[Elecraft] Fwd: K4 SDR version

Jim Brown jim at audiosystemsgroup.com
Tue Jul 23 18:34:38 EDT 2019


Hi Wes,

I looked them up on the FCC AM Query page. 
https://www.fcc.gov/media/radio/am-query

The "intermediate detail" listing is the most useful.  KFLF is not in 
the database, but KFLT is.

In addition to power, three other factors affect signal strength. 1) 
Attenuation by groundwave increases a LOT with frequency. KVOI is on the 
low end of the band, KUAZ on the high end. It is so strongly 
frequency-dependent that the FCC technical regs publish ground wave 
curves for every 100 kHz or so. 2) Antenna directivity. All three are 
non-directional daytime, but KFLT is directional at night. 3) Antenna 
height. And, BTW, while KVOI runs 10kW daytime, their license is for 1kW 
night.

When you get a line listing, click on the call to get technical details. 
For KFLT, click on the "Electrical Field Strength pattern plot (PDF)" to 
see the antenna's pattern.

73, Jim K9YC

On 7/23/2019 2:58 PM, Wes wrote:
> KVOI is -7 dBm here on my 40-meter dipole.  On the 160 antenna it's 
> about 3 dB higher but that's folded over for the lightning season,  
> Despite running 7 dB more power and not being a much different 
> distance KUAZ is about 13 dB weaker.  I guess that's why the 
> commercial owner gave it to the U of A, took a tax write off and lets 
> the taxpayers fund it.  KFLF, (50 KW) further away still is -6 dBm.




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