[SFDXA] Daily HF Radio Wave Propagation Forecast
k2rr
k2rr at bellsouth.net
Sat Feb 11 16:05:40 EST 2017
A prime example is 75m. Here in NH Europe is great, normally S9. Yesterday at East coast sunset I asked for US stns to join a qso I was having with a G; no takers. Then Paul called me (3B8HC). HE PEAKED AT 59+5. After chatting for a few minutes ( he appeared to want to continue our QSO) I thanked him for a nice conversation and left the fq to him. Darn if 25 or more EU and US stns suddenly appeared. Lot of people listen or stay glued to the dx clusters but don't call in unless a 'rare one' suddenly appears.
Hope you are both well.Rich
Sent from my Verizon, Samsung Galaxy smartphone
-------- Original message --------From: Bill <bmarx at bellsouth.net> Date: 2/11/17 1:09 PM (GMT-05:00) To: k.siwiak at ieee.org, sfdxa at mailman.qth.net Subject: Re: [SFDXA] Daily HF Radio Wave Propagation Forecast
Kai,
I agree. As a ham for nearly 60 years, nothing is more surprising than
someone calling a CQ on a seemingly dead band and someone else
answering. We hear nothing but if everyone is listening it seems quiet.
For this report it is simple, but his own explanation is:
"Please keep in mind that this is a relatively simplified HF radio wave
propagation forecast, so as to keep it easily understandable by the average
radio enthusiast."
So it is only a guideline and quick check on what an expert sees in the
numbers. A CQ can dispel all that hi.
Bill W2CQ
On 2/11/2017 11:04 AM, Kai wrote:
> Bill Thanks - this is good stuff, but "good, poor and fair" are
> relative terms, so don't give up yet.
> Among the radio "knobs" and controls that we can twiddle in our ham
> stations, is a "propagation knob".
>
> Despite propagation forecasts, the bands do not shut down like an
> on/off switch, but rather the path attenuation increases (sometimes
> very dramatically). That's where the "propagation knob" in your ham
> station can help.
>
> The propagation knob is your choice of operating mode, and it can make
> a significant dent in the propagation path loss.
> For example, turn the "knob" to JT65/JT9 mode to increase the
> propagation link margin by about 25 dB compared to CW (that is plus 4
> S units).
> The link margin for normal SSB, on the other hand, is 17 dB worse than
> the link for CW (minus 3 S units).
> For the AMers, the AM link margin is 27 dB worse than for CW (minus
> 4.5 S units).
> So the "propagation knob" lets you choose over a link-margin range of
> 52 dB (nearly 9 S units, or 160,000 in power) from AM to JT65/JT9!
>
> If SSB doesn't work, try dialing up CW for an additional 17 dB gain in
> the path. Or try JT65 for 42 dB more gain over SSB!
>
> The bottom line is, don't give up on a band because the forecast is
> poor. Instead, dial up a more "sensitive" mode or modulation.
> For additional details and modes, see, "How much 'punch' can you get
> from different modes", QST, Dec 2013, available at:
> http://sfdxa.com/meetings-and-awards/club-presentations.html.
> 73,
> Kai, KE4PT
>
> On 2/11/2017 08:00, Bill wrote:
>>
>> Images associated with this HF radio wave propagation forecast can be
>> found
>> at https://www.facebook.com/thomasfranklingiellaw4hm
>>
>> Issued on Saturday February 11, 2017 at 1200 UTC
>>
>> Global HF Radio Wave Propagation Forecast
>>
>> HAMATEUR & SW BROADCAST HF BANDS:
>>
>> NORTHERN HEMISPHERE RADIO WAVE PROPAGATION-
>>
>> 80-60 (75-60) meters- good at night and poor at day,
>>
>> 40-30 (41-25) meters- good at night and fair at day,
>>
>> 20-17 (22-15) meters- very poor at night and good at day,
>>
>> 15 (13) meters- very poor at night and fair to good at day,
>>
>> 12-10 (11) meters- very poor at night and poor at day.
>>
>> SOUTHERN HEMISPHERE RADIO WAVE PROPAGATION-
>>
>> 80-60 (75-60) meters- poor at night and very poor at day,
>>
>> 40-30 (41-25) meters- fair at night and poor at day,
>>
>> 20-17 (22-15) meters- fair at night and fair at day,
>>
>> 15 (13) meters- poor at night and fair at day,
>>
>> 12-10 (11) meters- very poor at night and very poor at day.
>>
>> Received RF signal strength scale-
>>
>> Very Good- +1 over S9 Or Greater
>> Good- S7-9
>> Fair- S4-6
>> Poor- S1-3
>> Very Poor- S0
>>
>> Meter Band Equivalents
>> Ham & SWL
>> 160-> 90
>> 80-> 75
>> 60-> 60
>> 40-> 49, 41
>> 30-> 31, 25
>> 20-> 22, 19
>> 17-> 16, 15
>> 15-> 13
>> 12,10-> 11
>>
>> Please keep in mind that this is a relatively simplified HF radio wave
>> propagation forecast, so as to keep it easily understandable by the
>> average
>> radio enthusiast.
>>
>> Globally HF radio wave propagation conditions are most evenly balanced
>> during the fall and spring equinoxes and most diametrically opposed
>> during
>> the summer and winter solstices.
>>
>> Conditions also change daily, weekly, monthly, yearly and by decade,
>> as the
>> sun rises and sets at different times and at different angles from the
>> ecliptic, as well as by radio wave frequency. This is due to changes
>> in the
>> maximum usable frequency (MUF), lowest usable frequency (LUF) and F
>> layer
>> critical frequency (FoF2).
>>
>> The D and E layers also come into play through RF radio wave signal
>> absorption and refraction. And then there is sporadic E (Es) radio wave
>> propagation that can really throw a wrench into the gears so to speak.
>>
>> Things like sporadic E (Es) radio wave propagation and lightning storm
>> static can impact HF radio wave propagation in an unpredictable
>> manner and
>> mostly bad.
>>
>> Ongoing solar, space and geomagnetic weather goings on also impact HF
>> radio
>> wave propagation conditions in a negative manner.
>> ------------------------------------------------------------------------------------
>>
>> Solar Space & Geomagnetic Weather Conditions On
>>
>> Friday February 10, 2017-
>>
>> Solar activity was low.
>>
>> Earth's magnetic field was quiet.
>>
>> The solar flux index (SFI) was 74.9 74.0 74.2.
>>
>> The official daily sunspot number (SSN) was 18.
>>
>> In 2017 there were 11 days with a daily sunspot number (SSN) of 0.
>> Considering that solar minimum won't occur for approximately three more
>> years, seeing daily SSN's of 0 is occurring unusually early.
>>
>> In 2016 there were 32 days with a daily sunspot number (SSN) of 0.
>> Considering that solar minimum won't occur for approximately three more
>> years, seeing daily SSN's of 0 is occurring unusually early.
>>
>> As we move forward towards the next solar minimum between solar cycle
>> #24
>> and #25 the number of days with a 0 daily sunspot number will
>> dramatically
>> increase. Eventually most every day for many many months will see a 0.
>>
>> In 2008 I forecasted solar cycle 24 to be the weakest in the past 100
>> years
>> and that came forecast verified. I also forecasted that solar cycle
>> 25 would
>> be virtually non existent, similar to the Dalton type solar minimum that
>> occurred in the early 1800's.
>>
>> Sunspot group #12635 was located near N13E01 with a simple beta magnetic
>> signature.
>>
>> No earth directed solar flares occurred.
>>
>> No earth directed coronal mass ejections (CME) occurred.
>>
>> No earth directed collapsing magnetic filament eruptions occurred.
>>
>> The 24 hour period 3 hour interval planetary K index (Kp) was at quiet
>> geomagnetic conditions 2 1 2 1 2 2 1 2.
>>
>> The maximum and minimum planetary A index (Ap) ranged between 9 and
>> 4, which
>> was at unsettled to quiet geomagnetic conditions.
>>
>> The averaged background x-ray flux was A5.9.
>>
>> The vertical component (Bz) of earth's magnetic field was +0.4 nT north.
>>
>> The Dst ranged between -19 and 0.
>>
>> No energetic proton events greater than 10 MeV (10+0) occurred.
>>
>> The maximum and minimum solar wind speed was 436 and 369. km/s.
>>
>> There was a recurrent transequatorial earth facing coronal hole #790
>> (#786).
>> During it's last passage across the earth facing side of the sun it
>> produced
>> minor (Kp-4) negative impacts on HF radio wave propagation.
>> --------------------------------------------------------------------------------------
>>
>>
>> The Kp geomagnetic indices are-
>> 0-2- quiet
>> 3- unsettled
>> 4- active
>> 5- minor geomagnetic storming
>> 6- moderate
>> 7- strong
>> 8- severe
>> 9- extreme
>> 10- our atmosphere just got cooked off like on Mars and we are all dead.
>>
>> The Ap geomagnetic indices are-
>> 0-7- quiet
>> 8-15 unsettled
>> 16-29- active
>> 30-49- minor geomagnetic storm
>> 50-99- major
>> 100-400- severe
>>> 401- our atmosphere just got cooked off like on Mars and we are all
>>> dead.
>> ------------------------------------------------------------------------------------
>>
>>
>> GENERAL GUIDELINES CONCERNING CORRELATION OF PROPAGATION INDICES TO
>> ACTUAL
>> HF PROPAGATION CONDITIONS-
>>
>> NOTE!!! The propagation indices "interpretations" are my personal
>> intellectual property. Therefore the radio wave propagation indices
>> interpretations contained herein is copyrighted © 1988-2017 by Thomas F.
>> Giella, W4HM, all rights reserved. Reproduction of information herein is
>> allowed without permission in advance as long as proper credit is given.
>>
>> All 14 of the following indices have to occur as described below in
>> order to
>> see the best global high frequency radio wave propagation possible.
>>
>> 1.) Dropping geomagnetic field indices numbers are better, Kp of 0 best.
>>
>> 2.) A daily sunspot number of 150 or higher, 200 or higher best.
>>
>> 3.) A daily sunspot number of greater than 100 for routine stable
>> formation
>> of the E Valley/F Layer ducting mechanism.
>>
>> 4.) Previous 24 hour Ap index under 10, fewer than 7 for several days
>> consecutively are best.
>>
>> 5.) Previous 3 hours Kp index fewer than 3 for mid latitude paths, fewer
>> than 2 for high latitude paths, 0 for several days consecutively is
>> best.
>>
>> 6.) Energetic protons no greater than 10 MeV (10+0).
>>
>> 7.) Background x-ray flux levels greater than B1 for several days
>> consecutively, greater than C1 best.
>>
>> 8.) No current STRATWARM alert.
>>
>> 9.) Interplanetary magnetic field (IMF) Bz with a (positive number)
>> sign,
>> indicates a lesser chance of high latitude path aurora
>> absorption/unpredictable refraction or scattering of medium frequency RF
>> signals, when the Kp is above 3.
>>
>> 10.) A -10 or better towards a positive number Dst index during the
>> recovery
>> time after a geomagnetic storm, as related to the equatorial ring
>> current. A
>> positive number is best.
>>
>> 11.) Rising positive T index number. The T Index tracks with the F2
>> layer
>> critical frequency (foF2) and sunspot number (SSN) and indicates the
>> capability of the F2 layer to refract RF signals.
>>
>> 12.) Galactic cosmic rays decrease to -3 units below zero and trending
>> towards zero.
>>
>> 13.) Energetic electron flux levels no greater than 2 MeV (2+0).
>>
>> 14. A solar wind speed of less than 300 km/s for several days
>> consecutively.
>>
>> ------------------------------------------------------------------------------------
>>
>>
>> Standard Disclaimer-
>>
>> Note! I use error prone RAW public domain data from the NOAA Space
>> Environment Center, other U.S. government organizations and educational
>> institutions, to produce my comprehensive radio wave propagation
>> forecast.
>> This data is gathered and made public by the U.S. Government using
>> taxpayer
>> $$$ (including mine).
>>
>> However the propagation forecast that I produce from the RAW public
>> domain
>> data is my personal intellectual property. Therefore this radio wave
>> propagation forecast contained herein is copyrighted © 1988-2017 by
>> Thomas
>> F. Giella, W4HM.
>>
>> Feel free to redistribute this solar, space and geomagnetic weather
>> discussion and HF radio wave propagation forecast, as long as you
>> redistribute it in it's entirety and give me credit for it.
>>
>> Also solar, space and geomagnetic weather forecasting is still an
>> inexact
>> science. The forecasts are not official but for educational and hobby
>> related purposes only and are subject to human error and acts of God,
>> therefore no guarantee or warranty implied.
>>
>> ______________________________________________________________
>> South Florida DX Assoc. "SINCE 1974"
>> SFDXA WebSite: http://www.SFDXA.com
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>>
>
> ______________________________________________________________
> South Florida DX Assoc. "SINCE 1974"
> SFDXA WebSite: http://www.SFDXA.com
> SFDXA Repeater 147.33+ 103.5 Tone
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> To UNSUBSCRIBE/EDIT: http://mailman.qth.net/mailman/listinfo/sfdxa
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>
______________________________________________________________
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