What does decent celestial navigation freeware on Android actually do?

Yes, I am at the middle of the 1500 km circle. Ie, at something like

1700 km. Those clocks are widely sold here, but they don't work on every room. Your graph explains it, but I already suspected it.

Pity there are no nearer transmitters. A network of transmitters, probably.

My clocks (I have 4) do not have a ferrite rod, like those in the wikipedia. Unless minimal and well hidden.

I guess all use the same chip, and it is faulty. Once the clock syncs well, it should reject an update that is more than some minutes off. Humm... but then there is the summer saving time change. But some clocks use 3 volts instead of 1.5 and work better.

I thought about that, yes, but not how to do it cheaply. A tablet would do, but more expensive.

Interesting, but complicated.

:-)

--
Cheers, Carlos.

Welcome to the world of the grownups!

--
Cheers, Bev 
     Nobody needs to speak on behalf of idiots, they manage 
     to speak entirely too much for themselves already.

They have ferrite rods buried inside somewhere. Even the "atomic wristwatch" has a tiny loopstick coil inside. Look for something like these, which are a bit large for a wrist watch: The key performance factor of a VLF receiver is the Q of the pickup coil. Higher Q doesn't produce more signal, but does dramatically reduce the inband noise levels. The higher the Q, the less noise is picked up, and therefore the better the SNR (signal to noise radio). Tiny rods are marginal, but do work. Big rods are much better for reception. Big loops are even better, but without the ferrite core, they tend to be huge.

Photos of both loops and loopsticks:

If it were easy, it would probably not be any fun.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

Very strange and improbable. The "atomic" clock works on VLF (very low frequency) around 60KHz. Most electrical smartmeters run spread spectrum around 900MHz. The gas meters tend to use VHF/UHF frequencies in the 160 and 460Mhz bands. Chances of interference between such widely spaced frequencies is unlikely.

However, there are plenty of noise sources that will trash VLF reception. Plasma TV's are a common problem. Switching power supplied found in everything from battery chargers to desk lamps are noisy. Some PV solar panels, converters, and inverters are horribly noisy. Same with some CCFL and LED lamps. HF (high frequency) ham radio was almost impossible at my house until I tracked down the culprit (cheap battery charger for my cell phone).

You can actually use a 128Kbit/sec sound card to hear (and see) the

60KHz signals. By implication, you can also see the nearby noise sources. Buy a 128Kbit/sec sound card or dongle. Download a copy of SDR Sharp. Go noise hunting. I'm sure you'll find something you didn't expect.

At least you're not at the talking clock stage. My eyesight is slowly deteriorating, but has a long way to go before I can't see a digital clock. Oddly, I have more problems with some colors. I can't focus on red LED's and orange Nixie tubes. It's just a big blurr without glasses. However, the blue fluorescent displays are easily visible. Try different colors and see if it helps.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

Nope. Between nightly updates, the watch free runs just like an ordinary digital watch. If it updates nightly, it doesn't have enough time to drift too far in 24 hrs. Besides, if it updated continuously, the updates would drain the battery. So, the WWVB receiver is powered on only after midnight, tries a few times according to some algorith, and then turns off for the night as soon as it gets a valid update.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

That's the weird part, my Casio watch seems to be the one most likely to sync up, so long as I orient it right when I go to bed, yet it's a miniscule antenna.

But having opened some of the "atomic" clocks I have it's also a surprise that the loopsticks aren't particularly long. Even the wall clock doesn't ahve a longer loopstick than the portable.

Michael

Ah, you did not spent the extra money ($4,400) for multiple lens in each eye like I did.

I went from two sets of glasses to none. Watch on wrist to TV and driving.

Sorry, you have only one chance at cataract sugery.

SHF

...

In between the two eyes I had several weeks with one new and one old.

The colors were oh so much better with the new eye and remain so for both eyes.

One thing about cataract sugary, do not delay it. Your eyesight may get worse at an increasing faster rate, I was almost blind even with one good eye as the old eye was so bad.

SHF

A friend just had those (+$3K over Medicare) done, and I envy her. My ophthodoc said that my astigmatism would make multifocal lenses worse than simple toric lenses (+$1K over Medicare), and I believed her. I've always had between 2 and 3 D of astigmatism on top of 2 or 3D of farsigntedness, and nobody in nearly 60 years of wearing glasses has ever been able to fully correct the goddam astigmatism. It's almost all gone now, and I thought about multi-focal contacts. Optometrist who seemed to know what he was doing said I wouldn't be happy with those either, and suggested monovision. That works, but not as well as I'd wish.

TMI, right?

Hubby's aunt's was botched badly -- wouldn't unfold or something. Not only couldn't she see, but it was really painful. The operation was redone and she's OK now. Rather different from "I'd like something better, please."

--
Cheers, Bev 
   "If you put the government in charge of the desert, there would 
    be a sand shortage within ten years."       -- M. Friedman (?)

No clue who said it first, but the consensus is that RF is magic.

The object of the antenna is to produce the best possible SNR, not the strongest signal. If you replace the tiny antenna with a bigger antenna, the WWVB signal will increase, but so will the received atmospheric noise level, resulting in no net improvement in SNR. What will change is the Q (essentially the bandwidth) of the receiver front end. A low Q wide band loopstick will pickup far more atmospheric noise than a high Q narrow band loopstick.

Notice how the atmospheric noise (mostly from lightning) increases dramatically as the frequency goes down:

Of course, there's a limit to how small a practical loopstick can be built. Mostly, the size of the wire to wind the loopstick, its resistance, and the characteristics of the ferrite material, set the lower limit. The loopsticks can be made smaller, if you can afford the fine wire needed to get enough turns.

There's also an upper limit to the size of the loopstick. It's possible to have such a high Q, that the bandwidth of the WWVB signal (about 5Hz) will not fit within the loopstick bandwidth. Temperature and mechanical stability will also be a problem with very high Q loopsticks. Orientation sensitivity also becomes somewhat of a problem.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

Thanks. I'm 68 solar revolutions old, so that's a real possibility. No sign of cataracts, but I'm borderline with glaucoma. Some of my friends have had cataract surgery and opted for strange combinations, such as one eye optimized for close work, and the other for distant and driving. They all say that it can be quite functional. Nobody mentioned color, but I'll ask.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

Oops. That should be a 192KHz 24 bit sound card.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

High pressure, drops, no damage yet? Likewise. The main reason I had my cataracts done was to get rid of the astigmatism (which glasses were never able to fully correct and which made contacts very nearly useless), and it worked really well!

I wouldn't dream of having permanent monovision (one eye for distance, one for near), but I have contacts like that. The brain deals with it

-- mostly -- but there's a certain amount of ghosting unless the light is really bright. My daughter doesn't even notice that with hers.

Cataracts turn the lens yellow. I was really surprised to see the difference in color between the two eyes. (I waited months to have the second eye done -- I wanted to be SURE!) The brain makes everything work together (my ski goggles are yellow, but within a minute or so the snow is all white again; when I take the goggles off the snow is slightly blue for a while), so it's not a real problem -- just interesting.

--
Cheers, Bev 
   "The object in life is not to be on the side of the 
    majority, but to be insane in such a useful way that 
    they can't commit you."              -- Mark Edwards

One problem with multiple lens in each eyes is sun glint during the sunny days and LED lights in dark rooms. After five years my mind is only partially reducing that effect. Any bright spot on DTV with a black background will have a halo.

I do NOT drive at night and do not recommend any one with multiple lens in each eye to do so.

The 4th of July Fireworks is interesting, each spot of light is a little Saturn with rings. All of them at once.

SHF

Don't you lose your binocular (3D) vision with that setup? I was offered that for my implants but declined. I never really minded wearing glasses all that much anyway. I have my implants set for indoor distances so only really need glasses for reading and driving.

My color improvement was amazing. I had no idea I was that bad. When they deteriorate slowly over the years you don't notice.

3 months for me. Between eyes I went to a Savers store and found some used glasses that had a lenses that worked for the new eye and knocked out the other lens for the old eye. Worked surprisingly well for that time I had unbalanced eyes. Looked a little weird though.

I've had the implants in ten years now with no problems. My eyeglass prescription never changes anymore which is nice. For some reason my pupils now give a green reflection which gives my grandkids a charge.

For those contemplating the procedure my only advice is don't wait.

Not that I've noticed. The out-of-focusness isn't that bad, especially when my pupils are stopped down. I would never have selected monovision IOLs, but I was surprised at how good the contacts are.

I had my IOLs set for distance. I spend most of my time doing close stuff, but I want to be able to see without glasses outside, which seems much more urgent. Besides, the 99-Cents-Only Store reading glasses work just fine, but you have to pay to get prescription distance glasses!

When my mom had her cataracts done her ophthoquack decided she should have near vision, which meant that she wore trifocals and hated them. She was really angry when I found out and told her that she could have chosen distance if that's what she wanted. The quack was a quack in other ways too, and another ophthalmologist spent half an hour on the phone trying to convince me not to report the bastard to the medical board. He won -- I knew I wouldn't be able to get a doctor to testify against the quack, but I was seriously thinking of picketing his office. Mom didn't want me to, so I didn't. "Ask me how Dr. Schiff blinded my mom..."

I just had one lens in my regular glasses replaced. Did the other one after the other eye was done. Glasses still improve my vision, but it's just SOOO much better than it was that I'm not about to complain. Well, maybe a little...

Slick.

Or at least wait until insurance covers it.

--
Cheers, Bev 
   "The object in life is not to be on the side of the 
    majority, but to be insane in such a useful way that 
    they can't commit you."              -- Mark Edwards

For sure. Mine cost me 50 bucks an eye.

Was that for 'normal' lenses or toric/multifocals? Medicare pays for ordinary lenses, but the user has to pay the difference for the fancy lenses. $1K each for torics and $3K each for toric multifocals.

--
Cheers, Bev 
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
"The language of victimization is infinitely extensible."  -- Me

On 12/2/2016 1:01 PM, The Real Bev wrote: > On 11/30/2016 11:15 PM, AL wrote: >> On 11/30/2016 10:51 PM, The Real Bev wrote: >>> On 11/30/2016 09:20 PM, AL wrote: >> >>>> For those contemplating the procedure my only advice is don't >>>> wait. >>> >>> Or at least wait until insurance covers it. >> >> For sure. Mine cost me 50 bucks an eye. > > Was that for 'normal' lenses or toric/multifocals?

Normal lenses with UV and blue light filter.

I'm on a Medicare Advantage (independent insurance company's) HMO plan and the $50 was an outpatient co-pay per procedure. I was offered other types of lenses at the time but it's been ten years and I don't remember what they were or any added costs.