Lassen Volcanic National Park

Status
Not open for further replies.

W7JYJ

Member
Joined
Aug 19, 2011
Messages
12
Anybody know of any changes/additions to the Lassen VNP mixed-mode P25/analog repeater system
since Aug, 2011? Are the frequencies, PL-tones and NAC still the same as provided by "usfsengine"
and "rpoole23" below.

TIA, Larry, W7JYJ

usfsengine:

According to the Region 5 Smokejumper Frequency Guide the following are listed for Lassen Nat'l Park

ch rx tx name
1 172.4625 165.6000 Table Mtn.
2 172.4375 166.3375 West Prospect
3 169.7875 164.1625 Mt. Harkness
4 169.8125 163.025 Turner Mtn.
5 168.6125 168.6125 General Use
6 163.7125 163.7125 General Use
7 168.3500 168.3500 LNP Tac 1
8 163.1000 163.1000 LNP Tac 2

Hope this helps. If they are good let me know and I will do a form so a DB Admin. can input them on the RR.

And from rpoole23:

Took a trip through Lassen Volcanic Park today. I'm glad I read through these posts beforehand! I had programmed my work HT2000 with the "old" 170.050 freqs, and as previously described = nothing heard. I had along my Pro-106 and programmed in the other mentioned frequencies.

I heard mostly admin, museum staff on 172.465 mhz with a PL of 110.9
However on both 169.790 mhz (Mt. Harkness) and 172.440 mhz (West Prospect) both of these were in P25 mode and showed a NAC of 455.

Also 169.815 mhz (Turner Mtn) showed a PL of 110.9.

On both of the P25 freqs, there was clearly law enforcement rangers talking. Nothing heard on the other general use freqs that were listed. Did get to hear alot of Plumas SO, Lassen SO and Shasta SO, along with SHU and LNF fire communications. Nothing like being high up in the mountains!

Hope this helps with confirming the new frequencies in use at Lassen Volcanic Park.

Ray
 

W7JYJ

Member
Joined
Aug 19, 2011
Messages
12
Well -- 150 lookers but no replies. So I'll make my own reply.

Lassen VNP's new mixed-mode P25/analog repeater system seems to be worse than it was last
year after it replaced the old analog system. I've not heard any traffic on the Table Mtn repeater
in its Manzanita Lake coverage area. Maybe the freq pair was changed? West Prospect provides
some coverage in the Manzanita Lake area, but its not very good for HT's. Noisy in analog mode.

Today I was out hiking. An 11-mile loop hike from Summit Lake to Terrace Lake, Paradise Meadow,
Hat Lake and back to Summit Lake. I carried a Kenwood TK-5210 programmed for mixed mode.
The West Prospect Peak repeater worked well at the higher elevations up around 7500 to 8000-ft.
But down at Summit Lake (etc) the analog signal was often noisy and the P25 sometimes had
the usual Donald Duck/gurgling sounding audio when the RF was near threshold. Unless my
memory has gotten really bad, the old analog-only system with repeaters on Lassen Peak,
West Prospect and Mt Harkness sure worked better than what I've heard so far. I've also got a
Kenwood TK-2180 (analog only) and mostly the same results for analog FM.

Anybody know what's going on here? Did the recent fire cause some repeater system damage/problems?

For background, see the previous thread from last year -- 219243.

Thanks, Larry W7JYJ
 

W7JYJ

Member
Joined
Aug 19, 2011
Messages
12
Lassen VNP update

Well, 248 lookers and no other replies.

I just returned from a 12-day trip to LVNP. Attended a two-day photography workshop there in the
Manzanita Lake area and then spent the rest of my time there monitoring their mixed mode analog/P25
VHF radio system while camping and hiking around the Manzanita Lake, Summit Lake, Juniper Lake
and Warner Valley/Drakesbad areas.

Looks like the Mt Harkness fire lookout / repeater site's antenna installation was cleaned up compared to
last year's installation. See the picture below and compare with the antenna picture in thread #219243
from last year. Note the bent up dipole and the longer mast without guying. Its hard to imagine this thing
surviving the winter at 8,000-ft. Maybe they take it down before winter. The dipole loops appear to be part
of a 4-element antenna array with electrical downtilt. I wonder if they got the individual antenna element
feedlines hooked up properly for phasing downtilt? Those dipole elements look a little short for VHF,
but maybe they're loaded. And the spacing looks a little sloppy and probably isn't right. The yagi
antenna appears to be the UHF link to tie this repeater in with the other three repeaters at Table Mtn,
Turner Mtn and West Prospect Peak and the remote dispatching from Yosemite brought into the park area
by landline.

The Table Mt repeater site that serves the Manzanita Lake (NW area) of the park was having problems.
It repeats OK and it appeared to be feeding its received signals to the other three repeaters via its link,
but it was NOT repeating from the other three repeaters and nothing from the dispatcher. Thus the
inbound link side appeared to be dead. I never heard any user and dispatcher radio traffic on this
repeater. Rangers in the Manzanita Lake area seemed to be using the West Prospect Pk repeater,
which has marginal coverage in the Manzanita Lake area. Probably not LOS. Users were sometimes
noisy in analog mode and asked to repeat. Some P25 mode transmissions sometimes had excessive
echo, gurgling sounding audio, drop-outs, etc.

West Prospect Peak was reaching out as far as McArthur Burney Falls State Park far to the northwest,
but I observed poor coverage at lower elevations close-in around Summit Lake, along the main park road
in the burned Dersch Meadows area, and on the Terrace Lake and Paradise Meadow trails until I got up to
about 7500-ft and higher while hiking with Kenwood TK-5210 P25 and TK-2180 radios. I don't know what
the West Prospect repeater site installation looks like. But I wonder if it has a multi-element phased
array antenna with incorrect phasing given my experience with the poor signal quality in various park locations.

Mt Harkness was reaching out well to the Terminal Geyser, Boiling Springs Lake, Warner Valley floor,
Juniper Lake, Crystal Lake, along the main park road south of its summit, etc. And some areas north
of the road summit, including Summit Lake, though not real good IIRC.

The second picture below is the Mt Harkness repeater equipment in the field case and the battery
plant. Not much to see.

Anyway, with the Table Mtn repeater having problems and the mostly poor close-in lower elevation
signal problems with the West Prospect Peak repeater, the coverage and signal quality doesn't seem to
be as good as the old analog system in the north and northwest areas of the park based on repeaters at
Lassen Peak, West Prospect Peak and Mt Harkness before the upgrade to the mixed mode P25/analog
system last year. The Table Mt and Mt Harkness repeaters in the new system seemed to work well in
their coverage areas that I visited. So, its a mixed bag. Not working as well during my visit this
year as it was last year. And not working as well as the old analog-only system before it was replaced.

--Larry, W7JYJ
 

Attachments

Last edited:
Status
Not open for further replies.
Top