[AK-VHF] NET: 28 March - 146.52 FM

[Brandon Clark]

Very cool comments on the net Ed. It is great to have people doing this and
paying attention to how signals propagate through south-central. Good
information to have for emergencies, back country travelers, and public
service events. A repeater is not always the answer, and we can do more
than we realize using simplex.

To add to your comments, antenna tuning can also make for some big
differences in received signal strength. If one's antenna has much better
SWR in one part of the band then loss in the coax run will increase. This
will affect both radiated power and received signal for any communications
using that antenna. A few years ago I used some homebrew yagis from the
ARRL handbook that had this very issue: they were older designs that were
tuned SO preferentially for the weak signal portion of the band that you
could barely use them for FM.

Another related effect is a change in the radiated pattern with frequency.
This always happens to some extent, but a good design will minimize it
across the intended frequency range. Poor management of pattern change with
frequency can result in big swings in gain over the band as the primary
lobe changes shape.
Fun stuff,

Brandon

On Sat, Mar 28, 2020, 23:27 Edward R Cole <kl7uw at acsalaska.net> wrote:

> Interesting Net:
> 146.52 FM:
> KL3WF- S5
> KL4VB - NR
> KL4E - S9 (but Craig could barely hear me??)
> KL7QZ - S2
>
> so we QSY the net to 144.200 USB:
> KL7CA - S0 but copyable
> KL7QZ - S0 good copy
> KL3WF - S6 strong
> KL4E - S6 strong  (Craig had better copy of me)
> KA1NVZ - S9 very strong
> WL7XQ - S0 marginal copy
>
> Had several questions about the difference in reception between the
> two frequencies:
> It has been noted that a change of frequency can make significant
> change in signal.
>
> Temperature affects tropo prop usually by existence of layering (temp
> invertion).
> I've noted rain/snow and wind turbulence reduces signals on 2m and 222.
> Multi-path prop changes with frequency significantly;  path from
> KL7UW => Anchorage area passes over high terrain on north end of the
> Kenai Peninsula and likely reflects off mountains in the area.
>
> AL7JX in Anchor Pt. receives my signal best by pointing West across
> the inlet and probably reflects from the Alaska Range (best noted
> when I transmit on my omni-vertical).  When I use my yagi array we
> can only work each other if I point toward Anchorage (and not direct
> SW).  That suggests backscatter off the Chugach mountains.
>
> I've also noted signals better at beginning of the net and signals
> dropping some as sun rises higher!
>
> We will have extra fun next Saturday as Brandon-KL7BSC operates from
> Rendezvous Peak above Arctic Valley.  This will be a  SOTA trek.
>
> See you next week on 144.200 USB.
>
> 73, Ed - KL7UW
>
>
> At 07:55 PM 3/27/2020, Edward R Cole wrote:
> >Net will begin at 9:30 am on 146.52 FM (last Saturday of the month).
> >I will be running the FT-736R into amp with 85w* into 4-yagi array
> >at 52-feet pointed toward Anchorage.  Also will monitor 223.50  FM.
> >Wx is supposed to clear and get colder which may enhance prop a
> >little more than last week (inversion layer).
> >*Power reduced by high SWR above 146 MHz (normally 115-125w)
> >
> >Hope to see you tomorrow on the net!
> >
> >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
> >Please help support this email list: http://www.qsl.net/donate.html
>
> 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
> Please help support this email list: http://www.qsl.net/donate.html
>