[Gta04-owner] Status GTA04 GroupTour

[Thomas Gstädtner]

On 30.12.2011 15:08, Dr. H. Nikolaus Schaller wrote:
>> Which leads us to the persitent problem of producing new cases (or adapters
>> for existing cases). Maybe we can break the problem in two and try to find kits 
>> for the missing components (antenna, etc.) on one hand and desigining a 3D 
> 
> For these parts I have some components sitting on my office desk waiting
> to be evaluated next year ;). Those are some speakers bought from Mouser
> and I expect that they don't make bigger problems.
> 
> A minor problem is to find a good source for vibracall motors. Mouser has one
> in their catalog, but they are sold out for a long time and it appears they are EOL.
> 
> If someone knows a catalog distributor for such motors, please let us know.

These guys sell some:
http://pagermotors.com/Products.php?f_category=Pager
Other than that only Digikey seems to carry some stock of one model:
http://search.digikey.com/us/en/products/KHN4NX1RC/P14793CT-ND/2686253

> The most complex "missing" part is the UMTS antenne. This needs a very careful design
> so that we do not reduce the reception quality (remember the iPhone 4 issues?).
> 
> And even worse: if reception is bad, the transmitter has to increase the power
> which draws the battery empty even faster. So a badly designed antenna has
> dramatic effects on the overall performance.
> 
> Fortunately, we have a good RF engineer in our team, but as usual with volunteers
> development takes a little more time as expected.
> 
> Technically the idea is to make the antenna as a flexible PCB so we can easily
> add stubs or change trace widths and lengths at very low experimental cost
> (e.g. 20-30 EUR for each protoype). Only the measurement tools cost >5000 EUR...
> 
> This antenna can be bent and stowed into a small slot of the case.

The company "Round Solutions GmbH & Co. KG" (Aldafunk)  produces and
sells such antennas, they likely have the equipment to do this properly.
It is a German company, so I'm sure you could get in touch with them and
maybe even get a sample, e.g. this model:
http://www.aldafunk.com/GSM/UMTS-Antenna/Flexible-Adhesive-PCB-Dipole-Antenna-GSM-UTMS::92.html

> And finally, we may need a replacement battery in the future. But we can either
> use the Nokia BL05 or similar or find another one or it should not be too difficult
> to get a compatible battery through Alibaba.

As most high end phones don't come with replaceable batteries anymore,
it might not be the best idea to bet on a model-specific battery - it is
nice to have stock, but having underperforming or enormously expensive
batteries (like the higher-class Nokia ones) doesn't seem like the
smartest move.
These guys have a huge selection, might be worth checking out.
They sell it not only as cells but also as complete packs for easy assembly:
http://www.ibt-power.com/Battery_packs/Li_Polymer/Lithium_polymer_cells.html

> Looks as if we have many more ideas in this community than can be completed
> within Xmas- and New Year's holidays :)
> 
> Nikolaus
> 
> _______________________________________________
> Gta04-owner mailing list
> Gta04-owner at goldelico.com
> http://lists.goldelico.com/mailman/listinfo/gta04-owner

Regards,
thomasg