---

---

I mounted two LED into the plug. Green LED is for Tx and Red LED is for Rx.

It is very fantastic when I download the track at the dark room.

I succeeded in the connection between Visor and GARMIN, without using an external power supply.

Several changes will be necessary before the practical use , because my circuit is an experiment stage.

If you want to use only NMEA data, you can use this circuit. But this circuit works only with eTrx-Summit(Not eTrex), eMap. Because conventional-GARMIN does not have complete RS232C output.
My experiment circuit is here. MAX3221 is powered by TX of Visor.

The simple circuit diagram for connecting GARMIN to CASIO E-55. e55ae.gif
The regular circuit diagram for connecting GARMIN to CASIO E-55. e55tr.gif
The anticipation circuit diagram of the genuine cradle. e55gn.gif

Circuit diagram is here.

Right angle arrangement antenna and automatic switching unit for GBR-21.
Automatic switching circuit diagram is here.

I bought active-GPS-antenna from AKIZUKI-DENSHI. But it does not work. So, I removed all electronic parts and added MAR-6 amp. Circuit diagram is very simple. please check here. You can apply this circuit to your own patch antenna,whip antenna,GP antenna etc.

One day, I was testing the current consumption of external antenna. Whereat, GPS12 and eMap which does not connect to an antenna are receiveing the satellite signal!! It is very strange but useful.

Now I call it "Cascade Antenna (Re-Radiating Antenna)" and use it at indoor test of GPS.

I am Japanese. Probably, I cannot understand your English completely. You need superhuman imaginative power, in order to understand my English.