searching the fed bands

[mkewman]

so i've been searching the fed bands... but it's a pain!!!! i get so many paging and data frequencies sprinkled in, and locking them out is tedious. and data skip isn't keeping those away.

is there specific areas that i should search to avoid these freqs?

is there a better way?

 

[SCPD]

Fed Band

Are you sure thats DATA? It could be Digital Communications. Almost nationally the FBI, Marshal's, DEA, ATF, Department of Home Security etc. are all Digital with either fulltime or partial Encryption. Both Digital and DES will sound simular to DATA Bursts to untrained ears.

 

[sflmonitor]

Are you sure thats DATA? It could be Digital Communications. Almost nationally the FBI, Marshal's, DEA, ATF, Department of Home Security etc. are all Digital with either fulltime or partial Encryption. Both Digital and DES will sound simular to DATA Bursts to untrained ears.

I think it depends on where you are. For example, when I monitor the VHF fed band while driving around south Florida, I get a lot of paging interference along with intermod stuff. My suggestion would be to purchase an intermod filter if it gets really bad.

 

[gmclam]

It depends on WHAT Fed agencies you want to hear. I am fairly close to you (Fair Oaks) and I pick up a lot of stuff from the USFS. I do "hear" US Marshall broadcasts, but since they are digital and I am not yet digital equipped, I do not get to listen to what they're saying (yeah I know they could be encrypted too). I've found activity in the UHF low band - 408 to 411 MHz but it is not frequent.

Is there anything specific you are interested in listening to?

 

[sflmonitor]

It depends on WHAT Fed agencies you want to hear. I am fairly close to you (Fair Oaks) and I pick up a lot of stuff from the USFS. I do "hear" US Marshall broadcasts, but since they are digital and I am not yet digital equipped, I do not get to listen to what they're saying (yeah I know they could be encrypted too). I've found activity in the UHF low band - 408 to 411 MHz but it is not frequent.

Is there anything specific you are interested in listening to?

I don't think it really matters WHAT agencies he wants to hear since most agencies have multiple frequencies spread throughout the VHF fed band. The original question was if there were specific areas to search in order to avoid paging frequencies. Since most of these paging transmissions interfere due to intermod, the easiest way to avoid them is to either lock them out or use filters. Of course, if you already have the agency-specific frequencies and tones, then you can avoid the whole thing. But the topic here is on scanning the band.

I would personally recommend to scan the complete fed VHF / UHF bands (162 - 174MHz & 406 - 420MHz) as not to miss anything.

 

[gmclam]

"Searching" is not the "best way" because of the pains stated. Agreed, programming in the frequencies and "scanning" is a much better way, but then you miss things not known. Signal Stalker (or Close Call) work better than searching, but only for strong signals. In addition, you still have the issues with pagers and birdies.

So that is why I asked what agencies he wants to hear. If he's just browsing for whatever is out there, we've covered the basic issues. If he wants to hear something specific, we can direct him to the freqs he needs so he can program them in.

 

[74596]

I've found activity in the UHF low band - 408 to 411 MHz but it is not frequent.

I also hear activity in the range of 408-411 MHz and I'm local to you...
I'm able to hear the transmissions, but I have not been able to get any idea of what organization is using the frequencies.
One frequency in that range (408-411) showed as having some encrypted transmissions, but I can't remember which specific frequency it was. I'll listen more and pay more attention so I can maybe have a guess as to who is using these frequencies and which ones may or may not be encrypted.

GMCLAM, you have any other ranges you like to scan for federal transmissions??

 

[SkipSanders]

I believe some scanners will not decode P25 digital while in 'search' mode, only while in regular scan/manual mode (or trunking mode). Others do.

First thing for a searcher to do is learn what a P25 digital voice signal sounds like, so you can recognize them when heard.

Also, keep an eye on the display, if it shows 'DG' upper right on the Pro-96, you have a P25 signal. If it sounds like a bunch of chirps, peeps, and blurps, it's encrypted. Otherwise, it should be clear voice.

 

[SCANdal]

Am I making a mistake?

I believe some scanners will not decode P25 digital while in 'search' mode, only while in regular scan/manual mode (or trunking mode). Others do.

.Also, keep an eye on the display, if it shows 'DG' upper right on the Pro-96, you have a P25 signal.

Skip,

I'm about to buy a PRO-96 for the purpose of searching for digitial signals. Is the PRO-96 one of the scanners that will not decode (to voice) P25 transmissions while in search mode?

SCANdal

 

[SkipSanders]

My Pro-96 decodes them fine in search mode. Note that like most others, it won't decode if you have a CTCSS or DCS mode on, or their associated tone search modes. (Which you shouldn't have when looking for P-25, since it's incompatible with either, anyway.)

I might, myself look into the Uniden 396T instead, though, since it allows setting the proper step sizes for search, which the Pro-96 does not. The 96 has a preset search step for each set of frequencies, and you can't change it when it's wrong. This means, for one area, that the fed VHF range, 162-174, is in 5 KHz steps, not the handier for feds 12.5, and you can't override it. At least, I would look into it if I weren't broke...

 

[wannabescannist]

Are you sure thats DATA? It could be Digital Communications. Almost nationally the FBI, Marshal's, DEA, ATF, Department of Home Security etc. are all Digital with either fulltime or partial Encryption. Both Digital and DES will sound simular to DATA Bursts to untrained ears.

What does a digitally encoded transmission sound like?

 

[gmclam]

GMCLAM, you have any other ranges you like to scan for federal transmissions??

Here is an abbreviated list. I've just added most of the frequencies to my scanners and have not had time to log transmissions yet. This does not include most aviation channels or "national" channels; just US government channels.

 

[74596]

Here is an abbreviated list. I've just added most of the frequencies to my scanners and have not had time to log transmissions yet. This does not include most aviation channels or "national" channels; just US government channels.

NICE! THANKS!

 

[SkipSanders]

Just for info, here's what a search of 162-174 MHz produced yesterday in San Diego.

You think pagers are bad, try living near the mexican border! They swarm all over this range!

Having a 396, with its ability to lock out large numbers of channels in search, is very, very handy for this range.

All P25 were encrypted, with the usual occasional 'forgot to turn it on, or it's broke' clear voice.

163.650 P25
164.600 Analog
167.400 P25
167.525 P25 ID'ed by occasional clear as Border Patrol
167.550 P25
167.725 P25
168.500 P25 ID'ed by occasional clear as Border Patrol
168.850 P25
171.175 P25
172.400 P25
172.900 P25
173.450 P25
173.975 P25

More from saturday, after I noticed I had set 25 KHz steps instead of the 12.5 KHz I'd intended to set, silly me...

165.9125 P25
169.3875 P25
170.0625 P25
170.3750 P25
170.8375 P25
171.5125 P25
171.5375 P25
172.5125 P25

 

[SkipSanders]

Just so you can compare what a day or two of 'search' caught, compared to a fairly complete list of JUST ICE (Immigration and Customs Enforcement) for the San Diego area some one else put together, here's a list of what's supposed to be in use by ICE here in San Diego.

153.9950 BORCOM/BLUE
154.1750 Inland Fire
154.9200 CLEMARS 1
154.9350 CLEMARS 2
154.9400 COMM 1
155.1600 SAR 1
155.2350 SAR 2
155.4750 NALEMARS
156.0750 CALCORD
157.1000 USCG 22
-------------------------
163.1870 TACCMN
163.2000 Tac 1
163.2000 Temecula Tac
163.6250 Indio North
163.6250 XLVON
163.6750 XRED/XHIPAS
163.7250 XSCM
164.5500 JCOMM
164.5500 NASTAR
164.5500 USCG
165.5870 COCALT
165.5880 CTAC1T
165.5880 JIOPTT
165.8500 BETA L
165.8500 San Clemente Tac
165.9000 Gate
165.9000 Tac 3
165.9750 Temecula West
166.2250 Calexico POE W
166.2250 El Cajon Detent
166.4630 TCOMM
166.4630 US Customs
166.6370 Temecula East
166.9120 MA4 SP
167.2130 COCALC
167.2130 JIOPCP
167.2630 El Cajon BORSTAR
167.3000 MA4TT
167.3750 MA4 PM
167.4000 MA1 MC
167.4250 COCAL0/CTAC10
167.4250 JIOP OM
167.4500 Calexico East
167.4620 MA1 TT
167.5000 COCALM/CTAC1M
167.5000 JIOPMC
167.5250 MA4OM
167.5500 El Cajon 2
167.6500 El Centro East
167.7000 San Clemente POE
167.7250 MA4MCC
167.7750 El Centro West
168.0250 USF Sentry
168.5000 El Cajon 1
168.8000 COCALS/CTAC15
168.8000 JIOPSP
168.8250 Otay Mesa POE
168.8250 San Ysidro POE
168.8250 SDIAP
168.8260 Temecula POE
168.8270 Calexico POE E
168.8500 Campo 2
169.3870 Chula Vista 3
169.4500 US Customs
169.6380 Transportation
170.0630 Chula Vista 2
170.3750 Pinos
170.6000 Indio South
170.6620 JIOPBM
170.7630 Calexico West
170.8350 MA4 CP
171.1750 MA1 CP
171.5380 Lyons
171.8000 MA1 BM
171.9880 JTAC
172.2880 MA1 PM
172.4000 Imperial Beach 1
172.4500 MA1 SP
172.5120 Brown Field 2
172.9870 Boulevard 2
173.1620 Blue 1
173.1620 Boulevard 1
173.1880 El Cajon 3
173.4500 Brown Field 1
173.4750 Imperial Beach 2
173.6500 Campo 1
173.9750 Chula Vista 1

(Note that they 'rounded off' frequencies, actual channels are on 12.5 KHz spacing, so if it says 172.2880, it's REALLY 172.2875, etc.)

 

[mkewman]

I'm really looking for federal law enforcement (marshalls, DEA, ICE, DHS, Customs, etc etc etc) and anything airborne (fire air operations etc) for the most part i have the most commons programmed.

the amount of birdies and pagers is INSANE.

i already know what p25 sounds like, and that's NOT what i'm hearing. i'm hearing a lot of data streams though in addition to the paging and birdies. I know what telemetry sounds like.

 

[iMONITOR]

What does a digitally encoded transmission sound like?

Digital Modes Samples
http://www.kb9ukd.com/digital/

 

[SkipSanders]

I notice you don't mention antenna/preamps or the like, mkewman, so I guess I'll mention that in many non-rural areas, an outside antenna, much less one with any pre-amp, is a 'bad thing' for interference. If you're searching with an outside antenna, try using just the on-radio rubber duck for initial searches, to see if you can avoid front end overload causing intermods from all the pagers all over everywhere.

 

[WayneH]

the amount of birdies and pagers is INSANE.

Program in a tone. I don't know of any agency (around NorCal) that doesn't use one.

 

[mkewman]

I notice you don't mention antenna/preamps or the like, mkewman, so I guess I'll mention that in many non-rural areas, an outside antenna, much less one with any pre-amp, is a 'bad thing' for interference. If you're searching with an outside antenna, try using just the on-radio rubber duck for initial searches, to see if you can avoid front end overload causing intermods from all the pagers all over everywhere.

this evening i tried starting off with a duck, you were right, it made a significant difference. thanks!