[PSUBS-MAILIST] (no subject)

Thu Jan 10 14:20:44 EST 2019

Just to be clear, these units employ ultrasonic acoustic transmission through water, and not radio, which is electromagnetic radiation and rapidly attenuated in water.

You're boosting 12 VDC to 24 VDC with some sort of DC-DC converter? What is your 12 V source? The boat battery? Engine running may actually be better in that scenario, because the battery should be charging at higher than nominal voltage. Once you shut the engine off, you're relying entirely on the chemical potential of the battery, which could fall below nominal quickly if it's nearing the end of it's useful service life.

Check the voltage with a multimeter, both upstream and downstream of the converter.

If that is the culprit, the best way forward is probably to replace the engine alternator with one which outputs 24 Volts, use two 12V batteries in series, and eliminate the converter.

Sean

-------- Original Message --------
On Jan 10, 2019, 12:07, hank pronk via Personal_Submersibles wrote:

> Sean,  now that mention that, I have a battery  powering the electric motor connected to the radio with a power converted that converts 12v to 24 v.  I just asked my wife if they were motoring while talking and they may have been.  That means there could have been a voltage drop to the radio.  Could that be the culprit?
> Hank
>
> On Thursday, January 10, 2019, 12:00:01 PM MST, Sean T. Stevenson via Personal_Submersibles <personal_submersibles at psubs.org> wrote:
>
> I'm suspecting the available transmit power of the surface unit as the culprit here.
>
> Sean
>
> -------- Original Message --------
> On Jan 10, 2019, 11:46, hank pronk via Personal_Submersibles < personal_submersibles at psubs.org> wrote:
>
>>
>
> Sean, on 27 kHz the radio is crystal clear but at 225 feet, the surface radio can hear me clearly but in she sub it was very clear but super quiet.  I am assuming that I need to get onto the 10khz side for range.  Unfortunately Gamma came with the wrong paperwork for the come.  I ended up with Delta's paperwork and the radios are different.  The link you sent shows a very similar radio and it says 3km for the 27 kHz side, so this makes me wonder if I have a simple problem with my 27 kHz side.
> I have no clue if it is strait frequency.  I can look in my paperwork to see if there is anything at all.
> Mine has a pinger also
> Hank
>
> On Thursday, January 10, 2019, 10:11:27 AM MST, Sean T. Stevenson via Personal_Submersibles <personal_submersibles at psubs.org> wrote:
>
> This would be the direct successor to your unit:
>
> https://www.subsea-import.com/subphone-580---580tx.html
>
> Sean
>
> -------- Original Message --------
> On Jan 10, 2019, 09:53, hank pronk via Personal_Submersibles < personal_submersibles at psubs.org> wrote:
>
>>
>
> Sean,
> I have a radio in the sub and a matching radio in the boat.  Yes it is 9khz  and probably very old school.
> Hank
>
> On Thursday, January 10, 2019, 8:32:42 AM MST, Sean T. Stevenson via Personal_Submersibles <personal_submersibles at psubs.org> wrote:
>
> A few questions:
>
> 1) Who are you communicating with / what is the hardware on the receiving end?
>
> 2) I presume you meant to type 9 kHz instead of 9 Hz? 9 Hz would be infrasonic and require an immense amount of power to transmit, in addition to not having sufficient bandwidth for voice comms. 9 kHz, on the other hand, still doesn't sound like a standard comms frequency. Human hearing covers 20 Hz - 20 kHz. 9 kHz would be audible, not ultrasonic. Active sonar transducer perhaps?
>
> Sean
>
> -------- Original Message --------
> On Jan 9, 2019, 18:01, hank pronk via Personal_Submersibles < personal_submersibles at psubs.org> wrote:
>
>>
>
> Sean,
> I have no clue what the wattage is.  These are the original coms that came with Gamma, they are rack mount.  The picture shows a spare 27 and the big one is a 10 hs but I need 9 hz
> hank
>
> ----- Forwarded Message -----
> From: hank pronk <hanker_20032000 at yahoo.ca>
> To: hank pronk <hanker_20032000 at yahoo.ca>
> Sent: Wednesday, January 9, 2019, 5:58:41 PM MST
> Subject:
>
> Sent from my iPhone
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