I was searching in the 169 to 173 mHz using an SDS200 and the latest ProScan software. I found what I thought were NAC's of 303 but then they changed to something else today. I stopped the search and just sat on a freq. Same NAC 303. Using DSD+ FastLane I'm getting a NAC of 100. Any ideas? RSSI is between -50 and -104.
SDS100/SDS200: Incorrect NAC
- Thread starter CrewRest
- Start date
Multiple Agencies/Depts using same freq with different NAC? My state has a set of freqs they use across the state, each county uses the same four frequencies but are supposed to use a specific NAC for the county, doesn't always happen often I see the generic NAC of 293. Could be same type of thing, like a FED Common. Just a guess here.
I get that, and thought that that might be the case, but when I run DSD+ side by side with SDS200, DSD+ will show N100 and SDS200 will show N303.
Trunking or Conventional? Are you receiving the same transmission with two different NAC's is what you're saying?
ecps92
Member
What specific Freq are you getting conflicting NAC's on ???
Program both and see which one works. Delete the other. If you realize one of them seems bogus, where absolutely nothing is heard, you can submit your updated findings to RR. If you recieve on both, try to identify them and submit to RR.
ecps92
Member
As already suggested, there are many shared frequencies within the Federal Spectrum even across small states such as CT and RI
that can both be heard from one monitoring point.
Till the OP returns and provides us with the actually frequency, any/all posts are right now Speculation
Ok, the Freqs are all Federal. Here is an example I found on 1, the NAC's don't match and I believe the SDS200 is incorrect.
Freq. SDS200 NAC DSD+ NAC
170.5375 303,156,349 100,100,100
Freq. SDS200 NAC DSD+ NAC
170.5375 303,156,349 100,100,100
As I said, plug in both. Loose what you don’t want.
Replying to ecps92;
I don’t care how many frequencies are listed… it’s only the ones you find active, within range, whatever pops up at your location. It certainly isn’t going to be the entire list of federal frequencies. I don’t need to wait for the OP to list specific frequencies before offering advice on determining the correct NAC in this particular situation. Now that the OP has listed the frequency it makes no difference. So whats the point of waiting for the OP to list frequencies? Did I miss something in your meaning?
Replying to ecps92;
I don’t care how many frequencies are listed… it’s only the ones you find active, within range, whatever pops up at your location. It certainly isn’t going to be the entire list of federal frequencies. I don’t need to wait for the OP to list specific frequencies before offering advice on determining the correct NAC in this particular situation. Now that the OP has listed the frequency it makes no difference. So whats the point of waiting for the OP to list frequencies? Did I miss something in your meaning?
ecps92
Member
So now you are indicating it is 4 different NAC's being observed
Are you sitting on the single freq with the SDS or Scanning/Search ??
Yes, sitting on the Freq, SDS200 shows different NAC's, DSD+ shows only one NAC. Can't be both.
Sitting on Freq SDS200 shows different NAC's, DSD+ shows only one NAC. I don't think both can be correct.
ecps92
Member
-k my first though (if Scan/Search) is was going to be Overload and latency in the scanner clearing out it's memory.
Now, (not knowing that radio) I might go toward overload, but will leave that to some of the Locals as well as others with the SDS series.
Now with that said, $349 is not a known Federal NAC in your area, is it a NAC on something else ? Local Trunk ? or Public Safety ? in your Area?
Even the Adj +/- freq don't have that NAC or the two others you are getting
The correct NAC will show up every time your SDS200/100 listens to a transmission while using the search/scan feature. Monitor a specific frequency and learn how many NAC ‘s appear. If there are more than one agency sharing the frequency they may or may not share the same NAC also. But whatever you hear, regardless of what NAC may appear, needs to be identified so it can be an accurate submittal to the RR database. I believe someone mentioned Ct. in a post. Since I also live in Ct. (central Ct.) I can try to duplicate your findings if that is where you are also. Let me know if this might help.
I look at NAC’s the same way I look at PL’s and DPL’s-they do the same thing. I was wondering if the FCC allows the use of NAC’s in place of PL’s and DPL’s on the VHF and UHF bands, or is it a specific mode type, a technical hardware question that might limit NAC usage?
I look at NAC’s the same way I look at PL’s and DPL’s-they do the same thing. I was wondering if the FCC allows the use of NAC’s in place of PL’s and DPL’s on the VHF and UHF bands, or is it a specific mode type, a technical hardware question that might limit NAC usage?
ecps92
Member
For that Freq in FLA there are only 3 possible NAC's and only two for his QTH the 3rd is over at Homestead
$F00 - last reported in 2012
$100 - which he should be getting as the Sarasota Repeater for the wide-area ICE
the others the OP reported are very likely false hits, based on multiple scanners monitoring in that area in the past.
for the OP, does your radio have the ability to change the IFX ?? see if this is an image issue...
DSD+ provides the correct NAC of 100 for this site. Both the SDS100 and SDS200 are not providing the correct NAC. I'm still investigating but I'm tending to say that on a Fed P25p1 conventional system the NAC is unreliable using the SDS100 or SDS200. Both the SDS100 and 200 have the updated Firmware and the Waterfall Activated. This occurs on both strong and weak signals.
Something similar is happening at my location with my SDS200 after the latest firmware update. The Everglades National Park repeater is on 172.525 with a $555 NAC. Lately I’ve been getting a $293 NAC on that frequency when the repeater is active and really transmitting $555. BTW, there is no repeater in my area on 172.525 and $293 NAC. I have to do some more testing but I’m leaning towards a firmware issue. Maybe.
Thanks for input!
You’re welcome. I’m away from home but will try to simulate the issue next week when I get back. I’ll post anything I find.
Not that I know of.
