My wife found this book at a yard sale this morning.
Shortwave Receivers Past & Present: Communications Receivers 1942-1997 [Paperback]
VOA is heard by more than 93 million people in more than fifty languages. This book is an "insider´s story", reflecting the transformation of VOA from a propaganda organ to a more respected source of information, from shortwave in World War II to multimedia in the twenty-first century.
The author, Alan L. Heil, worked at the VOA as foreign correspondent, senior manager, and deputy director from 1962 until his retirement in 1998.
Buy this Book Today!
or read more about it...
Friday, September 16, 2011
Subscribe to:
Posts (Atom)
My Stamp Collecting Blog
Counter Added January 1, 2011
HOW TO READ PROPAGATION NUMBERS
The A index [ LOW is GOOD ]
- 1 to 6 is BEST
- 7 to 9 is OK
- 11 or more is BAD
Represents the overall geomagnetic condition of the ionosphere ("Ap" if averaged from the Kp-Index) (an average of the eight 3-hour K-Indices) ('A' referring to amplitude) over a given 24 hour period, ranging (linearly) typically from 1-100 but theoretically up to 400.
A lower A-Index generally suggests better propagation on the 10, 12, 15, 17, & 20 Meter Bands; a low & steady Ap-Index generally suggest good propagation on the 30, 40, 60, 80, & 160 Meter Bands.
SFI index [ HIGH is GOOD ]
- 70 NOT GOOD
- 80 GOOD
- 90 BETTER
- 100+ BEST
The measure of total radio emissions from the sun at 10.7cm (2800 MHz), on a scale of 60 (no sunspots) to 300, generally corresponding to the sunspot level, but being too low in energy to cause ionization, not related to the ionization level of the Ionosphere.
Higher Solar Flux generally suggests better propagation on the 10, 12, 15, 17, & 20 Meter Bands; Solar Flux rarely affects the 30, 40, 60, 80, & 160 Meter Bands.
K index [ LOW is GOOD ]
- 0 or 1 is BEST
- 2 is OK
- 3 or more is BAD
- 5 is VERY VERY BAD
The overall geomagnetic condition of the ionosphere ("Kp" if averaged over the planet) over the past 3 hours, measured by 13 magnetometers between 46 & 63 degrees of latitude, and ranging quasi-logarithmically from 0-9. Designed to detect solar particle radiation by its magnetic effect. A higher K-index generally means worse HF conditions.
A lower K-Index generally suggests better propagation on the 10, 12, 15, 17, & 20 Meter Bands; a low & steady Kp-Index generally suggest good propagation on the 30, 40, 60, 80, & 160 Meter Bands.
Terms of Service
[In accordance with Title 17 U.S.C. Section 107, this material is distributed without profit, for research and/or educational purposes. This constitutes 'FAIR USE' of any such copyrighted material.]
I am not responsible for any thing that happens to your mental health, computer and all personal property because you visited my site.
This site is a collection of some things sent to me by e-mail, obtained from other blogs and the internet. If there is a picture or quote that is copyrighted to you let me know and I will remove your item .
Thoughts expressed in my blog are just that . I give My Opinion on the many events, products and how too, reported by the media and other web-sites.
Do not use this blog site to obtain weather events or disasters information. What I post may not be correct. Always get information from the proper media, weather (NWS)(NOAA)
Pacific Tsunami Warning Center and USGS sites
I am not responsible for any thing that happens to your mental health, computer and all personal property because you visited my site.
This site is a collection of some things sent to me by e-mail, obtained from other blogs and the internet. If there is a picture or quote that is copyrighted to you let me know and I will remove your item .
Thoughts expressed in my blog are just that . I give My Opinion on the many events, products and how too, reported by the media and other web-sites.
Do not use this blog site to obtain weather events or disasters information. What I post may not be correct. Always get information from the proper media, weather (NWS)(NOAA)
Pacific Tsunami Warning Center and USGS sites
