[AK-VHF] NET: 19 Dec. - 144.200 USB

Edward R Cole kl7uw at acsalaska.net
Tue Dec 22 16:22:42 EST 2020 


Charlie,

I received the attachments direct to my 
e-mail.  The AK-VHF reflector does not pass 
attachments (spam  protection).  Best to link to 
a webpage or use dropbox for those.

I'm guessing the profiles were made on 
Radiomobile sw.  I did a couple for paths to KL6M 
and others some years ago but could not figure 
how to save them other than printing them.

Definitely some terrain in the north part of the 
peninsula that blocks direct signals.  I don't 
recall the added attenuation but your numbers seem reasonable.

-152 dBm is pretty low for most station other 
than eme.  But antenna gain and transmit power help offset that.

MY theoretical 2m eme sensitivity antenna gain is 
-170 dBm range.  Minimum round-trip moon-bounce 
path loss is -254.4 dB on 144-MHz at perigee.

73, Ed - KL7UW

At 09:24 PM 12/21/2020, you wrote:
>All-
>The embedded path profiles apparently did not 
>make it through. I've attached them to this email
>73, Charlie
>
>On Tue, 22 Dec 2020 01:15:07 -0500, chazmo at alaska.net wrote:
>
>Ed- I have been toying with the idea to recreate 
>a 125 mile link I did with my Kenwood TH-D72A 
>and an Elk 2M/440 LPD from Haleakala Summit to 
>Kapolei. I was easily able to talk to KH6OWL and 
>some other one-ways on Oahu running just 5W. 
>KH6OWL was running 25. Due to the 10,000 foot 
>high "tower" on my end with sharp dropoff, the 
>FFZ was completely unobscured on my end with 
>minimal obscuration on the Kapolei end due to 
>terrain. He lives on the west side of the 
>Kapolei golf course with a clear view of 
>Haleakala over a lake... No towers required. 
> From the online version of Radiomobile:
>
>
>
>Free space loss
>121.62
>dB
>
>
>Obstruction loss
>9.78
>dB
>
>
>
>Total Loss 139dB
>
>
>Looking around Anchorage, the best driveable 
>spot I could find is on a road called Tower 
>Estates. From Google Streetview, there appear to 
>be no parking signs where I want to set up, but 
>I can park down the road and walk. The terrain 
>drops off sharply just like Red Hill 
>(Haleakala). Putting the data into radiomobile, 
>here is what I get for path loss with an 
>8m(phase center) high antenna on your end.
>
>
>
>Free space loss
>115.29
>dB
>
>
>Obstruction loss
>28.51
>dB
>
>
>
>Total path loss of 152.64dB
>
>As you are most likely aware, there is a hill on 
>Meimi Ave. southeast of Daniels Lake which is a 
>huge detriment to this path. To overcome this, 
>you would need a 50 meter high antenna to match 
>the 125 mile path loss of 139 dB. Increasing 
>your antenna gain can overcome much of this, as 
>does installing a taller tower with the tradeoff 
>of longer cables with more loss. Just for fun I 
>set up a link from Tower Estates to the top of 
>that hill on Meimi Ave- it has a path loss of 
>136dB with both antennas 2m AGL. The main 
>obstruction then becomes the terrain where the 
>path crosses the Swanson River Pipeline Access 
>Road near 60°48'4.40"N 150°50'58.65"W.
>Meimi Avenue was apparently only recently 
>connected to Alexander Road. Future repeater site?
>Actually looking around, a good place for a 
>repeater would be Scenic View Loop. There 
>already appears to be a tall lattice tower there 
>but there also appear to be residences as well. 
>60°46'43.45"N 151° 7'44.67"W It has a path 
>loss of 130dB even without the tower. Any hams looking for a retirement home?
>This is of particular interest to me as working 
>for the FAA, it was a challenge to get a link 
>from Site Summit to Kenai as we moved much of 
>our operations there in the early 1990's. KL6M 
>is very familiar with this conundrum. Now we 
>have much more readily available and powerful 
>tools to perform this analysis- most importantly 
>Google Earth and Radiomobile. Anyway, food for thought. 73, Charlie
>
>On Mon, 21 Dec 2020 19:34:16 -0900, Edward R Cole wrote:
>
>And another correction KL7CE should be AL7CE. I think this is
>another example why using phonetic alphabet is useful.
>I am not sure if I have talked with these gentlemen, before, so calls
>are not familiar to me (as they may be to Anchorage stations).
>
>Also AL6O asked me some questions about what is needed to work out
>60+ miles (short version answer, below);
>
>1. Antenna: 10dBi gain; very big vertical or a 8-11 element yagi
>2. Height: 30-foot min; 50-feet is better (unless you live at high elevation)
>3. Coax: RG8 & RG213 have high loss at 144-MHz (2.2 dB/100-foot
>means 60% gets to the antenna); LMR-400 is 1.5 dB/100-foot 70% gets
>there); don't even think of using RG-58 (4.5 dB loss).
>4. Power: 50w (more is nicer; I run 120w)
>5. Preamp: You can't work them if you can't hear them; this is the
>"secret" to weak-signal reception. Min 0.5 dB NF, 18 dB gain
>Most preamps don't bypass in transmit so you need coax relays to
>bypass the preamp.
>
>This pretty much listed in the order of priority.
>
>My four yagi array came down in the Nov. 2nd wind storm. I am trying
>to get my two yagis (17.35 dBi) system for use (high SWR at this point).
>So I am using a Cushcraft ARX-270 dual-band vertical: 11 dBi on 144;
>13 dBi on 432. The antenna is 17-foot long, base mounted at 20-feet
>above ground.
>I live at 135 feet above sea level - 2 miles from the Inlet.
>
>73, Ed
>
>
>At 04:26 PM 12/21/2020, Edward R Cole wrote:
> >Correction K67O should be AL6O:
> >
> >At 11:21 AM 12/20/2020, Edward R Cole wrote:
> >>Net report:
> >>
> >>144.200 (using FT-736R and vertical):
> >>KL3WF - S2 (band varying over several minutes)
> >>KL4VB - NR
> >>KL7XJ - S5 (13.8 miles ESE of me near Kenai College)
> >>KL7GRM - S9 (17.4 miles south of me in Echo Lake area south of Soldotna)
> >>KL7H - S1 (new call for KL4E)
> >>KL7CA - NR
> >>KL0YO NR
> >>KL7CE - NR
> >>KL6O all by relay by KL7H
> >>KL6M heard after net
> >>
> >>223.50 (using BCM-220 and two CC 220-11 yagis):
> >>KL7H - 2bars
> >>KL7T - NR
> >>KL5T - NR
> >>KL4RP - NR
> >>224.94 Rptr -2bars
> >>
> >>Next weekend Net will be on 146.52FM
> >>
> >>73, Ed
> >>Merry Christmas
> >>
> >>At 11:32 PM 12/18/2020, Edward R Cole wrote:
> >>>The begins at 9:30am on 144.200 USB. I also monitor 223.50 FM
> >>>Six more shopping days until Christmas!
> >>>
> >>>Hope to see you on the net tomorrow!
> >>>
> >>>73, Ed - KL7UW
> >>> http://www.kl7uw.com
> >>>Dubus-NA Business mail:
> >>> dubususa at gmail.com
> >>>______________________________________________________________
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> >>>
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> >>
> >>73, Ed - KL7UW
> >> http://www.kl7uw.com
> >>Dubus-NA Business mail:
> >> dubususa at gmail.com
> >>______________________________________________________________
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> >
> >73, Ed - KL7UW
> > http://www.kl7uw.com
> >Dubus-NA Business mail:
> > dubususa at gmail.com
> >______________________________________________________________
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>
>73, Ed - KL7UW
>http://www.kl7uw.com
>Dubus-NA Business mail:
>dubususa at gmail.com
>
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>
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73, Ed - KL7UW
   http://www.kl7uw.com
Dubus-NA Business mail:
   dubususa at gmail.com

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