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

Tue Dec 22 01:15:07 EST 2020

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 <kl7uw at acsalaska.net> 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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>>
>>73, Ed - KL7UW
>> http://www.kl7uw.com
>>Dubus-NA Business mail:
>> dubususa at gmail.com
>>______________________________________________________________
>>ak-vhf mailing list
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>
>73, Ed - KL7UW
> http://www.kl7uw.com
>Dubus-NA Business mail:
> dubususa at gmail.com
>______________________________________________________________
>ak-vhf mailing list
>Home: http://mailman.qth.net/mailman/listinfo/ak-vhf
>Help: http://mailman.qth.net/mmfaq.htm
>Post: mailto:ak-vhf at mailman.qth.net
>
>This list hosted by: http://www.qsl.net
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73, Ed - KL7UW
http://www.kl7uw.com
Dubus-NA Business mail:
dubususa at gmail.com

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