Hotspot mode - Apparently stuck in TX

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F1RMB
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Re: Hotspot mode - Apparently stuck in TX

Post by F1RMB » Sun May 24, 2020 9:10 am

Hi,
toybizarre wrote:
Sun May 24, 2020 9:00 am
Hello to all,

i have the same problem....
OpenGD77 last firmware
Raspberry pi 3 amd 1 (same problem) last pi-star

when i configure all.....and the radio go in TX....the end
Pi-star stuck in tx (Only pi-star)....the radio will only transmit for 1 second.

Same problem with raspbery 1 .... with or without the CAST option...

Any solution?
Thanks
Check the "dmesg" output, but I bet it's the same problem as usual, too much RF going back to the USB port:
- Try to reduce the output power,
- Use an external antenna,
- Put some ferrite beads around the data cable.

Cheers.
---
Daniel
73 de Daniel.

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kd2lh
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Re: Hotspot mode - Apparently stuck in TX

Post by kd2lh » Sun May 24, 2020 3:06 pm

The problem had that appearance here also, and the combination of ferrite beads on the USB cable (at both ends) and the usage of an external antenna placed several feet away from the radio and RPi has solved this.

Note that other things can also radiate magnetic fields and induce interference voltage in the USB cables. This includes being too close to the rear of a large computer display or adjacent to another operating hotspot antenna.

Marc

toybizarre
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Joined: Sun May 24, 2020 8:49 am

Re: Hotspot mode - Apparently stuck in TX

Post by toybizarre » Mon May 25, 2020 7:39 am

Woooow....resolved!! :)

50mW and radio distance from raspberry and it works!!!

Thank u

kt4lh
Posts: 156
Joined: Sun Jan 12, 2020 4:27 am

Re: Hotspot mode - Apparently stuck in TX

Post by kt4lh » Mon May 25, 2020 2:52 pm

I have a cheapie magmount antenna I use on my hotspot to get the RF away from my desk, use it for both my mmdvm board and the GD77. Haven't had any issues like this, so I guess it's far enough away.

I have also run the GD77 on my primary antenna at the house, and on 2W I get solid coverage on the back side of a hill half a mile away at a spot I'm at pretty regularly, so that's pretty nice. Never tried to see how far it goes with good LOS. I might try that today, I found a location 5.5 miles away with good LOS (according to heywhatsthat) which I need to go to anyway. :)

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kd2lh
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Re: Hotspot mode - Apparently stuck in TX

Post by kd2lh » Mon May 25, 2020 7:46 pm

It gets spotty because of the hills, but I've worked through my hotspot from a mile and a half away from the mobile in my car.

I've got a gain mag mount antenna placed about 10 feet from the GD77 running hotspot mode at 2 watts. It's on the second floor of the house inside my lab room, and unfortunately my house is surrounded by ridges that cause the spotty interference. It regularly is useful about a mile from the house on the high side of the ridge...

Properly sited and with a decent mobile antenna, these should operate a fair range if there is no obstructive terrain. They should be ideal for supporting an event.

kt4lh
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Re: Hotspot mode - Apparently stuck in TX

Post by kt4lh » Tue May 26, 2020 9:12 pm

Ha, so today on 2W on a modest antenna on the roof at 30ft, which is about 20ft HAAT for a 1 mile radius, I had looked at heywhatsthat and noticed a spot I know well has a big red blob for line of sight, and it's right at 5.5 miles away. I brought the big antenna and my homebrew yagi and drove into the parking lot and I immediately heard my hotspot with my NA810 antenna on my MD380 ;) Just worked.

RF is neat.

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kd2lh
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Re: Hotspot mode - Apparently stuck in TX

Post by kd2lh » Tue May 26, 2020 10:26 pm

Nice! and Digital RF is really neat... Depending upon terrain, a 4 watt hotspot and small number of low power hotspots could support an entire event ...

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