GD77 Bad RX-audio with fully charged battery

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oe7abh
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GD77 Bad RX-audio with fully charged battery

Post by oe7abh » Mon Mar 27, 2023 2:43 pm

Hello Colin and GD77 team,

with a fully charged battery (>90%) the RX-AUDIO is not so good....
Is it possible to fix the RX-audio problem with a hardware modification on the GD77? I would be willing to solder a little too.

73 Alfred OE7ABH
http://tyrofly.at/funk.htm
Last edited by oe7abh on Tue Mar 28, 2023 8:58 pm, edited 2 times in total.

G4EML
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Re: GD77-RX Audio

Post by G4EML » Mon Mar 27, 2023 8:04 pm

Jason VK7ZJA developed a fix for the audio amp.
It is near the bottom of this document https://nq4t.com/anytone/GD77mods.htm

Colin G4EML

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oe7abh
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Re: GD77-RX Audio

Post by oe7abh » Tue Mar 28, 2023 2:34 pm

Hello Colin,

Thanks for the link.
Fixed bad RX audio today. (Battery charge over >90%). RX audio now works UFB!
There is a little more space for the SMD resistor than in the instructions, an SMD soldering pad is free directly behind it!
10k resistor replaced with 15k!

Image

73 Alfred OE7ABH
http://tyrofly.at/funk.htm

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Re: GD77 Bad RX-audio with fully charged battery

Post by oe7abh » Wed Mar 29, 2023 7:25 am

Hi david,

in our club are many GD77 devices from the bad RX audio at 100% charged battery.
My modification has fixed the error. I am thrilled...
Whether the own device is affected, one can recognize fast. Charge the battery to 100% and listen to a QSO....
But the soldering is not suitable for beginners....

73 from Austria, Alfred OE7ABH

G4EML
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Re: GD77 Bad RX-audio with fully charged battery

Post by G4EML » Wed Mar 29, 2023 11:02 am

The problem didn't affect all radios. It may be that the factory made a change or it may just be down to luck with different batches of amplifier chips.

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