Digest for sci.electronics.repair@googlegroups.com - 15 updates in 5 topics

avagadro7@gmail.com: Aug 25 09:24AM -0700

for 18 Ga wire out of dashboard receiver.
 
want to separate connectors n pull receiver out during sensitive parking.
 
several dc and 4 stereo connectors if possible with no distortion/loss .
 
broadcast quality .....
dplatt@coop.radagast.org (Dave Platt): Aug 24 12:41PM -0700

In article <6dirrb98cu6lo5gvi6gn6tkgma166o5b12@4ax.com>,
>right? So it can combine the signals audibly but not electrically,
>because if they mixed here, they would get mixed on all the other
>speakers too?
 
That could be. Dual-voice-coil woofers are fairly common.
 
>But couldn't they do that in the woofer amplifier and use a standar
>speaker with only one voice coil?
 
An advantage to using them, is that you can use a 2-channel audio
amplifier (left and right), run each channel through a crossover, and
then feed each channel's "woofer" signal to a separate voice coil on
the woofer.
 
You can certainly do the trick you're thinking of, but it would
require an amplifier with at least three channels (left, right, and
woofer) and would require that the woofer-to-mid/tweeter crossover be
performed prior to amplification. There are certainly audio setups
which work this way, but they're somewhat more of a "custom" job.
 
>Also one pair of wires, unplugged from the car, has 32 ohms between
>them, and the other pair has 2.5. That's a bad sign, isn't it?
 
Possibly.
 
Another possibility is that what you have is a specialized woofer,
meant for use wiht an active-feedback "servo" amplifier. One wire
pair (and coil) would be the actual "driving" voice coil... probably
the one with 2.5 ohms DC resistance (a 4- or 8-ohm nominal impedance
at audio frequencies). The other coil would be a "sense" coil, whose
output would be proportional to cone velocity.
 
A servo amplifier would use feedback from the sense coil to control
the output to the voice coil. This approach can allow the amplifier
to provide deeper bass with a flatter frequency response, without
requiring a critically-tuned enclosure for the woofer.
 
You'd probably need to find a model number on the woofer, and look up
the data sheet, to figure out whether you have an actual problem (open
or shorted voice coil) or a servo-amplified single-channel subwoofer.
 
Inspecting the wiring at your amplifier or head-end unit would also be
instructive. Check to see if it has two outputs for the woofer, or a
single woofer output and a "sense" or "feedback" or "servo" input for
the other pair of wires.
 
>speaker was facing me, I couldn't see this.
 
>How good do you think it will sound with only one channel? Will I
>keep steering the car towards the side of the road?
 
No, but if you use it to listen to the radio, you might end up being
pulled either towards right-wing talk radio or left-wing NPR/APR
stations :-)
Micky <NONONObobbyburns1111@gmail.com>: Aug 24 08:02PM -0400

On Wed, 24 Aug 2016 12:41:11 -0700, dplatt@coop.radagast.org (Dave
Platt) wrote:
 
>the output to the voice coil. This approach can allow the amplifier
>to provide deeper bass with a flatter frequency response, without
>requiring a critically-tuned enclosure for the woofer.
 
This is all very interesting. I understood most of it but will read
it one or two more times.
 
>You'd probably need to find a model number on the woofer, and look up
>the data sheet, to figure out whether you have an actual problem (open
>or shorted voice coil) or a servo-amplified single-channel subwoofer.
 
Actually I have the model number because the Simply Speakers kit to
repair in includes the model number, for my make, model, and year car,
and tomorrow I'll go hunting for into.
 
>instructive. Check to see if it has two outputs for the woofer, or a
>single woofer output and a "sense" or "feedback" or "servo" input for
>the other pair of wires.
 
I'm not sure how to get the amp out of the car or where I could look
at it. It's behind the back seat, and attached somehow.
 
But I did look more closely at the speaker and alas, the wire to the
2.5 inch coil has been cut. At first I thought it just broke off, but
the end shows no wire, both ends show some of the red insulation, and
the wire is now 1 or 2 mm. too short to reach the other piece. I
could pull some through the zip tie, but plainly the last guy thought
this voice coil was a problem. And after he cut the wire, then he
unplugged or never plugged in the speaker.
 
I had hoped the speaker was just never plugged in at the assembly
plant. I had a 1965 car which had big fresh air vents at the
driver's and passenger's outer ankle, but no fresh air. When I had
time to take off the kick panel, I saw that the cable was never
connected to the doors. Also, my brother couldn't pull the car away
from a stop without lurching forward. I thought he didnt' know how to
drive. After he gave me the car, it took a couple months before I
found that the wire to the vacuum advance was missing. The T-
connection was hidden behind something else, and only because I had
climbed up on something to get to the middle of the engine compartment
did I notice this. Adding a hose made everything good.
But no such luck with this speaker.
 
I will repair it tomorrow or Friday and install it anyhow. I have
wireless speakers working off my PC and two are the left channel and
two are the right, and they are in 4 different rooms. More to the
point, I didn't notice that one of my two desk speakers was not
working. About 1 song in 30 or 40, I couldn't hear the singer. Maybe
that was what made me put my ear next to the other speaker and learn
that it was dead!
 
So apparently my standards are low, and I might like a one channel
woofer.
 
 
>No, but if you use it to listen to the radio, you might end up being
>pulled either towards right-wing talk radio or left-wing NPR/APR
>stations :-)
 
That does sound dangerous.
avagadro7@gmail.com: Aug 25 09:21AM -0700

goo.gl/r8SSXT
JW <none@dev.null>: Aug 24 01:07PM -0400

As the Subject says: I have a Linksys WRT54GS v.2 wireless router which
occasionally drops to 1.0 Mbps and stays there. Signal strength still
shows excellent. Can't even ping the router via a wireless connection when
it happens. Great fun when I'm throwing a bid in at the last moment on
eBay. :(
 
I have to unplug the thing for it to recover.
 
Happens once a day or so, but sometimes not for several days or more.
Wired connections work fine.
 
Firmware version: v4.71.4
 
There seems to be a number of complaints out there on this, but no
solutions.
http://www.linksysinfo.org/index.php?threads/wrt54gs-wireless-connection-speed-dropping.6854/
http://www.dslreports.com/forum/r13974684-Wireless-WRT54GS-Speed-54Mbps-down-to-1-0-Mbps
https://community.linksys.com/t5/Wireless-Routers/Speed-drops-to-1-0-mbps/td-p/15913
 
Checking the update page, there's no firmware updates. Funny, there used
to be... Maybe they pulled the plug on this model?
http://www.linksys.com/us/support-article?articleNum=148629
 
Thanks.
whit3rd <whit3rd@gmail.com>: Aug 24 01:05PM -0700

On Wednesday, August 24, 2016 at 10:09:15 AM UTC-7, JW wrote:
> occasionally drops to 1.0 Mbps and stays there. Signal strength still
> shows excellent. Can't even ping the router via a wireless connection when
> it happens.
 
The channels available for WiFi are all unlicensed; if there's a strong second
WiFi user (or other device in the 2.4 GHz band) its broadcast could swamp
yours, except for pauses between transfers.
 
Signal strength might be excellent, but the road is crowded.
jack4747@gmail.com: Aug 25 06:07AM -0700

Il giorno mercoledì 24 agosto 2016 19:09:15 UTC+2, JW ha scritto:
 
> Checking the update page, there's no firmware updates. Funny, there used
> to be... Maybe they pulled the plug on this model?
> http://www.linksys.com/us/support-article?articleNum=148629
 
there are firmware update, just not from Linksys:
 
http://www.dd-wrt.com/site/index
 
Bye Jack
JW <none@dev.null>: Aug 25 11:11AM -0400

On Thu, 25 Aug 2016 06:07:24 -0700 (PDT) jack4747@gmail.com wrote in
>> http://www.linksys.com/us/support-article?articleNum=148629
 
>there are firmware update, just not from Linksys:
 
>http://www.dd-wrt.com/site/index
 
Thanks. Looks like I have already have the last version ever released by
Linksys.
http://dd-wrt.com/wiki/index.php/Linksys_WRT54GS_v2.0
JW <none@dev.null>: Aug 25 11:12AM -0400

On Wed, 24 Aug 2016 13:05:43 -0700 (PDT) whit3rd <whit3rd@gmail.com> wrote
>WiFi user (or other device in the 2.4 GHz band) its broadcast could swamp
>yours, except for pauses between transfers.
 
>Signal strength might be excellent, but the road is crowded.
 
Thanks, I don't think it's that given the symptoms (requires power cycle)
Micky <NONONObobbyburns1111@gmail.com>: Aug 24 07:38PM -0400

On Fri, 19 Aug 2016 19:49:33 +0100, MJC <gravity@mjcoon.plus.com>
wrote:
 
>> perhaps this is android speak
 
>Pretty certain mobo=motherboard, but I think "i7" is too enigmatic, as
>well.
 
I think that is intergallactica station 7, which iirc is Andromenica,
or maybe Ardmore.
Micky <NONONObobbyburns1111@gmail.com>: Aug 24 07:44PM -0400

On Fri, 19 Aug 2016 13:02:08 -0700 (PDT), "jfeng@my-deja.com"
 
>You can get pc-board mount SATA data connectors on eBay. This seller has 2 for $3.79+$0.80(shipping)
>http://www.ebay.com/itm/2-Pcs-New-Sata-7-Pin-DIP-Straight-Female-Connector-For-Hard-Drive-HDD-/181864444077?hash=item2a57f730ad:g:gfkAAOSwQ15XOX7X
 
How is it that they can ship from ShenZhen, Guangdong, China for 80
cents? I suppose they put everything in a big box and pro-rate the
shipping, but when I get things in the mail, it doesn't seem like that
was done.
 
>http://www.ebay.com/itm/10-Pcs-New-Sata-7-15-Pin-Straight-DIP-Female-Connector-For-Hard-Drive-HDD-/171977931322?hash=item280aaefa3a:g:BIkAAOSwxehXOX89
 
>Same prices for connectors of the other gender.
 
>Disclaimer: I know nothing about this eBay vendor, but I have purchased from other vendors on eBay.
 
Me too. Various things. I've always had good results except I bought
a camera, new but without a box or instructions or anything, and it
didn't have a battery which I think it should have either had or
denoted that it didn't have. That cost me, after shopping, $15. Still
the total was cheaper than elsewhere, but not as much. The camera
works fine.
Clifford Heath <no.spam@please.net>: Aug 25 10:26AM +1000

On 25/08/16 09:44, Micky wrote:
> How is it that they can ship from ShenZhen, Guangdong, China for 80
> cents? I suppose they put everything in a big box and pro-rate the
> shipping
 
China Post (aka the Chinese government) provides free shipping
for small parcels. So "big box" here means "shipping container"
and "pro-rate" is at zero cost... except to the postal services
in the destination countries.
"jfeng@my-deja.com" <jfeng@my-deja.com>: Aug 24 05:38PM -0700

On Wednesday, August 24, 2016 at 4:44:24 PM UTC-7, Micky wrote:
> How is it that they can ship from ShenZhen, Guangdong, China for 80 cents?
I don't know, but it works. Last year, I bought a USB header from a Hong Kong vendor for US$1.77 and it arrived in a reasonable length of time.
 
I assume that the manufacturing cost of the connectors is less than 1 yuan, and the price to the middleman is 2-3 yuan. That would leave some room for shipping and a profit.
"Gareth Magennis" <soundserviceleeds@outlook.com>: Aug 25 02:00AM +0100

"bitrex" wrote in message news:5pHtz.52889$Z%.47195@fx35.iad...
 
 
I had some free time the other day and figured out the issue with
my basket case i7 (bent power supply connection pin on the
motherboard.) It's powering up now.
 
Unfortunately it looks like the ribbon cable connector has been
damaged for the SATA drive on the mobo as well, so the clamp
dosent "catch" with the cable when it's inserted and the clamp
pressed down. I considered taping it in but on this type of
connector, where it isn't a friction fit, I don't think it will
apply enough pressure to keep it secure.
 
Any suggestions? Dab of superglue or hot glue gun, maybe?
 
 
 
 
 
 
 
I've been on this planet a few years now, and have yet to find a situation
where Superglue is a good idea.
It pretty much just does not work, except for sticking your fingers
together.
 
Hot melt glue sometimes works, but does not adhere well to many surfaces.
 
 
Silicone glue/sealant pretty much sticks to everything, is flexible and
shockproof, and can be peeled off without damaging anything if you need to
have another go.
Win, win, win, in my book, I rarely use anything else now.
 
 
 
 
 
Gareth.
Jerry Peters <jerry@example.invalid>: Aug 24 08:11PM

> 10 inches above the water heater - so I don't really think I can get the
> old anode out without removing the entire water heater, which I don't
> really want to do.
 
Doesn't seem like it, especially if it's part of the water inlet tube.
For low clearance separate anode rod applications there's a special
replacement rod that has periodic narrow sections, so you can bend
it to get it to fit.
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