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-   -   2.4 radio in a sub? (http://www.rcuniverse.com/forum/rc-submarines-119/9779404-2-4-radio-sub.html)

rva1945 06-03-2010 09:02 PM

2.4 radio in a sub?
 
Has anyone successfully tried a 2.4GHz radio system in a sub?

martno1fan 06-04-2010 03:38 AM

RE: 2.4 radio in a sub?
 
Wont work the signal wont go through water.

rva1945 06-04-2010 07:39 AM

RE: 2.4 radio in a sub?
 
That's what I guess, but did someone try it?

Taxidriver 06-04-2010 02:15 PM

RE: 2.4 radio in a sub?
 
Sure some one tried it all those years and it didn't work. No need to try it again. Wiress cameras on 2.4Ghz dont work under water for the same reason. In fact until recently Spectrum did not even recommend using they 2.4Ghz radio in fast boats because the spary could interfere with the reception.

tsenecal 06-05-2010 07:48 PM

RE: 2.4 radio in a sub?
 
an individual i know personally showed me his "fixed" dumas gato sub.

the original dumas leaked like a siv, so he "fixed" it by using the original plastic hull as a mold to make a fiberglass duplicate.

he showed me it running in the local pond. it was a dynamic diver that would drive forward fast enough to dive, and when it got about 4" below the surface, the failsafe would kick in, and it would pop to the surface like a cork. it worked well enough for him, but was basically useless as far as i was concerned.

he was running it with an original spektrum dx6 and an ar6000 receiver, with the two antennas running up the periscopes of the sub. because of the way he had the antennas, i think he could have run it at periscope depth for a reasonable amount of time, but because it was a dynamic diver, there was no way he could consistently keep it at a specific depth.<br type="_moz" />

ALPHA__OMEGA 06-23-2010 06:27 PM

RE: 2.4 radio in a sub?
 
So what is the recomended raidio frequency for a sub? Comming from Heli's I'm kind of used to not haveing to worry about cross frequency interactions. Anything for a sub thats blue tooth similar?

AQUASUB 06-23-2010 08:12 PM

RE: 2.4 radio in a sub?
 
I would stick with 75mgz why take a risk from the start?.

ALPHA__OMEGA 06-23-2010 09:17 PM

RE: 2.4 radio in a sub?
 
<span class="ProductHeading">Well i know dsm2 (spektrum &amp; JR) work great for planes and helis. btw, I just saw this, http://www.spektrumrc.com/Products/D...odID=SPMMR3000. Any one know how deep it will go?
</span>

Skip Asay 06-23-2010 11:31 PM

RE: 2.4 radio in a sub?
 
"Any one know how deep it will go?"

About as deep as any other 2.4gHz system will go. In other words, it won't.

Skip Asay

Hydro Junkie 06-24-2010 01:07 AM

RE: 2.4 radio in a sub?
 
I would recommend using the 27MHz band for submarines. I know the Navy used to use a ULF band for subs to communicate submerged and either one of the VHF or UHF for surface communications. Sorry but that's as much as I feel I can say without getting myself in trouble with "the man" :D

tsenecal 06-24-2010 04:11 PM

RE: 2.4 radio in a sub?
 
Alpha_Omega

the spektrum marine radios such as the mr3000 you linked to are designed for boats - it even says so in the product description on the link. they will not work on submarines.


the proper frequencies to use for submarines are the following:

whatever MHZ frequencies that are legal for ground use in your country.

for me (USA) legal frequencies are 75mhz range, 50 mhz range* and 27mhz range

*50mhz are available if you have a HAM radio license.

the effective differences between these frequencies are negligible. 27mhz in actual use is no more effective than 75mhz.


do not bother with 2.4ghz. period. It will not work EFFECTIVELY with submarines.<br type="_moz" />

Hydro Junkie 06-24-2010 05:24 PM

RE: 2.4 radio in a sub?
 
Normally I would agree with you, but not for sub use. Due to the way radio waves react with water, the 27MHz is a better choise for longer range and better reception. For any other boat, I'd go 75MHz in a heartbeat.

tsenecal 06-24-2010 05:59 PM

RE: 2.4 radio in a sub?
 
Hydro Junkie,

do you have a link or other data to back this up?

I have been running several model subs for several years now (but not decades), and have a transmitter that uses separate modules, so that the only variable in the equation was in fact the frequency, (same sub, same transmitter, same model of receiver) I have done the testing myself to see this with my own eyes (I had heard the stories that i should go with 27mhz for best range) and that personal testing showed that the only reason to choose a 27mhz frequency over a 75mhz is due to traffic (if everyone at the pond is on 75mhz, it is easier to find a free channel on 27mhz or 50mhz) I could understand improved range if it was an order of magnitude difference in frequencies, but in the spectrum scale we are talking about (27mhz vs 75mhz), and the particulates in the water we float in (do you run your sub in a pool filled with distilled water?) there might be a difference of say 73" vs 72" before the failsafe kicks in.


The biggest improvement i have personally seen is using a PCM capable receiver instead of a PPM receiver.
<br type="_moz" />

Skip Asay 06-24-2010 08:33 PM

RE: 2.4 radio in a sub?
 
Many years ago, when 72mHz was still legal for boats, I did a test to compare 72 and 27. I installed a complete 72mHz system (RX, battery, and servo operated ballast blow) in my sub and then proceeded to put the boat at periscope depth and run it. I had complete control over both systems at a range of at least 100 yards. And yes, I had to use binoculars to see it! I've also put my boat on the bottom in over 25 feet (w/75mHz) and never lost control. As far as I'm concerned, FOR OUR USE, there's no difference between 27, 50, 72, or 75mHz. Yes, in controlled laboratory testing, I'm fairly certain that 27 will be better than 75 but I think the difference would be measured in INCHES. But let's face it. Why bother having a radio that will penetrate 30 feet of water at 100 yards if there's no way to see it at that distance and depth?

Skip Asay

rva1945 06-24-2010 09:57 PM

RE: 2.4 radio in a sub?
 
"Why bother having a radio that will penetrate 30 feet of water at 100 yards if there's no way to see it at that distance and depth?"

I agree 100% with that. In fact, if the 2.4GHz radio system lets me control my sub at 6 feet deep and up to 20 feet from the shore, who asks for more?

tsenecal 06-24-2010 10:31 PM

RE: 2.4 radio in a sub?
 

Quote:

ORIGINAL: rva1945

"Why bother having a radio that will penetrate 30 feet of water at 100 yards if there's no way to see it at that distance and depth?"

I agree 100% with that. In fact, if the 2.4GHz radio system lets me control my sub at 6 feet deep and up to 20 feet from the shore, who asks for more?

<div style="background-color: rgb(255, 255, 255); padding-top: 5px; padding-right: 5px; padding-bottom: 5px; padding-left: 5px; margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font-family: Arial, Verdana, sans-serif; font-size: 12px; ">rva1945,

the reason 2.4 GHZ is a no go is because it IS an order of magnitude greater than the 27, 50, 72, or 75 MHZ radios. It is also a harmonic frequency with water. that is why microwave ovens work so well. its kind of like the old AM radios trying to get a good signal through concrete.


you won't get 6cm penetration when standing right on top of it, let alone 20 feet away.<br type="_moz" /></div><br type="_moz" />

Aeroprado 08-23-2011 09:36 AM

RE: 2.4 radio in a sub?
 
<div closure_uid_bkusga="1411" class="almost_half_cell" id="gt-res-content"><div closure_uid_bkusga="1410" dir="ltr" style="ZOOM: 1"><span a="undefined" c="4" closure_uid_bkusga="1409" lang="en" id="result_box"><span closure_uid_bkusga="1383" class="hps">Friends.</span></span></div><div closure_uid_bkusga="1410" dir="ltr" style="ZOOM: 1"><span a="undefined" c="4" closure_uid_bkusga="1409" lang="en" id="result_box"><span closure_uid_bkusga="1383" class="hps">
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rva1945 08-23-2011 09:41 AM

RE: 2.4 radio in a sub?
 
Well, someone did the test for me some weeks ago: he built a scratch-built RC sub, and once at the pond he came to me worried because it stopped working as soon as it dived, I asked him:

"Are you using a 2.4GHz radio system?"
"Yes" - he replied.
"Thanks, that's all I wanted to know..."

Aeroprado 10-06-2011 02:37 PM

RE: 2.4 radio in a sub?
 
Friends.

<span id="result_box" lang="en" closure_uid_fxcy0z="175" a="undefined" c="4"><span class="hps" closure_uid_fxcy0z="5596">Thanks</span><span closure_uid_fxcy0z="5597">, much</span> <span class="hps" closure_uid_fxcy0z="5598">the answers,</span> <span class="hps" closure_uid_fxcy0z="5599">and how</span> <span class="hps" closure_uid_fxcy0z="5600">I changed</span> <span class="hps" closure_uid_fxcy0z="5601">my radio</span> <span class="hps" closure_uid_fxcy0z="5602">a short time,</span> <span class="hps" closure_uid_fxcy0z="5603">to 2.4</span> <span class="hps" closure_uid_fxcy0z="5604">ghz</span><span closure_uid_fxcy0z="5605">, I have to</span> <span class="hps" closure_uid_fxcy0z="5606">buy</span> <span class="hps" closure_uid_fxcy0z="5607">one for my</span> <span class="hps" closure_uid_fxcy0z="5608">submarine, the</span> <span class="hps" closure_uid_fxcy0z="5609">staff was</span> <span class="hps" closure_uid_fxcy0z="5610">unanimous</span> <span class="hps" closure_uid_fxcy0z="5611">in</span> <span class="hps" closure_uid_fxcy0z="5612">72.75</span><span closure_uid_fxcy0z="5613">,</span> <span class="hps" closure_uid_fxcy0z="5614">and 27</span> <span class="hps" closure_uid_fxcy0z="5615">MHz</span><span closure_uid_fxcy0z="5616">,</span> <span class="hps" closure_uid_fxcy0z="5617">giving preference</span><span closure_uid_fxcy0z="5618">,</span> <span class="hps" closure_uid_fxcy0z="5619">for operation in</span> <span class="hps" closure_uid_fxcy0z="5620">PPM</span><span closure_uid_fxcy0z="5621">.</span></span>

Turbobearcat 10-23-2011 03:12 PM

RE: 2.4 radio in a sub?
 
Nowhere does it say it's not for Submarines
http://www.spektrumrc.com/ProdInfo/F...000-MANUAL.pdf

http://www.spektrumrc.com/Products/S...odId=SPMMR3000

I will no tdoubt you Skip but I would like to ask when did you last try to use this type of receiver in a sub?


I would be cruising 20 feet or more out but would never dive unless I was close enough to shore to be able to see the sub..

So with having 4 antenna to pick up a signal, do you still think the 75Mhz FM would still be better than 2.4Ghz?

rva1945 10-23-2011 03:52 PM

RE: 2.4 radio in a sub?
 
I can say that it won't work. We tested it in a dynamic diving submarine and no sooner it dived that it lost signal.

Regards,
Robert

2daice 01-05-2012 03:58 PM

RE: 2.4 radio in a sub?
 
look up a company in Germany Alexander Engle. They sell a 40 mhz Robbie Futaba that works perfactly. The only limit is line of sight. Altho not legit in the US there is no or Very limited interferance and with a sub speed is NOT a factor.

Turbobearcat 01-18-2012 12:29 PM

RE: 2.4 radio in a sub?
 
Guys I was told last night by my hobby shop that if you want a 2.4Ghz radio to work they do make a "hoop" antennae that is designed for that radio..

Now my Hobbyshop is well known in the area so I might ask for more information on this subject from them but they are saying they have a dumas sub with a 2.4 and it runs just fine underwater AFTER the antennae is installed.

rva1945 01-18-2012 12:34 PM

RE: 2.4 radio in a sub?
 
Wanna see it working!!

But if high freq signals can't penetrate water, how will it work?

Turbobearcat 01-24-2012 05:42 PM

RE: 2.4 radio in a sub?
 
I am going to talk to the guy and I want to see his set run....

He said the main reason why people say it won't work - old timers refuse to go to the new radios and receivers..mainly because they are misinformed of what the radios can do.


I am willing to try it and find out- if it does not work then I will swap out the receiver with a boat.. no harm no foul.


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