GPS (GP-02) kit module fitted in a GD-77

[F1RMB]

Hi,

Here is a small hack I made on one of my GD-77.
I fitted a GP-02 tiny GPS module and a 8x8 active GPS antenna.

20231008_112626-scaled.jpg (207.97 KiB) Viewed 5394 times

20231008_112707-scaled.jpg (172.11 KiB) Viewed 5394 times

20231008_112821-scaled.jpg (174.28 KiB) Viewed 5394 times

20231008_174154-scaled.jpg (194.18 KiB) Viewed 5394 times

20231009_162141-scaled.jpg (187.97 KiB) Viewed 5394 times

20231011_110345-scaled.jpg (243.78 KiB) Viewed 5394 times

20231010_095015-scaled.jpg (235.97 KiB) Viewed 5394 times

20231010_095008-scaled.jpg (172.52 KiB) Viewed 5394 times

20231011_120310-scaled.jpg (220.83 KiB) Viewed 5394 times

Some screengrabs:

GD-77_screengrab-2023-10-11_16_35_02.png (892 Bytes) Viewed 5394 times

GD-77_screengrab-2023-10-11_16_35_10.png (1.03 KiB) Viewed 5394 times

GD-77_screengrab-2023-10-11_16_11_28.png (1.03 KiB) Viewed 5394 times

Cheers.
---
Daniel

[CU7AAZ]

Hi,

Here is a small hack I made on one of my GD-77.
I fitted a GP-02 tiny GPS module and a 8x8 active GPS antenna.

20231008_112626-scaled.jpg
20231008_112707-scaled.jpg
20231008_112821-scaled.jpg
20231008_174154-scaled.jpg
20231009_162141-scaled.jpg
20231011_110345-scaled.jpg
20231010_095015-scaled.jpg
20231010_095008-scaled.jpg
20231011_120310-scaled.jpg

Some screengrabs:
GD-77_screengrab-2023-10-11_16_35_02.png
GD-77_screengrab-2023-10-11_16_35_10.png
GD-77_screengrab-2023-10-11_16_11_28.png


Cheers.
---
Daniel

Wowww Daniel,

Good Job!

73s
CU7AAZ

[VK3KYY]

Daniel

Can post a link to the module and the antenna

I know the antenna is https://www.aliexpress.com/item/1005004473774121.html

But I'm not sure of the exact GP-02 board you bought.

What glue did you use for the GPS module ? Some sort of epoxy?

[F1RMB]

Hi Roger,

It's this one (with the PCB and ceramic antenna, which I removed (double-sided tape):
https://fr.aliexpress.com/item/32764345698.html

Yes, the antenna is the active one, 8x8mm, from your link (the board supports active antenna).

About the glue, it's just a bit of sanitary silicone sealant I put some kapton tape under the board for insulation.

The power control is done using a N-Channel MOSFET (AO3400, cheap and I have plenty), and 2 resistors (300kΩ between Source and Gate, 200Ω on the Gate line).


Cheers.
---
Daniel

EDIT: resistors value updated.

[VK3KYY]

Hi Roger,

It's this one (with the PCB and ceramic antenna, which I removed (double-sided tape):
https://fr.aliexpress.com/item/32764345698.html

Yes, the antenna is the active one, 8x8mm, from your link (the board supports active antenna).

About the glue, it's just a bit of sanitary silicone sealant I put some kapton tape under the board for insulation.

The power control is done using a N-Channel MOSFET (AO3400, cheap and I have plenty), and 2 resistors (100k between Source and Gate, 1k on the Gate line).


Cheers.
---
Daniel

Thanks.

I use the same GPS module , with built in antenna, on the outside of the GD77 which I modified

I have 2 of those modules with antenna, so I can easily unsolder and remove the antenna from one of those boards

I checked my other modules and they are all ATGM336H with external active antenna, but the ATGM336 modules have the battery on one side of the PCB and the GPS rx on the other wise of the PCB, which makes them too thick to fit inside the radio, as they are double the thickness of the GP02 board

Also. The performance of the ATGM336 modules seems worse than the GP-02, so I prefer to use GP-02


BTW.

Is it possible to control the power of the GPS using only one N channel FET ? I thought a N and P channel were needed, i.e this is what is in the MD9600 and probably also in the RT3S/UV380

[F1RMB]

Hi Roger,

Yes, N-Channel is switching the GND of the board, not the VCC (Drain is connected to the GND of the board, Source to the main GND).
Am I wrong (I used that few times) ?.


Cheers.
---
Daniel

[BI4VWR]

你好，请问这是什么设备

[SA0BUX]

Hi Roger,

Yes, N-Channel is switching the GND of the board, not the VCC (Drain is connected to the GND of the board, Source to the main GND).
Am I wrong (I used that few times) ?.


Cheers.
---
Daniel

https://www.learningaboutelectronics.co ... ircuit.php

[bg5bdt]

good aftenoon

dear

Do you have a detailed wiring principle circuit diagram

[bg5bdt]

Hi,

Here is a small hack I made on one of my GD-77.
I fitted a GP-02 tiny GPS module and a 8x8 active GPS antenna.

20231008_112626-scaled.jpg
20231008_112707-scaled.jpg
20231008_112821-scaled.jpg
20231008_174154-scaled.jpg
20231009_162141-scaled.jpg
20231011_110345-scaled.jpg
20231010_095015-scaled.jpg
20231010_095008-scaled.jpg
20231011_120310-scaled.jpg

Some screengrabs:
GD-77_screengrab-2023-10-11_16_35_02.png
GD-77_screengrab-2023-10-11_16_35_10.png
GD-77_screengrab-2023-10-11_16_11_28.png


Cheers.
---
Daniel

good aftenoon

dear

Do you have a detailed wiring principle circuit diagram