Path Survey on Sunday......

Discussion in 'Survival Communications' started by BTPost, Aug 14, 2015.


  1. BTPost

    BTPost Old Fart Snow Monkey Moderator

    I am going on a Day Trip, on sunday the 16th, to do a Path Survey for the Discovery Channel Production Team, that does the filming of the show "Alaska Bush People" They seem to have a Comms problem, between their Office in Hoonah, Alaska, and the "BrownTown" Filming Site, 10.1 miles south, at the head of Port Fredrick, Alaska in Salt Lake Bay. One would think that any good Vhf Radio with Good Antennas could make a 10 Mile hop without any issues, but that doesn't seem to be the case, from what they tell me. AlaskaChick & I are both going, because I need another Licensed Ham Operator, for both ends of the Path, and she is the only Ham I can get, in a hurry....

    I will be using my two Kenwood TM-D710As as the Transceivers, (50 Watts on VHF & UHF) and using a VHF 4 element Yagi on the Town end for Vhf, and a PhelpsDodge Corner Reflector, on Uhf.... Momma will be on the Town end, for the tests. I will be in a Boat, going down the waterway and will use the Vessels Vhf antenna for Vhf, and a 10 element Cross Polarized Yagi for Uhf. In looking at the USGS Topo Maps of the Area, there is NO Direct Path. Only 600' to 2100' Mountains in between, down the shoreline, and Salt Lake Bay, is a small bay, tucked in behind these Mountains, toward the east. I will be looking for a natural Bounce Path, off the Mountains on the West side of Port Fredrick, if one exists, and if NOT, well they are going to be in a pickle, for sure.

    There are two possibilities if no Natural Bounce Path can be found.
    First is the use of a Passive Repeater. The Idea is you take TWO High Gain Antennas, and connect them together with some Extremely Low Loss Coax. The Point one directly at the Town End, and the other at the BrownTown End, back in Salt Lake Bay. The higher the Frequency used, the smaller the High Gain Antennas are, for the added Gain, over a path that doesn't exist between the two Ends, without the Passive in the middle. We do this at Microwave Frequencies, all the time, but at Uhf, it is an iffy proposition.
    The second possibility is to scrap Vhf & Uhf altogether and move to HF, and MF using Single Sideband Radios on the Alaska Private Fixed Frequencies. One hundred Watts, on a nice MF Frequency of 2.450 Mhz USB ought to be easily heard anywhere within 150 Miles, and with the selections Of MF & HF Frequencies available, it should work out well, and with a side bonus, by installing a SSB Radio on their Vessel, M/V Integrity, they would Good Comms, anywhere in SE Alaska from BrownTown.
    So, I hope Momma gets back tomorrow, from her trip to NYC, and Rochester, NY. So I have a second Operator for this trip. Wx is expected to be good for the next three days.... Will make a Report here, when we get back....
     
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  2. ghrit

    ghrit Ambulatory anachronism Administrator Founding Member

    With mountains in the way, think NVIS?
     
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  3. sec_monkey

    sec_monkey SM Security Administrator

    Good luck BT :) Be safe!
     
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  4. NotSoSneaky

    NotSoSneaky former supporter

    Hope you're not sailing on the "Integrity". [tongue]
    Best wishes. [coo]
     
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  5. Yard Dart

    Yard Dart Vigilant Monkey..... Moderator Site Supporter++

    Good luck on the mission....stay safe!
     
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  6. kellory

    kellory An unemployed Jester, is nobody's fool. Banned

    .....on a three hour tour, a three hour tour. The weather started getting rough. The tiny ship was tossed. And if not for the .......,,;) go get 'em, Professor.
     
  7. Tully Mars

    Tully Mars Metal weldin' monkey Site Supporter+

    Very cool BT! If anyone can get their comms up to snuff it'd be you!:)
     
  8. Georgia_Boy

    Georgia_Boy Monkey+++

    Great news! Maybe we'll get to see you two as participants in an upcoming episode? I like your 2450 USB option for that mountain jump.....
    GB
     
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  9. My geography is a bit rusty, sorry. Is your latitude in the footprint of the satellite phone network? A TV production crew will certainly be able to afford a satellite phone.

    I've never used passive repeaters at UHF; please let us know how it works out.

    Sounds like a good option.

    Good luck!

    William Warren
     
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  10. BTPost

    BTPost Old Fart Snow Monkey Moderator

    We have returned Home, in one piece, each..... We are both EXHAUSTED.... Long Day... but very rewarding. UHF path has been found, with a single bounce, off a natural Rock Face. I was just BLOWN AWAY, and never expected this particular Path to exist. Further details, tomorrow...
     
  11. sec_monkey

    sec_monkey SM Security Administrator

    [applaud] [applaud] :)
     
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  12. BTPost

    BTPost Old Fart Snow Monkey Moderator

    Ant-2.

    Ok, these were the antennas that we used for the Path Study. We set the Corner Reflector on top of two Card Tables stacked up, in front of the Big Office Window, at the Hoonah Office, and pointed it to the south, down Port Fredrick, toward the "Narrows" AlaskaChick stayed at the on that end of the link. The Radio was one of the Kenwood TM-D710As powered by a 120Vac/12Vdc Power Supply. We found that we had an issue with the Power Supply, in that it wouldn't Power the Radio @ the 50 Watt Output Level, but would Shutdown, by the OverCurrent Protection. So I set the Power back to the 25Watt Power Level and had to call that "Good enough". Then I took the other Kenwood TM-D710A and the Crossed Yagi with me, in the chartered 25Ft Munson LandingCraft with a 225Hp Yamaha Outboard, and started from the Hoonah Harbor, and headed south, down Port Frederick. This Radio was powered from the CigLighter Socket, on the vessel, so we had the full 50Watts of RF Power. We Stopped every mile, or so, and did a Radio Check, on 449.550 Mhz with the Office Setup, and noted the Signal Strength, of the contact. During the first 5 miles, we just left the Crossed Yagi's laying on top of a Plastic Fish Tote, and point south, as the signal Strength was 6 Bars, with Full Quieting. At about mile 7, the Signal Strength from the Office had dropped to about 3 Bars, but still Full Quieting, so at this point, I had Momma do a 30 Second Transmission, while Mike, the Production Aid who was sent to do the Grunt work, grabbed the Crossed yagi, and slowly swung it around 360 degrees, as I noted the Signal Strength, We were still getting a stronger Signal from the Mountains, farther down to the south, than from a direct path back to town. At mile 9 were were in the Middle of the "Narrows" with Salt Lake Bay, another mile ahead, and off to our left. Signal Levels were down to 2 Bars, and a little "Scratchy" but still easily understood Verbal Comms, HOWEVER the Signal Popped up to 4 Bars at two spots on the compass. One was still to our southwest, and one was directly south. The last check was done, after the "Narrows" and when we were able to see directly into, and all of Salt Lake Bay, to our left, but still out in Port Frederick. Signal Strength was from 1 to 2 Bars with the Strongest, 3 Bars, directly to our West, off the Mountain directly to our west, and a 2 Bar Hit from further south, down toward the head of Port Frederick. I told Momma that we would head to the Cabin, at the Head of Salt Lake Bay, and try from the Beach, but I was dubious, and if they didn't hear from us in an hour or so, it would be a BUST. We then went to the USFS Dock halfway up Salt Lake Bay on the North Shore, offloaded all the gear, and loaded it on a Transport Truck, for the Trip to the site, up an old Logging Road, two miles further to the east. The last 200Yds was a trail thru the woods from where the Transport Truck parked. When we arrived they were Burning Film, on the beach, so we had to wait about 20 minutes, before we could get things setup for the last Radio Test. They had to round up a 12Vdc Battery, to run the Radio, and of course it was DEAD, so go find a Honda 1Kw Genset and Battery Charger, and then charge the Battery at 30 Amps, for another Half Hour. Once that was done, Mike held the Crossed Yagi's and pointed them directly down Salt Lake Bay, to the west, and at the Mountain where we had the strongest Signal, during our last Test. Low and BEHOLD Momma came in Full Quieting, with 3 Bars of Signal Strength. Absolutely Blew me away.... The Office Folks were all at lunch, but we HAD a UHF Path, that was SOLID. If we moved off the Mountain, by more that a few degrees, the path died, but it was there and good and strong. We went to lunch, and Momma was going to be coming down to the Site, on the Crew Boat, soon after the Last Check. I spent considerable time, with the Brown Family, in the Cabin, while waiting for Momma to arrive, and discussion the Comms situation, and now that we had a "Confirmed Path' what we could do to alleviate their Comms issues, as well as the Production Teams Comms Issues, which really are two different things. Just a NOTE here, for those that have seen the show. The Family are JUST as Portrayed, personality wise, for sure.... A great Bunch, and very Nice Folks.

    PathStudy.
     
    Last edited: Aug 23, 2015
  13. Altoidfishfins

    Altoidfishfins Monkey++

    Way cool, BT.
    When I was a radio tech in the open pit mining industry, we used to ricochet UHF ( around 460-470 mhz used for telemetry) off the open rock faces of the pit in order to get signal to mobile equipment that was operating beyond line of sight. We used 4 bay dipoles with either 4 or 8 degree electrical downtilt at the repeater end (we had three GE Mastr II, and a Tait). Worked like a charm. Of course we were trying to communicate into and out of a big hole in the ground. But the principle is the same.
     
    Last edited: Aug 18, 2015
  14. Did you get to try out the passive repeater?

    William Warren
     
  15. BTPost

    BTPost Old Fart Snow Monkey Moderator

    Didn't need to, but that may change, when the Snow covers the Rock Face, this winter... Time will Tell.... If we need to, we can build one, and install it, in a week or so....
     
    sec_monkey likes this.
  16. BTPost

    BTPost Old Fart Snow Monkey Moderator

    Thought I would post the System Design, for the Proposed System Upgrade. Right now they have just two sets of 4 Watt UHF HandiTalkies. One set at each site, that can communicate only with others at that same Site.
    ABP-System.

    I spec'd the following Sinclair Panel Antennas for the Link path.

    Sinclair_SP304V 00001.

    I like these because of the Gain and the resistance to our Winter Wx. (Snow and Ice) Also they do not LOOK Like Antennas, especially if they are painted the same as the Buildings that they are Flush Mounted to. Which is a consideration, when filming around the Salt Lake Bay Site.

    I spec'd the Morad 460HDs, Because they are very small, and "Rugged" in the extreme, as attested to by the use of their VHF Cousins, almost exclusively thru-out the North Pacific Fishing Fleet.

    Spec VHF-HD and UHF HD-style antennas.
    With the System as designed, any of the Handhelds, that transmit on their Ch-16, will be picked up by the Receiver, at that sites associated Base Station. Which will intern, then Transmit that received Audio, across the Link Radio to its counterpart, at the other Site. When that Link Radio receives the signal, it will trigger that sites Associated Base Radio, which will then transmit the audio to ALL the Handhelds at that site, that are on Ch-16. It is a completely automatic System, that requires only that the Originating Handheld, transmit on it's Ch-16, and that there be at least One Handheld at the other Site on Ch-16. They are using Ch1-4 at each site for local Comms, but they can Switch to Ch-16, to get a Message from the other Site, very quickly.

    I just about GAGGED when the Sinclair Rep said that the Panel Antennas were $3300.00US EACH. However, after talking to the Head Guy, who didn't bat an Eye, at that price, I figured, "It is his money", and I only use the Best Gear in my System Designs. He is writing up next years Budget, now, and this Upgrade, will go in with that Budget, and we will see just how bad they REALLY need the Comms. There is NO Cellular, WiFi, or ANY conventional Comms at the Salt Lake Bay Site. They have tried SAT Phones, but this is Alaskan Rain Forest, and unless they are on the beach, and out from under the trees, that is a NO GO, and it cost $10US per Minute, so their Costs are steep, using that for Comms.

    All in all it is an interesting Project. Now we wait for an OK, or "Can't afford it......"
     
    Last edited: Mar 29, 2016
  17. HK_User

    HK_User A Productive Monkey is a Happy Monkey Site Supporter

    Great deal, and here I was taking it easy in the CCU,
     
  18. BTPost

    BTPost Old Fart Snow Monkey Moderator

    The Head Dude just called, and we are doing the System..... and he wants it in, and operational, before the end of September.... Now it is my turn to scramble..... POs go out tomorrow morning.... Whew.....
     
    Last edited: Sep 3, 2015
  19. Yard Dart

    Yard Dart Vigilant Monkey..... Moderator Site Supporter++

    Congrat's BT..... looking forward to the continuing news and adventure. :)
     
    Tully Mars likes this.
  20. NotSoSneaky

    NotSoSneaky former supporter

    Looking like there's gonna be a season 3 of ABP. [tongue]
     
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