I’m still enjoying playing with my homemade 50-inch tunable loop antenna. I attempted to build a metal-free support for it out of wood and PVC (except for screws at the very bottom). However, I was unsatisfied at the lack of ease of rotating the loop, and more importantly, I was unable to detect any benefit of the metal-free support over the aluminum tripod you can see in my earlier post.
The presence of the metal post sticking up into part of the loop is supposed to especially affect the nulling ability of the loop. That is, if you are picking up a station, rotating the antenna 90 degrees should strongly diminish, or eliminate that station allowing you to pick up something else. I did not see any difference (at the 1-2 dB level) in the nulling ability of my antenna when switching between mounts. It could be that my antenna isn’t nulling well enough for this to be an issue (i.e., it’s not symmetric enough, or my pick-up loop isn’t sufficient).
I have two 1000-watt omni-directional transmitters within 2 miles of my home and I can generally reduce their signals as displayed on my SDR software by about 25 dB, and can occasionally hear another station in those “nulls” even though the local signal is still 35+ dB above the noise. During daytime when I only have one station on a frequency, I can null out stations that are less than about 25 dB above the noise level. Hardly anybody on the Internet talks about how much nulling they get, so it’s hard to know if that’s any good. In Section 6B, this page says that 60 dB nulls are possible, but then says that 30 dB nulls of nighttime skywave signals is about the limit.
Anyway…I managed to get lucky with monsoonal thunderstorms this weekend and had two good evening sessions as I start to run out of “easy pickins” and have to work harder to get new stations.
Evening of the 6th local time (into early morning of the 7th), new catches:
570 KLAC, Los Angeles, call at 9:53pm, 5000W, with KNRS nulled out
590 KQNT, Spokane, call at 9:59pm, 5000W; this is a good one at nearly 1000 miles
680 KKYX, San Antonio, weak signal at 10:36pm, 10000W, based on webcast and classic country music
720 WGN, Chicago, call at 11:00pm, 50000W, 1417 miles
760 XEES, Chihuahua CH, weak at 11:14pm, 1000W, counting based on webcast and city mention
790 KFPT, Clovis, weak at 11:29pm, 2500W, based on local ads and format
910 KPOF, Denver, very weak at 12:00am, 1000W, extremely lucky call among
1240 KJAA, Globe, “Jukebox 1240” call at 12:12am, 1000W, only 127 miles away, first station on this freq
1330 KCKM, Mohanans TX, call at 12:30am and mostly clear medium signal, 1000W, surprised to get a good, isolated signal on this from nearly 600 miles away, first station on this freq
1440 KAZG, Scottsdale, call at 12:57am, allegedly just 52W, but only 79 miles away, however, I have to null the 24-hour 1000-watt transmitter on 1450 just 1.8 miles away to get adjacent frequencies; new freq
1480 KPHX, Phoenix, call at 1:00am, 500W
1500 KSTP, St Paul, call of “1500 ESPN” at 1:16am, 50000W, this is easy to identify without full call letters since it’s clear channel and the only 1500 ESPN station; 1256 miles
Evening of the 7th
540 XETX, Nuevo Casas Grande, Chihuahua, 700W, got call letters and “La Ranchera de Paquime” slogan at 9pm; this was really nice because Mexican stations don’t always identify very often and I’m not used to hearing letters spoken in Spanish; had to null out what I presume was XESURF out of Tijuana to get this one
1270 KIML, Gillette WY, call at 9:59pm over a bunch of other stations, 1000W; 770 miles and new freq
1220 KDOW, Palo Alto CA, call at 10:20pm, just 145W nighttime power, had this one earlier, but couldn’t confirm call until now, if the power is correct, that’s a good one at 577 miles; new freq
So, for my current location since August 16th, I’ve logged 152 stations on all but 7 frequencies from 540-1700. (Namely, 1180, 1250, 1340, 1390, 1410, 1460, 1610.)