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[sub john]

HI Mike
 Lip seals on prop shafts are not made of rubber and should not degrade over time, and there is no heat to speak of to course a problem, the silicone rubber o ring even with it being in there 20 years it looked no different from the day it was put in plus it didn't look worn, but if you use silicone rubber bath sealent it's normally good for 10 years and the biggest problem why it would degrade is sun light being on it
        John

[MikeA]

dunno then. what are you going to do?

[sub john]

HI Mike
Was talking to some body else who is into model subs and also in to engineering he was saying it is probably because prop shafts are to full of lubricant so for the time being I'm going to leave them alone. Have tried to see if i can feel side movement on shafts but all seems OK did wonder if it was because prop shafts where bent but i can not see any thing wrong
    JOHN

[sub john]

hi all i thought id post these pictures i have found of the sub they are from 1993 so along time ago now

[MikeA]

hey john where you been?? pics look great also got to say that the lake your sailing at looks similar to wear i sail.

[sub john]

HI Mike
  Have been up to my neck with electronics, and also been helping my son custom build a computer tower and water cool it what a game that has been, it is running the CPU at about 26GHZ it is fast but he is doing my head in. 

Pity that the pictures came out a bit dark of the sub on the water but it does show that it has been under the water a few months ago i brought a camera come camcorder does 1080p format with memory card picture quality is brill hopefully will get to use it when i take the sub out later this year to video it

You said it looks a lot like the water where you sail i don't know how deep it is where you go but it is about 90ft deep where i used to sail it trouble is when you sail in water that deep if you lose the sub you might not get it back and it is a big piece of water to go looking for a 12ft sub even with divers
    John

[MikeA]

the place i sail is an old iron ore quarry havent a clue how deep it is, I heard theres a bus at the bottom of it lol. Anyway keep us posted with your progress.

[sub john]

HI Mike
  You said that there is a bus at the bottom of the quarry where you sail hope the driver is still not in it. I found on hear a circuit for speed controller has got relay for forward and reverse with art work for PCB board and has got HEX file for programming pic have printed off art work to make PCB if you are interested let me know, i know you said that you didn't won't to have to program a pic for speed controller as you are not into programming but i can do one for you

How i have got rid of that son of mine with that Mickey mouse computer i might be able to get on with other things will have to test that H bridge for circuit for you and try it on servo amp and see if it rock and rolls, all so won't to get some more done on my sub, had it switched on the other day and it was about 6 below out side and it still worked fine spent hours trying to flatten the battery's
            John

[MikeA]

I should hope so I got a return ticket! I might make a complaint to bus depot get my money back it still hasnt arrived!!

From what i gather making my own esc's is no more cheaper than buying them, which was the original intent and purpose.

If you can get it to work using an old £1.50 servo then that would be fine, If i can learn how to do it and no what to look for as in fets and stuff i can buy a batch of old busted servos, and eventually  salvage fets and stuff from electrical junk dumped in the street. If it dont work then never mind

as it stands at the minute i use car esc's and i spend no more than a tenner on them. I think i have 1 boat that has a marine esc in it and that was a birthday present.

Anyway about your sub. have you had any brainwaves lately how to get the video to work, or are you still pondering that? You know last time we was talking about it i had an idea dunno if it would work of course. You said that youl control your sub on 27mhz ok. Well what if your video link was on that too, now obivously you wont get enough data down one 27mhz rf link so what about if it was sent down 3 or 4 seperate rf links using 27mhz crystals or whatever to stay in there own bands. Say the sub spliced the video data into 3 or 4 data streams on board the sub, send the data down the 3 or 4 rf links which then is picked up buy receivers. Then computer software compiles the data streams backtogeather to make an image on a laptop or something.

Anyway theres my thinking dont even know if its possible, out my depth now

[sub john]

HI Mike
  Sorry for long delay in replying, i have not been very well but seem to be getting better now. Fine on wonting to use servo amp to make speed controller, if you won't to get hold of some good fets try and get hold of some mother boards out of computers as some of these fets have a very low on resistance from drain to source, and the lower this is the less heat you get from the fet i even do this myself. Some of them are very good fets

Won't to get back on to video link for under water, you said about using modems to make low frequency video link you posted a link on hear for some company that was starting to develop one of these units trouble is if you was to try to put it in to a model sub i don't think i would get all the gear in side of my 12 ft sub, but now the weather is getting a bit better i should be able to start to do tests in water with out getting frost bit.

Had a small problem with that sub of mine drifting of one of the oscillator's which you did not see unless the sub was on for quite a while in the end i locked it with  a crystal should not have been a problem but it works OK now
Have been looking in to being able to use LF for model sub's and being able to make a small unit that would fit in to a small sub i think i have found the ideal chip to use as it would make a small unit but i just don't know if there is a big enough market to make it worth doing
                     John

[Subculture]

Chicken and egg situation I think.

I think people would need to see the benefit of a LF system to decide if it's worth going for.

Much as I'd like to see something like this come along I think the market would be small for as long as inexpensive 40mhz equipment is available, as the performance of such systems is generally satisfactory for the majority of users (e.g. out of sight before out of range).

[sub john]

HI Subculture
 I think i have to say that i think you are wright, with cheap 40MHZ radio's out there i can not see any one wonting to spend a lot of money on LF as a lot of these people with model subs seem to only go in shallow water, one of the benefits of going LF is not having to worry about somebody else on the same channel as you, especially at model shows

Have also been looking into sonic control of subs under water that looks quite possible as i know how to make high power transducers for RX and TX could be looking to go 500FT down in the water, but as you know i like playing around with electronics

A lot of people seem to look at electronics as being TABO and some thing to stay away from but not me i like the challenge to do difficult projects that's what i get my buzz out of but sad to say once i get it working i loss interest very quick and then pick up the ball and start on some thing else
                            John

[Subculture]

I think the sonic system would have more of a market, as you can use that in salt water as well as fresh.

[MikeA]

HI Mike
  Sorry for long delay in replying, i have not been very well but seem to be getting better now. Fine on wonting to use servo amp to make speed controller, if you won't to get hold of some good fets try and get hold of some mother boards out of computers as some of these fets have a very low on resistance from drain to source, and the lower this is the less heat you get from the fet i even do this myself. Some of them are very good fets

Won't to get back on to video link for under water, you said about using modems to make low frequency video link you posted a link on hear for some company that was starting to develop one of these units trouble is if you was to try to put it in to a model sub i don't think i would get all the gear in side of my 12 ft sub, but now the weather is getting a bit better i should be able to start to do tests in water with out getting frost bit.

Had a small problem with that sub of mine drifting of one of the oscillator's which you did not see unless the sub was on for quite a while in the end i locked it with  a crystal should not have been a problem but it works OK now
Have been looking in to being able to use LF for model sub's and being able to make a small unit that would fit in to a small sub i think i have found the ideal chip to use as it would make a small unit but i just don't know if there is a big enough market to make it worth doing
                     John

hope you get well soon. The thing about the modems was for control, the post i made on 16th of feb was about using rf to send video link. I suppose if the same problem occurs with space then then yeah thats an obsticle but would splicing the video data into seperate rf streams and recompiling them on land work?

as far an the esc is concerned have you got it to work?

mike

[sub john]

HI Mike
   Using modems to send data back from sub or what ever if you was sending back 3 data streams i suppose the hardest bit would be putting it all back together to make a video picture but you could use the PC on the land to do all the hard work so then would just need soft ware to do it. It would be interesting to know what frequency they are using for link.

Speed controller have got H bridge to work forward and reverse but have not connected up to servo amp yet will have to give it a try
                                            John

[sub john]

HI Subculture
     I think sonic link is the way to go my thoughts are using sonic link you would not have to worry about using different radio bands in different country's as the sonic one as far as i know you  would not need  to worry about licence
problems but i might be wrong
   John

[MikeA]

HI Mike
   Using modems to send data back from sub or what ever if you was sending back 3 data streams i suppose the hardest bit would be putting it all back together to make a video picture but you could use the PC on the land to do all the hard work so then would just need soft ware to do it. It would be interesting to know what frequency they are using for link.

Speed controller have got H bridge to work forward and reverse but have not connected up to servo amp yet will have to give it a try
                                            John

it was just my idea not someone elses , using 27mhz rf frequencies.

i found this ages ago you might find it interesting:

http://web.mit.edu/people/millitsa/resources/pdfs/costas.pdf

a video of another test
http://www.youtube.com/watch?v=XwLxh6wOSP4

[sub john]

HI Mike
   If you was to use 27MHZ it would take up to much band width, the links that you posted was very interesting reading part of if they are using 75KHZ but on video there was a bit of time lag and if they moved quick moving hands and arms you could see time lag if they moved fast plus the picture quality  did not have high definition but saying that it was still good, i think they said the range was about 1000 meters which is pretty good, will have to go back and read a bit more.
                     John

[sub john]

HI ALL
Have been working on low frequency  video link for under water, when tried unit it didn't seem to have much range at all under water have gone back to it to find out what the problem is and found out that when the antenna was in the water for some strange reason the phase locked loop which locks it on to frequency was not locking but as soon as unit was put in to 50R load to take place of antenna it would work fine, in the end had to put a separate screen around phase lock loop circuit seems to lock on to frequency OK now but need to go back down the canal and have a play a round with it and see if it works
           Sub John

[MikeA]

getting closer john well done

[sub john]

HI MIKE
Thought I'd let you know how it is going with low frequency video link, tried it early hours of this morning set up antenna in the garage and transmitted in to the house signal was so Strong receiving end could not even tune off it but it proves that the phase lock loop now works OK.

Going to try hard this week to connect up your servo amp to H bridge drive circuit and see if i can get it to rock and roll
                    Sub John

[MikeA]

what frequency are you using then? or is that a secet  how good is the picture? Why does the frequency need to lock and what does 50r load mean ? lol 

[sub john]

HI Mike
You asked what the frequency is of the low frequency video link that is TOP SECRET!!! ITS A CLOSED BOOK

Picture quality is as good as normal analog TV used to be so it is pretty good of course it is in colour

The phase lock loop which is the PLL CIRCUIT FOR SHORT  this is what locks it on to frequency but also means you can change channels with out having to change crystals so can change channels just by flicking a switch

PS got my last job repaired today so will have a look at your speed controller next
   John

[MikeA]

im not suprised its top secret john. If it works you will probably be the first bloke ever to successfully transmit live colour footage through water. There are marine research programs with millions of government funding invested in them trying to achieve the same goal!! If and when you get it on youtube MOD will be your case with a big cheque!

Id appreciate you having a go at my esc as i got some bits n bobs for it to go in 

[sub john]

HI Mike
      Low frequency video link just having a go for my own satisfaction to see if it can be done, it is still early days yet just glad i have sorted out the problem with PLL chip not locking on to frequency even if it comes down to i can only transmite 300 feet through water i would be happy with that. It makes me laugh when people say they have transmitted TV through water on 2.4GHZ through about 10FT of water at that frequency the maths don't work there is no way you would be able to do it.The RF power needed to do it would be incredable.

No problem with speed controller with a bit of luck get round to having a look tomorrow
    John