Intresting Engine

This is the tricky mechanism to learn:

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I used it on my hydraulic loader to allow the bucket to drop to 30 degrees from vertical when fully raised, to dump sticky wet snow.

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--jsw

Reply to
Jim Wilkins
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"Jim Wilkins" fired this volley in news:np1k70$4lj$1 @dont-email.me:

We were running crypto'd voice in 1968 on Navy River Boats, over in 'Nam; and I think they'd been using them for several years by the time I got there.

The unit was about the size of a medium-sized benchtop oscilloscope (like a Tek 525). We changed the 'Cac' code every day, as part of our pre-mission checkouts.

Lloyd

Reply to
Lloyd E. Sponenburgh

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Tactical crypto machines were smaller, lighter and less secure, since your comms about your mission became 'stale' and useless to ambush you once you returned to base. The good stuff, the KG-13 and KY-3, weighed several hundred pounds.

We were safeguarding Army payroll data, which sounds silly until you realize that -where- troops were paid was important, not how much they made. For example Putin would really like to know if US tank commanders started receiving their pay in Ukraine.

The Navy had a very serious leak back then:

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--ave52G

Reply to
Jim Wilkins

"Jim Wilkins" fired this volley in news:np269q$3h8$1 @dont-email.me:

The KW-7 looks darned familiar! I think that was the one we had on the boats.

Lloyd

Reply to
Lloyd E. Sponenburgh

It was meant to be used with a Teletype.

Reply to
Jim Wilkins

The

My only quibble is that the trick, at least on the Honda, is this also means the intake valve CLOSES late, allowing some of the charge to be pushed back into the intake manifold. So, the compression stroke starts with the piston part way up the cylinder. This ends up with pretty low compression (or cylinder pressure, if you prefer) at ignition.

I'm guessing the trick in the Nissan engine is they effectively reduce displacement while still achieving a good cylinder pressure at low horsepower settings. That ought to improve efficiency.

Jon

Reply to
Jon Elson

I've never paid much attention to Atkinson engines, so I don't know what Honda is doing. BTW, the reason usually stated for *not* using the Atkinson cycle in regular engines is that they're not very tractable. I have read that they're slow to respond to the throttle, but beyond that, I don't have a clue.

There must be a lot going on with the Nissan engine, combining the turbocharger, the variable compression, and the Arkinson cycle. They may have published a paper on it with SAE. That's where you get the details.

Reply to
Ed Huntress

"Jim Wilkins" fired this volley in news:np287g$a6q$1 @dont-email.me:

Well, then, that wasn't the one . Ours was voice.

Lloyd

Reply to
Lloyd E. Sponenburgh

A $12k more expensive saw makes a "slightly better cut" and you think I want to get rid of my new used saw which I haven't yet assembled? OK, I'll go out back and lob it in your direction. It might miss your yard by 623 miles, but...

I wish I had it together right now. I have to build a cabinet door for a client. A local cabinetmaker wanted $400 to do one for me. I asked him why he thought $25 worth of wood and an hour of his time would be worth that. It'll take me considerably longer because I don't have his shapers and spray booth, but I'll do a hand rubbed oil finish instead. In the interim, I'll rip with the Makita SP6000J and route with the rail and stile set from HF. Both make very decent cuts.

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In 2 weeks, when I retire, I'm going to start getting a usable shop back together and add a few dozen feet more shelf space. Then maybe I'll be able to see floor in there again.

I can't wait!

Reply to
Larry Jaques

The only reason they'd be slow to respond is if the mechanism that changes the valve timing is slow. I'm sure this is true in the Honda hybrid engine. They put a rotary hydraulic cylinder in the intake cam sprocket, and I'm guessing the control valve on that has a small orifice so that the computer can keep up with the change in valve timing. I assume it has some sensor on the cam so it can measure the valve timing every cam revolution. So, it probably takes a dozen cam revolutions to make a large change in timing.

I can't imagine any other reason why it would be all that slow to respond. If there was some kind of immediate angle sensor in the sprocket so the computer had instant feedback of the valve timing, it could probably respond a lot faster. The hybrid system masks this, you can even see it on the battery gauge. Any time you push down on the gas pedal, the hybrid system applies power until the ICE ramps power up, the revers if you ease up on the pedal. it only takes 1/4 to 1/2 second to respond.

Yup, sounds like a lot to manage.

Jon

Reply to
Jon Elson

Yes, KW is ciphered teleprinter, KY is ciphered voice.

Jon

Reply to
Jon Elson

I see that Nissan published several papers on the development of this engine, but the last one I saw was from 2006. I just read the abstract.

Reply to
Ed Huntress

On Wednesday, August 17, 2016 at 10:54:26 AM UTC-4, Lloyd E. Sponenburgh wr ote:

$1

Is this similar to the control head?

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That was the only voice scrambler I saw used on Marine aircraft in Vietnam. I figured the Navy used the same one but maybe the river boats were differ ent? Had to change the codes at midnight every night. Code books were locke d in a safe with two thermite grenades inside. If we got overrun, were supp osed to set the grenades on top of the safe and set them off.

Garrett

Reply to
Garrett Fulton

Garrett Fulton fired this volley in news: snipped-for-privacy@googlegroups.com:

That doesn't ring any bells, mentally. I don't know. It was a long time ago in a land far, far away! I thought I remembered it being about half as big as the radar head.

I remember that we had TWO forms of encryption. First was the box itself. Then, when we had to convey specific coordinates (say, for a strike, but NOT while under fire), we used a paper code-scrambler wheel, which they changed-out every week.

They weren't taking any chances that Charlie could figure us out from our radio comms.

Lloyd

Reply to
Lloyd E. Sponenburgh

Radio Intercept was a very important weapon in the fight against U-boots, which were required to frequently report their position so they could be vectored toward Allied shipping.

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Although the position report was strongly encrypted, the direction they transmitted it from told the anti-sub forces all they needed to hunt it down. The Germans were well aware they could be located the same way they tracked down spy transmitters in France, but they didn't realize the British system could find them instantaneously using a method they had dismissed as inaccurate. It -was- inaccurate from distant land bases, but good enough when the HF/DF direction finder was on a destroyer trailing the sub.

I heard about Spread Spectrum in 1970, though not if we used it in small tactical radios. It makes a radio transmission indistinguishable from static.

--jsw

Reply to
Jim Wilkins

One thing the KY-28 units would do was to make a single "boop" sound in the headsets when you keyed the transmitter. Let you know it was ready to encrypt audio. Never saw the paper wheel units. Yeah, long time ago but it was interesting equipment.

Garrett

Reply to
Garrett Fulton

Garrett Fulton fired this volley in news: snipped-for-privacy@googlegroups.com:

Yep. That was it!

Lloyd

Reply to
Lloyd E. Sponenburgh

Well, anyhow, a belated welcome home Sailor. Thank you for your service. :)

Reply to
Garrett Fulton

Garrett Fulton fired this volley in news: snipped-for-privacy@googlegroups.com:

Thank you, sir! L

Reply to
Lloyd E. Sponenburgh

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