Few words about me:From very childhood I loved computers, electronics, lasers, sulfuric acid and liquid nitrogen. I always wanted to be making microchips, UAVs and see nuclear explosion.
Now I am doing software engineering and in the spare time - some microelectronics and physics/chemistry experiments.
I live and work in Russia, Moscow.
Fuming nitric acid synthesisIt is not that easy to buy 100% nitric acid due to it's instability (and hence special requirements for transportation) and wide range of it's applications. Distillation does not allow one to get above 68%. If we cannot live without 100% - we'll have to synthesize it ourselves. Last time I did that using quite inconvenient and unsafe method (decomposition of lead(II) nitrate, then dissolving mix of liquid nitrous oxides in 68% nitric acid. This process was too scary to describe in detail
This time I went for conventional and relatively safer route: potassium nitrate (100g) + 98% sulfuric acid (125ml, ~50% excess). You can then distill nearly 100% pure nitric acid.
Final result was reached much easier and faster. Yield was 50ml (which is ~50%, had no more time and ice to continue the process). Next time I will ether have to try something more high-tech (like Peltier cooling with Liebig condenser - Graham's condenser seems to be an overkill and strictly speaking you cannot use it at this angle), or run the process at winter (but it's probably not a good idea to store >100ml of 100% nitric acid due to it's instability).
I've tried a bit of final product right away by etching Texas Instruments IC with very chemically durable plastic.
First light of Skywatcher 120ED refractor telescope - Moon and SaturnJust received my new telescope - Skywatcher 120ED. With my old 10" dobsonian it was almost pointless to observe from the balcony - air turbulence was extremely severe and leaving no chances to catch even single clean frame. That's another reminder than bigger is not always better.
Venus and Saturn today
Good old A77ii+Sony 500F8
Upgrade time! LGA2011 FTW #2Progress in CPUs was getting slower in recent years due to lack of competition from AMD (until recently). 5 years ago I moved to LGA2011 with i7-3820 (4 cores, 32nm), not waiting for Ivy Bridge. Recently ebay got filled with lots of used server CPUs on LGA2011 which were compatible with my motherboard. That was extremely tempting and much more interesting than upgrading to yet another boring quad core system.
I went for E5-2695v2 - 12 cores, 30Mb of L3 cache, 22nm (Ivy Bridge). That is one of the largest commercial dies - enormous 492 mm².
This all currently costs mere 295$ (just 4 years ago Intel was charging whopping $2336 for that).
Task manager looks beautiful now:
A look inside Russian 28nm MIPS CPU - Baikal-T1Many of you might have heard about Baikal-T1 - Russian implementation of dual core Imagination Technologies MIPS P5600 32 r5 with on-board 10Gb Ethernet. Baikal was the first to implement P5600 core in silicon.
CPUs itself (had to go through 4 pieces to get a good die):
Read more on zeptobars.ru →
Time for decent SDR: Ettus N210 - 40Mhz of RF bandwidth
Although it is surreal to see 50Mhz of spectrum in realtime (40Mhz bandwidth using UBX-40 - 10-6000MHz RF frontend) - it is only available on the host in 8-bit mode (it already requires 800Mbit/s - using otw_format=sc8 in device string). In 14-bit ADC mode we can "only" fit 25Mhz through gigabit Ethernet. But if you're ready to do custom processing on internal FPGA - one can do better.