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A 6 channel GPS receiver from 1993

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Re: A 6 channel GPS receiver from 1993

#51

Post by jdietrich »

eastbound wrote: post #50
jdietrich wrote: post #36

Earlier quoted context omitted.

>What does a six-channel GPS receiver even mean? Is more channels more better? The operating principle of GPS is more complex than I can usefully summarise in a comment, but essentially the satellites are continuously broadcasting an extremely accurate time signal that the receiver uses to calculate the time-of-flight to each satellite. GPS receivers need signals from a minimum of four satellites to provide a locatio…

How does encryption work on GPS signals? Since it seems the military have access to better accuracy, it’s not just a wavelength that is broadcasted.

Prior to 2000, the civilian signal (C/A code) was deliberately degraded by the addition of small random variations in the time signal, but this is no longer the case. A separate military signal (P-code) still exists, which is encrypted in order to prevent spoofing; to my knowledge, the encryption scheme used for the military signal is still classified.

Re: A 6 channel GPS receiver from 1993

#52

Post by aziaziazi »

TedDoesntTalk wrote: post #18

The original GPS receivers in the late 80s and early 90s did not have maps. And they used LCD screens. The one I owned by Lowrance required 6 AA batteries. Not AAA. Not rechargeable. Optional power through a cigarette-auto cable, but that's not helpful when on foot. It burned through batteries like crazy. I owned this one: https://web.archive.org/web/20231104153749/http://retro-gps.... (Lowrance GlobalNav Sport) 160…

Wondering why « No rechargeable » ? I recall rechargeable AAs in late 90, didn’t they exist in early 80 ?

Re: A 6 channel GPS receiver from 1993

#54

Post by hexmiles »

aziaziazi wrote: post #52
TedDoesntTalk wrote: post #18

The original GPS receivers in the late 80s and early 90s did not have maps. And they used LCD screens. The one I owned by Lowrance required 6 AA batteries. Not AAA. Not rechargeable. Optional power through a cigarette-auto cable, but that's not helpful when on foot. It burned through batteries like crazy. I owned this one: https://web.archive.org/web/20231104153749/http://retro-gps.... (Lowrance GlobalNav Sport) 160…

Wondering why « No rechargeable » ? I recall rechargeable AAs in late 90, didn’t they exist in early 80 ?

Not OP, but i remember having a camera that use AAs and would not support rechargeable. While it powered up, it would not take photos and instead shutdown. I think they used to be able to deliver less power, also when i put them in the gameboy the little led was a tad dimmer that non rechargeable one even when fully charged

Re: A 6 channel GPS receiver from 1993

#55

Post by bee_rider »

mananaysiempre wrote: post #46
bee_rider wrote: post #15

Earlier quoted context omitted.

I wonder if it was the pre-90’s black/grey market, or the intervening decades of open trade.

I’d guess the former, but only because I’m honestly surprised anything designed or manufactured under government mandate post (generously) 1985 actually works. The collapse of the Soviet Union might have marked the start of open (!) looting, but with rare exceptions Soviet research organizations have been in pure subsistence mode for a decade or more before that.

The Kinzhal is a sort of heavily modified Iskander, I mean all ballistic missiles are rocket science but it is not some super futuristic weapon.

Re: A 6 channel GPS receiver from 1993

#57

Post by ljf »

aziaziazi wrote: post #52
TedDoesntTalk wrote: post #18

The original GPS receivers in the late 80s and early 90s did not have maps. And they used LCD screens. The one I owned by Lowrance required 6 AA batteries. Not AAA. Not rechargeable. Optional power through a cigarette-auto cable, but that's not helpful when on foot. It burned through batteries like crazy. I owned this one: https://web.archive.org/web/20231104153749/http://retro-gps.... (Lowrance GlobalNav Sport) 160…

Wondering why « No rechargeable » ? I recall rechargeable AAs in late 90, didn’t they exist in early 80 ?

Even in the early 90s my good rechargeable batteries (AA) only put out 1.2v when freshly charged and dropped lower than that as they ran. They also ran far shorter than duracell or similar expensive batteries.

So one the voltage may have been too low and two the usable loge might have been too short for these power hungry devices

Re: A 6 channel GPS receiver from 1993

#58

Post by _whiteCaps_ »

aziaziazi wrote: post #52
TedDoesntTalk wrote: post #18

The original GPS receivers in the late 80s and early 90s did not have maps. And they used LCD screens. The one I owned by Lowrance required 6 AA batteries. Not AAA. Not rechargeable. Optional power through a cigarette-auto cable, but that's not helpful when on foot. It burned through batteries like crazy. I owned this one: https://web.archive.org/web/20231104153749/http://retro-gps.... (Lowrance GlobalNav Sport) 160…

Wondering why « No rechargeable » ? I recall rechargeable AAs in late 90, didn’t they exist in early 80 ?

I had a radio that could handle rechargeable vs non - it included a dummy AA battery that you used when using non-rechargeable batteries, so you'd use (IIRC) 7 rechargeables + 1 dummy or 8 rechargeables.

Re: A 6 channel GPS receiver from 1993

#59

Post by saltcured »

TedDoesntTalk wrote: post #18

The original GPS receivers in the late 80s and early 90s did not have maps. And they used LCD screens. The one I owned by Lowrance required 6 AA batteries. Not AAA. Not rechargeable. Optional power through a cigarette-auto cable, but that's not helpful when on foot. It burned through batteries like crazy. I owned this one: https://web.archive.org/web/20231104153749/http://retro-gps.... (Lowrance GlobalNav Sport) 160…

The first "portable" GPS receiver I ever saw was during a tour of a relative's military base in the mid to late 1980s.

It was mounted in a travel case where the lid removed exposed the control panel. I want to say it was about the size of a shoe box. Similar in length and height to one of those hinged metal ammunition cans, but wider if I remember correctly. It seemed hefty enough to have a lead-acid battery inside, but they did not give details.

You set it on the ground and waited minutes for a fix. Then it just displayed numeric grid coordinates of your location with segmented digit display cells somewhat like a 1970s calculator.

Re: A 6 channel GPS receiver from 1993

#60

Post by gambiting »

assusdan wrote: post #19
gambiting wrote: post #14

Earlier quoted context omitted.

It's incredibly racist, offensive and ignorant to assume that "Eastern Block" means just Russia. Many former "eastern block" countries nowadays are firmly with the west and oppose Russia and their stupid invasion with all their might. Being bundled together with the Russians is the most personally offensive thing I've ever read on HN.

Could you please also stop bundling all russians together? Not all of us oppose "the west" and support our stupid invasion.

I didn't say either thing though? I said many of us here in the former Eastern Block oppose Russia - and I personally find being bundled with the Russians offensive, as I am not a Russian. Anything you read into it beyond this point is your own interpretation.
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