Strange/distorted audio on 155.535

Status
Not open for further replies.

n0xmz

Member
Joined
Dec 5, 2004
Messages
39
Location
Austin, TX
Listening in Dallas. It's hard to describe the sound. At first, I thought maybe I was off 5 or 10 kHz so I put it in a ham radio VFO. Tuning around, that doesn't seem to be the case as the audio sounds like crap no matter where I go. When they key up, the first syllable or two is intelligible then it all goes to garbage. I can still make out some words though so I'm doubting it's encryption.
 

texasemt13

CenTex DBA
Database Admin
Joined
Jun 6, 2007
Messages
2,370
Location
Hunter, TX
Are you hearing Texas DPS Richmond, P25 digital with NAC 146? Garbage is how I describe a weak digital signal.
 

n0xmz

Member
Joined
Dec 5, 2004
Messages
39
Location
Austin, TX
Not P25, it's all analog. It sounds kind of like a wideband signal trying to get through a narrowband filter. When I say wide, I mean wider than 5kHz.
 

SCPD

QRT
Joined
Feb 24, 2001
Messages
65,126
Location
Virginia
Listening in Dallas. It's hard to describe the sound. At first, I thought maybe I was off 5 or 10 kHz so I put it in a ham radio VFO. Tuning around, that doesn't seem to be the case as the audio sounds like crap no matter where I go. When they key up, the first syllable or two is intelligible then it all goes to garbage. I can still make out some words though so I'm doubting it's encryption.
If it sounds like a digital waterfall its more than likely AES-256 encryption. Greenville PD use it and it is 100 percent annoying. Voice inversion sounds like Donald Duck on mass doses of caffeine. One sure way to tell is to program a HT up with Voice Inversion on, If you still cant hear nothing but garble Id bet its AES. (for some odd reason I just lost commas on my keyboard.)
 

Russell

Texas DB Admin
Database Admin
Joined
Dec 18, 2002
Messages
1,515
Location
Dallas (and Austin) Texas
155.535 is widely used by the Dallas County Community College District for patrols, as well as, parking lot alert stations (push the emergency button, and announcement is made, and campus cops come). Every campus has their own PL and they always step all over each other. They don't hear it on the individual campuses, but somebody monitoring with no PL (or the wrong PL) will get all campuses and the associated noise. You may be hearing two conversations at once with differenent PLs, a district wide broadcast with different PLs at each campus, or the emergency boxes with their lousy audio.

Russell
 

mancow

Member
Database Admin
Joined
Feb 19, 2003
Messages
5,935
Location
N.E. Kansas
Cable TV leakage? You often get that first syllable then it goes off the grid only to return when the person pauses or takes a breath.
 
Status
Not open for further replies.
Top