Shenandoah National Park P25
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W4UVV
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It's Fine Here
The SNP 166.9000 mhz. P25 repeater is superstrong here in Prince George, Co., Va. 125 air miles away today/evening along with three 170 mhz. simulcast possibly "shadow" P25 remote site repeaters in the SNP.
The SNP 166.9000 mhz. P25 repeater is superstrong here in Prince George, Co., Va. 125 air miles away today/evening along with three 170 mhz. simulcast possibly "shadow" P25 remote site repeaters in the SNP.
Shenandoah additional
Ok, Good info, a couple of further observations from my end might help
further locate the new sites. I live in Berkeley Springs,WV. 171.7 is loud
and clear on a Bendix portable P25 radio so I'd say its going to be the new
north end repeater. As I drove north from Winchester today I also monitored
the 172.675 albeit a weaker signal. I heard one of the units reference 'Big
Mountain' which is west of the park. It would make sense that they added one
there for coverage. It already has a USFS 171.525 repeater there. I would
make a swag that 172.675 is at Big Mt. I did hear P25 traffic on the 166.9
but very weak. I originally thought it was an image on my end however with
your info I would make another swag that it is now probably a south end
repeater. Also if you heard 173.675 that would seem to indicate a 4th
repeater site as well. Maybe on the east side off the drive?
Ok, Good info, a couple of further observations from my end might help
further locate the new sites. I live in Berkeley Springs,WV. 171.7 is loud
and clear on a Bendix portable P25 radio so I'd say its going to be the new
north end repeater. As I drove north from Winchester today I also monitored
the 172.675 albeit a weaker signal. I heard one of the units reference 'Big
Mountain' which is west of the park. It would make sense that they added one
there for coverage. It already has a USFS 171.525 repeater there. I would
make a swag that 172.675 is at Big Mt. I did hear P25 traffic on the 166.9
but very weak. I originally thought it was an image on my end however with
your info I would make another swag that it is now probably a south end
repeater. Also if you heard 173.675 that would seem to indicate a 4th
repeater site as well. Maybe on the east side off the drive?
W4UVV
Member
SNP Remote Sites-more
I just checked SNP reception. I am located in Prince George Co. approximately 125 air miles SSE of the SNP. All of my receivers are fed from the same tower mounted pre-amped antennas. I use a 796D for P25 reception and have other analog receivers. The 796D is not the most sensitive receiver. 166.9000 mhz. is solid P25 reception just above threshold with infrequent brief chopping. 173.6750 mhz. P25 has severe audio chopping. Nothing heard on 171.9000 mhz. or 172.6750 mhz. For relative signal strength comparisons only using an analog R7000 receiver, 166.9000 mhz. is S3, 171.9000 mhz. is slightly above S1, 172.6750 mhz. S2 and 173.6750 mhz. S3.
SNP vhf/uhf relay transmitters are located at Big Mtn., Fork Mtn., Hogback Mtn., Loft Mtn. and Mt. Pony,
166.9000 mhz. repeaters are located at Loft Mtn., Camp Hoover, Thorton Gap, Luray, Hogback Mtn., Front Royal, Big Meadows, Sawmill Run, Rockfish Gap, Dickey Ridge, Simmon's Gap, Piney River, Mt. Howe's Arm, and Swift Run Gap.
Possibly one of these P25 remote site repeaters is located at one or more of the vhf/uhf relay sites. Since inftrastructure currently exists at these sites I would tend to doubt them being located at new sites, but it is possible.
Since all P25 audio is transmitted simultaneously via all the repeaters comm content is not helpful as to identifying the specific location of any one of the remote site repeaters.
I just checked SNP reception. I am located in Prince George Co. approximately 125 air miles SSE of the SNP. All of my receivers are fed from the same tower mounted pre-amped antennas. I use a 796D for P25 reception and have other analog receivers. The 796D is not the most sensitive receiver. 166.9000 mhz. is solid P25 reception just above threshold with infrequent brief chopping. 173.6750 mhz. P25 has severe audio chopping. Nothing heard on 171.9000 mhz. or 172.6750 mhz. For relative signal strength comparisons only using an analog R7000 receiver, 166.9000 mhz. is S3, 171.9000 mhz. is slightly above S1, 172.6750 mhz. S2 and 173.6750 mhz. S3.
SNP vhf/uhf relay transmitters are located at Big Mtn., Fork Mtn., Hogback Mtn., Loft Mtn. and Mt. Pony,
166.9000 mhz. repeaters are located at Loft Mtn., Camp Hoover, Thorton Gap, Luray, Hogback Mtn., Front Royal, Big Meadows, Sawmill Run, Rockfish Gap, Dickey Ridge, Simmon's Gap, Piney River, Mt. Howe's Arm, and Swift Run Gap.
Possibly one of these P25 remote site repeaters is located at one or more of the vhf/uhf relay sites. Since inftrastructure currently exists at these sites I would tend to doubt them being located at new sites, but it is possible.
Since all P25 audio is transmitted simultaneously via all the repeaters comm content is not helpful as to identifying the specific location of any one of the remote site repeaters.
I just received 173.675. it first showed up for a sec as "LNK" and I didn't hear anything so I held there. a sec later I heard digital audio and it showed P25. I cannot find a CC or data channel.
I used to hear 166.9 all the time when I lived south of Harrisonburg. I have also been able to hear it now, a little north of Winchester.
I used to hear 166.9 all the time when I lived south of Harrisonburg. I have also been able to hear it now, a little north of Winchester.
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171.700MHz, P25 full strength in Berkeley Co WV
as in my last post, I cannot find a CC
as in my last post, I cannot find a CC
W4UVV
Member
Not a TRS
The 3 vhf P25 remote sites appear to be stand alones and not part of a TRS.
The 3 vhf P25 remote sites appear to be stand alones and not part of a TRS.
Shenandoah P25 sites
After monitoring all of the testing, I've heard the following 6 sites referenced in testing.
1) Big Mountain which is on the west side of SNP on the Massanuten range
2) Hogback on north end of the drive
3) Fork Mountain on the east side near Madison
4) Whiteoak probably near Skyland
5) Loft Mountain on the south end of the drive
6) Millers Head and I haven't a clue
Further listening from Berkeley Springs using crude signal strength comparison would suggest to me that 171.7 is most likely at Hogback. I have it full quieting, w only rare break out of audio on a portable. The next strongest when hooked to an outside discone is 173.675, then when I walk up the mountain to the south of me 172.675 starts to come in weakly. I have not heard 166.9 at all which probably suggests it is now on the south side.Possibly the 173 is on Fork Mtn or Whiteoak and the 172 on either Fork or Big Mt. I base that on knowing what the typical propagation is from all of those sites to my location.
After monitoring all of the testing, I've heard the following 6 sites referenced in testing.
1) Big Mountain which is on the west side of SNP on the Massanuten range
2) Hogback on north end of the drive
3) Fork Mountain on the east side near Madison
4) Whiteoak probably near Skyland
5) Loft Mountain on the south end of the drive
6) Millers Head and I haven't a clue
Further listening from Berkeley Springs using crude signal strength comparison would suggest to me that 171.7 is most likely at Hogback. I have it full quieting, w only rare break out of audio on a portable. The next strongest when hooked to an outside discone is 173.675, then when I walk up the mountain to the south of me 172.675 starts to come in weakly. I have not heard 166.9 at all which probably suggests it is now on the south side.Possibly the 173 is on Fork Mtn or Whiteoak and the 172 on either Fork or Big Mt. I base that on knowing what the typical propagation is from all of those sites to my location.
when I heard htem today, they mentioned Rockfish and Big Meadow about a lot of bike traffic.
W4UVV
Member
SNP-P25 Sites
Very good. Miller's Head is a summit at approximately 3,400 ft. elevation located in the general area of Big Meadows. I can access the 444.4000 mhz. ham repeater on Fork Mtn. from here and since I was hearing part of 173.6750 mhz. earlier with chopping I would guess it may be on Fork Mtn. I suspect in time someone will obtain the frequency/site location info and post it. Since the SNP lies approximately NNE/SSW, I suspect that the transmit antennas are phased nulling NW and SE locations adjacent to the SNP. There's no use in wasting RF in an omni-directional pattern. If that's being done it will obviously impact reception especially outside the SNP. The plus side is the transmitters are located at 2,000-3,500 ft. levels.
I don't understand why you are not hearing 166.9000 mhz. as it is a multi-site T/R operation. At your elevation I would think you would hear something even with antenna phasing. Previously the analog signal here was spotty but I am receiving it significantly better P25 digital. P25 ground wave distances have tended to be very impressive.
FYI, do your worst case scenario testing around noon daily.
Very good. Miller's Head is a summit at approximately 3,400 ft. elevation located in the general area of Big Meadows. I can access the 444.4000 mhz. ham repeater on Fork Mtn. from here and since I was hearing part of 173.6750 mhz. earlier with chopping I would guess it may be on Fork Mtn. I suspect in time someone will obtain the frequency/site location info and post it. Since the SNP lies approximately NNE/SSW, I suspect that the transmit antennas are phased nulling NW and SE locations adjacent to the SNP. There's no use in wasting RF in an omni-directional pattern. If that's being done it will obviously impact reception especially outside the SNP. The plus side is the transmitters are located at 2,000-3,500 ft. levels.
I don't understand why you are not hearing 166.9000 mhz. as it is a multi-site T/R operation. At your elevation I would think you would hear something even with antenna phasing. Previously the analog signal here was spotty but I am receiving it significantly better P25 digital. P25 ground wave distances have tended to be very impressive.
FYI, do your worst case scenario testing around noon daily.
gcgrotz
Member
As of this morning, I am hearing nothing in Charlottesville on 166.900, data or FM. I used to hear it quite well on a portable with rubber duck in the house. Listened to a lot of the fire fighting efforts on that freq this past spring.
I'll try to get all those freqs programmed in the '396 and see what I hear in my travels this week. SNP usually comes in quite well all over here. As W4UVV, I can hit the 444.400 repeater easily, and another 2m machine in Madison, even with a handheld.
P.S. I just heard a unit making a traffic stop at Loft Mtn overlook on 166.900 P25 @09:18 Loud and clear on the '396 in the house. On the FM system the mobiles were usually weak and scratchy into the repeater. Better sounding audio than the Albemarle Co 800 P25.
I'll try to get all those freqs programmed in the '396 and see what I hear in my travels this week. SNP usually comes in quite well all over here. As W4UVV, I can hit the 444.400 repeater easily, and another 2m machine in Madison, even with a handheld.
P.S. I just heard a unit making a traffic stop at Loft Mtn overlook on 166.900 P25 @09:18 Loud and clear on the '396 in the house. On the FM system the mobiles were usually weak and scratchy into the repeater. Better sounding audio than the Albemarle Co 800 P25.
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gcgrotz
Member
Just put the freqs listed here in the scanner. 171.900 is a Hydrological monitoring repeater located in the SPD building at Bearden Mtn, a few miles north of Afton/I-64, along the AP trail. It constantly transmits data bursts from stream monitoring equipment. It is an old GE MastrII.
W4UVV
Member
171.7000 mhz.
FYI the SNP remote site transmitter is 171.7000 mhz. and should not be confused with the IFLOWS 171.9000 mhz. transmission on Bear Den Mtn. I receive the 171.9000 mhz. transmission 24/7 varying from S3 to S7 and use it as a "beacon" indicator of high vhf band conditions, i.e., ducting, etc. IFLOWS transmitters typically are about 5 watts power,with exceptions for higher powered ones in poorer LOS locations. The Bear Den Mtn., transmissions are destined for direct reception at the Staunton, Va. IFLOWS processing site. IFLOWS processing sites typically are City PDs or county SOs and computer output data is transmitted via landline links and eventually consolidated at the NWS in the DC area. Depending on the location of the IFLOWS stream and/or rain gauge transmitters, the packet information may be relayed via microwave at selected VSP transmitter sites to the appropriate IFLOWS processing site.
ILFLOWS has a good webpage with frequency information and graphics. The techs also can talk via the backbone vhf/microwave IFLOWS network and I have heard them on a couple of 170-171 mhz. frequencies in the past. IFLOWS Tech headquarters is at the Tri City Airport near Bristol/Blountville, TN. They keep busy with computer processing problems and trouble shooting power supply problems at various IFLOWS remote field locations.
IFLOWS is a separate radio system and not affliated with the NPS.
FYI the SNP remote site transmitter is 171.7000 mhz. and should not be confused with the IFLOWS 171.9000 mhz. transmission on Bear Den Mtn. I receive the 171.9000 mhz. transmission 24/7 varying from S3 to S7 and use it as a "beacon" indicator of high vhf band conditions, i.e., ducting, etc. IFLOWS transmitters typically are about 5 watts power,with exceptions for higher powered ones in poorer LOS locations. The Bear Den Mtn., transmissions are destined for direct reception at the Staunton, Va. IFLOWS processing site. IFLOWS processing sites typically are City PDs or county SOs and computer output data is transmitted via landline links and eventually consolidated at the NWS in the DC area. Depending on the location of the IFLOWS stream and/or rain gauge transmitters, the packet information may be relayed via microwave at selected VSP transmitter sites to the appropriate IFLOWS processing site.
ILFLOWS has a good webpage with frequency information and graphics. The techs also can talk via the backbone vhf/microwave IFLOWS network and I have heard them on a couple of 170-171 mhz. frequencies in the past. IFLOWS Tech headquarters is at the Tri City Airport near Bristol/Blountville, TN. They keep busy with computer processing problems and trouble shooting power supply problems at various IFLOWS remote field locations.
IFLOWS is a separate radio system and not affliated with the NPS.
gcgrotz
Member
W4UVV: OK, now I get it. Yeah, I use 171.900 sometimes as a reference. I'm not sure of its actual power out. There is also a voice repeater sitting next to it. Maybe I'll try to find an excuse to get up there. Somewhere I have all the freqs, input/output, for both of them. Thanks for the web info, I went and looked at it, it could be interesting to watch during "tropical" weather.
Sitting here with the scanner listening to 166.900, it sounds very good here. It seems like there are some bugs they are working out, loss of audio at one of the consoles, some mobiles with problems, stuff like that. Overall it should be a big improvement.
By any chance do you know any of the guys at CommTronics in Ettrick? I worked with them a lot in a previous life in the paging business.
Thanks again,
george AA4D
Sitting here with the scanner listening to 166.900, it sounds very good here. It seems like there are some bugs they are working out, loss of audio at one of the consoles, some mobiles with problems, stuff like that. Overall it should be a big improvement.
By any chance do you know any of the guys at CommTronics in Ettrick? I worked with them a lot in a previous life in the paging business.
Thanks again,
george AA4D
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Heard 171.7 loud and clear on a rubber duck antenna, Pro-96 in Williamsport, MD this morning before leaving for work......
Carl
Carl
W4UVV
Member
171.9000 mhz.
What type of antenna is being used at the 171.9000 mhz. IFLOWS Bear Den Mtn. site? That's the one I am hearing here. The voice repeater at the same location is one of the voice repeaters in the ILFLOWS backbone network. In the past I have heard them on 171,1250 mhz. which is a Bear Den Mtn. site and 171.2750 mhz. I am not sure where that one is located.
Advise me by private email if you wish all of the IFLOWS frequencies and site information. I can extract it from my master file and email it to you.
I do not know anyone who works for Commtronics.
What type of antenna is being used at the 171.9000 mhz. IFLOWS Bear Den Mtn. site? That's the one I am hearing here. The voice repeater at the same location is one of the voice repeaters in the ILFLOWS backbone network. In the past I have heard them on 171,1250 mhz. which is a Bear Den Mtn. site and 171.2750 mhz. I am not sure where that one is located.
Advise me by private email if you wish all of the IFLOWS frequencies and site information. I can extract it from my master file and email it to you.
I do not know anyone who works for Commtronics.
gcgrotz
Member
I haven't been to Bearden in a while, someone else takes care of it now. As I recall, most of the VHF ants are of the folded dipole array variety. SPD uses 4 elements and there are some 2 element and the ones with 2 elements 180deg apart on the same pipe for a total of 4. I think those are the IFLOWS ants. They also had a spare unused ant/feedline. You actually have to trace out the lines to figure it out. The tower is only 90ft tall and has pcs and microwave ants on it also. Some of the VHF ants were quite low, one just above ground level. That's a great spot up there, maybe I'll make up an excuse to get up there and take a few pics.
I'll email you later about the IFLOWS info, got to get to work now, thanks.
I'll email you later about the IFLOWS info, got to get to work now, thanks.
gcgrotz
Member
Also noted: yesterday (Tue) the park had coverage teams all around making test calls with the dispatcher reading back the serial (?) number of the test. They were using 166.900. I haven't heard anything in the south on the 17x.xxx freqs yet.
166.900 was solid copy on I64 all the way to Gum Spring with 1/4 wave VHF mag mount on roof.
166.900 was solid copy on I64 all the way to Gum Spring with 1/4 wave VHF mag mount on roof.
6-7-06
0944 hours
Hearing park staff or Radio Techs doing grid square tests on 171.7 from here in Williamsport, Md.
They 5/9, and not a hint of distortion......
Carl
0944 hours
Hearing park staff or Radio Techs doing grid square tests on 171.7 from here in Williamsport, Md.
They 5/9, and not a hint of distortion......
Carl
gcgrotz
Member
Yes, I heard that today too. I was in downtown Charlottesville, they appeared to be simulcasting 166.900 (5 bars) 172.675 (4-5 bars) and 171.700 (0 bars but decoded just fine). This was with '396 and 1/4 wave magmount on roof tuned to RR band. Made for a lot of good traffic to copy. I also heard 172.675 east of Zion Crossroads on I64. Never heard 173.675, don't know where that's located. Those sites on the BlueRidge have always talked out well to the east.
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