[AK-VHF] contest

[Ed Cole]

Ken,

Certainly strange phenomena.  Signals south-bound were refracted but not 
signals north-bound.

You know I even ran 800w-FT8 and 500w-MSK144 for the latter half on 
Sunday.  Also wondered if additional height at Murphy Dome might have 
put you above an inversion layer?

KL6M on the Anchorage hillside is about 1,000 foot ASL and times he is 
on wrong side of an inversion causing signal loss on 2m.  Usually an 
inversion helps the path from Nikiski to Anchorage.

Saturday we had snow falling which seems normally to add some 
attenuation to VHF signals; Sunday was clear-sunny in Nikiski.

I got a lot of experience with snow/rain fade at UHF when I worked in 
Nikiski as comm tech.  Our company had comm gear on top of Mt. Bede 
(3300-foot ASL) at southern end of the Peninsula and tested the UHF 
control link weekly.  Rainy/snowy wx often lowered the link signal 
margins by up to 6-dB (Fade margin was 10-12 dB so we did not lose the 
link).

Looking at the direct path between BP64 and BP40 it passes over the AK 
Range and Cantwell, and runs to the east of Talkeetna.  The path is 
also east of Mt. Susitna.

Another thing that might be affecting the signal is my 6m ground-gain 
lobe is 8.4 degrees elevation which maybe puts my signal too high.  I 
regularly used ground-gain on 6m-eme so have that well established.

I would like trying 2m and 6m over this path (once I have my four-yagi 
2m array back in-service).  Several years ago I worked KL7EDK using it 
on SSB running 150w via Mt. Denali bounce (and enhanced tropo conditions).

Thanks for the contact from BP64 and attempts from BP54.


73, Ed - KL7UW



On 1/17/2022 9:08 PM, Ken K wrote:
> Thanks to everyone who listened for me. In addition to working KL7UW and 
> AL7LO on Saturday, I also decoded K7YK a few times. I’ve used the 3-el 
> yagi and less power for previous QSOs into Southcentral and the Kenai 
> Peninsula when the band was closed. Since stations south of the range 
> apparently decoded me much more frequently than I decoded them, I think 
> the lack of contacts may have been related to a very strong inversion 
> going on here this weekend. A common occurrence here when warm air 
> pushes in over a very cold stable air mass; it often results in vivid 
> displays from Fairbanks of a phenomenon known as Fata Morgana, a type of 
> mirage that reflects images directly above themselves.
> 
> Saturday was typical; from my vantage points, I could see the peaks of 
> the Alaska Range reflected upside down above the range. It’s a cool 
> thing to see. I’m guessing refraction of radio waves blocked my 
> reception somehow. Here’s a good site for descriptions of tropospheric 
> dx modes: https://www.dxinfocentre.com/propagation/tr-modes.htm. The 
> Twitter feed for the National Weather Service Fairbanks office Jan 14 
> has a good description and picture of the Fata Morgana. It was still 
> happening this afternoon.
> 
> I'll send a check log in for the contest. Lets try again this spring; I 
> think we’ll have better luck.
> 
> 73,
> Ken NL7B
> On Sunday, January 16, 2022, 09:58:13 PM AKST, Ed Cole 
> <kl7uw at acsalaska.net> wrote:
> 
> 
> Hope everyone enjoyed the contest.
> 
> Very little activity except on 6m-FT8 for me:
> Happy to work three grids: BP51, BP64, BO49
> 
> Working Ken-NL7B/R in Fairbanks in grid BP64 on FT8 was the most
> gratifying.  We also tried from Murphy Dome (BP54) both days but Ken
> could not see me.  I got his FT8 signals both days and his MS using
> MSK144 on Sunday.
> 
> Ken was using a 3-element yagi so guess it was not quite enough from BP54.
> 
> KL7HBK BO49 was a nice surprise which increased my grid count to three.
> Final score 45
> 1 144
> 1 222
> 6 50
> 
> Please consider submitting a log and indicating club membership of "AK
> VHF-Up Group" if a member.  Club gets mention in contest results if
> three logs or more are submitted.
> 
> Go to: http://www.arrl.org/january-vhf <http://www.arrl.org/january-vhf>
> 
> use: www.b4h.net/cabforms/ to make a cabrillo log
> it will link you to the log submission form after you complete your log
> entries.  Note: voice modes are entered as ph, digital modes as dg, cw
> as cw.
> 
> 
> 73, Ed - KL7UW
>