Scanner Strange Noises??

[topgun1986]

New to scanners, so these "noises" may be obvious/common to some, but would like to know what they are.

Sound A
http://youtu.be/lHeIxyjtY1k

Sound B
Scanner Noise 3 - YouTube

Sound C
Scanner Noise 5 - YouTube

Sound D
Scanner Noise 6 - YouTube

[topgun1986]

The scanner is a Radio Shack Pro-163, connected to a J-pole antenna. I have it mounted in my shack even though it is a mobile unit. Has worked great with the J-pole, but was curious what these noises were I hear maybe once an evening if that.

[Fuzy_GSXR1000]

I think number 5 is your scanner hitting on a MotoTurbo digital encrypted signal....I recognize this because where I work they went to that system. So you know what I did right? One night I brought my 197 to work and we keyed up our radios asking security for radio checks and that's what you hear from your scanner my friend....best analogy.....the radio sound from the movie "Independence Day"

[lazierfan]

I think #3 is a pager service, most likely hospital, given the 159.63 freq.

[DickH]

Originally Posted by topgun1986

New to scanners, so these "noises" may be obvious/common to some, but would like to know what they are.

Sound A
http://youtu.be/lHeIxyjtY1k

Sound B
Scanner Noise 3 - YouTube

Sound C
Scanner Noise 5 - YouTube

Sound D
Scanner Noise 6 - YouTube

You might find them here: Digital*Modes*Samples

[Redneck0410]

Sound D sounds like an EDACS control channel. Could not access Sound A. Sound B is likely a pager of some sort. Sound C is a MotoTrbo as a previous poster indicated.

[ampulman]

Sound D = EDACS control channel

[kb2vxa]

You'll also find this very helpful: W2SJW - Radio Sounds

BTW Scott is one of our NJ database administrators and a long time friend.

[nd5y]

Sound B sounds almost like AX.25 packet radio. 159.63 is licensed to several electric companies in MO so it is probably a SCADA channel.

[benbenrf]

TopGun

When you ask what they are, what is it exactly you'd like to know: modulation type (e.g. FM or AM or QAM or BPSK or QPSK or FSK or COFDM .... or whatever), or is it the content (audio or video for example).

Of course the displayed frequency, the region or area of broadcast along with bandwidth and any associated and displayed RDS info will often enable one to get online and search Google to quickly ID the rf transmission, but the truth is that to ID many digital (and analogue type for that matter) modulations with any degree of accuracy from just recorded audio alone is not easy. It requires recording (IQ form is one of the most practical ways to go about recording received rf transmissions) to be replayed, displaying the waveform on a monitor - the closer to bit level you can zoom in or get the monitor to display at, the more accurately the modulation can be defined.

Been able to recognize a modulation type from its recorded sound alone was a highly prized skill in the Cold war days. It still is today, GCHQ, the NSA and other 3-letter agencies, go to great lengths to hang on to the few folk who can recognize both modulation type and encoding from a sound recording – and there not many folk around who have this skill. It requires years & years of experience.

Compliment the recorded audio reply with an onscreen spectrogram type display of the waveform, with a good zoom-in function to get as close to bit level as possible - and there are consumer level software products for enthusiasts to do this – and identification becomes easy.

But, ID’ing modulation is often only the first step to recovering any audio or video or data or whatever content. A complete “what is it?” answer will also require the encoding to be recognized and dealt with e.g. in QAM modulated signals encoding could be 64bit or 128bit or 256bit, and that’s an additional step to be undertaken if you want to extract & listen to the audio or view the video. But, so long as no encryption has been applied it’s then a fairly straightforward process to extract the video or audio – a good quality off-the-shelf sound card running a custom software patch on a fast enough PC will often be all that is needed.

[kb2vxa]

(;->) You forget this is the newbie forum, I'll bet he has no idea what you're talking about.

[topgun1986]

You're right. I do not know what that means, hence the name of the forum.
Thought posting in this forum would excuse my posts from certain criticisms.

By the question "what it is", lets start with...
-are they digital signals being picked up by my analog scanner?
-are they analog signals that my scanner is not designed to decode/pick up?
-or are they "birdies" I hear about but not quite sure I know the meaning of?

Thanks!

[Redneck0410]

Originally Posted by topgun1986

You're right. I do not know what that means, hence the name of the forum.
Thought posting in this forum would excuse my posts from certain criticisms.

By the question "what it is", lets start with...
-are they digital signals being picked up by my analog scanner?
-are they analog signals that my scanner is not designed to decode/pick up?
-or are they "birdies" I hear about but not quite sure I know the meaning of?

Thanks!

What is the EDACS control channel? Put simply, it transmits the data of the trunking system and turns it from the sound you list on youtube to intelligible sound. Whether or not it is a digital signal that you are hearing and have listed and inquired about here would depend on the area of SE MO you are in. I did a frequency search on the frequency in the video. I can't tell you for sure if it's digital or not, as it lists that frequency as both EDACS Standard (Analog, in other words) and P25 (Digital). If you're in an area where it's P25, then no, you're not supposed to be able to pick up the traffic. Just looking at the EDACS video on youtube, I can tell you with 100 percent certainty your scanner is not set to trunk-track that system. EDACS systems must be put into a bank in Logical Channel Number order. To do this, you must first find the county you reside in here: http://www.radioreference.com/apps/db/?sid=965 (The link I provided is for the "Analog" system, assuming that is what's being heard. If your specific county is not listed, it very well could be the digital system you're hearing. Whether or not THAT requires a LCN, I don't know as I do not have a digital scanner. Analog definitely does need an LCN. Anyway, once you find your county, assuming it's analog, the little numbers (01, 02, etc.) are your channel numbers to match up in the scanner. Since you have it in bank 1, that would be 101, 102, etc. Program all the frequencies in their appropriate channel slots, then hit Function+Trunk, that will take you into the Talkgroup menu, where you can set what you want to hear. Just enter whatever talkgroups from the database you want to hear, then you can set the bank to "Closed" mode (Function+Delay). If you need additional help, let me know via PM and I will help you out.

-Shawn

[wingmaker]

D is definitly a EDACS control channel. B paging type or somekinda data being sent, like maybe the call sign, I heard that was possible. On C how long does it last, and if its like an all day thing maybe a control channel, or could be TRBO. LOVE and BLESSINGS

[kb2vxa]

"-are they digital signals being picked up by my analog scanner?"
Yes.

"-are they analog signals that my scanner is not designed to decode/pick up?"
No.

"-or are they "birdies" I hear about but not quite sure I know the meaning of?"
No, birdies are generated internally by local oscillators (frequency conversion stages) that show up as dead carriers.

[benbenrf]

Originally Posted by topgun1986

You're right. I do not know what that means, hence the name of the forum.
Thought posting in this forum would excuse my posts from certain criticisms.

By the question "what it is", lets start with...
-are they digital signals being picked up by my analog scanner?
-are they analog signals that my scanner is not designed to decode/pick up?
-or are they "birdies" I hear about but not quite sure I know the meaning of?

Thanks!

Remember, you may not like, understand, appreciate or agree with someone elses contribution - thats fine, but (and this is not directed to you topgun1986) in choosing to to express disgreement folk can go about it constructively or arrogantly - completly ignore the later.

So, I certainly was not critisizing you and I don't believe anyone else was. What I was trying to share with you were some of the considerations that often need to be thought through to get an accurate answer to the questions you asked.

If there is anything you do not understand about what I wrote, ask me to explain, and I will be more than happy to. That is after all the purpose of a forum is it not: to share with others and help them.

[topgun1986]

benbenrf...

I appreciate any and all help I recieve on this forum. This site is by far the greatest resource of info I have yet to find on the web.

The majority of my problems seem to be self created, by purchasing equipment/toys that look cool and sparkly, only to find out once I get home and plug them in, that I really should've just stuck with that wooden block thing.

That being said, I'm still trying to wrap my head around trunking, then it is on to EDACS, then hopefully P25.

[benbenrf]

I identify with your comment about toys and equipment with lights and which looks cool - I use recivers from an old company called Watkins Johnson - in particular (but not only) their 8617B-S1 types recievers. In terms of reciver performance there is nothing on the market today this side of $10K that comes close to what these units are capable of. They can be picked up on ebay for around $600 - $1000 and are based on old fashioned TTL logic and cards that can be changed to acomodate whatever one wants to do with them.

They have a ton of rear panel outputs - many of which can be used to feed signals to a PC, and that is where all the work is done i.e. in the digital domain on a PC. The WJ receiver is used to do little more than function as a rf front-end w3ith a bunch of filters and different bandwidths.

Howver, what I need to keep in mind is that the above reflects my approach to using receivers and scanners. That is not the case for many other folk - who are quite content to put down $200 - $500 and take what they get for it. In terms of rf performance you are never going to get much, but the functions that many modern day scanners/receivers offer are fantastic when looked at in terms of the volume/size and practicality of such units. And, for many of these folk the pleasure lies not so much in the technical background and detail, but in simply listening to the audio or whatever. So, why then should they go to the lengths I go to? They shouldn't is the correct answer.

This is a hobby that can be approached from a whole bunch of different levels. Find the level you are going to be comfortable with and build up your knowledge and hardware around that level - and thats how you going to get the best enjoyment.

[DickH]

Originally Posted by topgun1986

... That being said, I'm still trying to wrap my head around trunking, then it is on to EDACS, then hopefully P25.

EDACS and P25 are just different types of signals, like AM is different than EM. Trunking is trunking is trunking. Here is a simple explanation of how trunking works.

Motorola Trunking (the most common type):

The object of trunking is to allow many users to share a relatively few frequencies.
A trunking system is controlled by a computer. Information (data) is exchanged between the system radios and the computer on a control channel, sometimes called a data channel. It sounds like a strong buzz.
A large system can have up to 28 freqs., 4 of which may be used as control channels. The control channel may be changed once a day or as often as the programmer decides. Some scanners need only the control channels to track an entire system. Just put in the 4 Control Channels.

Each group of users (Fire, Police, etc.) is assigned TALK GROUPS. In a Motorola Type II system, the most common type, TGs are usually in 32 number steps starting with 16 and going up to 65536; 16, 48, 80 --- 4656, 4688, 4720 --- 28944, 28976, etc. System radios can have more than 100 TGs programmed into them.

After all the freqs. have been entered and it is "trunking", the Banks become SCAN LISTS where you enter the Talk Groups you want to hear.
Use the Talk Group numbers in the DEC column, not in the HEX column.

When a user pushes the talk button on his radio, data is sent to the computer. The computer chooses an unused freq. and sends that data to all the radios using the TG of the originating unit. This all happens in a fraction of a second and it happens EVERY TIME a radio is used.

EXAMPLE:
Fire Dispatch calling Engine 4 (TG 4528 on 856.7125)
Engine 4 answering Dispatch (TG 4528 on 852.2625)
Respond to 73 Elm Street (TG 4528 on 855.9625)
Engine 4 responding (TG 4528 on 851.6375)

If you have entered TG 4528 into your scanner, it will decode the control channel data and change your scanner freqs. to follow the conversation on TG 4528.

This should get you started, but you should read the manual carefully. You may need to read it several times.

EDACS and LTR systems use the same principles, but they can not do Control Channel Only trunking, the TG numbering is different and the frequencies must be entered into specified channels in the scanner.

[benbenrf]

A number of intro’s to P25 can be found on the web:

Project 25 - Wikipedia, the free encyclopedia

http://www.dvsinc.com/papers/p25_training_guide.pdf

This 2nd article is a great 70page plus PDF formatted online document – though perhaps a little technical for those with limited or no electrical background or understanding of rf subject matter, it is none-the-less an interesting read supported with nice graphics throughout.

…. and I am sure there are many more P25 intro’s to be found on Google.