Search found 14 matches

Go to advanced search

by STHboy
Sat Feb 10, 2007 1:59 am
Forum: Main Outdoor Warning Sirens Board
Topic: Really Good Tornado video with Siren
Replies: 15
Views: 11005

That's an interesting video. After watching it I too believe the siren is an STH-10, mainly based on the tone, which is noticeably lower than the 2001s I've heard. Those tend to have a higher pitch despite being 12-port sirens (like the STH-10) because of the DC motor, plus the rotor of the STH-10 i...
by STHboy
Fri Sep 29, 2006 1:43 am
Forum: Main Outdoor Warning Sirens Board
Topic: More ATIs going up
Replies: 22
Views: 15683

That was my point exactly. I forget that sarcasm doesn't always work through text, anyone can interpret it as they see fit. I'm just saying that people seem to have it in their heads that newer = better. I have a couple of radios from 1925 that are very simple machines of wood, metal, bakelite, and...
by STHboy
Sun Sep 24, 2006 5:55 pm
Forum: Main Outdoor Warning Sirens Board
Topic: Windmill powered sirens
Replies: 6
Views: 5331

Yes, straight-line winds can be just as dangerous and destructive as a tornado. If the wind gets above a certain point, I think that an automatic detection device would be a good solution. That's very true. Most Central New York residents will remember the Labor Day Storm of 1998 which caused an es...
by STHboy
Sun Sep 24, 2006 4:13 pm
Forum: Main Outdoor Warning Sirens Board
Topic: A question about a large horn picture from the old forum.
Replies: 8
Views: 6038

Here is the page with the photos of that siren - or whatever it was! Go forward a few images to see both of them. The second one is very odd-looking. My earlier speculation was that they're microwave horns of some sort, or perhaps accoustic sensors. But they look rather foreign compared to even the...
by STHboy
Sat Aug 19, 2006 12:12 am
Forum: Main Outdoor Warning Sirens Board
Topic: ACA Hurricane
Replies: 76
Views: 55344

Do the projectors always rotate, or can they aim them at an area, for example, towards town? It's unusual for a directional siren to have its rotation disabled, but the Thunderbolt's rotator can be disabled manually by a switch in the motor starter cabinet. The operator would set the rotator to &qu...
by STHboy
Thu Aug 10, 2006 2:41 am
Forum: Main Outdoor Warning Sirens Board
Topic: "Resultant" tones caused by dual-toned sirens
Replies: 8
Views: 7960

This is an interesting topic - I had noticed that sound in recordings of dual-tone sirens, notably the one of UVFR's SD10. You have to listen closely to realize that the siren is producing a fourth interval, not an octive between the high tone and the resultant tone. But you really have to get close...
by STHboy
Tue Aug 08, 2006 10:51 pm
Forum: Main Outdoor Warning Sirens Board
Topic: Twin Cities siren activation frequency
Replies: 12
Views: 11078

So if you can figure out what the frequency is is there a possible way to manipulate that frequency? Im just asking I don't plan on doing anything. Most likely not. The data packets heard are probably FSK (Frequency Shift Keying), which requires specialized equipment to interact with. It is an actu...
by STHboy
Mon Aug 07, 2006 6:18 am
Forum: Main Outdoor Warning Sirens Board
Topic: Twin Cities siren activation frequency
Replies: 12
Views: 11078

Thanks for the reply there. I've spent many hours googling over that frequency with no clear result! One site I ran across said all of the Twin Cities sirens were activated by the Hennepin County Sheriff. Then I ran across a frequency marked "Civil Defense" under Hennepin County on RadioRe...
by STHboy
Wed Aug 02, 2006 5:50 am
Forum: Main Outdoor Warning Sirens Board
Topic: Twin Cities siren activation frequency
Replies: 12
Views: 11078

The siren test is tomorrow, and I have yet to get a response. So I'll throw it up again and see if I get a last minute response. I'll be recording the Allertor from Central Park in the St. Anthony district of St. Paul, and will be located across the park so it's not horribly loud. I'm also going to ...
by STHboy
Tue Jul 25, 2006 5:35 am
Forum: Main Outdoor Warning Sirens Board
Topic: Pretty good STL-10 recording
Replies: 5
Views: 5872

Unless my ears are deceiving me, that siren sounds like it doesn't have enough power. I would imagine that's the single-phase version of that siren, which, like the single-phase version of the very similar STH-10, uses a 7.5HP motor rather than the 10HP motor found in the three-phase version of the...

Go to advanced search