Re: [IRCA] Rockworks 4 DXpedition - April 7th
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Re: [IRCA] Rockworks 4 DXpedition - April 7th



No stations above 1600kHz this morning, Guy? 1611 and 1629 were briefly close to audio here for a minute or two.

The noise in your small Flag seems quite bad. A small (4' on a side) ALA100 east-west loop here delivers -115dB (relative to full scale on the NetSDR) below 520kHz, and -105dB above 1700kHz. KAPS-660, right in line with the loop is at -65dB. My full scale east-west FLG100 shows -100dB noise both above and below the MW band, and KAPS is at about -40dB when not nulled. (sorry, I don't have a Perseus here for direct comparison with your observations)

So the Flag has at least 25dB more oomph, but nothing like that much extra noise. (a 50 ohm dummy delivers about -120dB noise floor).

I wonder where your extra noise is coming from?

best wishes,

Nick


At 20:08 07-04-14, you wrote:
This morning brought somewhat better DX results at the Rockworks 4 cliff,
although we've come to expect MUCH better when DXing at the coast. See
below for my meager catch of three TPs and four Kiwi stations.

A return to the ALA100M electronics that I used in November made my loop
antenna work as it should. A check that Perseus owners sometimes make when
evaluating antennas and the band noise is to look at the noise level at
1720 kHz with the full 2000 kS/s sampling rate and 1600 kHz span.
Yesterday's small Flag loop registered a pathetic -85 dBM on 1720 kHz,
while the ALA100M used this morning showed a -100 dBm noise level. This is
approaching the low -110 dBm noise floor that I find on DXpeditions using
much larger antennas (usually phased delta Flag arrays with 40m spacing).

David Aichelman in Arizona mentioned to me after my antenna comments
yesterday that he's always had noise problems with remotely terminated
loops. Perhaps that is what was going on with the unacceptable noise level.
One thing I have not tried is a pot or resistor wired directly on the
vehicle-mounted Flag loop; David says that a direct connection always works
better for him. I plan to stick with the ALA100M bi-directionl loop for
tomorrow's DXing session though.

Here is a link to a folder of pictures (with captions) of the antenna, plus
a couple others:

https://app.box.com/s/40gppjhyv5h6run75zqe


My loggings from April 7th:
---------------------------------------------------------------------

594 JAPAN JOAK NHK1, Tokyo, Apr 07 1312 - Japanese talk by male and female.
Weak signal. (Atkins-OR)

765 NEW ZEALAND R Kahungunu, Napier-Hastings, Apr 07 1301 - Male and female
in Maori. Fair level and strengthening. (Atkins-OR)

1008 NEW ZEALAND Newstalk ZB, Tauranga, Bay of Plenty, Apr 07 1256 - talk
in English by male announcers and mentions of Auckland. Fading down before
TOH. Back up 1302, with string of ads mentioning Otago, Auckland, and other
NZ cities. "Newstalk ZB" ID at 1305. Poor at tune-in but improving nicely.
(Atkins-OR)

1035 NEW ZEALAND Newstalk ZB, Wellington, Apr 07 1253 - Only audible for a
couple of minutes 1253-1254, upon review of Perseus recording. Low level
audio of Kiwi-accented male reading some numbers and a schedule of some
sort. Probably parallel to 1008 Newstalk ZB, but 1008 hadn't yet faded up.
Poor signal, and tentative. (Atkins-OR)

1503 NEW ZEALAND R Sport, Wellington, Apr 07 1327 - Mostly poor with male
talking in English and mentions of "Sports Radio". (Atkins-OR)

1566 SOUTH KOREA HLAZ FEBC, Jeju, Jeju-do, Apr 07 1308 - Very good signal
with slow hymn in Japanese. (Atkins-OR)

1575 THAILAND VOA, Ban Phachi, Ayutthaya, Apr 07 1337 - Weak signal of
female talk in SE Asian language; PAL lists Khmer at this time. (Atkins-OR)

73,

Guy Atkins
Puyallup, WA
DXing at Rockworks 4 Cliff, Oregon coast
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