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Hi Jim,<br>
<br>
OK, I did one more test. This time, I tested both my tablet GPS and my
TomTom GPS. Both devices were running on battery power and had no
connection to the car at all. I plugged the fm transmitter into the
headphone output of my boombox. I started the test with 10 - 11
satellites being tracked by the TomTom and about 7 being tracked by the
tablet. The moment I plugged the fm transmitter into the cigarette
lighter, the TomTom went down to tracking only 3 satellites and the
signal levels on those decreased substantially, so it would sometimes
lose the fix. The tablet went down to tracking no satellites. Once I
remove the fm transmitter from the outlet, both units return to
normal. I do think the GPS receiver in the tablet is weak, for
whatever reason, but this problem is not the tablet. It's definitely
the fm transmitter and it's definitely RADIO based. This thing is SO
fired from my collection of gadgets.<br>
<br>
Sincerely,<br>
<br>
Ron<br>
<br>
<br>
On 5/6/2012 7:13 PM, Jim Kinney wrote:
<blockquote
cite="mid:CAEo=5PxOxqYGxNwiOLaYwFghRmDRxDfNo4RoEMkdL6SUWTRbZw@mail.gmail.com"
type="cite">
<p>Last tast: plug the transmitter into a different sound source like
the boom box. I'm betting the fault is with the tablet. </p>
<div class="gmail_quote">On May 6, 2012 10:37 AM, "Ron Frazier (ALE)"
<<a moz-do-not-send="true"
href="mailto:atllinuxenthinfo@techstarship.com">atllinuxenthinfo@techstarship.com</a>>
wrote:<br type="attribution">
<blockquote class="gmail_quote"
style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<div text="#000000" bgcolor="#ffffff">
Hi Jim,<br>
<br>
I think I'm just giving up on that particular product / project. I now
have a wire running from the tablet's headphone jack into a small boom
box sitting on the seat. It works, and I don't have to fret with it.
It's a shame, because, with the FM transmitter, I could use one less
piece of relatively large equipment and clear the seat up if the tablet
is on the dash. There's no easy way to test the FM transmitter without
plugging into the cigarette lighter as that's where it gets its power.<br>
<br>
Sincerely,<br>
<br>
Ron<br>
<br>
<br>
On 5/4/2012 4:51 PM, Jim Kinney wrote:
<blockquote type="cite"><br>
Ron,<br>
<br>
That test doesn't isolate power drop on audio output from signal
overlap.<br>
<br>
to test that the FM transmitter is overlapping the GPS signal, you need
a secondary GPS receiver other than the tablet.<br>
<br>
It really sounds (ha!) like the tablet has a bad headphone jack or the
FM transmitter has a fault and is pulling power down the audio line.<br>
<br>
<br>
Try your test again but with the transmitter NOT plugged into the car
power jack. <br>
<br>
<div class="gmail_quote">On Fri, May 4, 2012 at 3:21 PM, Ron
Frazier
(ALE) <span dir="ltr"><<a moz-do-not-send="true"
href="mailto:atllinuxenthinfo@techstarship.com" target="_blank">atllinuxenthinfo@techstarship.com</a>></span>
wrote:<br>
<blockquote class="gmail_quote"
style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<div text="#000000" bgcolor="#ffffff">Hi Jim, and all,<br>
<br>
I've tested this several times and confirmed the behavior. It's
definitely not power. Today I tested this as follows with the tablet
running on battery power.<br>
<br>
I start the tablet on battery power and run a program called GPS test.
I get a nice clean fix on 5 - 6 satellites, a positional accuracy of 15
ft or so, and SNR values in the 26 - 31 range (this program doesn't
specify the units). Those satellites are color coded in yellow by this
program. I have a podcast playing in the background on the tablet's
internal speakers. I have the fm transmitter plugged into the
cigarette lighter but the AUDIO cable is not plugged into the tablet.
So, sound is coming from the tablet's speakers, and nothing is coming
from the car's speakers. Everything is fine. GPS works.<br>
<br>
I plug the AUDIO cable in from the FM transmitter into the tablet's
headphone jack. Sound starts coming out of the car's speakers, as it
should. Immediately, SNR's for the satellites drop below 20,
satellites with a fix drop to 0 - 1, and the position fix is lost.
I've confirmed this several times. It is exceedingly strange.<br>
<br>
I've officially fired the FM transmitter. I don't think I have the
packaging to take it back to Fry's. It's a NAXA NA-3029 if anyone's
interested. I'd recommend avoiding this unit.<br>
<br>
I've gone back to my old method. I have a boom box with aux input
sitting in the seat, and I run a wire from the tablet to the boom box.
Messy, but it works.<br>
<br>
Sincerely,<br>
<br>
Ron
<div><br>
<br>
<br>
<br>
On 5/1/2012 8:19 AM, Jim Kinney wrote:
<blockquote type="cite">
<div class="gmail_extra">that sounds more like an internal
power
issue. The device draws more power on a bus that is available for both
the gps and it to run to gps falls down.<br>
<br>
To see if it's actually radio interference, check you cell phone gps
next to it and see if it also chokes.<br>
<br>
<div class="gmail_quote">On Tue, May 1, 2012 at 12:20 AM, Ron
Frazier
(ALE) <span dir="ltr"><<a moz-do-not-send="true"
href="mailto:atllinuxenthinfo@techstarship.com" target="_blank">atllinuxenthinfo@techstarship.com</a>></span>
wrote:<br>
<blockquote class="gmail_quote"
style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">I
have
one
of those cheap fm transmitters that broadcasts audio from a<br>
portable device to the car stereo. It works great to send sound from my<br>
tablet to the car. However, it also jams the tablet's GPS system. When<br>
I plug in the transmitter, the number of satellites the tablet has a fix<br>
on goes from 6 or more to 1 or zero immediately. The GPS fails to<br>
work. If I unplug the fm transmitter, the GPS works again. Anyone ever<br>
seen that happen?<br>
<br>
Ron<br>
<br>
</blockquote>
</div>
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</blockquote>
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<br clear="all">
<br>
-- <br>
-- <br>
James P. Kinney III<br>
<br>
As long as the general population is passive, apathetic, diverted to
consumerism or hatred of the vulnerable, then the powerful can do as
they please, and those who survive will be left to contemplate the
outcome.<br>
- <i><i><i><i>2011 Noam Chomsky<br>
<br>
<a moz-do-not-send="true"
href="http://heretothereideas.blogspot.com/" target="_blank">http://heretothereideas.blogspot.com/</a></i></i></i></i><br>
</blockquote>
</div>
</blockquote>
</div>
</blockquote>
<br>
<br>
<br>
<pre class="moz-signature" cols="72">--
(To whom it may concern. My email address has changed. Replying to former
messages prior to 03/31/12 with my personal address will go to the wrong
address. Please send all personal correspondence to the new address.)
(PS - If you email me and don't get a quick response, you might want to
call on the phone. I get about 300 emails per day from alternate energy
mailing lists and such. I don't always see new messages very quickly.)
Ron Frazier
770-205-9422 (O) Leave a message.
linuxdude AT techstarship.com</pre>
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