Bike comms - electronics peeps please read

[mr.z]

The radio in question is an mr200...
i've been trying to make a headset and managed it last night,

I used

Cheep headphones
Small mic (the same as the mic inside the unit, i had one of these laying around )
Soldering iron (+ solder obviously)
Lighter
Glue stick

Took about 20 minutes (need some soldering practice i think) and cost a grand total of arround £2

Now here is my question, the problem with this radio is that it has no space on the plug for ptt, its voice activated, as its for motorbike use and i'd imagine wind noise will have the vox going on allot on motorways e.t.c. being able to deactivate it would be perfect so..
would it be possible to bodge a ptt button on?, i was thinking by using a low ampage switch on the MIC line, so the VOX can operate only when the button is depressed, effectively giving it a PTT button, would that work?
Obviously not perfect but is there any obvious reason this would not work?

i'm also thinking of powering it from the bike with some sort of cigarette lighter adapter, it uses 4aaa batterys and i was planing on wiring it into the battery panel on the back with a mono jack connector ...

any advice on the ptt bodge would be greatly appreciated
____________________
>RidingSkills<->Tech Tips<->MyBikes<

[carvell]

The mic bodge will work fine - it'll no doubt add some interference when you talk, as the switch isn't shielded or anything, but if you can live with that it'll work.

As regards to hooking it up to the bike battery, you'll need to make/buy a transformer to take the voltage down from 12 to 6 and then use some resistors or something a bit more effective to knock a lot of the current off.
____________________
Yamaha TDM 850

[mr.z]

excellent, will have a go, i would use a mono headphone connecter so i can unplug it from the bike.. if i used something like ps/2 (pc mouse/keyboard) cable that be any better? reason being i think that is shielded?

I never really thought to bother but the radios were £20 for two, got them cheeper from work and figured they would be handy sometime (they are cheeper on e-bay too) bike to bike coms for under £25 is bound to be worth a go
____________________
>RidingSkills<->Tech Tips<->MyBikes<

[carvell]

I'd just use the mono headphone connector if I were you - they're designed for audio, a PS/2 connector won't be any better.
____________________
Yamaha TDM 850

[mr.z]

oops,
sorry i ment i was thinking of useing the ps/2 cable and the monojack on the end, if its not going to make any signifcant difference i probably wont bother, just use the cable on the jack...
Not sure whati will dowith the powering though, i'd prefer to get a ciggy addapter, would it do anythink to regulate the power? don't want to fry the radio when the bike is at max output
____________________
>RidingSkills<->Tech Tips<->MyBikes<

[carvell]

Ah rite, I don't think a normal keyboard cable is shielded, but it probably won't make much difference.

All a cigerette lighter adapter does is put the + and - terminals of the battery in a round tube, so you can easily plug things into it. The voltage of the battery is not changed.

If the radios have a cigerette lighter plug on them then you can plug into this fine, if not you'll have to step down the voltage and current to match what the 4 AA's would give it.
____________________
Yamaha TDM 850

[mr.z]

Ah, u allways had the impression ciggy addapters would regulate the power to some degree, or at least fry before reaching more than a certain limmit...annoyingly there is a power adapter available but it uses the same plug as the headset :/

I should really have payed more attention in gcse eletronics

I will get the multimeter on the batterys and see how much its giveing out, then look from there

Thanks up to now, though i have a bit more to work out
____________________
>RidingSkills<->Tech Tips<->MyBikes<

[carvell]

The cigerrette lighter has a fuse, but that's about it.
____________________
Yamaha TDM 850

[Demonic69]

If the unit doesn't have a recharging circuit you're most likely gonna fry it with any kind of current.
____________________
Back on a Blade. Just feels so right.

[mr.z]

hmm now i think about it i will probably just stick with batterys for now, even get some rechargeables later...

I will post up a mini guide maybe when its finished and tested, there are mr200s going on e-bay for £15/20 bike to bike for less than £25 is damn good going!
____________________
>RidingSkills<->Tech Tips<->MyBikes<