[Solved] Pi-Star cannot receive OpenGD77's signal

VK3KYY
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Re: [Solved] Pi-Star cannot receive OpenGD77's signal

Post by VK3KYY » Sun Aug 02, 2020 10:15 am

G4EML wrote:
Sun Aug 02, 2020 10:02 am
The internal AFC of the ADF7021 does not work correctly with pulsed TDMA signals as used by DMR. In fact the chip struggles to lock on these signals with or without AFC. Hence the need to fine tune the frequency to minimise the errors.
Colin

Thanks for the info.

BG9EGA
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Location: Shaanxi, China

Re: [Solved] Pi-Star cannot receive OpenGD77's signal

Post by BG9EGA » Mon Aug 03, 2020 1:05 am

My devices are working fine.
Bit Error Rate <0.5%
Thanks everyone for your help!
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VK3KYY
Posts: 2816
Joined: Sat Nov 16, 2019 3:25 am
Location: Melbourne, Australia
Contact:

Re: [Solved] Pi-Star cannot receive OpenGD77's signal

Post by VK3KYY » Mon Aug 03, 2020 5:14 am

You may want to change the orientation of the 2 antennas on the hotspot, because it stands those 2 antenna are oriented for maximum coupling of the Tx to the Rx.

BG9EGA
Posts: 6
Joined: Tue Jul 28, 2020 3:29 am
Location: Shaanxi, China

Re: [Solved] Pi-Star cannot receive OpenGD77's signal

Post by BG9EGA » Mon Aug 03, 2020 6:50 am

Thanks for reminding!
Another knowledge blind spot.
I have adjusted.

I found a duplex board using ceramic antenna. How about this?
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