> > Any suggestions or recommendations for transmitting data 5km to 10km ?
>
> Audio modulation into a PRS CB would probably work

> DSE has a small PRS unit for $100 ish that would do the job

www.dse.co.nz

D1742 (Uniden UH037) is $99, 500mW, 3km line of sight
D1760 (Uniden UH050XR) is $469, 1W/5W, no range given,
but presumably >> than 3km

The D1760 at 1W would do the 5km range. 5W would definitely
cover 10km. Looking at the pictures the aerials seem acceptable
Get rid of everything except the transmitter and we're in business

> An FX604 modem IC would do the job (see me for cct) or almost
> anything else at all

This one ?

http://www.cmlmicro.com/products/Datasheets/Docs/fx604ds.pdf

> 0.3 x 8765 hrs =~ 3000 mAH/year.
> Alkaline C cells would do this

Yup, given the duty cycle I didn't think there'll be too much of
a problem with batteries. Consumption will be a little more as
I planned on 3 repetitive transmissions for reliability

> > - Aerial acceptable only if short, stubby, robust etc
>
> Ah - maybe more info needed - if a Yagi at far end OK then can still work

How big would the receiving aerial need to be if picking up a 5W
transmission from 10km ? There are some limitiations because the
receiver will be hand-held

> > - Receive capability not needed
>
> You're not going to receive the data you send ? :-)

No. Part of the brief is, I quote, "waste as much of Joe's time on
this, all for no result, and then disappear without paying". Clot

> > Apart from the tx, everything else is pretty much sorted. A couple of
> > days ago someone mentioned the 340 as a better choice for a very
> > low-power sleeping micro. Is that true it's better than the PIC ?
>
> Yes. Can be very very very low

I got some pdfs on the 430. Considering what else is in the circuit,
sub-uA looks achievable. At a glance TI appear to have some free
low-end dev tools that would get me started. I'm reluctant to take on
yet another learning curve, but if duty calls...............

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