ALCO trunking - interference from 863.9375?

[greeder221]

A few days ago I started getting interference from 863.9375. Today it's not as bad but over the weekend it made scanning virtually impossible. Anybody else experiencing this? I'm in Fremont monitoring Fremont/Newark PD mostly. Any ideas how to deal with this? Squelch adjusting has no effect. Using BC346XT with latest firmware. Thanks.

 

[kma371]

What are you getting on the other freq? What type of interference?

 

[greeder221]

Thanks KMA. Other freqs seem fine, I do get traffic when this one hasn't stopped the scanning. I don't even have it loaded in as an ALCO trunking freq. It just stops the scanner at FPD ch1 or NPD ch1, sometimes something else. The interference sounds like a rapid-fire, studder, machine-gun or motorboat sound. This actually happened a couple months ago and lasted 2-3 weeks and then went away. Is this possibly a freq on the new system that's being tested? Like I said, I don't even have it loaded but it shows in the display when the problem happens.

 

[kma371]

What scanner are you using?

Sounds like it might not be programmed correctly for the rebanded system.

 

[greeder221]

This is what I have programmed for ALCO trk:

851.10000 851.33750 851.37500 852.41250 852.45000 852.58750
852.62500 852.75000 852.78750 852.91250 852.95000 853.11250
853.15000 853.27500 853.31250 853.56250 853.60000 853.72500
853.76250 853.91250 853.95000

863.9375 is not programmed at all. The radio is a BC 346XT. Thanks KMA!

 

[greeder221]

Just noticed I have 853.95000 programmed also, which isn't listed in the RR database for ALCO. That wouldn't be the problem would it?

 

[DickH]

Just noticed I have 853.95000 programmed also, which isn't listed in the RR database for ALCO. That wouldn't be the problem would it?

The problem is you do not have the band plan for a rebanded system in your scanner. You have 852.9500, a rebanded freq., in your scanner. When the scxanner sees the channel number for that freq., it is a new one resulting from the rebanding. Your scanner does not recognize it as 852.9500, it thinks it is 863.9375.
I suspect you are seeing other 862 and 863 freqs. showing up on your display, but without any sound because no one may be on those freqs.
To check it out, add 10.9875 to any of the 851 to 853 freqs. that have a zero in the 4th decimal place and you will see the exact 862 or 863 freq. that shows up on your display.
For example, when 851.1000 is active it will display as 862.0875.

 

[greeder221]

Thanks Dick! I'm a little confused but I'll chew on your response and try your suggestion when I get a chance tomorrow. But just so I'm clear, the rebanded band-plan would be the system frequencies listed for ALCO trunking in the RR database, correct? Alameda County Trunking System, Oakland, California - Scanner Frequencies

 

[SCPD]

Wirelessly posted (Mozilla/5.0 (Linux; U; Android 2.3.4; en-us; pcdadr6350 Build/GRJ22) AppleWebKit/533.1 (KHTML, like Gecko) Version/4.0 Mobile Safari/533.1)

You need to be sure your BC346XT has the latest firmware installed to support rebanding. See here:

http://wiki.radioreference.com/index.php/BC346XT

Look about half way down the page under Features.

 

[SCPD]

Wirelessly posted (Mozilla/5.0 (Linux; U; Android 2.3.4; en-us; pcdadr6350 Build/GRJ22) AppleWebKit/533.1 (KHTML, like Gecko) Version/4.0 Mobile Safari/533.1)

...

 

[DickH]

... But just so I'm clear, the rebanded band-plan would be the system frequencies listed for ALCO trunking in the RR database, correct?

No, those are the rebanded freqs. The band plan is in the scanner firmware. To put in a new band plan in some scanners you need to do it via software. I don't know about your scanner so just do as triptolemus outlined and you should be OK.
Also, you do not need all the freqs., only the control channels (in red in the database). Be aware there can be up to 4 CCs used in a Motorola system, so at some point they may use a 4th one and your scanner will stop working if/when they change to a 4th one. So, if you have all the freqs. already programmed in, that's fine.
Your scanner reads the data sent by the control channel and tunes to the correct freq. - even if it has not been programmed in.

 

[greeder221]

Thank you all who responded and helped me with this issue. I haven't had a chance to try this yet but should be able to in a day or two. I never really understood the rebanding issue and thought is was just a matter of using the new freqs. I think I have a grasp on the issue now and it will probably clear up a couple other anomalies I've experienced. Thanks again to everyone! This is a very responsive and helpful forum.

 

[greeder221]

Arghh! Now I hear nothing on ALCO Trk. BC346XT. I update firmware 1.50.00 and I applied the new bandplan with FreeScan.
Site Type:
Mot Custom/Reband Type II
Lower Freq Upper Freq Step Offset
851.02500 854.00000 25.0 440
851.01250 868.98750 25.0 0
And now the system seems totaly dead. Am I missing a step? After rechecking the settings I noticed FreeScan keeps changing the upper freqs: 854.00000 -> 840.00000 and 868.98750 -> 869.98750
First I thought I mis-typed and corrected them, but FreeScan keeps changing them back! Any ideas? Thanks.

 

[SCPD]

Here - I just downloaded the system from the RadioReference database into freescan... this is what it looks like. Compare each field on both screens to what you have.

Failing that, I'd try one of two options:

1) delete the entire entry and try again from scratch.
2) splurge for a RR subscription and download the the system that way.
3) I could attach a freescan file with Alameda County TRS in it.

 

[Radiobern]

I programmed in the Alco system using Freescan without issue. See the attached file I created, it has no talkgroups, but it will scan for any active talk group. Let me know if it works.

 

[SCPD]

Attached is a ZIP file containing the FreeScan file with Alameda County TRS created via RR download.

You could give this a try, too.

 

[greeder221]

Got it! Before trying the two files from Radiobern and triptolemus (and thanks to you both for supplying those!) I, once again, corrected the 2 upper freqs for the band plan and this time 854.00000 was not changed down to 840.00000. I'm not sure why this kept happening yesterday but everything is fine now so I'm not gonna worry about it. It must have been the way I was uploading it. I even get Union City PD load and clear when I couldn't get anything from them before. Thanks again for everyone's assistance, and helping me to fully understand the rebanding process!

 

[SCPD]

Good - enjoy it while you can. ALCO TRS will be dead soon with EBRCS coming online.

Glad you got it working.

 

[greeder221]

Thanks. I've been scanning since the eighties. I had this one for about two years before I finally decided to sit down a figure out this DMA thing. Now I understand I'll have to go through this all again with a new scanner once the new system comes online which seems fairly close. Thanks again and thanks to KMA for the constant updates on the new system.