[SADXA] FW: FW: 40m F layer Propagation DX Corridor Graphic for Phoenix - From W7EXG

Thu Dec 8 03:23:35 EST 2016

To everyone on the list.   The Map was forwarded by my computer but was missing when I ( and apparently everyone else) received the message.   Current guess is that the club's mail reflector strips any attachments.   I will try and think about this tomorrow to see if there is a work-around.

73,

Larry Brown, W7LB
SADXA Secretary/Treasurer

-----Original Message-----
From: SADXA [mailto:sadxa-bounces at mailman.qth.net] On Behalf Of Bill Maynard
Sent: Wednesday, December 07, 2016 2:12 PM
To: Southern AZ DX Association E-Mail Reflector
Subject: Re: [SADXA] FW: 40m F layer Propagation DX Corridor Graphic for Phoenix - From W7EXG

I didn’t receive the map ??
Bill  W7ZT  Mesa
> On Dec 7, 2016, at 12:56 AM, Larry Brown <w7lb at earthlink.net> wrote:
> 
> 
> 
> 
> 
> From: Bill Davis [mailto:billdav8 at q.com]
> Sent: Tuesday, December 06, 2016 7:14 PM
> To: W7LB
> Subject: 40m F layer Propagation DX Corridor Graphic for Phoenix - 
> From W7EXG
> 
> 
> 
> Hi Larry,
> 
> 
> 
> Attached is a graphic I presented to the SADXA Group, on the 40m F 
> layer Propagation Corridor. Can you please distribute this email and 
> attachment to the SADXA Group, as they may find value, especially in 
> the next 4 to 6 weeks. I think you have the
> distribution list.   
> 
> 
> 
> Thanks!! Bill
> 
> 
> 
> TO: SADXA Group
> 
> FROM: Bill Davis W7EXG
> 
> 
> 
> Although the attached graphic was developed in My Oct. 20th 
> presentation, I will quickly summarize for those who may not have 
> attended.
> 
> 
> 
> Here are the Key Points:
> 
> 
> 
> A.  40M DAY DX can Occur in the F layer when EMUF < 7.0 MHz < MUF.
> 
> B.  After Sunrise, the EMUF builds slowly, allowing 40m F layer 
> DAYTIME DX along the Terminator, until EMUF exceeds 7.0 MHz.
> 
> C.  Prior to Sunset, the EMUF decays slowly, allowing 40m F layer 
> DAYTIME DX along the Terminator, after EMUF decreases below 7.0 MHz.
> 
> D.  Although the TIME and DISTANCE for 40m F-Layer Propagation is 
> Latitude dependent, trans-equatorial propagation is limited at the 
> Equator to about 2.6 Hrs, or a 40m F-Layer DX DAY Corridor distance of 
> about 2600 mi.
> 
> E.  Although this propagation would appear to be a 40m Day-Time DX 
> Corridor, a 40m Long Path into the DARK side of the Terminator will 
> also emerge from the Antipode into the Long Path 40m DAY region, 
> taking advantage of the 40m Day Corridor.
> 
> F.   In order to keep the 40m DX signals within the +/- 2600 mi
> Propagation Corridor (and low EMUF DAY region), the Great Circle 
> Bearing should be within +/- 38 Degrees of the Sunrise and Sunset 
> Terminator.
> 
> G.  Since the Terminator varies every day, [annually changes +/-
> 23.45 degrees], and the 40m Propagation Corridor changes +/- 38 
> degrees about the Terminator, then the angular region of the +/- 40m 
> Propagation DX Corridor is changing every day.
> 
> H.  The Bearing Map shows two Terminators.
> 
> a.   One Terminator at +23 degrees occurs at SR for Dec. 21st, or
> SS for June 21st. 
> 
> b.   The Second Terminator is at -23 degrees (337 deg) for SS for
> Dec 21st, and SR for June 21st. 
> 
> c.   The Equinox terminators on 3/21 and 9/21 are not shown, but
> both SR and SS Terminators would be shown as a 0 deg to 180 deg line.
> 
> 
> 
> HOW TO READ THIS MAP.
> 
> 
> 
> Note on Dec. 21st, the SR terminator is +23 deg.  Thus, the 40m
> F-layer DX propagation angular range  is from  345 deg to 61 deg.
> (or 241 deg to 165 deg) 
> 
> (Note this covers N/E Africa, EU, and Asia and ZL land)
> 
> 
> 
> Note on Dec. 21st, the SS terminator is -23 deg (or 337 deg).
> Thus, the 40m F-layer DX propagation angular range is from 299 deg
> to 15 deg. (or 195 deg to 119 deg) 
> 
> (Note this covers the Far East, Asia, and South America)
> 
> 
> 
> Note the Angular Range for Dec. 21st, covers 68% of the World, and
> represents the 40m F-Layer DX Opportunity for ONE DAY.. Dec. 21st.
> 
> 
> 
> 
> The Same 40m opportunity occurs on June 21st. 
> 
> 
> 
> Thus, in the Next 4 week time period, there will be an excellent
> opportunity for 40m DX 2.6 Hours before and after the Terminator,
> at SUNRISE and SUNSET.
> 
> 
> 
> I KNOW I DID NOT SAY THERE WOULD BE A QUIZ, BUT THERE IS!!  
> 
> 
> 
> QUESTION: WHAT DOES THE CIRCULAR CIRCUMFERENCE OF THIS BEARING MAP
> REPRESENT?  
> 
> 
> 
> Good Luck with the MUF (> 7.0 MHz) for whatever bearing you chose.
> Path MUF is not always co-operative. 
> 
> 
> 
> Hopefully, someone will get their 40m DX awards in the next 4
> weeks, by hanging out at the Terminators. There will be much to
> hear during this time frame, and perhaps not just on 40m. 
> 
> 
> 
> You may recall, we worked HEARD on 4/2 after Tucson SS to 4:30Z.
> Bands worked were 40mLP, 30m, 20m, and 17m SP. 
> 
> 
> 
> Best 73s, 
> 
> 
> 
> Bill W7EXG
> 
> W7EXG at Q.COM
> 
> 
> 
> 
> 
> ---
> This email has been checked for viruses by Avast antivirus software.
> https://www.avast.com/antivirus
> ______________________________________________________________
> SADXA Website http://www.sadxa.org
> 
> SADXA mailing list
> Home: http://mailman.qth.net/mailman/listinfo/sadxa
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:SADXA at mailman.qth.net
> 
> This list hosted by: http://www.qsl.net
> You can support qsl.net: http://www.qsl.net/donate.html

______________________________________________________________
SADXA Website http://www.sadxa.org

SADXA mailing list
Home: http://mailman.qth.net/mailman/listinfo/sadxa
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:SADXA at mailman.qth.net

This list hosted by: http://www.qsl.net
You can support qsl.net: http://www.qsl.net/donate.html

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus