Baofeng DM-1801

iw0dt
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Joined: Sat Nov 16, 2019 11:01 am

Baofeng DM-1801

Post by iw0dt » Sun Nov 17, 2019 9:21 am

Buongiorno Roger, volevo sapere se il DM-1801 può funzionare con il firmware OpenGD77 come Hotspot.
Grazie

k8upe
Posts: 19
Joined: Sat Nov 16, 2019 2:15 pm

Re: Baofeng DM-1801

Post by k8upe » Sun Nov 17, 2019 2:44 pm

Translation:
Hello Roger, I wanted to know if the DM-1801 can work with the OpenGD77 firmware as a hotspot.
Thanks

VK3KYY
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Location: Melbourne, Australia

Re: Baofeng DM-1801

Post by VK3KYY » Sun Nov 17, 2019 7:47 pm

DM-1801 looks similar on the outside, but if you take the radio apart you will find it’s not the same hardware

It uses a slightly different CPU the main PCB is completely different , hence the firmware won’t run on this or any other radios

It won’t even run on the GD-77S,

VK3KYY
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Location: Melbourne, Australia

Re: Baofeng DM-1801

Post by VK3KYY » Sun Dec 01, 2019 10:11 pm

BTW.

If anyone has a schematic diagram for a DM-1801 it would probably be possible to modify the OpenGD77 firmware to work with that radio, but I can't find a schematic for it anywhere

ok3js
Posts: 9
Joined: Wed Apr 22, 2020 3:15 pm

Re: Baofeng DM-1801

Post by ok3js » Sun May 03, 2020 10:09 am

The problem with the falling hotspot openGD77 on DM1801 and the freezing MMDVM (also Pi-star) solved, it is RF performance.

Everything works OK up to 500mW, at 750mW and above it freezes. Apparently a HF signal is induced into the USB cable and kills the Pi Zero process.

I'll put on a ferrite cable and see what's next.


---------------------------------------------------
Problém s padajícím hotspotem openGD77 na DM1801 a zatuhávajícím MMDVM (i Pi-star) vyřešen, je jím RF výkon.

Do 500mW vše pracuje OK, u 750mW a výše dojde k zatuhnutí. Zřejme se indukuje do USB kabelu VF signál a umrtví proces Pi Zero.

Osadím kabel ferity a uvidím co bude dál.

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F1RMB
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Location: Grenoble, France

Re: Baofeng DM-1801

Post by F1RMB » Sun May 03, 2020 10:19 am

Hi,
ok3js wrote:
Sun May 03, 2020 10:09 am
The problem with the falling hotspot openGD77 on DM1801 and the freezing MMDVM (also Pi-star) solved, it is RF performance.

Everything works OK up to 500mW, at 750mW and above it freezes. Apparently a HF signal is induced into the USB cable and kills the Pi Zero process.

I'll put on a ferrite cable and see what's next.


---------------------------------------------------
Problém s padajícím hotspotem openGD77 na DM1801 a zatuhávajícím MMDVM (i Pi-star) vyřešen, je jím RF výkon.

Do 500mW vše pracuje OK, u 750mW a výše dojde k zatuhnutí. Zřejme se indukuje do USB kabelu VF signál a umrtví proces Pi Zero.

Osadím kabel ferity a uvidím co bude dál.
Yes, that's a well known problem.
Also, if you want more coverage or using more power, an external antenna is the way to go.


Cheers.
---
Daniel

ok3js
Posts: 9
Joined: Wed Apr 22, 2020 3:15 pm

Re: Baofeng DM-1801

Post by ok3js » Sun May 03, 2020 1:08 pm

Yes, an external antenna will probably solve it.

I have for more than a month ordered from AE 5m pigtail SMA - PL259 and 3 el. yagi antenna.
I'm waiting for delivery.

It is pleasant to cover the surroundings with 500mW, it is much better than 10mW with a small mmdvm hotspot.

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EB3AM
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Location: Catalonia, not Spain
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Re: Baofeng DM-1801

Post by EB3AM » Sun May 03, 2020 2:39 pm

I bought a baofeng dm-1801 with the intention of using it as a hotspot, but the operation is very bad. As you say it kills the connection with the raspberry, which is not the case with radioddity.
I ran the hotspot with 4w and outdoor antenna a long time with the GD77, no problem. But the Baofeng, above 500mW is impossible to run for an hour straight.

LY1RF
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Joined: Sun Mar 01, 2020 12:05 pm

Re: Baofeng DM-1801

Post by LY1RF » Sun May 03, 2020 2:56 pm

No problem with my 1801, pi2 and diamond x200 external antenna - hotspot works all day at any power you set it, 5w too...
Maybe try to change usb cable, or rpi power adapter...

ok3js
Posts: 9
Joined: Wed Apr 22, 2020 3:15 pm

Re: Baofeng DM-1801

Post by ok3js » Sat May 09, 2020 8:08 am

Tested with a small magnetic antenna with a 5m cable from Aliexpress. Mmdvm no longer freezes and runs at 2W.
I have an antenna on the balcony about 7m above the ground. I live on a slope above the valley, about 50m above the river, and I tested the coverage in two villages in other valleys, I have a range of about 6km as the crow flies. :D :D :D :D

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