Monday 30 April 2012

Fundamental changes

It seems to me that we need to make two fundamental changes.

First to reform the banking business - more service not product, stop the money go round, e.g. CDS. Stop pouring good many after bad - if you make a poor investment you must be allowed to loose it, e.g. housing equity versus mortgage loans.

Second to change our gaze from making money as a life goal, to making wisdom or intellectual achievement as our life goal. After all we are better designed to think than just shove money around.

Thursday 26 April 2012

Lots of Amateur Radio circuits

Here's a bunch of Amateur Radio circuit ideas, none have been tested!

A two SA612 receiver: The first is a mixer amplifier feeding the IF crystal filter, followed by a second as mixer/beat oscillator giving an audio output

RX 3

An unusual receiver with a balanced detector, an audio amplifier and a local oscillator using a CMOS invertor

RX 4

Here's a mixer using a CMOS switch. With as RF preamp and audio amplifier.

RX 5

What could be simpler? a one transistor radio. With a balanced mixer and simple VFO

RX 6

Now something different: an electronically tuned ATU, for receive only obviously.

RX ATU

Lastly an SWR meter, with easily wound torrid transformers SWR METER

Torroids from torrid.info:

Screen Shot 2012 04 26 at 16 49 58

Tuesday 24 April 2012

Money - I have a theory about that

Maybe we have got everything the wrong way round? Incessant publicity or news mongering these days insists that financial markets want Europe to fix things. It seems that we have all borrowed too much, but the corollary of that is the someone lent us too much, and who was it? The banks!

So maybe the right way forward is for Europe to fix the banks? And there is a lot to be said for that. After all money belongs to society, it is something we have created to allow us to trade. It is not a plaything for banks to make their financial instruments, or products. Finance is after all a service not a productive industry, they have no such things as products, and should only provide services. And they are not very good at that.

Most of their business just involves swallowing up capital, making it go round and round faster, if the capital becomes too scarce then they avidly look for other ways to get or create some. For example, inflated house prices, they get millions on their books in assets by promoting higher and higher, bigger and bigger house prices and bubbles. Credit cards and loans and sharks - again a licence to print more money, and they regularly lend 10-50 times more money than they actually have, its called leverage.

Then if they make a mistake and some of their loans go bad, that is we don't pay up, then they bully us for more money saying their will be a global crash. Maybe but it might be just what is needed. The problem is how to protect you and me and our savings, no problem to write off our debts! Thank you!

Its just that the banks take little or no risk on their loans, you buy a house, it belongs to them as they just advanced the money on a loan and kept the deeds. You start to pay it back. Now the market in houses falls and your house is not worth what you paid for it - more common to day than you might think - you are in what they call negative equity, you do not have the asset value to pay off your loan. But the banks has lost nothing, they still have the value of the loan you signed up to. Surely they should take a risk too? If the house market falls, their assets should also have lower value? No?

Money I repeat is ours not the banks. We earn it, we spend it, they just facilitate it going round. The huge debts built up today are a misuse of money and entirely the banks fault.

Sunday 22 April 2012

UK's lost moral compass

As a society we have a choice: open or police state.

And I am talking about surveillance: CCTV, Internet, mobile phone… all of these are increasingly being used to survey people's place and actions. The actions may be criminal, but that is in the spectrum of society. Not all of society is good. And punishing the bad is not a way to reform society. Even prisons now focus on reform of the individual rather than punishment, the re-enforcement of moral values.

UK has more CCTV cameras than any other country in the world, they are used for viewing the most absurd activities: like emptying the wrong things into a wheely bin.

Internet surveillance is reaching increasingly across all of us, when we thought we had finally a tool to improve society's communication and understanding, the UK government want to treat it with special concern and monitor all communications. They surely are stupid, the internet is just like standing talking to a friend on a street corner - or is that illegal now too?

Mobile phones are widely used to track people, as long as you have your phone switched on it spends an amount of time polling for the nearest cell tower, so that it knows where you for are any incoming phone call. This information is all in a computer and accessing it provides a way to track you. Even shopping complexes are using it now to track shoppers as they go round and build a view of there activities.

So it is time to say NO. We do not want to be tracked and monitored. The intrusion outways the risk of non-detection and crime prevention.

There is a better way to improve society: that is to improve our moral education. This is the job of churches, mosques and other moral or religious establishments. A challenge that they are not facing up to today. When we elect (sorry appoint) a new archbishop of Canterbury soon, let's keep this very much in mind.

Saturday 7 April 2012

About SDR

Here are a few slides I just made explaining how SDR works: SDR Slides 001 SDR Slides 002 SDR Slides 003 SDR Slides 004 SDR Slides 005 SDR Slides 006 SDR Slides 007 SDR Slides 008 SDR Slides 009 SDR Slides 010 SDR Slides 011 SDR Slides 012 SDR Slides 013

RF Matching

In my quest to get up to speed with Amateur Radio (see my previous posts about amplifiers and the such) I need an ATU - or antenna tuning unit. At the moment all I have as an aerial is a length of wire from the upstarts bedroom window down to my study. This in no-way matches the input of my small Software Defined Radio (Acorn G0NQE model). And all I get is tons of loud hissing or, as amateur call it, QRM.

So I looked first into a simple LC matching network. But what values to use.

Lc

If you assume their are just restive source and load then:

Xl = sqrt(Rs ( Rs - Rl)

Xc = Rl sqrt(Rs/(Rl - Rs))

For Rs = 50R and Rl = 1000 this would yield:

Xl = j217.9R and Xc = 229R

Now, if the frequency is 3.6MHz, then:

C = 1/(2pi x f x Xc) or 193pF and L = Xl/(2pi x f) or 9.6uH.

That was easy wasn't it?