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[david48]

As some of you will have noticed on here I am building Fairmount Alpine useing Action gear and the diagram  drawn up for Irishcarguy (how are you doing) .Well all I can say It is a fair challenge trying to get it all in .On the face of it there looks loads of room until you start .Tryin to keep every thing tidy and still need to fit another P 92and fuse .Its  a fair job drawing it on 3 sheets of  A4 if only thy could be folded up put in the hull and it worked .Keeping everything low down, soCof G is not to high is a task.
   Anyone know of a reason why I can not fit the speaker it's a 8ohm 100mm square near the drive motors , it will fit in ok will the motors have any effect ,the Noise Thing and amp are going to beat deck level under the super structure .I have looked on Component Shop but could not decide which are the best plugs and sockets to make insitu  battery chargeing  to buy .
David.

[derekwarner]

David.....is this the type of 8ohm x 100 sq speaker you are thinking about? [nominal 100 diameter with a 100x100 mounting plate]

Just check the recommended mounting ....enclosed or open mounting?....do you have sufficient open air space via windows or vents for the sound to penetrate and become audible?

On face value...the speaker does appear to be well suited to model marine applications from its material/construction ...the ACTion noisy thing.... nominates a 10W x 8 ohm speaker....

If the drive motors are earthed and have anti static capacitors installed......I would not see a reason of the close proximity to the speaker as having an electro magnetic influence on the speaker

I am sure Inertia-DM will offer constructive comment to your questions.......Derek

http://www.google.com.au/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&cad=rja&uact=8&ved=0CCMQFjAB&url=http%3A%2F%2Fwww.kitronik.co.uk%2F3322-10w-8-ohm-100mm-square-mylar-cone-speaker.html&ei=0C-_U6PJMYHgkAWx3oCoBQ&usg=AFQjCNFnWOx68Xm0zmKArwhWon9WoRqsog

[david48]

Thank for that Derek ,I was looking last night I might / will have to cut vents there a few vent covers on the superstructure I could open up and fit grills . When you say motors earthed do you mean a earth to the case and grounded back to an earth plate /shaft tube.
David

[inertia]

I very much doubt if mounting the speaker close to the main drive motors would affect the sound.
Component Shop can supply a 3-1/2" (90mm) 12W mylar-cone speaker to suit if that would fit the model better. Encasing the back of it will greatly increase the volume by preventing the air from the back of the cone interfering with the sound coming out of the front.
If they are long distance apart then it might be a good idea to use a screened lead between the P100 and P101 amplifier - the negative connection forming the screen.
DM

[GAZOU]

Code: [Select]

I very much doubt if mounting the speaker close to the main drive motors would affect the sound.

Yes , Yes DAVE it is possible, remember you ........................
Never solved

[inertia]

Jean-Pierre
I don't believe that the problem you had was attributable to mounting the speaker too close to the motor.
With hindsight I think that the problem was due to the fact that the two steam sound units both use an FM radio chip (TDA7000) to generate white noise for the steam "hiss" effect. Unfortunately these tiny radio receivers were also picking up the RFI from the very large motor in your model and sending it to the speaker; call it a design flaw if you wish, but one of the very few that Craig Talbot ever made. I dare say that some more experimenting with screened cables and shielding might have reduced it to an acceptable level but I doubt if it would ever have completely eliminated it.
To be honest both units were designed almost twenty years ago and we inherited them from Craig. I would happily have taken them off the market. P56 in particular is a pain to assemble and sourcing the long-obsolete FM radio and amplifier chips became increasingly difficult, but they continued to be popular, and you were the only customer who ever had such extreme problems with them.
The smaller P64 Steam Engine sound doesn't have the same chip so doesn't suffer the same problem, although there isn't that "hiss" when the engine is idling.
The newer P100 sound system uses digital samples of a real steam engine and steam whistle rather than a electronically synthesized sounds, so it wouldn't be affected by RFI from the motor.
Dave M

[david48]

Thanks DM ,lots of heat sinks and trying to find space for a fan, all good stuff.On with trying to back speaker today .
Sometime I will try to post pictures ,but not until l am happy with the set up .
Thanks again
David

[GAZOU]

Dave 

You found now the cause of the problem.

I am happy there

Good day and hello your charming wife.

[inertia]

J-P
Charming wife says "Bonjour, Jean-Pierre! Il est bon de vous entendre à  nouveau."
DM

[malcolmfrary]

Expanded polystrene makes a good speaker backing.  On a smaller speaker, I had good results using a styrofoam cup.  A bit of creativeness with disposable picnic plates or dishes might work.  It doesn't need to be totally airtight, "near enough" is going to be "good enough" in a case like this.
RFI being picked up should be cured by fairly normal means, meaning the usual motor suppression, but there may be a case for fitting suppressors to both the input and output leads of the amplifier to quench any RF being picked up there. 
Speaker leads picking up even a faint RF signal can, and do, pass the signal into the amplifier output stages.  Being semiconductors, they act as the old cats whisker and detect it.  Then they amplify it so that you can hear it properly.  I used to get a neighbours taxi radio breaking through my Hi Fi way back when they used actual radio.