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Monday, September 10, 2018

Radio Calculator Program v1.0015

In the process of developing the Radio Data MW program (the program that creates those neat HTML mediumwave pattern maps available at the upper right), I needed some way to convert values back and forth to check accuracy of calculations. Conversions like watts to dBw, mV/m to dBu, microvolts to dBm, etc. I came up with a little calculator "app" that satisfied the need, and called it Radio Calculator. I present it here for your download and use.

Questions about how dB relates to ratio of values (both watts and voltage), passive loop antenna output, wavelength, radio horizon, field strength, and even sine and cosine tables are all covered in a simple to use format.

The program is written in the old standby Visual Basic. It's been tested on Windows 7 through Windows 10.

Install is simple. Download the file from the link at the upper right of this page, unzip, and run the RadioCalculator.exe file. The file is small at 22 KB. There are no special requirements.

I hope you enjoy it and can make use of it.

Some screenshots:

Decibels and Ratio Conversions

Field Strength Conversions

Voltage and Power Conversions

Passive Loop and Antenna Factor Calculations

Wavelength Information

Various Tables, Including Sine and Cosine

Friday, September 7, 2018

Early Fall Conditions Improve

KMON-560 Great Falls, Montana Logged

Logged KMON-560 (5 KW) Great Falls, MT overnight at 01:00 AM local, 08:00 GMT. Also dancing around in there was KSFO-560 (5 KW), San Francisco, CA. I'm in the pattern null of both of these. Although KSFO is fairly routine, I'm surprised at hearing KMON. They're only delivering about 67 watts to me in that notch. Maybe on day power? Will try again tonight. Really hoping to hear Beaumont, TX KLVI-560 (5 KW) one of these days. I'm just a little off the main western lobe. Denver's KLZ-560 usually dominates all.

Japan JOUB-774 Makes The Trip This Morning

Japan JOUB-774 was in there at the local 06:00 hour, 13:00 GMT. Weak audio and time pips at the top of the hour. Just before sunrise in SW Arizona.

Heard on my new Sangean ATS-909X barefoot. I find the sensitivity on the Sangean to be excellent as opposed to some of the reviews. The AGC is a bit overly sensitive, but if you ride the RF gain down a bit it settles down. Old tech, the Sangean, I know, but I'm a happy late purchaser. Superb audio too.

Monday, July 9, 2018

The Good Old Days Of Mediumwave DXing

The blog has been lying low for quite awhile. Time allowing, I'd like to present some new ideas.

I occasionally hear talk of the "good old days" of mediumwave DXing, usually referring to back in the 1960s and earlier. The talk is of nightly cross-country DX, of hearing Los Angeles on the east coast, of foreign stations as a regular occurrence. Usually it gets around to a discussion of how fewer stations were on the mediumwave band in those days. I always wondered what a comparison would look like.

Recently, I came across a 1941 Stephenson's Radio Bulletin on a great site called American Radio History:

https://www.americanradiohistory.com/index.htm

They have scanned many articles and magazines from all eras of radio history, back to the 1920s.

I decided to tabulate the 1941 list of mediumwave stations against today's 2108 list and see what it looks like. This has been a project idea I've been thinking about for a long time. I just haven't been able to get a station list with the data readably usable, so I decided to write some code to extract it.

Presented below is the mediumwave radio world of 1941 compared to today's 2018. The 2018 US station counts are all nighttime stations only, at current nighttime power levels. The 1941 station data includes all stations from that year (tabulated in January, 1941). Less than 10% are restricted in their nighttime use of power , a few are daytimers only. That just means there would be even less interference than what can be extrapolated from the table.

So, were these the good old days? I would say so. In 1941 we only had about 31% of the RF wattage flying around at night. There were a total of 833 stations transmitting at night, as opposed to the approximately 4058 transmitting at night tonight. What the table doesn't show is that the stations transmitting at night in 1941 generally transmitted at a higher power than those of today, Fewer stations at higher powers = better DX.

 -----1941-2018 DIFFERENCES ON THE MEDIUM WAVES-----

 530  (2018) #Stations =   0    TotalWatts =       0
      (1941) #Stations =   0    TotalWatts =       0

 540  (2018) #Stations =  20    TotalWatts =  49,620
      (1941) #Stations =   0    TotalWatts =       0

 550  (2018) #Stations =  24    TotalWatts =  77,923
      (1941) #Stations =   9    TotalWatts =  33,000

 560  (2018) #Stations =  23    TotalWatts =  60,320
      (1941) #Stations =   9    TotalWatts =  33,000

 570  (2018) #Stations =  19    TotalWatts =  53,379
      (1941) #Stations =   9    TotalWatts =  24,250

 580  (2018) #Stations =  24    TotalWatts =  97,298
      (1941) #Stations =   7    TotalWatts =  31,000

 590  (2018) #Stations =  27    TotalWatts =  61,390
      (1941) #Stations =   5    TotalWatts =  17,000

 600  (2018) #Stations =  23    TotalWatts =  55,021
      (1941) #Stations =   5    TotalWatts =  17,000

 610  (2018) #Stations =  27    TotalWatts =  67,795
      (1941) #Stations =   7    TotalWatts =  26,500

 620  (2018) #Stations =  23    TotalWatts =  68,577
      (1941) #Stations =  11    TotalWatts =  38,250

 630  (2018) #Stations =  25    TotalWatts =  55,374
      (1941) #Stations =   6    TotalWatts =  17,200

 640  (2018) #Stations =  15    TotalWatts =  71,660
      (1941) #Stations =   3    TotalWatts =  55,500

 650  (2018) #Stations =   8    TotalWatts = 113,420
      (1941) #Stations =   1    TotalWatts =  50,000

 660  (2018) #Stations =  12    TotalWatts = 125,179
      (1941) #Stations =   2    TotalWatts =  50,500

 670  (2018) #Stations =   9    TotalWatts = 121,003
      (1941) #Stations =   1    TotalWatts =  50,000

 680  (2018) #Stations =  20    TotalWatts = 226,216
      (1941) #Stations =   3    TotalWatts = 102,500

 690  (2018) #Stations =  19    TotalWatts =  53,274
      (1941) #Stations =   0    TotalWatts =       0

 700  (2018) #Stations =   8    TotalWatts =  73,690
      (1941) #Stations =   1    TotalWatts =  50,000

 710  (2018) #Stations =  15    TotalWatts = 201,560
      (1941) #Stations =   3    TotalWatts =  65,000

 720  (2018) #Stations =   6    TotalWatts = 111,286
      (1941) #Stations =   1    TotalWatts =  50,000

 730  (2018) #Stations =  29    TotalWatts =   4,714
      (1941) #Stations =   0    TotalWatts =       0

 740  (2018) #Stations =  28    TotalWatts = 196,021
      (1941) #Stations =   4    TotalWatts =  52,250

 750  (2018) #Stations =   8    TotalWatts = 139,630
      (1941) #Stations =   2    TotalWatts =  52,500

 760  (2018) #Stations =  11    TotalWatts = 119,771
      (1941) #Stations =   4    TotalWatts =  57,000

 770  (2018) #Stations =  10    TotalWatts = 122,180
      (1941) #Stations =   2    TotalWatts =  60,000

 780  (2018) #Stations =   8    TotalWatts = 115,049
      (1941) #Stations =   9    TotalWatts =  29,750

 790  (2018) #Stations =  41    TotalWatts =  60,498
      (1941) #Stations =   3    TotalWatts =  58,500

 800  (2018) #Stations =  29    TotalWatts =  16,513
      (1941) #Stations =   2    TotalWatts = 100,000

 810  (2018) #Stations =  16    TotalWatts = 207,678
      (1941) #Stations =   2    TotalWatts =  51,000

 820  (2018) #Stations =  12    TotalWatts =  73,335
      (1941) #Stations =   1    TotalWatts =  50,000

 830  (2018) #Stations =  11    TotalWatts = 154,750
      (1941) #Stations =   4    TotalWatts =  57,000

 840  (2018) #Stations =  10    TotalWatts =  83,105
      (1941) #Stations =   0    TotalWatts =       0

 850  (2018) #Stations =  17    TotalWatts = 229,930
      (1941) #Stations =   4    TotalWatts =  56,250

 860  (2018) #Stations =  27    TotalWatts =  81,799
      (1941) #Stations =   2    TotalWatts =  51,000

 870  (2018) #Stations =   9    TotalWatts =  63,500
      (1941) #Stations =   2    TotalWatts = 100,000

 880  (2018) #Stations =  16    TotalWatts = 132,022
      (1941) #Stations =  12    TotalWatts =  15,250

 890  (2018) #Stations =  11    TotalWatts =  83,810
      (1941) #Stations =   8    TotalWatts =  27,500

 900  (2018) #Stations =  42    TotalWatts =  16,948
      (1941) #Stations =  11    TotalWatts =  30,000

 910  (2018) #Stations =  48    TotalWatts = 103,992
      (1941) #Stations =   0    TotalWatts =       0

 920  (2018) #Stations =  43    TotalWatts =  51,396
      (1941) #Stations =   8    TotalWatts =  19,500

 930  (2018) #Stations =  48    TotalWatts =  61,745
      (1941) #Stations =   5    TotalWatts =  16,500

 940  (2018) #Stations =  31    TotalWatts = 102,952
      (1941) #Stations =   7    TotalWatts =  27,000

 950  (2018) #Stations =  42    TotalWatts = 175,799
      (1941) #Stations =   4    TotalWatts =  15,500

 960  (2018) #Stations =  43    TotalWatts =  65,320
      (1941) #Stations =   0    TotalWatts =       0

 970  (2018) #Stations =  50    TotalWatts =  84,713
      (1941) #Stations =   3    TotalWatts =  11,000

 980  (2018) #Stations =  43    TotalWatts =  77,055
      (1941) #Stations =   1    TotalWatts =  50,000

 990  (2018) #Stations =  37    TotalWatts =  57,793
      (1941) #Stations =   2    TotalWatts =  51,000

1000  (2018) #Stations =   8    TotalWatts = 107,940
      (1941) #Stations =   2    TotalWatts =  51,000

1010  (2018) #Stations =  33    TotalWatts =  97,098
      (1941) #Stations =   5    TotalWatts =  17,000

1020  (2018) #Stations =  11    TotalWatts = 164,600
      (1941) #Stations =   2    TotalWatts =  51,000

1030  (2018) #Stations =  16    TotalWatts = 123,103
      (1941) #Stations =   0    TotalWatts =       0

1040  (2018) #Stations =  10    TotalWatts =  68,113
      (1941) #Stations =   4    TotalWatts = 100,750

1050  (2018) #Stations =  45    TotalWatts =  67,845
      (1941) #Stations =   4    TotalWatts =  61,000

1060  (2018) #Stations =  20    TotalWatts =  70,437
      (1941) #Stations =   3    TotalWatts =  61,000

1070  (2018) #Stations =  21    TotalWatts = 110,877
      (1941) #Stations =   3    TotalWatts =  50,600

1080  (2018) #Stations =  16    TotalWatts = 145,216
      (1941) #Stations =   3    TotalWatts =  60,000

1090  (2018) #Stations =  10    TotalWatts = 157,238
      (1941) #Stations =   1    TotalWatts =  50,000

1100  (2018) #Stations =   8    TotalWatts = 115,240
      (1941) #Stations =   5    TotalWatts =  72,000

1110  (2018) #Stations =  10    TotalWatts = 141,012
      (1941) #Stations =   2    TotalWatts =  55,000

1120  (2018) #Stations =   9    TotalWatts = 103,705
      (1941) #Stations =  13    TotalWatts =  13,350

1130  (2018) #Stations =  18    TotalWatts = 164,484
      (1941) #Stations =   2    TotalWatts =  70,000

1140  (2018) #Stations =  14    TotalWatts = 150,746
      (1941) #Stations =   2    TotalWatts =  30,000

1150  (2018) #Stations =  48    TotalWatts = 113,462
      (1941) #Stations =   1    TotalWatts =  50,000

1160  (2018) #Stations =  25    TotalWatts = 126,221
      (1941) #Stations =   2    TotalWatts =  15,000

1170  (2018) #Stations =  13    TotalWatts = 139,368
      (1941) #Stations =   1    TotalWatts =  50,000

1180  (2018) #Stations =  14    TotalWatts =  80,935
      (1941) #Stations =   3    TotalWatts =  56,000

1190  (2018) #Stations =  20    TotalWatts = 103,867
      (1941) #Stations =   1    TotalWatts =  50,000

1200  (2018) #Stations =  14    TotalWatts = 148,070
      (1941) #Stations =  72    TotalWatts =  16,350

1210  (2018) #Stations =  19    TotalWatts =  98,977
      (1941) #Stations =  68    TotalWatts =  14,750

1220  (2018) #Stations =  43    TotalWatts =  55,519
      (1941) #Stations =  10    TotalWatts =  28,250

1230  (2018) #Stations = 164    TotalWatts = 156,357
      (1941) #Stations =   7    TotalWatts =  23,000

1240  (2018) #Stations = 154    TotalWatts = 148,812
      (1941) #Stations =   5    TotalWatts =  11,750

1250  (2018) #Stations =  52    TotalWatts =  65,657
      (1941) #Stations =   9    TotalWatts =  21,000

1260  (2018) #Stations =  51    TotalWatts =  90,041
      (1941) #Stations =  10    TotalWatts =  25,250

1270  (2018) #Stations =  53    TotalWatts = 114,009
      (1941) #Stations =   9    TotalWatts =  17,700

1280  (2018) #Stations =  52    TotalWatts =  53,333
      (1941) #Stations =   8    TotalWatts =  17,250

1290  (2018) #Stations =  48    TotalWatts =  83,100
      (1941) #Stations =   9    TotalWatts =  25,700

1300  (2018) #Stations =  59    TotalWatts = 130,076
      (1941) #Stations =   9    TotalWatts =  21,000

1310  (2018) #Stations =  55    TotalWatts =  66,965
      (1941) #Stations =  69    TotalWatts =  15,550

1320  (2018) #Stations =  56    TotalWatts =  72,802
      (1941) #Stations =   6    TotalWatts =  21,500

1330  (2018) #Stations =  53    TotalWatts =  84,399
      (1941) #Stations =   8    TotalWatts =  23,500

1340  (2018) #Stations = 163    TotalWatts = 154,407
      (1941) #Stations =   9    TotalWatts =  16,250

1350  (2018) #Stations =  56    TotalWatts =  48,789
      (1941) #Stations =   6    TotalWatts =  19,000

1360  (2018) #Stations =  58    TotalWatts =  58,040
      (1941) #Stations =   8    TotalWatts =  10,750

1370  (2018) #Stations =  53    TotalWatts =  87,796
      (1941) #Stations =  81    TotalWatts =  18,350

1380  (2018) #Stations =  58    TotalWatts = 129,410
      (1941) #Stations =   5    TotalWatts =   9,000

1390  (2018) #Stations =  54    TotalWatts =  78,856
      (1941) #Stations =   6    TotalWatts =  18,000

1400  (2018) #Stations = 175    TotalWatts = 170,415
      (1941) #Stations =   6    TotalWatts =  16,500

1410  (2018) #Stations =  56    TotalWatts =  53,636
      (1941) #Stations =   8    TotalWatts =   9,500

1420  (2018) #Stations =  61    TotalWatts =  53,262
      (1941) #Stations =  61    TotalWatts =  13,450

1430  (2018) #Stations =  57    TotalWatts =  97,857
      (1941) #Stations =   8    TotalWatts =  20,000

1440  (2018) #Stations =  56    TotalWatts =  44,551
      (1941) #Stations =   7    TotalWatts =  13,500

1450  (2018) #Stations = 175    TotalWatts = 167,406
      (1941) #Stations =   7    TotalWatts =  15,000

1460  (2018) #Stations =  65    TotalWatts =  77,316
      (1941) #Stations =   2    TotalWatts = 100,000

1470  (2018) #Stations =  47    TotalWatts =  62,378
      (1941) #Stations =   3    TotalWatts =  15,000

1480  (2018) #Stations =  63    TotalWatts =  72,040
      (1941) #Stations =   3    TotalWatts =  15,000

1490  (2018) #Stations = 182    TotalWatts = 174,560
      (1941) #Stations =   2    TotalWatts =  60,000

1500  (2018) #Stations =  13    TotalWatts = 121,038
      (1941) #Stations =  62    TotalWatts =  14,450

1510  (2018) #Stations =  12    TotalWatts = 144,770
      (1941) #Stations =   0    TotalWatts =       0

1520  (2018) #Stations =  18    TotalWatts = 196,492
      (1941) #Stations =   0    TotalWatts =       0

1530  (2018) #Stations =  11    TotalWatts = 110,763
      (1941) #Stations =   3    TotalWatts =   3,000

1540  (2018) #Stations =  23    TotalWatts = 149,357
      (1941) #Stations =   0    TotalWatts =       0

1550  (2018) #Stations =  50    TotalWatts =  41,851
      (1941) #Stations =   2    TotalWatts =   6,000

1560  (2018) #Stations =  19    TotalWatts =  90,638
      (1941) #Stations =   0    TotalWatts =       0

1570  (2018) #Stations =  55    TotalWatts =  28,476
      (1941) #Stations =   0    TotalWatts =       0

1580  (2018) #Stations =  43    TotalWatts = 109,951
      (1941) #Stations =   0    TotalWatts =       0

1590  (2018) #Stations =  59    TotalWatts =  63,336
      (1941) #Stations =   0    TotalWatts =       0

1600  (2018) #Stations =  58    TotalWatts =  96,127
      (1941) #Stations =   0    TotalWatts =       0

Total watts 2018 = 10,829,145
Total watts 1941 =  3,389,200

If you want a good example of present-day nighttime confusion, one only has to look at a single channel, perhaps one of the worst. 1490 KHz, one of our US graveyard channels has 182 stations transmitting all at once. The results are shown below. Reception contours are set to the 0.1 mV/m level, a level which should generate signal in even the most marginal receiver, within range.

Good days must be ahead.

The Graveyard (and only part of it). 1490 KHZ