Originally Posted by kd5dga
It has been a few years since I have monitored the Tx. DPS. I live in Killeen Texas and when I did listen to the DPS I mainly scanned the frequencies that were used by the Lampassas office. Now since the DPS is going to APCO-25, how many frequencies in the central Texas area have moved over to APCO-25? I have a PRO-197 scanner that is capable of APCO-25 but my knowledge in APCO-25 is very limited. Right now I have dowloaded from rr.com the frequencies that are used by the Lampassas office and have them uploaded to my PRO-197 via WIN500. Now my BIG question is can a scanner scan and still pick up different frequencies that are both conventional and APCO-25 nak'd?
Your Pro-197 will handle DPS just fine. Almost all of DPS is digital now. The only exception in North Texas, that I'm aware of, is for the units working the tollways, which they do under contract with NTTA.
For your area, or any other, the APCO-25 channels for DPS are handled by the 197 just as any other conventional frequency. But instead of a PL/CTCSS tone, or DCS code, your using the NAC code.
In Win500, since you imported it, you should already be set up. But, what you should see, in the "Squelch" column, is "NAC" (without the quotes), then in the "Squelch code" column, make sure that the NAC code is entered. Looking at the database page
, it appears that the Lampassas dispatch is on 155.4525, with a NAC of 128. Note that the mobiles are on 154.7025, also NAC 128. DPS does not always use repeater mode. So, often, the base will be on the dispatch frequency, but unless your close to one of the vehicle, usually 5-10 miles, you'll never hear them, because they be on a different frequency (in this case, the 154.7025, NAC 128). For locations farther away from a dispatch office, you will hear both sides on a mobile repeater, like that shown for Pontotoc (159.2100, 119 NAC).
If you'll look at the 'Statewide APCO-25 Channel Plan', then glance through the various region detail, you'll see the same frequencies are used repeatedly. There are a few different NAC codes used to separate the transmissions, but there's a lot of duplication. For instance, the frequency pair for Lampassas, Base B2 (base on 155.4525, mobiles 154.7025, NAC for both 128) is the same one used here for DPS Dallas. There are a number of repeaters listed, but two main frequencies- 159.2100 & 159.2175. What differentiates them is the individual NAC codes assigned.