HFU HF Underground

Loggings => Utility => Topic started by: Land5urfer on April 03, 2013, 1855 UTC

Title: EAM Activity on 3 Frequencies
Post by: Land5urfer on April 03, 2013, 1855 UTC: This morning between 1143 - 1154 Z, Offutt AFB transmitted, I believe, the same 30 character message on USB frequencies: 11175, 4724, and 8992.

8992 was as clear as usual in SW Ontario, but the other two were just barely audible.
Title: Re: EAM Activity on 3 Frequencies
Post by: Token on April 03, 2013, 1931 UTC: The "typical" (many times a day) frequencies for simultaneous EAMs are 4724, 6739, 8992, 11175, 13200, and 15016 kHz, all 6 carrying the same audio. These are not the only frequencies that might carry parallel EAM transmissions, they are just the most common. How clearly you hear each frequency will depend on propagation. How many echos you hear in a transmission, and how deep they are, will also depend on propagation.

When the source is airborne the maximum number of frequencies can be smaller, depending on the platform. Some aircraft types only support 3 or 4 parallel networks / transmissions on HF. When the source is airborne you might also find the same EAM on UHF.

T!
Title: Re: EAM Activity on 3 Frequencies
Post by: Land5urfer on April 04, 2013, 1703 UTC: Quote from: Token on April 03, 2013, 1931 UTC
The "typical" (many times a day) frequencies for simultaneous EAMs are 4724, 6739, 8992, 11175, 13200, and 15016 kHz, all 6 carrying the same audio. These are not the only frequencies that might carry parallel EAM transmissions, they are just the most common. How clearly you hear each frequency will depend on propagation. How many echos you hear in a transmission, and how deep they are, will also depend on propagation.

When the source is airborne the maximum number of frequencies can be smaller, depending on the platform. Some aircraft types only support 3 or 4 parallel networks / transmissions on HF. When the source is airborne you might also find the same EAM on UHF.

T!

Thanks for your insight, Token.

It seems EAMs are a lot more abundant in light of the N. Korea situation.

Land5urfer, out.
Title: Re: EAM Activity on 3 Frequencies
Post by: 07code04stalker1776 on April 04, 2013, 1811 UTC: Land5urfer Land5urfer This is 07code04stalker1776 ;D I did copy Offutt calling McClellan around 1340z
Title: Re: EAM Activity on 3 Frequencies
Post by: skeezix on April 05, 2013, 0005 UTC: Can also catch some unencoded EAMs on 6925 kHz.
Title: Re: EAM Activity on 3 Frequencies
Post by: glimmer twin on April 07, 2013, 1314 UTC: the 6925 EAMs are by far the most interesting ones
Title: Re: EAM Activity on 3 Frequencies
Post by: Land5urfer on April 07, 2013, 1537 UTC: Thanks for the 6925 tip, guys.
Title: Re: EAM Activity on 3 Frequencies
Post by: 07code04stalker1776 on April 07, 2013, 1940 UTC: 6925 as in a pirate radio station?
Title: Re: EAM Activity on 3 Frequencies
Post by: desmoface on April 07, 2013, 2037 UTC: I was just minding my own bidness, trying to come to grips with using my new sdr and it's software, when out of the blue, I come upon this:

http://www.youtube.com/watch?v=DYH5zPPVFWc

As you can tell (at around the 1:20 mark), I'm still learning how to tune this wacky thing, LOL. You crazy kids, you.

Steve
Title: Re: EAM Activity on 3 Frequencies
Post by: skeezix on April 07, 2013, 2122 UTC: What was on 14940?
Title: Re: EAM Activity on 3 Frequencies
Post by: desmoface on April 07, 2013, 2143 UTC: 14940?

Steve
Title: Re: EAM Activity on 3 Frequencies
Post by: 07code04stalker1776 on April 09, 2013, 0213 UTC: McClellan gave a message of 39 characters followed by a message of 114 characters earlier. A lot of long messages today.
Title: Re: EAM Activity on 3 Frequencies
Post by: Land5urfer on April 09, 2013, 2346 UTC: Quote from: 07code04stalker1776 on April 09, 2013, 0213 UTC
McClellan gave a message of 39 characters followed by a message of 114 characters earlier. A lot of long messages today.

Good catch! Can you recall the time and frequency of both messages?
Title: Re: EAM Activity on 3 Frequencies
Post by: skeezix on April 10, 2013, 2250 UTC: Quote from: desmoface on April 07, 2013, 2143 UTC
14940?

Steve

In the video, there was a carrier on 14940 and his 2nd VFO was set to that as well.
Title: Re: EAM Activity on 3 Frequencies
Post by: desmoface on April 11, 2013, 0030 UTC: Ahhh, very observant.. Took a while for me to figure that out, LOL. There wasn't anything there worth mentioning.

Steve