Digest for sci.electronics.repair@googlegroups.com - 17 updates in 5 topics

oldschool@tubes.com: Oct 29 03:01PM -0600

On Sun, 29 Oct 2017 13:24:24 +0000 (UTC), Bruce Esquibel <bje@ripco.com>
wrote:
 
>I'll give ya a +1 for both of these, in 1990 remote control sets were not
>entirely standard issue, especially on the lower end (which MW falls into)
>and trying all 999 codes might be the only way.
 
I once tried all 999 codes on a Universal remote. NONE of them worked. I
just wasted a lot of my time doing it. Some, if not most of them are not
as "universal" as they claim to be.
John-Del <ohger1s@gmail.com>: Oct 29 04:11PM -0700

On Sunday, October 29, 2017 at 12:16:48 PM UTC-4, Allodoxaphobia wrote:
> > and trying all 999 codes might be the only way.
 
> No one has yet mentioned the ultrasonic or RF remote controls....
 
> Jonesy
 
 
If there was an audio or rf remote used in a 1990 domestic TV, I'm unaware of them, and I repaired just about every TV that was ever sold in this country. TVs went IR in the late 70s - an RCA B&W remote portable being the last "impac" tuning fork clicker that I'm aware of (mechanical tuner with AC motor drive).
Sjouke Burry <burrynulnulfour@ppllaanneett.nnll>: Oct 30 12:30AM +0100

On 30-10-2017 0:11, John-Del wrote:
 
>> No one has yet mentioned the ultrasonic or RF remote controls....
 
>> Jonesy
 
> If there was an audio or rf remote used in a 1990 domestic TV, I'm unaware of them, and I repaired just about every TV that was ever sold in this country. TVs went IR in the late 70s - an RCA B&W remote portable being the last "impac" tuning fork clicker that I'm aware of (mechanical tuner with AC motor drive).
 
A tv repair guy told me about a mystery repair, where they were
called in several times for a tv which was switching channels
all the time.
remote control was using sound.
He finally found the reason for the errors.
He saw a parrot opening its beak, each time the tv switched.
The stupid bird imitated the sonic when he disliked the tv program....
Cure? Remove the bird.....
Mike Coon <gravity@mjcoon.plus.com>: Oct 30 10:33AM

In article <59f66444$0$1714$e4fe514c@textnews.kpn.nl>,
burrynulnulfour@ppllaanneett.nnll says...
 
> He saw a parrot opening its beak, each time the tv switched.
> The stupid bird imitated the sonic when he disliked the tv program....
> Cure? Remove the bird.....
 
No, promote the bird to "genius"! Replace TV.
 
Mike.
John-Del <ohger1s@gmail.com>: Oct 30 06:43AM -0700

On Sunday, October 29, 2017 at 7:30:58 PM UTC-4, Sjouke Burry wrote:
> He saw a parrot opening its beak, each time the tv switched.
> The stupid bird imitated the sonic when he disliked the tv program....
> Cure? Remove the bird.....
 
You just triggered a long dormant memory. One of the tricks techs would do on the early ultrasonic remote receivers was to jingle their keys right at the TV's microphone. If the TV responded in any way, we'd just order a new transmitter. Of course, the old "impac" tuning fork "clickers" never quit entirely.
 
Young guys could put the transmitter right against their ear and hear them work. Whether they were fundamental or harmonics they were hearing I don't know.
"tb" <nospam@example.invalid>: Oct 30 02:57PM

On 10/29/2017 at 8:56:01 AM Roger Blake wrote:
 
 
> As others have pointed out it is quite possible that set did not come
> with a remote control. Is there a visible infrared receiver on the
> front?
 
Yes, there is an infrared receiver on the front of the TV set. And the
TV came with its own remote control which still works.
 
I was just hoping to use a single remote control for TV and converter
box, instead of two...
 
--
tb
John-Del <ohger1s@gmail.com>: Oct 30 09:15AM -0700

On Monday, October 30, 2017 at 10:57:54 AM UTC-4, tb wrote:
> box, instead of two...
 
> --
> tb
 
 
Then what you need is a learning remote. They used to be popular - don't know if they still make them. Google "learning remote".
whit3rd <whit3rd@gmail.com>: Oct 29 11:23PM -0700


> Freeze spray is still with us. It is useful for tracing intermittents and components that fail when warmed up. But, be very careful with it. Cold spray hitting an overheated part or board can cause fractures - which can cause trace failure.
 
But, it has other uses. A little freeze spray onto one of dozens of DC/DC converters
identified the source of an annoying crosstalk situation, and we gained about 6 dB of
extra signal/noise, once I'd isolated the ripple source. You can also (roughly) identify hot
components, by observing how fast the frost dissipates.
tabbypurr@gmail.com: Oct 30 04:56AM -0700

On Monday, 30 October 2017 06:23:14 UTC, whit3rd wrote:
> identified the source of an annoying crosstalk situation, and we gained about 6 dB of
> extra signal/noise, once I'd isolated the ripple source. You can also (roughly) identify hot
> components, by observing how fast the frost dissipates.
 
I suspect an IR thermometer is about the same price as a can of freeze spray nowadays.
 
 
NT
"pfjw@aol.com" <pfjw@aol.com>: Oct 30 05:18AM -0700

> I suspect an IR thermometer is about the same price as a can of freeze spray nowadays.
 
About. But, here is the biggest issue with these devices. I have a reasonably good one, with a reasonably fine pitch. The target diameter at 12" is 1.5". For those using the new currency: 38mm at 300mm. For an idea of target-creep, 3" at 36", 75mm at 900mm, and so forth.
 
Which must be kept in mind when in use. The little laser light is merely a visual guide, not the size of the target.
 
Peter Wieck
Melrose Park, PA
Tim R <timothy42b@aol.com>: Oct 30 05:19AM -0700

We have a FLIR camera at work.
 
It was $3500 when we bought it but well worth it for diagnosing hot components.
 
I see they're only $5-600 on Amazon now. There's even an iPhone version for $200.
Jeff Liebermann <jeffl@cruzio.com>: Oct 29 12:41PM -0700

On Sun, 29 Oct 2017 16:42:22 +0000 (UTC), harry newton
>the radio says transmit power is 26dBm into a built-in 18dBi dish antenna,
>so the EIRP of the stock unit set for the USA would be too high at
>26+18=44dBm in the USA.
 
Are you doing point to multipoint or point to point?
 
<https://www.air802.com/fcc-rules-and-regulations.html>
 
5GHz is different quite different. Might be helpful if you describe
what you're using for hardware, what band you're using, and your
wireless network topology.
 
>whatever the USA legal limit is); but why would AirOS report bogus number
>then?
 
>What are those decibel numbers in AirOS actually *telling* me?
 
One of the dangers of updating firmware is that the saved or stored
values might not work with the new firmware if they've shifted memory
location between versions. This is almost guaranteed for major
revision changes in firmware. Less so for minor changes. When in
doubt, print your your settings, reset the router, and manually setup
the numbers. Krack firemare tweeks seem to be a rush job and fall in
the category of "customer tested software".
 
You mention that "it's all set to the defaults" which is rather
ambiguous. Did you reset the router after installing the firmware
update?
 
Busy patching the roof today before the sky falls on me tonite.
--
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
harry newton <harry@is.invalid>: Oct 29 09:35PM

He who is Jeff Liebermann said on Sun, 29 Oct 2017 12:41:28 -0700:
 
> Are you doing point to multipoint or point to point?
> <https://www.air802.com/fcc-rules-and-regulations.html>
 
Thanks Jeff.
 
Given the 2.4 GHz antenna dish is 18 dBi, the chart says the max is
a. Point to multipoint
(18dBm or 63mW transmit) into (18dBi antenna) = (36 decibels or 4 watts)
 
b. Point to point
(26dBm or 400mW transmit) into (18dBi antenna) = (44 decibels or 25 watts)
 
The radio is set up as an access point, exactly how you suggested Rod Speed
set up his antenna outside his house to feed his neighbor Wi-Fi where his
neighbor is only a few hundred feet away line of sight.
 
So I'm overdriving the radio by accident, I think.
I thought they throttled themselves so that they'd never exceed the limit.
 
> 5GHz is different quite different. Might be helpful if you describe
> what you're using for hardware, what band you're using, and your
> wireless network topology.
 
I have plenty of 5GHz Ubiquiti equipment (Rocket M5, for example, with a
30dBM dish), but this particular radio is one of my smaller ones, which is
the Ubiquiti PowerBeam M2 400, which is only 26 decibels of transmit into
an 18dBi antenna.
 
But even so, it has no problem getting to the legal limit it seems, where
it must be defaulting to the legal limit for point to point even though
it's set up as an access point hanging off a wired router acting as a
repeater.
 
It only has to paint the barn with 2.4GHz WiFi to feed the cameras which
are about a half kilometer away, which is nothing for this type of WiFi
radio.
 
> You mention that "it's all set to the defaults" which is rather
> ambiguous. Did you reset the router after installing the firmware
> update?
 
The radio rebooted itself after the firmware update.
 
What I mean by defaults is the radio is set up to be an access point at a
certain IP address in bridge mode, but that's all I set. The rest is
whatever defaulted after I set it.
 
So I didn't touch the antenna setting.
Nor did I touch transmit power.
 
So it *defaulted* to the 44 Watts, which, for a home radio, is overkill
unless I'm going 10 miles but it's not even half a mile that I'm going.
 
So I'll dial down the transmit power.
Thanks.
 
NOTE: For those reading this, if you need an access point to paint an area
between hundreds of feet and a couple of miles away with 2.4GHz or 5GHz
WiFi signal, you can get Ubiquiti or Mikrotik radios for about the same
price as you paid for your last home router - but which are so much more
powerful (aka directional) than a radio with an omni, that it isn't funny.
 
> Busy patching the roof today before the sky falls on me tonite.
 
Good luck with the roof!
 
Our power went out again yesterday (it goes out once a month) and we didn't
even have much wind coming up from your side of the ocean.
Jeff Liebermann <jeffl@cruzio.com>: Oct 29 01:16PM -0700

On Wed, 25 Oct 2017 21:15:52 -0400, micky <NONONOmisc07@bigfoot.com>
wrote:
 
>I need to put a momentary on switch in my dashboard, and the one I
>bought doesn't have a hex nut for the top nut but a round serrated ring
>to hold the switch in place.
 
I use these:
<https://www.harborfreight.com/3-piece-long-reach-hose-grip-pliers-37909.html>
$15 for 3 pliers. They're made for removing automotive hoses, vacuum
lines, fuel lines, etc. You can't tell from the photo, but the
insides of the cricular area is serrated for a better grip, which
should mate somewhat with your switch nut. The 45 degree tip angle is
also handy for clearing other junk on a front panel.
 
More:
<https://www.google.com/search?q=hose+grip+pliers&tbm=isch>
 
--
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
Andy Burns <usenet@andyburns.uk>: Oct 29 04:53PM

harry newton wrote:
 
> I think what you're saying is that if they can get to *any* of your
> devices, over the Internet, then, *from those devices*, they can intercept
> your traffic to, for example, your Linux laptop or Android smart phone.
 
I think in your case you say your house is out of wifi range of your
neighbours; but since you're advising friends and family, it could be
that one house's fridge/camera/thermostat hacks the neighbour's wifi
traffic ...
harry newton <harry@is.invalid>: Oct 29 05:29PM

He who is Andy Burns said on Sun, 29 Oct 2017 16:53:03 +0000:
 
> neighbours; but since you're advising friends and family, it could be
> that one house's fridge/camera/thermostat hacks the neighbour's wifi
> traffic ...
 
I understand only the *basics* of that argument, which is that if you have
device 0 (the router), and then client 1 (refrigerator) and client 2
(Android phone), and client 3 (linux laptop) that *all* are vulnerable.
 
The basic argument is that if someone gets in on client 1, 2, or 3, then
the *whole* network is compromised.
 
But is it?
 
If client 1 is a refrigerator with very poor security, I get it that they
can hack easily into client 1.
 
All I'm asking is how does access to client 1 give them access to router 0
which "controls" the entire LAN?
William Unruh <unruh@invalid.ca>: Oct 29 06:21PM

> can hack easily into client 1.
 
> All I'm asking is how does access to client 1 give them access to router 0
> which "controls" the entire LAN?
 
It doesn't directly. But they now have control of a wireless card, which they
can adapt (software) to listen in on the traffic between your computer and the
router (remember that the wireless signal goes everywhere), and can then
subvert the communication between the computer and the router forcing the
system into negotiation replay. I have no desire to figure out exactly how to
do that, just that with fridges etc around with zero security, they have an in
to your local network, and quite possibly can use that to run a Krack on the
computer and the router.
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