National Park Service Rangers

[mikew]

As of Oct 7, 2022 the Lake Mead 170.050 frequency that is normally very active has been silent. Have they moved out of the VHF band or transitioned to a Trunked System ? Anyone have any information on this?

 

[akawolf]

I'm curious if there is activity on the other VHF freqs.

Subcategory: National Park Service/Lake Mead National Recreation Area (Arizona Federal)

Subcategory: National Park Service/Lake Mead National Recreation Area Details (Arizona Federal)

www.radioreference.com

Frequency Tone Alpha Tag Description
167.125 RM 123.0 PL LM Rangers MtP Lake Mead Rangers (Simulcast of 172.4625mhz) (Mt Perkins)
170.050 RM 107.2 PL LM Ranger MtW Lake Mead NRA Rangers (Mt Wilson)
172.4625 RM 526 NAC LM Rangers MtP Lake Mead Rangers (Mt Perkins) P25
172.600 RM 123.0 PL LM LEO/MtPer Lake Mead NRA LEO/Fire Mt Perkins Rpt
166.300 RM CSQ LM PARK OPS Lake Mead NRA Park Ops (Non LEO)

 

[737mech]

I'm running a P25 nac search file on my scanner from 162-174. No control channels detected yet. Not sure maybe they will go UHF?

 

[AZMONITOR]

A few minutes ago I found the LMNRA law enforcement channel for the Lower Basin which appears to have replaced the 170.050 repeater. The new repeater output is 169.6250 with a NAC of 68f and P25. Last night there was still some analog activity on 166.300R, their support channel, primarily non-LE activity. I still hear a little activity on 167.1250R. Happy listening.

 

[AZMONITOR]

The base still IDs' as "700" and references were made to the Hemenway launch ramp and the usual mobile ID's in the 400 series were heard. No question about it. It is the LMNRA.

 

[n4njj]

The base still IDs' as "700" and references were made to the Hemenway launch ramp and the usual mobile ID's in the 400 series were heard. No question about it. It is the LMNRA.

Is "700" the unit/console ID that displays or a verbal call sign or both?

 

[AZMONITOR]

The call of 700 is the callsign assigned to the dispatch center in Las Vegas that they have used for many years. It's verbal and often heard when field units call the dispatch center.

 

[AZMONITOR]

A second NAC code is also appearing with the new frequency of 169.6250 and it is 293.

 

[AZMONITOR]

A third NAC code just appeared with the new frequency of 169.6250 and it is E38.

 

[mikew]

Thanks AZMONITOR, the Park Ranger traffic from 170.050 has moved to 169.6250 P25, I am now hearing them again.
After the changes have been sorted out the database will need to be updated.

 

[es93546]

The call of 700 is the callsign assigned to the dispatch center in Las Vegas that they have used for many years. It's verbal and often heard when field units call the dispatch center.

This is the numerical portion of of their license which is KOJ710 in Boulder City at dispatch and KOJ700 at the primary remote base on Red Mountain. NPS callsigns always include numbers in the 700 series. Some examples from other parks, KOJ720 is the NTIA license for Capitol Reef National Park in Utah so their headquarters ID's as "720." Dinosaur National Monument in Colorado and Utah, has a NTIA license of KAC790 so their headquarters ID as "790." In California parks are starting to drop this system so Yosemite National Park identifies as "Yosemite" even though their headquarters has a NTIA license of KMC719. Sequoia-Kings National Parks has a NTIA license of KMC735, but ID's as "Ash Mountain" where the park HQ is located. Just like any other agency they use their NTIA license every 10 to 15 minutes when signing off.

 

[AZMONITOR]

Thanks AZMONITOR, the Park Ranger traffic from 170.050 has moved to 169.6250 P25, I am now hearing them again.
After the changes have been sorted out the database will need to be updated.

The new frequency appeared in the database yesterday along with the primary NAC. It's a strong signal heard in Kingman with an outside antenna. Many years ago the Grand Canyon NP switched from an analog system to P25 and their radio signals can sometimes be heard in Kingman.

 

[ecps92]

Unsure of your exact monitoring location but the $293 is likely NPS Grand Canyon - Admin - Hopi Point Repeater

A second NAC code is also appearing with the new frequency of 169.6250 and it is 293.

 

[AZMONITOR]

What was interesting is that the NAC of 68F came up most often and always when I heard NPS LMNRA dispatch and the other two (NAC 293 and E38) when just a few mobiles were engaged in conversation with LMNRA dispatch. The NAC codes would sometimes, but not often, go back and forth between 68F when the base was transmitting and 293 or E38 when a few mobiles were talking. Sometime in the past I heard that most LE transmissions in the GCNP were encrypted. Hopefully, LMNRA will not follow the lead of the GCNP.

I am about 150 miles straight line distance from the GCNP and 50-75 miles to the LMNRA depending upon the boundary. I was also using a beam antenna pointed in the direction of Boulder City for VHF which helped to hear them.

 

[737mech]

So is it safe to say the 68F is the new NAC for LMNRA 700? Not 293 or E38?

 

[AZMONITOR]

What is interesting is that while searching from 162.0000 to 174.0000 I am not hearing any other frequencies that might be suggestive of a second repeater for the LMNRA law enforcement radio traffic. Under the old analog system there was a second repeater on another frequency that covered the river and Lake Mohave well South of Hoover Dam all the way down to Katherine's Landing which is near Bullhead City, AZ. I am wondering if there are multiple repeater sites all using 169.6250 and all radio traffic is being broadcasted on all sites at the same time. I continue the search from 162 to 174 MHz while monitoring 169.5250 on another radio. It's not likely that I will hear a repeater input frequency given my location which is many miles away from the LMNRA boundary.

 

[AZMONITOR]

Thanks AZMONITOR, the Park Ranger traffic from 170.050 has moved to 169.6250 P25, I am now hearing them again.
After the changes have been sorted out the database will need to be updated.

What you might do, considering your location is in Boulder City, search between 162 and 174 MHz and see if you can locate the repeater input frequency. Some mobile units might easily be heard on the input frequency. Thank you.

 

[mikew]

I will follow your suggestion AZMONITOR as I am located on top of the hill overlooking Lake Mead. I have a very strong signal on the 169.6250 frequency but often miss the reply on the mobile side. I am monitoring just the single frequency and have reduced the delay time but still seem to miss some traffic which leads me to think I don't have everything I need programmed in yet. Some days there is not much activity so may take me a while to do the search. F.Y.I I have two BCD996xt's and three BCD996P2's at two locations so I will put them to work!

 

[ecps92]

Since the topic of multiple repeater sites was mentioned, if (just a WAG) could be that each Repeater is passing it's own unique NAC
Dispatch only needs to hit the $68F Repeater, but users (Portables/Mobiles) select either $68F, $293 or $E38

I will follow your suggestion AZMONITOR as I am located on top of the hill overlooking Lake Mead. I have a very strong signal on the 169.6250 frequency but often miss the reply on the mobile side. I am monitoring just the single frequency and have reduced the delay time but still seem to miss some traffic which leads me to think I don't have everything I need programmed in yet. Some days there is not much activity so may take me a while to do the search. F.Y.I I have two BCD996xt's and three BCD996P2's at two locations so I will put them to work!

 

[AZMONITOR]

When monitoring the new repeater for the LMNRA on 169.625R I have noticed that another frequency, 164.525 is active without a NAC, but with a lot of noise. As soon as dispatch stops transmitting the signal on 164.525 stops. Given my far distance from the LMNRA dispatch center, it's possible that 164.525 is the input frequency to 169.625. Perhaps those listeners who are closer to Lake Mead than I, might wish to monitor 164.525 and see if they hear any input traffic to the repeater. That input signal might be the dispatch center. If you are close you might hear some mobile units. Thank you.