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#38612 - 16/09/2001 11:45 Rio Car Tuner Module -- Weak Signal Strength
ProtonVehiCROSS
new poster

Registered: 16/09/2001
Posts: 36
Loc: Seattle, WA
ISSUE: Radio reception is exceptionally good at full strength, but it diminishes substantially with a loss of even 1-2 bars of signal srength.

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I just received my Rio Car tuner. I've hooked it up to my Isuzu VehiCROSS' antenna connector using the Rio-supplied antenna adapter.

I can receive most radio stations pretty well, with a "maximum" signal strength indicated. However, as I go up and down hills, or turn corners, often the signal strength will drop by 1-2 bars. Although it's probably normal to lose some strength as you make your way around town, it's probably *not* normal to have such a minor change be audible.

Even when the signal strength drops ONE bar from maximum, the sound become noiceably quieter. As the signal strength fluctuates -- even just 1-2 bars -- so, too, does the audio quality, and quite substantially I might add. I don't recall my OEM tuner behaving in this manner; it would tune radio stations with exceptional clarity unless the signal was extremely weak. Turning corners and going up and down hills did not cause audible distortion/depreciation of the radio reception.

Is this nromal tuner behavior? (i.e., is this tuner module just very sensitive/fussy?)

Or could I have hooked it up incorrectly? My car does NOT have a power antenna (i.e., my antenna is ALWAYS "up"). However, I still wired the blue "antenna" wire from the radio *tuner module* to to the "antenna control wire" on my car's wiring harness (I did not wire the *seemingly* redundant control wire from the docking sled, however, as I assumed the tuner module's control wire would acomplish the task). I did this because I suspect that my vehicle *might* have power amplification of radio signals. I'm led to believe this because:

a) the antenna is about half the length of a typical antenna, coated with plastic, and clearly has a wire wrapped around it underneath the plastic sheath, almost like a cellular phone antenna;

b) there was an antenna control wire indicated on the harness, so I figured it must be there for a reason;

c) the antenna plug behind the dash also had a couple wires going into the wiring harness.

The VehiCROSS is a limited-production vehicle that is built on the Isuzu Rodeo chassis, but still has some marked differences (i.e., no ground wire, for example - all components must be grounded to the chassis, even though a ground wire is (misleadingly) present on the harness). In other words, just because there's an antenna control wire on the harness, doesn't necessarily mean that it serves a purpose.

Any ideas? Thanks in advance for your help.

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Grant Eaton
ProtonVehiCROSS
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#38613 - 16/09/2001 12:42 Re: Rio Car Tuner Module -- Weak Signal Strength [Re: ProtonVehiCROSS]
tfabris
carpal tunnel

Registered: 20/12/1999
Posts: 31600
Loc: Seattle, WA
My tuner doesn't exhibit the behavior you describe. You are the second person to mention the sudden changes in volume. I'd be curious to see what Hugo has to say about this?

Your antenna sound similar to the kind of antenna I had on my VW GTI. It was a Fuba antenna (OEM'd to VW) with a small power amplifier in its base. There was a power wire that paralleled the antenna wire-- the factory radio supplied some constant voltage to that wire. Without this, the power amplifier did not boost the signal and you got poor reception.

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Tony Fabris
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Tony Fabris

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#38614 - 16/09/2001 16:18 Re: Rio Car Tuner Module -- Weak Signal Strength [Re: tfabris]
loren
carpal tunnel

Registered: 23/08/2000
Posts: 3826
Loc: SLC, UT, USA
i get pretty much the same behavior as described when driving around town here in San Francisco. When it locks on to a signal full strength, it's great, but i get pretty constant changes in strength and signal quality which causes a lot of static and a softer volume level.


|| loren.cox ||
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#38615 - 16/09/2001 23:39 Re: Rio Car Tuner Module -- Weak Signal Strength [Re: loren]
altman
carpal tunnel

Registered: 19/05/1999
Posts: 3457
Loc: Palo Alto, CA
There may well be tweaking to do on the DSP parameters; it will "dim" out the audio if it thinks the signal strength is getting too low for good audio quality. Possibly, this is set to be a little too sensitive.

Check that 12v is going up the antenna control lead if you can (the tuner module has a current limiting cut-out on the wire) - it will supply 150mA so this shouldn't be an issue for an antenna amp.

Hugo



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#38616 - 16/09/2001 23:41 Re: Rio Car Tuner Module -- Weak Signal Strength [Re: ProtonVehiCROSS]
altman
carpal tunnel

Registered: 19/05/1999
Posts: 3457
Loc: Palo Alto, CA
Just re-read this... what "seemingly redundant control wire" from the docking sled? There isn't an antenna control wire here. If you mean the blue wire, that's an amp power control line (isn't it connected to your amp?)

Hugo


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#38617 - 17/09/2001 10:14 Re: Rio Car Tuner Module -- Weak Signal Strength [Re: altman]
ProtonVehiCROSS
new poster

Registered: 16/09/2001
Posts: 36
Loc: Seattle, WA
I was referring to the blue amp wire on the docking sled, which I *thought* the Rio Car manual said could be hooked up to control a power antenna as well as the amp turn-on. Currently, it is hooked up to control the amp turn-on ONLY.

Only the blue antenna control wire from the tuner module is hooked up to the antenna wire on the car's wiring harness.

1. I will check the blue antenna control wire from the tuner to make sure it's sending a 12-volt signal to the (presumed) antenna power amplifier.

2. The DSP setting is an interesting note. Is this user-changeable? It should be noted that:

maximum signal strength = excellent sound
loss of 1 bar = significantly diminshed volume
loss of 2 bars = further diminshed volume
loss of 3 bars = static, further diminished volume, unusable


Grant

Edited by ProtonVehiCROSS on 17/09/01 06:19 PM.

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Grant Eaton
ProtonVehiCROSS
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#38618 - 17/09/2001 10:19 Re: Rio Car Tuner Module -- Weak Signal Strength [Re: ProtonVehiCROSS]
tfabris
carpal tunnel

Registered: 20/12/1999
Posts: 31600
Loc: Seattle, WA
The purpose of having two separate control wires is for cars with motorized antennas.

There's no point in raising the antenna just to listen to MP3 files. The antenna should only raise when you switch to the tuner module.

___________
Tony Fabris
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#38619 - 17/09/2001 10:24 Re: Rio Car Tuner Module -- Weak Signal Strength [Re: ProtonVehiCROSS]
altman
carpal tunnel

Registered: 19/05/1999
Posts: 3457
Loc: Palo Alto, CA
Diminished volume could well be a DSP config problem, yes. If you're starting to get static, that's just normal signal breakup - the DSP doesn't invent static and mix it in when the signal level drops.

It's not user changeable - well, not in release builds anyway. I suspect we won't be doing a release that changes this until the v2.0 betas (otherwise v2.0 will just get later) but in theory a sensitivity slider could be added to emplode to tweak this behaviour - but I'm wary of changing the default that others are happy with.

Hugo



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#38620 - 17/09/2001 10:41 Re: Rio Car Tuner Module -- Weak Signal Strength [Re: tfabris]
tms13
old hand

Registered: 30/07/2001
Posts: 1115
Loc: Lochcarron and Edinburgh
In reply to:

The purpose of having two separate control wires is for cars with motorized antennas.

There's no point in raising the antenna just to listen to MP3 files. The antenna should only raise when you switch to the tuner module.




There's also no point powering the antenna amp just to listen to MP3 files. Is the output on the tuner's "antenna" lead sufficient to control/power the antenna amp?

The power amp is a different (and potentially confusing) issue, of course - that should be switched (not powered) from the player.


(Not an issue for me personally, I'm just trying to clarify)

--
Toby Speight - 040103385
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#38621 - 17/09/2001 11:08 Re: Rio Car Tuner Module -- Weak Signal Strength [Re: tms13]
altman
carpal tunnel

Registered: 19/05/1999
Posts: 3457
Loc: Palo Alto, CA
Yes, the power antenna lead will supply ~150mA before auto shut-off. Most antenna amps take <50mA.

Hugo



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#38622 - 19/09/2001 11:45 Re: Rio Car Tuner Module -- Weak Signal Strength [Re: tfabris]
jwtadmin
enthusiast

Registered: 05/09/2000
Posts: 210
Loc: Ipswich, MA
My Tuner experienced this EXACT same behaviour a few days after installation.
It seems that the module slipped a bit further into the dash, from when I installed it.
I found that reposistioning the tuner module under my dash fixed this.

John

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