LTR Passport ?

[Airdorn]

Is there ANYTHING out there... any program at all, besides that LTRtrunk/LTRdump thing where you have to have some special homebrew circuit, that will monitor LTR Passport?

Thanks for any info!

[DaveNF2G]

No. LTR-Regular is the only scannable format.

[Airdorn]

I wonder why?

That Eric dude did it, and I saw messages where I think he and someone else said Passport was a piece of cake.

There's a fair amount of public safety on Passport these days. I wonder why it hasnpt taken-off more?

[slicerwizard]

Are you looking for a scanner + simple discriminator tap + sound card solution?

[Airdorn]

Yes!

There's a local township to me that uses Passport for their public safety radio system.

Thanks

[slicerwizard]

Guess I better get PassPort-Analyzer/Tracker out the door...

[DaveNF2G]

I thought you were looking for a computer-less solution.

[NW0U]

How can you tell by listening?

I'm getting to the point of trying to map some systems that may become complex (with multiple sites listed to the same licensee).

How can you tell regular LTR from Passport on the air?

[cubn]

Originally Posted by NW0U

How can you tell regular LTR from Passport on the air?

On the regular systems, the repeater clicks are 10-seconds apart and on the LTR Passport Systems, the repeater clicks are 2-seconds apart.

[NW0U]

Originally Posted by cubn

On the regular systems, the repeater clicks are 10-seconds apart and on the LTR Passport Systems, the repeater clicks are 2-seconds apart.

Hmm. Are you sure about this? I'm hearing LTR-trackable systems that click ("strobe" squelch break) anywhere from 10 to 50 seconds apart and the don't have predictable regularity. (I'm just listening for audio rather than using a computer.)

[Airdorn]

Originally Posted by DaveNF2G

I thought you were looking for a computer-less solution.

No.

I'm looking for a solution where I don't have to build-up a special mod to the discriminator tap.. or using a data slicer, or dicer, or whatever that thing is that you have to build and plug into the serial port.

[Airdorn]

Originally Posted by NW0U

Hmm. Are you sure about this? I'm hearing LTR-trackable systems that click ("strobe" squelch break) anywhere from 10 to 50 seconds apart and the don't have predictable regularity. (I'm just listening for audio rather than using a computer.)

There's 11 LTR Standard systems around here, and they all share the same characteristic: that unique 'chirp' of open air every 10 seconds. I know it contains sub-audible audio but it sounds like a short chirp to me, like someone keying-up a radio very briefly.

In contrast to that, the single LTR Passport in my area does the keying-up every 2 seconds.

Whether its 10 seconds or 2 seconds, both systems are VERY regular.

[NW0U]

Originally Posted by Airdorn

There's 11 LTR Standard systems around here, and they all share the same characteristic: that unique 'chirp' of open air every 10 seconds. I know it contains sub-audible audio but it sounds like a short chirp to me, like someone keying-up a radio very briefly.

In contrast to that, the single LTR Passport in my area does the keying-up every 2 seconds.

Whether its 10 seconds or 2 seconds, both systems are VERY regular.

Sounds a lot like admin preference in setups.
I have a number of LTR Standard systems I'm working on. Some send CWID on each channel (very helpful), some NEVER send CWID. Some send on a few channels.

So how else can you tell it's Passport? Can you map the channels but they don't track when programmed into a scanner?

[DaveNF2G]

Originally Posted by Airdorn

No.

I'm looking for a solution where I don't have to build-up a special mod to the discriminator tap.. or using a data slicer, or dicer, or whatever that thing is that you have to build and plug into the serial port.

You won't be able to avoid installing a discriminator tap in your scanner no matter what approach you use for decoding. The software requires unprocessed baseband audio.

[Airdorn]

Originally Posted by DaveNF2G

You won't be able to avoid installing a discriminator tap in your scanner no matter what approach you use for decoding. The software requires unprocessed baseband audio.

I never said I didn't have a discriminator tap.

[Airdorn]

Originally Posted by NW0U

Sounds a lot like admin preference in setups.
I have a number of LTR Standard systems I'm working on. Some send CWID on each channel (very helpful), some NEVER send CWID. Some send on a few channels.

So how else can you tell it's Passport? Can you map the channels but they don't track when programmed into a scanner?

Hmm, I think the CWID is different than that 10-second key-up on LTR Standard channels, or the 2-second one on Passport.

It looks like the CWID is on maybe a 10 minute timer, atleast on the LTR standard systems I monitor around here. When it happens, the channel hosting it gives some morse code and the system shows all the free channels.

[slicerwizard]

LTR and PassPort controllers have a number of adjustable timer settings:

- Idle Timer: controls idle bursts; 10 seconds is fairly standard for LTR home channels; 1 or 2 seconds is typical for PassPort home channels and collect channels - the fast rate is required for roaming (you can't switch to a site if you can't hear its carrier, and you ain't gonna do a strongest site search if you have to sit on each channel for 10 seconds); non home/collect channels on LTR and PassPort systems don't need to send idle bursts (Idle Timer = 0), but some operators just turn them all on

- CWID Time Interval: sets ID period; may only be legally required on one system channel, some operators enable it on all channels; the CWID character string is defined in a separate parameter

- LTR/PP Lead-in Timer: delays sending of low speed data until transmitter has stabilized after keyup; typical values are 200 to 500 ms; when timer is set too short, idle bursts get truncated and can't be decoded

There are other timers, like carrier loss delay (maintains comm during brief RX fades), PTT timer (how long a subscriber can transmit before being muted/isolated), ...

[BC_Scan]

hey lets call the dude what it is, that noise,or click or carrier etc, is officially called "the refresher pulse"

[NW0U]

The 1-2 sec pulse and the reason sound pretty reliable to me.

Thanks!

(I haven't encountered this in Colorado yet.)

[slicerwizard]

Originally Posted by BC_Scan

hey lets call the dude what it is, that noise,or click or carrier etc, is officially called "the refresher pulse"

Citation?