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Author Topic: Near 13205 kHz Phonetic Letters  (Read 2314 times)

Offline 4405486

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Near 13205 kHz Phonetic Letters
« on: April 06, 2010, 1828 UTC »
Using Radio Shack DX-396 RCVR stepped, incramental tunining, no SSB

Here in San Luis Obispo, California, I have:

13205 kHZ in progress 2332-2337 UTC 4/4/10 Fair signal
phonetc letters groups of five

13205 kHz in progress  0004-0008 UTC 4/5/10 Good Signal
phonetic letters groups of five

Closer to 13200 kHZ  0000 UTC 4/6/10  Fair signal
Sounded like short, three phonetic letter call-up; no traffic.

Based upon Audio Files, did resemble E10;however, so far have not found
anything too persuasive in Data Bases.

Times are acurate; Give the frequencies plenty of wiggle room. Think
is SSB.

Worthy of note:

V24 6730 kHz 1430-1441 UTC 4/5/10 Unusually good Signal. Strong through
low noise floor. Near AM Broadcast Band Quality.

V24 6730 kHz 1430-1441 UTC 4/6/10 This is the repeat transmission, what a
difference a day makes. Fair to good signal through moderate noise.

Some sort of pre Solar Weather enhancement on 4/5/10 ?

Offline 4405486

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Re: Near 13205 kHz Phonetic Letters
« Reply #1 on: April 07, 2010, 0239 UTC »
Toggled between 13205 and 13200 again this afternoon, do I have a passband
or what?

Probably much ado about not too much. I could make out phonetic letters and
an occassional number.

Could be anything from the Red Cross to Naval Commercial Shipping.
Could be Air Force; who else works on Easter Sunday?

Probably belongs in the Utility Section, and is good motivator to upgrade my
RCVR.

TNX

Offline Token

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Re: Near 13205 kHz Phonetic Letters
« Reply #2 on: April 07, 2010, 1348 UTC »
Most probably what you are hearing is an "EAM" (Emergency Action Message) or some other transmission as part of the "HF-GCS" (High Frequency Global Communications System).  13200 USB is one of their frequencies.  You will also find them on 4724, 6739, 8992, 11175, 13200, 15016 kHz, all USB, and often multiple frequencies at a given time.  Note that a 13200 USB signal would fall pretty much right between 13200 and 13205 for a 5 kHz tuning step AM only RX.

Re your V24 reports:  V24 often has an excellent path into California until its last couple time slots of the day, around 1530 it starts to fade, the 1620 slot is often marginal.  It has been confused for a broadcast station in the past during its lead-in music.  I also heard (well, recorded anyway, I was at work at that time) both of these transmissions and the one on 04/05 is most representative, the one on 04/06 was weaker than average.  The nice thing about that is you can expect conditions like you had on 04/05 much of the time, particularly during the best time slots, from 1330 to 1530.
T!
Mojave Desert, California USA

Offline 4405486

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Re: Near 13205 kHz Phonetic Letters
« Reply #3 on: April 10, 2010, 1738 UTC »
Thank you for the information. Based upon audio samples, that type of
transmission is what I observed.

Some type of private key, One-time pad encryption in use. I doubt the
Operators know the contents of the message. This is new to me; and
quite an eye-opener. TNX again.

Observed:

M94  6330 kHz  in progress-1404 UTC 4/10/2010  good signal
will listen for possible repeat tomorrow.

V24  5715 kHz 1430-1434 UTC 4/10/2010 poor to fair through noise

V24 6215 kHz 1500-1509 UTC poor through strong noise

RE: V24 6730 kHz 1430-1441  4/5/10 I know you monitor constantly;
I thought it was a stand-out signal for this time of year.

TNX

Offline 4405486

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Re: Near 13205 kHz Phonetic Letters
« Reply #4 on: April 11, 2010, 2108 UTC »
Observed repeat transmission this morning of what to the best of my knowledge is M94.

I have Central California Coast:

M94  6330 kHz 1400-1405 UTC  4/11/2010  Solid
ID 925

Also:

V24 5715 kHz 1430-1435 UTC 4/11/2010 good through noise
co-channel momentarily with jammer 1433 UTC

V24 6215 kHz 1500-1509 UTC 4/11/2010  Strong through noise