DavidEduardo said:
vibe said:
Great catch!! I'm thinking that w/ all the clutter on the AM Band the theoretical limit for long distance AM reception w/o any unusual antenna setup is about 1800-2000 mi.
From the West Coast it is quite easy to get Australians, New Zealand stations and quite a few Chnese, Philippine and other Asian stations which operate on the 9 kHz separation system... even thinks like Kota Kinabalu, Malaysia, on 1475 has been a visitor for decades since it was activated in the early 70's.
How do you do this? I know my standards of radio reception aren't the same as yours - for example I can just about pick something out from under the noise, while you like probably at least a 75dB signal to noise ratio (or whatever the 10mV/m you mention provides), but I still have yet to log ANYTHING from across the Pacific. I'm near 32°45'40"N 116°56'50"W, btw, using a cheap portable radio (Panasonic RQ-SW10). I also have a Select-A-Tenna, but even with that haven't logged anything.
I do have quite a few strong locals, for example 600, 690, 800, 860, 910, 1040, 1170, 1210, 1240, 1360, 1470, 1700 which all splatter fairly strong +/- 10kHz, weak +/- 20kHz (also 760 in the daytime), plus 760 nighttime and 1130 which splatter strong +/- 2 channels and somewhat weaker +/- 3 channels. Stations that are barely receivable (fringe) for me using the radio's built-in antenna are 670 KIRN, 870 KRLA, 930 KHJ, 970 KNWZ, 980 KFWB, 1020 KTNQ, 1050 XED, 1110 KDIS (note: inaudible due to 1130's splatter, if 1130 is off then I can hear it a little better), 1190 from L.A. area, 1290 from Santa Barbara, 1320 KKSM, 1340 from Santa Barbara, 1520 KVTA.
Any suggestions on how to log these stations? I can switch my radio to 9kHz tuning increments, but even that doesn't bring them in. I wonder if my radio's selectivity is just too poor for where I am when I'm trying to log the trans-Pacific stations...
Also you've mentioned something about a minimum 10mV/m field strength for reception in L.A. Does that mean on a cheap portable radio from inside a shielded metal building, with 100s of computers, fluorescent lights, etc, on, with a 90dB signal-to-noise ratio on the station on your radio, or what DOES it mean? Also, what are your estimates for minimum field strength for clear reception or fringe reception in a rural area?
Last night, btw, I was listening to KMIK from Tempe, AZ, and that station was coming in as strong as I've ever heard them. Using only the radio's built-in antenna, it was lighting the tuning indicator on the adjacent channel, something only a few locals, like KOGO, XETRA (unless they've changed their calls), KFMB, KECR, KSDO, KCBQ, and KLSD do. (I don't have the software installed now, but I've looked at field strength for some of the locals I just mentioned, and at my location it's about 10mV/m. Is it possible that KMIK's skywave signal at the time was that strong?) There was hardly if any trace of KBLA Santa Monica. Now, if I could figure out what antenna system to use to get that good reception in the daytime from my location.... Bruce Carter, which loop antenna should I build?
