For my development projects I recently ordered 10 pieces of 100x100mm double layer PCBs from ALLPCB and the process went great through and got 13 pieces as a bonus for only $5(!) including the express DHL delivery.

Order details: 10 pcs of 100x100mm PCBs for TSSOP, QFN, DSBGA with 0.5mm pitch 0.2mm pads, 8 – 32mil tracks, vias 0.4mm/40mil drill
Drilling accuracy: +-0.05mm as expected, 0.3mm holes, perfect for this precision class
Copper etch accuracy: perfect, sharp edges and peaks, follows 6mil details
Soldermask: no overflow, resolution superb, goes exactly even between 0.5mm spaced pads, no problem with arbitrary polygons, see the attached images
HASL finish: conform, no uncovered areas
Silkscreen: perfect, 0.1mm line, 0.8mm height text clear
Electrical test:  full
Time of fabrication: 27 hours from first step (cutting) to packing
Time from placing an order to delivery doors: 7 days, delays: 2 days to clear the soldermask requirements, 2 days on local holidays DHL delivery
Factory support: fast by email, clear and constructive, thanks to Della Deng

Only one restriction was unexpected: text on the bottom soldermask layer was refused by factory, they offer text only on silkscreen, this information is not published, arbitrary soldermask polygons are allowed.

OVERALL RATING: GREAT, fast and accurate process and express delivery by DHL, unbeatable value/price ratio, recommending ALLPCB for fast turn prototype boards.

Definitely will order again next time.

Freescale offers its Kinetis K10 – K60 series with TOWER System development boards support. ST comes with STM32F4xx, NXP with LPC4xxx, TI with LM4Fxxx. Production samples are available from all mentioned vendors.

Ionosphere conditions seem to follow a predicted tendency to reach a maximum in 2012/2013, so we may experience a long lasting DX openings and maybe blackouts :/ too.

This situation is obvious from the diagrams at NOAA Space center:

http://www.swpc.noaa.gov/SolarCycle/

http://www.swpc.noaa.gov/SWN/index.html

Signals often travel in mysterious ways, so we can reach Australia and Austria stations simultaneously from central Europe. It seems to be an effect of ionosphere reflections both low angle and Es and maybe some direction dependent reflections or scatterings as can be sometimes seen on ionograms, directograms and spectrograms.

Ionogram from station Pruhonice shows such a suspect reflections from E – NNE direction upto 9MHz f0F2 (light blue area).

Interesting effects can be seen on weak narrow bandwidth signals as WSPR are.

Below is the main window of WSPR codec in receive mode. Here you can see a repeating pattern of a fuzzy signal of unidentified transmitting wspr beacon because its frequency drifts too much. The cause of this drift is probably due to some ionospheric effect and Doppler shift [?]. Note the local time and the frequency!

Let’s see how beautiful show the mother nature is preparing for us in the next years..

to be continued