Tank Pressure Transmitters

[elbicho]

Anyone know the frequencies of the tank pressure transmitters?

 

[sphillips3]

I thought that all RF transmitting devices sold in the US must be registered with the FCC. Normally somewhere on the transmitter there will be an FCC ID number. You can take this number and go to the FCC Office of Engineering and Technology (OET) publicly accessible database and look up the "Grant of Authorization" for the device, which will document the frequency, power output, and type of modulation.

However, I checked my Uwatec Galileo Sol system and nowhere in or on the unit is any FCC registration information. I can't find anything in the FCC database granted to Scubapro or Uwatec, although they may not be the original manufacturer.

This seems a bit strange. Normally FCC Part 15 requires all this information to be provided with the equipment, but there may be an exemption for submersible applications. Need to do more research.

 

[scubafanatic]

All RF transmitting devices sold in the US must be registered with the FCC. Somewhere on the transmitter will be an FCC ID number. You can take this number and go to the FCC Office of Engineering and Technology (OET) publicly accessible database and look up the "Grant of Authorization" for the device, which will document the frequency, power output, and type of modulation.

...that's probably how al-Qaeda figured out to how to hack into the U.S. video drones over Afghanistan........

 

[sphillips3]

According to a Cochran manual I found on a German site:

Cochran uses 250 KHz
Oceanic uses 36 KHz
Uwatec uses 8 KHz

This probably explains why there is no FCC database entry for my Sol - 8KHz is actually an "audio" frequency so is probably exempt from Part 15 authorization requirements (I'm too tired to look it up now). There are entries in the FCC database for the Cochran units (250 KHz is a "radio" frequency).

Hope this helps.

 

[Joe45]

Last weekend I had some issue with my air pressure signal after using my two Ikelite AF35 Autoflash. The "No pressure Signal" Warning was coming up every minute after a picture was taken and sometimes I had a warning that the Pressure signal was lost. Looking to some answers of the frequency of the air transmiters, does anyone knows at what frequency does the Ikelite Strobes works? Does anyone had heard of this issue before? Is there any solution for this issue that anyone know about?

 

[bevansmw]

The reason the freqs are so low is because lower freqs propogate better under water. The lower the freq the better it'll propogate but also requires more power.

Being a Navy electronic tech im familiar with this type of stuff.. I think the manual for mine states the freq range.

Edit: Thought it was in manual, but found FCC ID in manual near the beginning for the Aeris one it's MH8A

Also note all are radio frequencies as it's electromagnetic energy being propogated, audio waves are compression waves - completely different. Just operates in a lower frequency band.

Civilian FM radio operates around 88-100mhz or so (Very High Frequency or VHF band)
Civilian AM is lower around 530-1630khz or .530-1.630Mhz (Medium Frequency or MF band)

30-300khz is considered Low frequency or LF
3-30khz is considered Very Low Frequency or VLF

The ones that were listed are all in the LF or VLF band.

Here's a spectrum chart for a little more info: http://www.adec.edu/tag/spectrum.html

 

[ba_hiker]

According to a Cochran manual I found on a German site:

Cochran uses 250 KHz
Oceanic uses 36 KHz
Uwatec uses 8 KHz

This probably explains why there is no FCC database entry for my Sol - 8KHz is actually an "audio" frequency so is probably exempt from Part 15 authorization requirements (I'm too tired to look it up now). There are entries in the FCC database for the Cochran units (250 KHz is a "radio" frequency).

Hope this helps.

audio is a sound wave, radio is 'electro magnetic' wave a totally different phenomena. both are waves and measured in hertz, but what's 'waving' differs. Ocean waves can be measured in hertz but have a very low frequency. an ocean wave with a 15 sec wavelength is about 0.06 hertz.

I can't remember exactly right now, but there is a power limit too that applies for many frequencies, particularly lower ones, and non commercial uses. I believe its something like 1/10 watts in the am and fm bands. Allows low power 'non-interfering' campus radios etc. Microbroadcasting - Wikipedia, the free encyclopedia Its also used for telemetry purposes (pressure transducers??).