etc., the list is endless.


what type of portable receivers would one use to listen to the bug? Would it look just like a portable scanner or what?
Yep, nothing special required.
 

n8emr

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If you want it to realistic then have them using a directional microphone. While the old analog phones could be heard on scanners but since digital phones have been the norm for almost 10 years and they cant be heard on a scanner.
 
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