Page 2 of 7
Re: Stop transmitting occasionally...
Posted: Thu Feb 20, 2020 9:24 am
by VK3KYY
OK
Re: Stop transmitting occasionally...
Posted: Sat Jul 18, 2020 2:18 pm
by F6GVE
EB3AM wrote: ↑Wed Feb 12, 2020 9:35 pm
Hello, I have been seeing an error in the hotspot mode.
Occasionally, while streaming internet audio, it stops transmitting, although the Pi-star still indicates TX. When this broadcast ends and another begins, the radio transmits again.
By monitoring the same TG with a Hat, the transmission is still active.
Hello, do you still have this trouble? Or did you find a workaround?
I have a new DM-1801 for a hospot use and I have the exact same issue
Re: Stop transmitting occasionally...
Posted: Mon Jul 20, 2020 10:56 am
by F6GVE
I think I found what was wrong
When I built the USB cable, I sold the "-" and the shield wires together.
I also had some micro drops when receiving from the hotspot-TX (DM-1801) even with the lowest power (13 mW) and no matter the antenna used.
I have unsoldered the shield from the USB part of the cable and everything seems allright at the moment
Re: Stop transmitting occasionally...
Posted: Mon Jul 20, 2020 11:29 am
by VK3KYY
F6GVE wrote: ↑Mon Jul 20, 2020 10:56 am
I think I found what was wrong
When I built the USB cable, I sold the "-" and the shield wires together.
I also had some micro drops when receiving from the hotspot-TX (DM-1801) even with the lowest power (13 mW) and no matter the antenna used.
I have unsoldered the shield from the USB part of the cable and everything seems allright at the moment
I can't see how that would fix it unless you only soldered the shield at one end, hence you made a small antenna from the shield
Re: Stop transmitting occasionally...
Posted: Mon Jul 20, 2020 11:30 am
by F1RMB
Hi Luc,
F6GVE wrote: ↑Mon Jul 20, 2020 10:56 am
I think I found what was wrong
When I built the USB cable, I sold the "-" and the shield wires together.
I also had some micro drops when receiving from the hotspot-TX (DM-1801) even with the lowest power (13 mW) and no matter the antenna used.
I have unsoldered the shield from the USB part of the cable and everything seems allright at the moment
Yeah, D- is not the ground, D+ D- are differential pair.
Cheers.
---
Daniel
Re: Stop transmitting occasionally...
Posted: Mon Jul 20, 2020 11:39 am
by VK3KYY
Yikes
I presume he meant that he had soldered the shield to the -ve "Negative" connection.
data line "D-" is not ground !!!
Re: Stop transmitting occasionally...
Posted: Mon Jul 20, 2020 11:44 am
by F1RMB
VK3KYY wrote: ↑Mon Jul 20, 2020 11:39 am
Yikes
I presume he meant that he had soldered the shield to the -ve "Negative" connection.
data line "D-" is not ground !!!
Ahhh, okay
Re: Stop transmitting occasionally...
Posted: Mon Jul 20, 2020 11:47 am
by F1RMB
Anyway, shielding is overrated
Re: Stop transmitting occasionally...
Posted: Mon Jul 20, 2020 11:55 am
by VK3KYY
F1RMB wrote: ↑Mon Jul 20, 2020 11:30 am
D+ D- are differential pair.
Yes. In theory there should not be much pickup on a differential pair, even though the wires are not a twisted pair.
Its more likely there is general RF induction through the whole cable, which gets rectified somewhere in the RPi into DC which causes problems.
Re: Stop transmitting occasionally...
Posted: Mon Jul 20, 2020 12:27 pm
by F6GVE
It will be more explicit like that
