IDAS Type D Trunking

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philacop

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Question. Can a IDAS type D trunking system be programmed and followed correctly on the upgrade?
IT is a 7 channel LTR type signaling trunked system wich has 2 of the 7 channels sending data bursts every couple seconds. IT also is Icom .
Any help on setting this type of system is greatly accepted . Thanks !!
 

cellphone

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I'm not having luck monitoring an IDAS Type D system (Phoenix-Mesa Gateway Airport Trunking System, Mesa, Arizona - Scanner Frequencies) when programmed as a NXDN Trunked system. When monitoring the frequencies as conventional, it works fine showing talkgroup ID and Radio ID info.

While attempting to monitor with my BCD436HP, I also verified the frequencies and channel numbers with DSD+.

I was reading in other threads that changing the frequencies from NFM to FM may help, but I have not had a chance to try this. Is anyone successfully monitoring IDAS Type D when programmed as a NXDN trunk system?
 

W4ELL

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I am having similar issues with, what I believe to be, an IDAS system.

It isn't in the RR DB yet but this is the FCC info on it:
ULS License - Industrial/Business Pool, Trunked License - WQLM715 - Arconic Inc. - Frequencies Summary

This isn't a very active system at all so I started by scanning all 10 frequencies conventionally and was hearing mostly NXDN motorboating with occasional voice decoding while seeing TG, UID, and AREA info with IDS as the indicator (occasionally I also saw NX4) . I was only hearing activity on 2 of the frequencies and at least one of them had a data burst every 5 seconds or so.

Then, I put all 10 frequencies into a NXDN trunk system (using IDAS TG format) and ran the LCN finder for several hours. It never even found 1 channel (it stayed at 0/10 the whole time) even though there was definitely traffic during the time frame (I was conventionally scanning with my other 436 at the same time). Just for giggles, I turned off the LCN finder and put the scanner in ID Search mode just to see if there was activity but I got absolutely nothing. I then changed the TGs over to NXDN TGs with no change.

Then, I read the claims about setting the channels as FM and Manual 8 threshold so I retested with those settings and noticed there was a noticeable improvement with NXDN decode (way less motorboating) and increased signal strength while scanning conventionally.

Lastly, I made the same changes on the trunked system (FM, Manual 8) and restarted the LCN finder. Unfortunately, nothing changed... the LCN finder ran for about 2 hours with no change (there was definitely activity during the time frame) and absolute silence when ID searching the system. I also changed from IDAS TGs to NXDN TGs and back again with no change.

I know the next step would be to submit logs... I am familiar with the process and would gladly do so, I just need to know what I should log?

Log while?
Scanning conventionally
ID Searching the trunked system
running LCN Finder on the trunked system
various combinations of the above with both NFM and FM settings
All of the above
 

UPMan

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If you could log while conventionally scanning for a couple of minutes. Then, zip it up and attach to this thread, our engineer will take a look at it.
 

UPMan

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[FONT=&quot]The messages to identify the home (control) channel are not received at all per that log.[/FONT][FONT=&quot]

[/FONT][FONT=&quot]So, ID scan, ID search, and LCN finder modes cannot find the home (control) channel.[/FONT][FONT=&quot]

[/FONT][FONT=&quot]Channel number included in the log:[/FONT][FONT=&quot]
[/FONT][FONT=&quot]Home: 5[/FONT][FONT=&quot]
[/FONT][FONT=&quot]Repeater: 5, 6, 8, 10[/FONT][FONT=&quot]

[/FONT][FONT=&quot]Could you get logs of each channel in conventional mode, one channel per log?[/FONT][FONT=&quot]

[/FONT]
 

W4ELL

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I will do that this evening.

Makes me wonder if they are using a frequency from another site or FCC license, I will investigate that separately.
 

Ubbe

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The digital decode works very badly with a lot of crc errors. If you are scanning during the log the home channel isn't received at all.

You can scan the voice channels, that you can receive, in conventional mode to monitor a call but as the home channel cannot be received you cannot trunk track, that a Uniden scanner needs to do.

If you listen to the channels in forced analog conventional FM mode, do they sound noise free (maybe hard to tell with an untrained ear) or do the signal strenght meter indicate more than 3 bars?
Have you found all channels of the system?

/Ubbe
 

W4ELL

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A conventional scan with the channels set to FM and manual digital threshold setting of 8, is almost night and day as far as digital decode quality as opposed to NFM AUTO.

The only reference I have for signal strength is that I am seeing 4 and 5 bars on FM versus 1 to 2 bars on NFM.

I am a little green at looking at the log output from the scanner so, when I glanced at it last night before submitting it, I didn't catch that the home channel wasn't being found. I plan to do a little more sleuthing this evening to see if maybe they are using a frequency not listed in the license... maybe one from another of their licenses.

If all else fails, I will break out DSD+ and see if it gives me any clues. I haven't set it up on my new laptop since this NXDN release but maybe that will be a weekend project along with a trip closer to the site.
 

Voyager

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A conventional scan with the channels set to FM and manual digital threshold setting of 8, is almost night and day as far as digital decode quality as opposed to NFM AUTO.

The only reference I have for signal strength is that I am seeing 4 and 5 bars on FM versus 1 to 2 bars on NFM.

I wonder if:

a) The scanner is off frequency

or

b) The transmitter is not on the carrier frequency you think it is. Some NXDN systems are spaced as close as 3.125 kHz which FM would pick up clearly but NFM might not.

Even if they are licensed for 452.200 MHz, for example, they may be using 452.203125 or 452.196875 MHz.

They could also be using 6.25 kHz steps in the same way. For the above example, 452.206250 or 452.193750 MHz might be the actual frequency in use.

While the x36 will not tune in 3.125 kHz steps, it will tune in 6.25 kHz steps. Set the bandplan to 6.25 and tune up and down and see if the signal is the same or better on an "adjacent frequency". This test will work for either case A or B above.

One thing you cannot assume (anymore) is that the licensed frequency will be the actual carrier frequency.
 

ki6bu

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Cellphone, have you had any luck in getting Gateway Airport? I'm just North of the airport in Mesa.
I'm also running DSD+ and monitoring the "control" channel. I get broken audio but I am getting errors, so this weekend I'm putting up a 6 element yagi to get me a better SNR.
I have had no luck with my 436HP what so ever.
 

Ubbe

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I wonder if:

a) The scanner is off frequency

I have to agree with that. As NFM shows less signal strenght the frequency could be offset or you have another transmitter in a neigbouring channel that interferes too much with your reception.

/Ubbe
 

W4ELL

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Thanks for the good suggestions... I actually already have my band default set to 6.25 in that band. I wasn't able to get closer to the site yesterday like I planned but I did some sleuthing from my house.

I put DSD+ on it last night (I live maybe 5 miles from the site) and confirmed 6 channel numbers (using NFM). Voice decode was marginal due to the antenna I was using but DSD+ was getting enough data to give me clues. The peaks in SDR+ seemed to be right on frequency (frequencies listed in the license).

It looks like channel 5 (452.25625) is the most active channel, although DSD+ never referenced a 'home channel' it is definitely the channel used most. According to the submitted x36 scanner logs from the other day, the scanner couldn't find the home channel but I am not sure how it is determining which channel should be the home channel.

I am not very familiar with how IDAS works exactly (I have done some reading) but it doesn't appear to have a SiteID or NetworkID in DSD+. I did notice that most of the UIDs and TGs were prefixed with 5 (5-xxx and 5-xx). I saw some private calls come through that had a TG of 9-xx which appeared to be being routed to Ch 9, I don't know if there is a correlation.

I actually made some adjustments to the location of my antenna and set everything back to Auto (modulation and digital threshold) on one scanner. The decode was actually pretty good, I didn't have as much motor-boating and the signal strength was 4 and 5 bars. (location location location)

I plan a trip closer to the site this weekend to eliminate any location/antenna anomalies and I'll be taking the laptop and SDR dongles with me to see if I can narrow down what is going on. I will also gather logs for each channel and submit them, as requested.
 

FLANO

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Cellphone, have you had any luck in getting Gateway Airport? I'm just North of the airport in Mesa.
I'm also running DSD+ and monitoring the "control" channel. I get broken audio but I am getting errors, so this weekend I'm putting up a 6 element yagi to get me a better SNR.
I have had no luck with my 436HP what so ever.

I was made aware of this thread, just after I left Gateway this afternoon. I parked on the airport grounds and spent a couple of hours there, and sadly, did not make any logs...Didn't realize it was an issue, until I attempted to run the 436 against it. Cellphone advised me after I had left :(

You mention "control" channel, but I found all five channels without a "control" channel. I did find a sixth frequency in the FCC database, but found no activity on it.

What was the frequency for the "control" channel ?

I may try it again...

Thanks,
 

Ubbe

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I actually made some adjustments to the location of my antenna and set everything back to Auto (modulation and digital threshold) on one scanner. The decode was actually pretty good, I didn't have as much motor-boating and the signal strength was 4 and 5 bars. (location location location)

Hmm, you are using the rubber duckie and monitoring frequencies in the 450-460MHz range.
Are you free from the "missing capacitor" interference that are noted particulary in this band?
You dont have any external antenna away from the scanner that you could try?

/Ubbe
 

ki6bu

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I was made aware of this thread, just after I left Gateway this afternoon. I parked on the airport grounds and spent a couple of hours there, and sadly, did not make any logs...Didn't realize it was an issue, until I attempted to run the 436 against it. Cellphone advised me after I had left :(

You mention "control" channel, but I found all five channels without a "control" channel. I did find a sixth frequency in the FCC database, but found no activity on it.

What was the frequency for the "control" channel ?

I may try it again...

Thanks,

I have played with it some more and it looks like TalkGroup 1 is on CH1, TalkGroup 2 is on CH 2. But then I have seen just a single instance of Talkgroup 1 on CH 2 and Talkgroup 4 (which showed up as RAMP) on CH 2. Very confusing system.
I will be putting up my Yagi this weekend. When I stated Control Channel, I put it in "", it was actually CH 2, so there is no real control channel.
I do see that other Freq. but I have not seen any activity there yet.

On the latest version of DSD+ the system shows up now as IDAS TB, I have no idea what TB is.
 
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W4ELL

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Hmm, you are using the rubber duckie and monitoring frequencies in the 450-460MHz range.
Are you free from the "missing capacitor" interference that are noted particulary in this band?
You dont have any external antenna away from the scanner that you could try?

/Ubbe

No, I am not using a rubber duckie at all. I am using a Spectrum Force wideband antenna both when mobile with both my 436 and while at home on both my 536. All of my home monitoring I did the other night was using both my 536 units using these antenna.

Neither of my 436 have the C1 capacitor but I honestly don't think this is an issue in this case.
 

RF23

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I have played with it some more and it looks like TalkGroup 1 is on CH1, TalkGroup 2 is on CH 2. But then I have seen just a single instance of Talkgroup 1 on CH 2 and Talkgroup 4 (which showed up as RAMP) on CH 2. Very confusing system.
I will be putting up my Yagi this weekend. When I stated Control Channel, I put it in "", it was actually CH 2, so there is no real control channel.
I do see that other Freq. but I have not seen any activity there yet.

On the latest version of DSD+ the system shows up now as IDAS TB, I have no idea what TB is.

I think TB means it is Trunked and CB means it is Conventional.
 
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