PLL tricks

Doubt it. They had mainframe computers and analog computers. The lunar lander had an onboard computer; ditto the S1B booster. I bet they simulated a lot of stuff.

The first people who invent things generally don't do it the best way. Copiers can improve it.

Most people now use small ARM chips and Linux in phones and tablets. I like massive CPU horsepower and gigabytes of fast DRAM for simulation.

Probably not. Some mass virus, like ebola or something, could be nasty. Or a comet, or a big volcano. But economics will muddle along.

People are buying less crap. TVs last a long time and are good enough. Ditto cars.

Verify hydrodynamic simulation code.

What they need is fresh tritium.

On a sunny day (Sat, 20 Sep 2014 10:41:02 -0700) it happened John Larkin wrote in :

Yes I played moon landing game on a PET2000 computah, it had a cassette drive for the program:

OTOH, Von Braun was a bottom up man, he started as kid playing with rockets, he and his German crew knew everything there was to know, and that is the only reason it worked, his brain, his neural net, no simulations. Basic math. It is always interactive, his first satellite was too high up.... he forgot to account for the rotation of the earth to give that extra push IIRC.

Copiers do, and copiers have been improved too:-) First there was Japan making better cameras (where is Kodak), now China is making better things, look at their fighter jets, those really fly, unlike the F35 that is slimulated.

Many if not most high end tablets have quad cores these days.

I could imagine people turning against engineering, burning engineers like witches. It does not take much to change group consciousness, create some sort of hysteria. You see them attacking ebola doctors now, and right they are! Them clueless doctors are spreading it all over the globe, big farma sees an opportunity to push an other global vaccine down peoples throats.

The old TV standard lasted many many years, then a short period of color using the same H and V frequencies, then digital, now DVB-S2 here, not to mention DVB-T, and even a new standard is in the making (better encryption too I think). Changes now every five or so years, people need to buy again and again and again. Same with computahs, a 10 year old computah is probably not worth repairing. Well, I still have a 10 year old computah somewhere... its off.

Even my Raspberry Pi version B is now old, the B+ version (bigger GPIO header) is now out.

On a sunny day (Sat, 20 Sep 2014 10:42:26 -0700) it happened John Larkin wrote in :

My tritium decay experiment is now running for 2 1/2 years. They cannot have it.

Now I'm confused. People buying less crap is *exactly* the one thing that will topple capitalism.

We can't let that happen and the entire free market is behind me on this.

Yeah, don't worry, socialists like Slowman will feed you.

So far, geeks are hot stuff. Gone are the days when nerdy guys lost the girls to jocks. You should see Dolores Park on a sunny weekend afternoon.

Conventional TV will soon die. The cable and satellite companies will just transport Internet traffic. Everything will be digital, watch-anytime, mostly commercial-free.

E-mail is all I've got, but I'd be happy to send them your way.

Mail me at my posted address (it's good), and I'll send you the articles.

Cheers, James Arthur

Thanks James. email is on the way.

Luxury. We used programmable calculators, mostly made of wood, and had to plow through the driving Southern California winters with pedal-power to do that. All that just to crash on a simulated moon, and die an ignominious, simulated death.

Cheers, James Arthur

Monty Python did it first. And they had to work a 29-hour day.

Open it in Firefox or Safari, or some other browser that supports MathML (not Google Chrome).

Clifford Heath.

Got the articles. Thanks.

Your return email address bounced so here's my reply:

Hi James,

Thanks very much for the articles. I think he is using the wrong approach to calculate the reduction in crystal Q. Transistor hFe is the DC current gain, not the gain at HF or VHF. It is cerainly not 100 with those transitors. Also I'm not sure about putting the crystal in series with the emitter. Using the grounded-base emitter impedance is a poor idea in my view. The series capacitors used in the Colpitts or Clapp would be much lower and much more repeatable.

But it is still interesting to see how circuits were designed in the days before LTspice.

His brain is not dead, but sleeping. When it wakes up, it may recognise the advantages of German-style socialism - more social mobility and a better education system, amongst others.

Sadly, the original Arthur was British, not American, so the magic may not work for our James Arthur.

So, Tom Swift, when did you get back from Mars?

I haven't seen this paper, you could send it to me and I can give my 2 cents worth.

In reality though, LTSpice is useless for low phase noise design. A professional level RF tool such as Cadence or Agilent is the only realistic way to to it. Periodic steady state phase noise is mandatory.

I say this from, literally, running 10,000s oscillator phase noise simulations over the last 5 years. Phase noise tools, spit out exactly what component is contributing what noise, allowing you to figure out what needs to be changed. Manual calculations are, essentially, impossible, e.g.

Example, I looked at the Wenzel oscillator

Teaser - in the clockosc.htm, the close in noise is not mentioned, why does the method shown of connecting the limiter to the oscillator severely degrade the close in phase noise? Hint: failure of Hajimiri-Lee method discussed in phasenoise.html above.

Correct answer gets a free SuperPSice licence :-)

Kevin Aylward

On a sunny day (Sat, 20 Sep 2014 14:26:29 -0700) it happened John Larkin wrote in :

Not sure, a single controlled channel to control the masses is very useful. Satellite can reach many homes, cable not everything. for Germany ARD, ZDF etc for the UK BBC(1-4).

Advertisers do big business here with free to air sat channels. Germany: prosieben.de sat1.de vox.de, rtl.de rtl2.de (type in browser), UK: C4, C5, ITV(1,2),

I would not pay for movies, those are not that great.

What I found peculiar is that a few weeks back 'Avatar' was announced on one of these free channels. Now 'Avatar' was a 3D production, but not a word about 3D. They transmitted it in normal resolution, 2D. Still watchable though. Is 3D dead?

Yes I have very fast cable too, on a regular basis the speed is increased it seems. downloading a Linux 4 GB DVD is very fast... youtube is fast too...

But cable, as in TCP/IP, shares bandwidth with other users, so the more start streaming movies the more the speed decreases IIRC. They do have movie on demand too, never used it. If a movie is really good I will hear about it and some day it will appear on one of those free to air sat channels.

There do not seem to be that many that are good, UK re-transmits the same ones over and over again. think I have seen the same 'bond' movies in the program list for at least 10 times. I mean how many times can you stand it... you know, I typed rm smoking_aces_german.ts terminator_3_rebellion_der_machinen_german.ts yesterday, had it running overnight recording from sat, yes they change the sound channel to German. sometimes the German sound is better than the original, they do not transmit the original sound. Anyways, just deleted it without watching it.

Caesar: "Give the people bread and games" That is when he was making war and conquering country after country, in the same way we bomb country after country and employ the fugitives as slaves here in low level jobs. Nothing much changed, but ask yourself where is the Roman empire now? The slaves had some uprising, Caesar was killed, that Cleopatra stuff, the Roman allies were treated like dirt by the now slaves in power, and turned against it, then all by itself the Roman armies were nowhere, it got overrun by 'barbarians' (talk about painting the enemies, these days we have Al Quada, well for the US mostly the rest if the universe), history repeats itself. As I stated I cannot say too much: prime directive: Do Not Interfere With Time line.

Thanks, that fixes it.

Cheers, James Arthur

Sure thing.

Odd. Your first e-mail came through fine, yet Mr. Heath's went to the spam box. Yahoo, ironically, is getting uppity.

(OTOH, George H.'s ISP rejects my emails no matter where I send them from. :-)

I think he's using hFE for d.c. bias and computing the effective emitter resistance, not r.f. gain. He later refers to the effect of the (emitter resistance + crystal ESR) on figure 6/7's r.f. gain.

But I was perhaps unfair in describing the preferred technique. Matthys also gives favorable report on the harmonic Pierce version, and says (in the earlier article):

"Using a reactive load on the crystal (as in the Pierce circuit) is a very effective way to obtain a high in-circuit Q."

His 2nd article (several years later) concludes:

"The Harmonic Pierce (Figure 9d) is a simple and excellent circuit whose short term stability is almost as good as the emitter coupled circuit. The Harmonic Emitter Coupled circuit (Figure 1) is a little more complex than the others and can have more parts, but it has the best short term frequency stability."

I've got another, slightly earlier 1983 article by Belcher that recommends the impedance-inverting Pierce configuration. He gets in-circuit Q~=70K.

Belcher also posts drift data showing that his improvements do not degrade the crystal's intrinsic tempco, as an indication that the crystal is in full control.

Unfortunately that article only scans legibly in gray-scale, which makes the file size impractical.

"Crystal Oscillator Circuits by Robert J. Matthys" came out in 1983, IIRC. That's the version I have, apparently since revised:

Format: Hardcover ISBN-10: 0894645528 ISBN-13: 9780894645525 Publisher: Krieger Publishing Company

Cheers, James Arthur

"At what carrier offset?" is always the question, of course.

At first glance, the 100pF coupling cap would seem to be a big problem at low frequency.

But we can't expect Wenzel--who's in the low-noise oscillator business--to put out his best secrets for free.

Cheers, James Arthur