Speg's 2015 Broadcast FM DX Log

Capitalized items are what were heard on the air to identify the station. Distances are in miles.
Red call letters indicate new stations. Tan call letters indicate new stations this year.
Explanation about estimation of critical frequency and electron density is at bottom of page.
Unidentified or unconfirmed list

             2015 Es
Days:                   3
Es Contacts:            7
 Different Stations:    6
 New Stations:          1
States:                 4 (ID MD MT WY)
Canadian Provinces:     0
Mexican States:         0
Countries:              1 (US)

July 27, 2015 (Es) from Norman OK 
Est. Critical Freq: 17.50 MHz.    Est. Electron Density: 3.80 x 10¹² /m³
Brief Es through strong tropo as I arrived at work

 FREQ  CALL      Time  Dist    ST City                  Format         Other information

 95.5  WPGC-fm  808 am 1156    md morningside           rhy top 40

June 29, 2015 (Es) from Norman OK 
Est. Critical Freq: 18.16 MHz.    Est. Electron Density: 4.09 x 10¹² /m³
A quick fade up on way home from work. Also an unid on 94.1

 FREQ  CALL      Time  Dist    ST City                  Format         Other information

 94.3  kbyi     530 pm  969    id rexburg               PUBLIC         BYU RADIO. 

April 18, 2015 (Es) from Norman OK 
Est. Critical Freq: 18.80 MHz.    Est. Electron Density: 4.38 x 10¹² /m³ (based on kchh)

 FREQ  CALL      Time  Dist    ST City                  Format         Other information

 91.1  kofg     525 pm  888    wy cody                  RELIGIOUS      COMING OUT OF LOVE WORTH FINDING SHOW
 94.1  kopr     520 pm 1078    mt butte                 CLASSIC ROCK   WEBSTREAM MATCH
 94.1  krkx     545 pm  926    mt billings              COUNTRY        WEBSTREAM MATCH
 94.3  kbyi     450 pm  969    id rexburg               CLASSICAL      BYU RADIO. RDS
 95.5  kchh     605 pm  915    mt worden                NEWS           RDS. NEWSRADIO

The critical frequency and electron density of the sporadic-E layer are estimated by calculating the minimum values to allow the reflection of the radio waves from the station requiring the highest critical frequency of the broadcast frequencies and distances observed. The following assumptions are used: (1) The height of the Es layer is 105 km, and (2) constant (no tilt), and that (3) the signal is affected only by the Es layer and not the temperature profile or weather in the elevations below the Es layer. Given otherwise similar parameters, the signal needing the highest critical frequency and electron density of the Es layer are those of shorter reflection distances or higher broadcast frequencies. The values listed were derived mathematically, but the 105 km height was used to compare values to the PROPLAB-PRO radio propagation computer program (which agreed reasonably well).