Bootstrapping access to space – from the White House

I just saw the post about bootstrapping our access to space via Slashdot and after a long upsetting day at work seeing this and thinking about what it means puts my day (and week) into perspective and makes me feel a little better.  It’s likely that none of these ideas are original and are obvious but I wanted to take the time to send an email even if all it is is just a vote in support of the goal.

The first thing is I believe that it might be the case that a lot of people would work on projects relating to space in return for food and board,  particularly if there is the promise of getting into space at some point in their career.  This isn’t a suggestion to use people as cheap labour but to think about the possibilities of creating extraordinary work environments for these kinds of projects.  Perhaps in a similar model to the idea of the Peace-corps
I also think that getting on board with Lockheed Martin’s recently announced project for a small fusion reactor should be made a priority relating to this project.  If this project pans out as is suggested, particularly given the small size targeted for the reactors there could be a natural match to space technology.
My final point is that it might be worth looking at the individuals who are signing up for a one way ticket to Mars.  That’s the level people will go to to work in space. So I think not everything should be about robotics.

Creating a new audio amplifier part 8.

After a bit of a long delay I’m going to call this finished.  I knew it was all working but it had been in a a testing phase for too long so I made a big effort to get the thing done. I’ve redone a lot of the internal wiring and put the front and back panels on.  These are made of an old server lid and are galvanized 1 mm steel sheet.  I had to cut the strips with a cutoff wheel in an angle grinder so I could then use tin snips.  It would have better to use a guillotine.  Steel is I think better than aluminium, it is stronger and I think it works better at shielding.  When I was testing the amplifier with the computer prior to finishing the panels I was getting some kind of electronic noise coming through, now I get nothing.  (I presume it must have been the graphics card that would generate audible harmonics because the rest of the computer would generate signals outside the audio range).

amp_front_covered

The main heat sinks are made from an old industrial air conditioning controller. The heatsink on the bridge is half a heat sink for some old cpu.  Note that the transformer from the old receiver is shielded, it seems to be very quite. The only issue is that I have no idea of the VA rating of the thing.

amp_from_front

I had to do a fair bit of hacking around on the front inner panel due to my not measuring properly where the pots and the audio were going to protrude.

amp_from_back

 

I’ve also replaced the old power switch with a DPDT and included a mains filter (no idea if that is needed) and a mov directly onto the IEC plug.  The speaker / headphone switch is another 240v switch of about 16 A and to the left is the resistor network for the headphone output.  I tried to make all the wires use plugs to make for easy repair.

amp_over_to_right

The heat sinks for the power amp chips are insulated from the chassis so I need no washers between the metal tabs of the chips.  This means the heat sink is at about -ve 30 something volts I think.  I tried to make the wiring as neat as I could and separate the blocks of function so the inputs are at the front of the amp near the pre-amp and the speaker plugs and headphone socket are along the back. This means the signal travels from low to high around from the front to the right and then through the power amp and then to the rear.  240 v is along the lhs edge and the DC is over to the left.

amp_rear

This is what it once looked like.

Receiver purchased for $10 from the tip.

Receiver purchased for $10 from the tip.

The original components in the receiver

The original components in the receiver