MPDC trunking freqs

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gwgvfdpio

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Having not monitored DC Police for a few years I'm re-programming my Pro-96 with the latest list of frequencies shown in the RR database. In doing this I find that the scanner receives transmissions if I park on any of several of the 460 mHz frequencies, but it refuses to follow the TGs from freq to freq. (I didn't have this problem with my original frequencies, nor do I have it on any other trunked system).

The database shows two "base" frequencies, 453.450 and 460.025, with a spacing of 12.5 for both and an offset of 380 for the first and 480 for the second. My original settings had 458.7750 as the base freq with 12.5 and 380. What is the correct base frequency, please? Also, the primary control freq appers to be 460.100 with secondary controls as 460.025 and 460.150. Is that correct?

All help is appreciated.


Ed
 

gwgvfdpio

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Thanks, but on a Pro-96 it doesn't seem possible to enter more than one base frequency, either by direct entry or using Win96. If you've done this with a Pro-96 I'd appreciate some guidance.
 

Dewey

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gwgvfdpio said:
Having not monitored DC Police for a few years I'm re-programming my Pro-96 with the latest list of frequencies shown in the RR database. In doing this I find that the scanner receives transmissions if I park on any of several of the 460 mHz frequencies, but it refuses to follow the TGs from freq to freq. (I didn't have this problem with my original frequencies, nor do I have it on any other trunked system).

The database shows two "base" frequencies, 453.450 and 460.025, with a spacing of 12.5 for both and an offset of 380 for the first and 480 for the second. My original settings had 458.7750 as the base freq with 12.5 and 380. What is the correct base frequency, please? Also, the primary control freq appers to be 460.100 with secondary controls as 460.025 and 460.150. Is that correct?

All help is appreciated.


Ed
The old 458.775/12.5/380 worked in the old days because DC was only using one table. However, when they picked up some new frequencies below 458.775, a second table was required. 458.775/12.5/380 is still mathimatically correct, but it will not get you all of the transmissions. You now must use the additional (newer) table, and since its base is 380, you have to shift the old 380 base (458.775) up where it should have been in the beginning.

Dewey
 

Dewey

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gwgvfdpio said:
Thanks, but on a Pro-96 it doesn't seem possible to enter more than one base frequency, either by direct entry or using Win96. If you've done this with a Pro-96 I'd appreciate some guidance.
Multiple tables can not be programmed into the Pro-96 by hand, so you MUST use Win96 or other software. Just check "Custom Tables", and fill in the blanks.

Dewey
 

ka3jjz

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And we have a pic of the tables, with the settings entered, at the bottom of our wiki article on Win96...

http://wiki.radioreference.com/index.php/Win96

73 Mike

[edit] Just to anticipate the inevitable question - OK this works for Win96, what about other software - here's how you do it with ARC396. Undoubtedly ARC996 is similar...

http://wiki.radioreference.com/images/3/34/Arc396uhf.jpeg

In fact this is a good topic for a wiki article in the location specific area. If someone were to upload a jpeg or gif from each of the major players of digital scanner software with working configurations for the DC system, it would be a snap to put them into a gallery, along with a description of why this is necessary. A sticky could then be built pointing to the article - since this topic comes up from time to time, it would save a lot of confusion. When I mean software, I mean;

ARC996
BCTool
FreeScan
Scan Control (any others?)

and since we have the PSR-500 and 600:
ARC500
Win500
PSRedit

Any takers? I'll be happy to help. Keep in mind that the wiki has a software-specified limit on the size of the graphics to 150k. I'll start the article with these 2 images.
 
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ka3jjz

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The article is constructed, and can be found here;

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

Details are needed as to why the 2 tables are required, and any tricks that folks have found useful when trunking this system. Don't forget P25 gain and other settings for the DMA scanners, any other settings (particularly for the GRE scanners) and tricks that work for the PRO-96/2096

73 Mike
 

Dewey

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Mike, since the other jpgs are mine, here's the matching FreeSCAN jpg. If you want to buy me one of the new GREs, I'll be happy to do one for it also. :D :D :D

Dewey
 

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ka3jjz

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Good, Dewey. I'll capture those images and set them up in the wiki. They're a tad big (both over 150k), but I can use Paint at work to cut the image size down. Now, if you will, please add some details to the article

73 Mike
 
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gwgvfdpio

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Many thanks to all, but something still isn't right. I've programmed the Pro-96 as you suggest and if I go into manual mode and step through the various 460 mHz freqs I can clearly hear transmissions. However, if I try to scan the frequencies I hear only some transmissions, and they all come up as 453.450 as the base frequency on the 96's data screen.

Here are my Win96 settings:

Ch Lo Ch Hi Base Offset Step

380 380 453.4500 380 12.5

480 518 460.0250 480 12.5


I have entered into the frequency banks the following:

MPDC 460.02500 MOT 0.0 D
MPDC 460.10000 MOT 0.0 D
MPD 460.15000 MOT 0.0 D
MPD 460.20000 MOT 0.0 D
MPD 460.25000 MOT 0.0 D
MPD 460.27500 MOT 0.0 D
MPD 460.32500 MOT 0.0 D
MPD 460.35000 MOT 0.0 D
MPD 460.37500 MOT 0.0 D
MPD 460.40000 MOT 0.0 D
MPD 460.42500 MOT 0.0 D
MPD 460.45000 MOT 0.0 D
MPD 460.47500 MOT 0.0 D
MPD 460.50000 MOT 0.0 D

There must be something that's right in front of my nose that I'm not seeing.

Ed
 

Dewey

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gwgvfdpio said:
Many thanks to all, but something still isn't right. I've programmed the Pro-96 as you suggest and if I go into manual mode and step through the various 460 mHz freqs I can clearly hear transmissions. However, if I try to scan the frequencies I hear only some transmissions, and they all come up as 453.450 as the base frequency on the 96's data screen.

Here are my Win96 settings:

Ch Lo Ch Hi Base Offset Step

380 380 453.4500 380 12.5

480 518 460.0250 480 12.5


I have entered into the frequency banks the following:

MPDC 460.02500 MOT 0.0 D
MPDC 460.10000 MOT 0.0 D
MPD 460.15000 MOT 0.0 D
MPD 460.20000 MOT 0.0 D
MPD 460.25000 MOT 0.0 D
MPD 460.27500 MOT 0.0 D
MPD 460.32500 MOT 0.0 D
MPD 460.35000 MOT 0.0 D
MPD 460.37500 MOT 0.0 D
MPD 460.40000 MOT 0.0 D
MPD 460.42500 MOT 0.0 D
MPD 460.45000 MOT 0.0 D
MPD 460.47500 MOT 0.0 D
MPD 460.50000 MOT 0.0 D

There must be something that's right in front of my nose that I'm not seeing.

Ed
In addition to having the frequencies set up as MOT, do you have the Bank set up as "MOT" (the "Type" box next to the "Tag" and "Closed" boxes at the top of the frequency list for that bank)?

Dewey
 

gwgvfdpio

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Dewey:

That's correct. "MOT" is entered for the frequency bank as well as for the frequencies themselves. It appars that only when 453.45 is the active base frequency am I receiving while scanning. I never see 460.025 pop up in the Pro-96's display window.

Strangely, I hear transmissions if I manually step through the various frequencies, but I don't hear the same transmissions while scanning them.

Trunked scanning is fine, BTW, for DCFD and the Montgo trunked system, so the problem must be with the setup and not with the radio.

Ed
 

Dewey

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gwgvfdpio said:
Dewey:

That's correct. "MOT" is entered for the frequency bank as well as for the frequencies themselves. It appars that only when 453.45 is the active base frequency am I receiving while scanning. I never see 460.025 pop up in the Pro-96's display window.

Strangely, I hear transmissions if I manually step through the various frequencies, but I don't hear the same transmissions while scanning them.

Trunked scanning is fine, BTW, for DCFD and the Montgo trunked system, so the problem must be with the setup and not with the radio.

Ed
Ok then, now it sounds like the second table is not entered. In Win96, ensure that you have "Multi Table" selected under "MOT 3600 CC" selected.

Dewey
 

gwgvfdpio

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Yes, that's also checked. I haven't been able to grab a screen shot, or I'd paste one, but here's what's in that table:

Ch Lo Ch Hi Base Offset Step

380 380 453.4500 380 12.5

480 518 460.0250 480 12.5


However, the scanner seems to now be working well, as I sit in my office at 13th and L, NW. This makes me think that my problem is actually signal strength at my home in Rockville. Guess I need to put up an outside antenna to hear those 450/460 mHz signals out in the boonies!

Consider this case closed and many thanks, again, for all of the help.

Ed
 
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