I'm still hearing Fire and EMS on the old analog system today.
San Francisco Public Safety going Digital June 2021
- Thread starter sffire
- Start date
Yep P25 TDMA sounds like that. It does sound much better with a commercial radio, versus certain SDR softwares if that's how you listened, and better decoding quality than some scanners. P25 TDMA squeezes 2 voice channels into 2 time slots in 12.5khz. I agree that with today's technology they can probably achieve better compression and enhancements for voice. This is not new technology unfortunately. I have been listening to a similar system for a couple years now and have adjusted to it and now understand what's being said pretty well. But there was a big learning curve at first, and I do prefer it sometimes today. P25 and analog voice both have their pros and cons. Who doesn't love the clear and clean analog. For me though, the consistency in the male and female voices helps with understanding what different people are saying using P25. But I can rarely clearly identify who it is that's speaking based on their voice because of that. P25 is always crisp, no more static noise, if there is reception issues often the digital data would still be able to make it through, and stuff that are missed will become silent parts or garbled. Occasionally when I come in contact with the little analog systems that are left in my areas I often find myself fighting the static in certain areas that are supposed to be within the system's range. I also noticed some analog transmissions sound echoy. DMR in my opinion sounds better than P25, not exactly sure why, as I think it's the same vocoder.
The P25 systems today despite the not so great voice, have features that some departments want like priority, encryption, accountability, extreme noise cancellation, and most importantly interoperability. Not to mention that it's now a standard and it's almost as they are forced to implement these systems at some point regardless.
I love hearing the analog systems, not many left in my area though, more and more disappear every year. Businesses go to DMR, and public safety to P25.
In all fairness, it sounds much better on the actual radios the services are using. The worst sounding parts are often due to simulcast issues that scanners like the BCT996p2 don't handle as well. You may be able to work around the simulcast issues with an attenuator and a directional antenna focused on a single site. I know that at 2 different locations, the 996 will sound less garbled and digital distortion at the location that can only see a single site clearly, than at the other location that can see multiple simulcast sites.
Some of the SDRs do a much better job than other radios. The Bluetail p25rx sounds much better than the 996p2 due to the way it handles simulcast transmissions. (There is a forum here for Bluetail if you want more info).
One thing I've been doing to make the sound better to my ears is running it through an EQ, giving a boost to 1-4k of a few db and rolling off the low end. Trying to simulate the frequency response of the speakers in the commercial radios.
But yes, the digital stuff sounds pretty bad to my ears as well. (But then I mostly stopped talking on cell phones due to the bad digital quality in the 2000s until the "HD" or "HQ" codecs started rolling out in the last few years.)
Makes me wonder what receiver you are using. When two local systems made the full switch to P25 simulcast, I had the exact same opinion. Then I bought an SDS-100 and wow, what a difference.
The analog system is still online, but not hearing any activity on it this morning.
Looks like they finally turned off Fire on the old analog system or at least unpatched it...
Yep.
I'll miss the sound of the old system.
I always found the old system to be quite crackly and static-y. But I know what you mean
On another note, they've changed the tone used for the automated dispatches on TG 932.
Eng74
Member
Did they turn it down some? I know it was rally loud the last time I was in the city.I always found the old system to be quite crackly and static-y. But I know what you mean
On another note, they've changed the tone used for the automated dispatches on TG 932.
Yeah, it’s a different tone and it’s a little softer.
The audio quality of the digital system seems to have improved now that the old system has been turned off. Is it my imagination? It even sounds pretty good on my BCT996P2. (Only issue is the 996 has is that sometimes it lets encrypted traffic through. The Bluetail doesn't do that.)
I also noticed the improved audio quality now that the two systems are no longer patched. And yes, I sometimes get the encrypted traffic on my 325p2 as well…
The SmartZone system has been shut down.
The bluetail P25rx is much better about muting the encryption I'm finding.
FYI running the 996p2 on our "SF-1033" channel (where we mix it with music and put some reverb and echo on it to make it sound more surreal)
The bluetail is still feeding SomaFM: SF Police Scanner: San Francisco Public Safety Scanner Feed Commercial-free, Listener-supported Radio
I run the bluetail through an audio limiter and EQ it to have a 6db boost around 2-4k but I may be changing that in the future. I just didn't want it to be so boomy if you're listening on bigger speakers.
FYI running the 996p2 on our "SF-1033" channel (where we mix it with music and put some reverb and echo on it to make it sound more surreal)
The bluetail is still feeding SomaFM: SF Police Scanner: San Francisco Public Safety Scanner Feed Commercial-free, Listener-supported Radio
I run the bluetail through an audio limiter and EQ it to have a 6db boost around 2-4k but I may be changing that in the future. I just didn't want it to be so boomy if you're listening on bigger speakers.
Odd, other than some audio level balancing needed, it sounds fine on my APX7000 and Unication G5. There's no distortion or garbled transmissions.
Interesting to note that a user of the new P25 Phase II
SF system said that using the speaker mike on his portable was problematic. Usually he could talk into is lapel mike without removing it from his jacket....Can't do that anymore...Distortion...he must remove the mike and speak directly into it....Comments? He also said that if a transmission was too long the radio would cut off and beep....He finds it hard to recognize the voices of his fellow team members on the new system< Comments
SF system said that using the speaker mike on his portable was problematic. Usually he could talk into is lapel mike without removing it from his jacket....Can't do that anymore...Distortion...he must remove the mike and speak directly into it....Comments? He also said that if a transmission was too long the radio would cut off and beep....He finds it hard to recognize the voices of his fellow team members on the new system< Comments
Yes, you have to speak directly into the mic rather than off to the side with this new P25 system...
Going from analog to digital is always a challenge for some users. They'll get used to it eventually.
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