I suspect my 98 Vectra has an amplified Aerial, as I have inserted an inline modulator to the aerial cable to allow me to plug in a minidisk player and listen to it via a preset radio station, and now my radio reception is very bad. The degradation in the received signal is too great to be insertion loss due to adding in the modulator. I am assuming that the aerial receives power for the amp via the coax aerial cable, hence by adding an inline modulator the aerial is no longer receiving power and therefore not amplifying the signal.
Q1 Is this the case or am I assuming too much?
Q2 If this is the case will the power on the aerial cable damage my modulator?
Q3 How do I put power onto the aerial cable to drive the amplified aerial and still retain the inline modulator?
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>Q1 Is this the case or am I assuming too much?
Your deduction sounds correct from the information given.
>Q2 If this is the case will the power on the aerial cable damage my modulator?
possibly; depends on the design. difficult to know for sure without more info
>Q3 How to I put power onto the aerial cable to drive the >amplified aerial and still retain the inline modulator?
I\'m pretty sure I\'ve seen these are available from specialist car audio places. Can\'t find any URLs at the moment; will have alook later if I get chance.
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Which body style Vectra do you have? Mine\'s the saloon which uses the rear screen for the aerial and has a slightly different set-up to the hatchback - I\'m not sure that there is an amplifier on the hatch.
If I remember correctly, there is a seperate feed to the amplifier module. I have the schematics at home and will check over the weekend and post on Monday
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Which body style Vectra do you have? Mine\'s the saloon which uses the rear screen for the aerial and has a slightly different set-up to the hatchback - I\'m not sure that there is an amplifier on the hatch.
Its a hatchback.
If I remember correctly, there is a seperate feed to the amplifier module. I have the schematics at home and will check over the weekend and post on Monday
Thanks for that
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I checked the schematics and yes it does have an amplifier for both the saloon and hatchback - just the aerials are different. The feed for the aerial amplifier is seperate from the aerial feed into the radio, ie. 12V shouldn't be present on the aerial coaxial cable, so I would have thought that the modulator would be okay.
Can you disconnect the aerial input at the rear of the radio and try just the modulator and CD alone?
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I checked the schematics and yes it does have an amplifier for both the saloon and hatchback - just the aerials are different. The feed for the aerial amplifier is seperate from the aerial feed into the radio, ie. 12V shouldn't be present on the aerial coaxial cable, so I would have thought that the modulator would be okay.
Are you using the schematics supplied in the Haynes manuel?
Can you disconnect the aerial input at the rear of the radio and try just the modulator and CD alone?
Not sure what you mean here... The modulator works great, it's the radio reception that is not good when the modulator is in circuit. I suspect that the degredation of the the signal quality is too great to be caused by the insertion loss of the modulator...... I guess the next thing to do is to try putting the modulator in another car that I know does not have an amplified aerial to confirm this.
Thanks for your time
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I have in the past seen an automotive aerial y connector. That is two aerial feeds into one so you have the amplified aerial signal and the modulator feeding into one lead into the radio.
This would eliminate any passthro attenuation caused by the modulator but will change the impedence of the feed to radio.
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Big Vern,
In a previous thread of mine, John S mentions the Vectra may indeed have an amplified aerial.
www.honestjohn.co.uk/forum/post/index.htm?t=7377&v...f
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Agreed it's not clear whether your aerial amplifier is phantom powered from the radio or has its own feed; if it is phantom powered then the link below shows a part that should do the job:-
www.sceniccaraudio.co.uk/Manufacturer.asp?Manufact...8
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Agreed it's not clear whether your aerial amplifier is phantom powered from the radio or has its own feed; if it is phantom powered then the link below shows a part that should do the job:- www.sceniccaraudio.co.uk/Manufacturer.asp?Manufact...8
Ahh ha!! that PC5-52 cable harness thing looks like it might just do the trick.... I am assuming that you connect the switched 12V onto the white wire and the Amp in the arieal picks up a suitable ground via it's mounting....
Do all bee sting arieals require an amp? I notice that the PC5-52 specifically mentions Vauxhall roof mounted aerials.. do VAG group and others that fit bee sting style aerials power them directly?
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I have finally got round to having another look at this. To cut a long story short the modulator has a relay in the Aerial connection such that when the modulator is powered only the o/p of the modulator is supplied to the radio.. the roof mounted Aerial is disconnected. This means that there is no conflict between the audio source I have connected into the modulator from any radio stations. However the modulator has to be off to get any decent radio reception.
I propose to get a latching push button to replace the traffic master switch on my dash to supply the modulator with 12V when I wish to use it. (I ripped the traffic master out as it was very annoying if you happend to knock the button)
I guess another fix to this could be to disable the relay in the modulator and take your chances with the interferance from radio signals, however I have long been looking for a use for my traffic master button :o)
Thanks for your help
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