[SFDXA] Daily HF Radio Wave Propagation Forecast

[Mike Williams]

Well you sound like an engineer Kai!  Well put!

73 de W4DL   Mike in EL96wf



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
> To Post: mailto:SFDXA at mailman.qth.net
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