Becker AR4201 AF AUX input - Help needed.

[Anonymous]

Posted by: Jock Munro on 09:03:54 11/13/14 Thu

http://contrails.free.fr/temp/AR4201-I+O.pdf shows pin 4 as the high but which is the low/negative?

The Garmin has a high/low (pos/neg) output via a 3.5mm socket on the back of the unit so I need to connect both wires to the Backer somehow.

Any suggestions/help would be greatly appreciated.

Cheers

[Anonymous]

Posted by: DL on 12:14:46 10/24/14 Fri

hello jock

pins 1 and 4 are the ones you want.

there may be some adjusting to do and there is a pot available on the side of the transceiver for that. Make sure that audio input is 1-8VPP a low impedance of 600ohm (check with garmin).

[Anonymous]

Posted by: Steve on 23:05:11 10/24/14 Fri

If your Garmin and Becker are connected to the same ground bus, then don't bother connecting the ground wire. Just have a single wire going from pin 4 to the tip of the audio connector on your Garmin. This will avoid ground loops and you will only need the ground wire if the 2 devices are connected to 2 different grounds. If you want to isolate against interference, then use shielded cable and just connect the shield to the ground on the connector at the Garmin end.

All the audio stuff in my Jab uses shielded cabling and just a single wire connection between devices connected to the same ground bus. In a Jab, you will probably find you only have 1 ground bus for everything so grounds between devices will not be necessary and connecting them could cause additional interference problems through ground loops.

[Anonymous]

Posted by: Jock Munro on 13:24:37 10/27/14 Mon

Hi both,

Thanks for the tips but it looks like the Garmin resistance is not hogh enough for the Backer. Garmin have told me that the jack on Speaker setting is 1 watt 8 ohm resistance on the Speaker setting and 33ohm on the headphone setting. The Becker needs 600ohm.

Think I'll just leave things as they are.

Thanks again.

[Anonymous]

Posted by: Steve on 20:28:57 10/27/14 Mon

It can still be done. Just put a potentiometer between them. A 1k linear pot should be fine with a 600ohm resistor before it. This will also allow you to adjust the volume between the 2 of them.

[Anonymous]

Posted by: Jock Munro on 09:03:54 11/13/14 Thu

Thanks for the additional information Steve but I've decided not to mess with it given the limited benefit overall against me cocking the Becker up.

Cheers