New HU - Managed to confuse myself!

[surfdude]

Sorry to bring this up again but I'm well confused!

Just fitted a new JVC 722 HU to my Octavia (2004 Elegance Estate PD130). Everything's OK except for the radio reception, which is where I'm confused.

I'm confused as to where the antenna amplifier is. Is it in the original radio (in which case I need to buy a booster), or is it in the antenna itself (just need to buy a powered antenna lead).

Also, assuming I just need to power the antenna, where is the best place to take the 12V feed from?

As a side note, I'm pretty impressed with the unit itself - can play stuff from a pen-drive via the USB port on the front. really handy!

Also, there was no need for any additional wiring changes (other than the antenna). The JVC connectors have no connection to the K-wire, and there are bullet connectors for switching the yellow/red wires

Thanks

Paul

[mannyo]

The amplifier is in the base of the antenna. The original HU was able to power this through the cable. An aftermarked unit requires a separate amplifier simillar to the one in this picture.

http://www.bluespot.co.uk/stock/vw.asp

You also really need to disconnect the "K" wire, as on the standard ISO connection this pin is used for something else, and if left connected earlier VAG diagnostic tools will be blown up if plugged in to your cars diagnostic port. The power is also reversed so if you find your HU forgetting its settings thats why. The linked item above will sort all the issues above and can be installed in minutes.

[dsmithmobile]

there is a booster that fits in between the aerial and the radio and you connect the 12v feed to it from the blue wire on the back of your jvc unit so its only powered up when the radio is,the part is an autoleads PC5-52,hope this helps

[surfdude]

Originally Posted by dsmithmobile

there is a booster that fits in between the aerial and the radio and you connect the 12v feed to it from the blue wire on the back of your jvc unit so its only powered up when the radio is,the part is an autoleads PC5-52,hope this helps

Thanks! That's what I wanted to hear - music to my ears (literally)

[b1ackb1rd]

Mine works without this booster ... which is £13.50 at Halfrauds.

[miho]

Originally Posted by dsmithmobile

there is a booster that fits in between the aerial and the radio and you connect the 12v feed to it from the blue wire on the back of your jvc unit so its only powered up when the radio is,the part is an autoleads PC5-52,hope this helps

Halford claims this part to be an antenna adaptor and signal separator. From their description it seems it is good for supplying an already amlified antenna with power. But it does not amplify the signal.

Is the Halfords description wrong?
http://www.halfords.com/webapp/wcs/s...tegoryId=31440
Michael

[dsmithmobile]

Its the correct part trust me ,halfords description is poor thats all and as said above its not an essential part as you will get some FM reception without but with one you will get a clearer signal and more stations especially on MW

[miho]

Originally Posted by dsmithmobile

Its the correct part trust me ,halfords description is poor thats all and as said above its not an essential part as you will get some FM reception without but with one you will get a clearer signal and more stations especially on MW

Some more news on this topic. Just got back from Halford where I picked up a P5-52. I tried my new JVC radio with and without it right in the parking lot. Reception is definitely much better with the part fitted. I did double-check the part´s description on the Autolead website. They also say it is a signal separator.

The following is what I make of all these information gathered. Unfortunately I don't have the time to verify that by measurements.

So it seems the original Skoda radios do not have an amplifier. The amplifier is in the original antenna. Also, this is the location where it makes sense from a radio engineering point of view. The power for that amplifier has to be supplied through the 'live' central wire of the antenna cable. However, the power may not enter the receiver input of the radio. This is achieved by the signal splitter (P5-52). It allows connecting a rather high DC voltage (12V) to the antenna without destroying the very sensitive (Microvolts) input of the radio. Essentially, the splitter will contain a capacitor. Not exactly black magic or rocket science... If you have some spare connectors, you can easily fabricate such a part yourselves and save a few quid...

The original radios must already output the 12V DC on the antenna connector which supplies the amplifier in the antenna. Maybe someone can check that?

Hope I didn't confuse anyone and it gives some background information for those seeking it.

Michael

[Goochie]

Interesting, Michael