• Effective immediately we will be deleting, without notice, any negative threads or posts that deal with the use of encryption and streaming of scanner audio.

    We've noticed a huge increase in rants and negative posts that revolve around agencies going to encryption due to the broadcasting of scanner audio on the internet. It's now worn out and continues to be the same recycled rants. These rants hijack the threads and derail the conversation. They no longer have a place anywhere on this forum other than in the designated threads in the Rants forum in the Tavern.

    If you violate these guidelines your post will be deleted without notice and an infraction will be issued. We are not against discussion of this issue. You just need to do it in the right place. For example:
    https://forums.radioreference.com/rants/224104-official-thread-live-audio-feeds-scanners-wait-encryption.html

Blacksburg Volunteer Rescue Squad

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K4NNW

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Mar 4, 2008
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151
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Bent Mountain, VA
During the past few months, I hadn't heard Blacksburg Rescue on 155.145, but tonight, during a little mountaintop scanning expedition, I discovered why. They're no longer using the old 100Hz PL, but rather a DPL (or DCS, as known by some) of 503. I'm not sure why, though. I'll let the experts figure that one out.
73,
Kenny
 

pogbobo

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Jan 9, 2007
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VA
I'm not sure when they changed ... I've been using DCS 503 for a few months... but before that I just left is open, until I recently moved and I started having intermod problems lol
 

KE4NYV

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Apr 18, 2003
Messages
1,002
Location
Williamsburg, VA.
Kenny,

Regardless of the tone they are using, if you listen without any tone on your receive side, you should hear them just fine. As long as they don't change the actual frequency.

For those who don't understand how PL and DPL work. They are subaudible tones that allow multiple users on a single frequency. Each "group" has a specific PL or DPL on both their transmit and receive frequency. When the channel is busy, the radio will indicate this, but unless the same PL/DPL they are using is being used, they will not actually hear the audio. The matiching PL/DPL will cause the receiver to open up the audio path and allow the traffic to be heard.

If you were to put in this frequency and then leave it in what we call CSQ or carrier squelch mode, you would hear all of the traffic, regardless of the PL/DPL they are using.

PL and DPL are also used to keep interference out. The only real way for interference to cause the receiver to open up would be to have the same PL/DPL with the intereference. Thats pretty rare.
 

K4NNW

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Mar 4, 2008
Messages
151
Location
Bent Mountain, VA
Jason, I must agree with you in regards to using carrier squelch. I just use tone squelch to keep out interference and and run a lower squelch on my receivers.
 
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