Transmitters

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Originally Posted by Joe Schofield

. Advice appreciated.

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Suggest speaking to your instructor first.

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Originally Posted by Joe Schofield

I'm starting Cavern / Intro to Cave in two weeks. I have enjoyed using the Suunto EON Steel with transmitter because it (with latest firmware) gives you an estimate of gas consumption and gas time. I glance at this periodially to give myself feedback on how well I'm conserving gas. As I move into Cave I will be trained back mount first. My thought was to use two transmitters and two SPGs for redundancy. I have no experience with the Suunto switching between transmitters and that effort is probably a waste of time. I do not think the Eon Steel will monitor both at once. I do see the simplicity of just using SPGs without adding any more variables to this new experience. Advice appreciated.

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Excessive redundancy is usually frowned upon, e.g. carrying two SPG's or two transmitters when using double tanks.
Carrying one transmitter with a regular SPG as a backup should be plenty.
As Kelly suggested, you may want to ask your instructor. Chances are he would even recommend or require you to ditch the transmitter altogether.

There's no need for two spg's on a set of manifolded doubles and it's just adding to unwanted clutter. If you have an SPG failure, your dive is over, head home.

When estimating how much time you have left, your brain is better than any gadget out there. Electronic gadgets that estimate your gas consumption rarely take into consideration things like stress or changes in work rate.

Your instructor should teach you these things.

Best of luck!

I will go with my instructors advice. I figured he'd probably ask me to ditch the transmitter too. I also figured he'd not appreciate a call at 2am when I came across this thread and posted my question. ;)

Reasons I use a transmitter:

• I can monitor and quickly check the pressures in up to 6 tanks by looking at 1 screen (instead of finding 6 different SPGs)
• Computer provides 'gas time remaining' calculation based on breathing rate. Optional alarm if significant change is detected
• Fewer failure points than an analog SPG (1 o-ring vs multiple o-rings and a spindle)
• No chance to get an incorrect reading, such as with a stuck needle. Either you have a valid pressure reading or no signal.
• Audible and vibrating alarm when pressure reaches a set limit (extra safety if you are task loaded)
• If all of my lights went out, I could still see my tank pressures on the illuminated computer screen

I don't see the transmitter batteries as a problem, as they last for hundreds of dive hours and most wireless computers will give you plenty of warning in advance (just like the computer's own battery). I also like that when I download my dive log, it tracks my air consumption throughout the dive. I can see what my exact RMV was for each part of the dive and track this over time to see improvement.

Some people have told me that transmitters may malfunction in certain environments, but I have taken them in wrecks and caves with no issue (these are the Oceanic/Hollis transmitters). They are not for everyone, but in my opinion they offer some nice advantages!

biggest issue with two transmitters and two SPG's is your hose routing will look atrocious with things going every which way. Will also require your transmitters to point in towards the manifold and that will restrict your ability to do valve drills.

No issues with one on the right post, but you don't need 4 things to monitor pressure when most only use one....

[QUOTE=madmosche;290902]Reasons I use a transmitter:

• I can monitor and quickly check the pressures in up to 6 tanks by looking at 1 screen (instead of finding 6 different SPGs)
• Computer provides 'gas time remaining' calculation based on breathing rate. Optional alarm if significant change is detected
• Fewer failure points than an analog SPG (1 o-ring vs multiple o-rings and a spindle)
• No chance to get an incorrect reading, such as with a stuck needle. Either you have a valid pressure reading or no signal.
• Audible and vibrating alarm when pressure reaches a set limit (extra safety if you are task loaded)
• If all of my lights went out, I could still see my tank pressures on the illuminated computer screen

1-You using more than one gas at a time? You dont see a chance of confusion here?
2-This is auto calculated on a dive. As Ken said: in your head.
3-Maybe valid, if you dont consider an electronic gadget a failure point in itself.
4-Really? NO chance?
5-God No. No alarms.
6-Perhaps. And how would this help? Just get out, already. If 3 lights fail, its a bad day...expect a cave-in. Or snow.

Here is what to keep in mind from my worthless dribble: I dont care if you use them; I dont think they are necessary (hell I dont even have gauges on my bailout); when I dive OC, I MAY look at my pressure twice on the entire dive. Maybe.

That's me, though. My consumption doesnt consume me (sorry) and seldom dictates the dive.

REMEMBER: use them, I do not care...dont feel you need to defend this choice. Doc Deep used them and they worked fine...probably still are working.

Bob

[QUOTE=floridabob;290907]

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Originally Posted by madmosche

REMEMBER: use them, I do not care...dont feel you need to defend this choice. Doc Deep used them and they worked fine...probably still are working.

Bob

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Might be too soon. Just sayin'.

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Originally Posted by tbone1004

that will restrict your ability to do valve drills.

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Doing a valve drill with your isolator is a huge waste of time.

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Originally Posted by madmosche

Reasons I use a transmitter:

• I can monitor and quickly check the pressures in up to 6 tanks by looking at 1 screen (instead of finding 6 different SPGs)
• Computer provides 'gas time remaining' calculation based on breathing rate. Optional alarm if significant change is detected
• Fewer failure points than an analog SPG (1 o-ring vs multiple o-rings and a spindle)
• No chance to get an incorrect reading, such as with a stuck needle. Either you have a valid pressure reading or no signal.
• Audible and vibrating alarm when pressure reaches a set limit (extra safety if you are task loaded)
• If all of my lights went out, I could still see my tank pressures on the illuminated computer screen

I don't see the transmitter batteries as a problem, as they last for hundreds of dive hours and most wireless computers will give you plenty of warning in advance (just like the computer's own battery). I also like that when I download my dive log, it tracks my air consumption throughout the dive. I can see what my exact RMV was for each part of the dive and track this over time to see improvement.

Some people have told me that transmitters may malfunction in certain environments, but I have taken them in wrecks and caves with no issue (these are the Oceanic/Hollis transmitters). They are not for everyone, but in my opinion they offer some nice advantages!

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The MTBF for spgs seem to be very minimal,otherwise you'd see a lot of posting from people about failures. But,when you've invested this much money in technology, ultimately you will use it. The big thing is have you practiced scenarios when something does fail? Do you have an automatic protocol for battery replacement, for example after x# hours dive time? I don't trust the device to give me dependable battery tracking. My Shearwater (as an example) will be in the red when it has a new battery sometimes, also I have had the computer go from yellow, then dead within a 30 min span.