Input Freqs

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jfab

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I know they are used for professional radios to TX, but do they serve any purpose for the average scanner listener? Is there anyway to find the missing input freqs that aren't in the DB? Maybe through a search using your scanner? Or by looking up the license?

Thanks!
 

dougjgray

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I believe that the input frequency is what the mobile radios use to transmit o the tower/repeater, they are probably not in the database because the repeater will rebroadcast it so there is nothing gained by monitoring it. plus you could only hear stuff pretty close to you. I believe the FCC makes the input *5 khz lower the output frequncy

*maybe it should 5 mhz
 
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dracer777

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There was also a discussion on creating a sort of "cop detection device" by putting only input freqs for state patrol, so you would only hear traffic when an officer near you transmitted.
 

ecps92

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To answer your question, they do serve a purpose to Scannists, but not all areas are worthing entering them into your scanner.

There are Depts that have been known to Shut off the Repeater, for Sensitive Communications with a unit or units in the field.

NYFD calls it disable the Mixer, other East Coast depts have different codes. You will still hear Dispatch, but not the Portable or Mobile.

Inputs are easiliy found for Public Saferty in the UHF, UHF-T and 800 Bands. Others vary as there is not standard.

450-470 UHF is +5 Mhz
470-512 UHF-T is +3 Mhz
800 Mhz is -45 Mhz

Hope this helps.

I know they are used for professional radios to TX, but do they serve any purpose for the average scanner listener? Is there anyway to find the missing input freqs that aren't in the DB? Maybe through a search using your scanner? Or by looking up the license?

Thanks!
 

fourthhorseman

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There was also a discussion on creating a sort of "cop detection device" by putting only input freqs for state patrol, so you would only hear traffic when an officer near you transmitted.[/QUOTE]

Cobra made one of these,,im pretty sure it was cobra,,
looked like a radar det,,had i think an antenna that extended from it ..

saw the page on tha manufacturers site a few years back,,
 

jfab

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thanks everyone!

Ecps92-do you know how to find inputs for VHF as well?

To answer your question, they do serve a purpose to Scannists, but not all areas are worthing entering them into your scanner.

There are Depts that have been known to Shut off the Repeater, for Sensitive Communications with a unit or units in the field.

NYFD calls it disable the Mixer, other East Coast depts have different codes. You will still hear Dispatch, but not the Portable or Mobile.

Inputs are easiliy found for Public Saferty in the UHF, UHF-T and 800 Bands. Others vary as there is not standard.

450-470 UHF is +5 Mhz
470-512 UHF-T is +3 Mhz
800 Mhz is -45 Mhz

Hope this helps.
 

ecps92

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VHF varies so widely, the typical ONLY location would be the FCC License and look for an FX of FX1 station, altho hit's hit-n-miss on many, unless you actually confirm it as an input.


thanks everyone!

Ecps92-do you know how to find inputs for VHF as well?
 

resq197

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For everything in Boulder County, I have the input right after the repeater output programmed, but locked out. The only time I would ever use them is like others have said, in case for some reason I can't hear the repeater or to get an idea of how close a remote unit is. For normal monitoring in Boulder, you won't hear the dispatch side on the input though since they're linked by phone line/microwave directly to the transmitters.

-Brian
 

dracer777

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Cobra made one of these,,im pretty sure it was cobra,,
looked like a radar det,,had i think an antenna that extended from it ..

saw the page on the manufacturers site a few years back,,[/QUOTE]

and it failed because it took too much time and knowledge to program, right? Couldve actually been a cool device. Maybe use 3 antennas externally mounted for triangulation? :D


Also, the input freqs DB is nowhere near complete. Do you just have what's in the DB programmed or did you actually find all the input freqs in boulder county?
 

jeffreyinberthoud

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I knew I recalled this correctly I wonder if any current scanner can do this

this is from 780 owners manual review from strong signals a million years ago....LOL

Q: What is Reverse Mode?
A: Many radio systems use a repeater setup which works using two frequencies; a low-powered input and high-powered output. Most of the time, listeners will opt to program the high-powered output frequency since this has the likeliest chance of monitoring signals.
When listening to the repeater frequency, it is possible to use the Reverse Mode feature to temporarily listen to the opposite repeater frequency. This is most useful if you normally listen to the output frequency. If you use the Reverse Mode in this case, the input frequency will be monitored and if a signal is heard, you know that the radio emitting the low-powered signal must be nearby.

For more details, see pages 69 & 82 of the BC780XLT Operating Guide.
 

scanlist

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I havent found anymore inputs. But I've been told there are ways to find them using a scanner.
The search button on many scanners feel neglected.

People are dancing around this so I will ask what exactly are you wanting to do with the input information?

Asking for VHF information of this sort and publicizing you have a VHF spectra will definitely raise suspicion.
 

poltergeisty

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:lol: Exactly! Like it's hard to find, plus the separation in KHz has been given already. I like haveing the inputs in one bank while out on a bike ride. They come up active all the time. I use the beep function so that I know what I heard was from the input frequency.

Use the reverse mode!
 
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