I’m not sure there is NO noise, but there are 40 of them in use in our data network and I’ve heard no complaints. ?

They are $15 from Amazon?

and $40 for 10 of them from Alibaba.?

But I can’t figure out how to send Alibaba money.? The web page is always broken in some way late in the purchase. ?

Can anybody buy from these people??

? ?Tadd

On Jul 13, 2021, at 4:27 PM, Dave R <daverickmers@...> wrote:

We see linear supplies that waste half the power as heat and smps supplies that raise the noise floor noticeably.

Can you detect any noise from the DROK? Their website isn't very technical. Amazon is famous for selling EMI plagued devices. 73

On Tue, Jul 13, 2021, 10:21 Tadd KA2DEW in NC via <tadd=[email protected]> wrote:

The acid test for all this is whether the Raspberry PI complains about under-volt.? If the PI doesn’t complain, EVER, you are probably in great shape. ?

Measuring the voltage at the PI makes sense.? Measuring the current doesn’t help much since the PI will draw what it draws. I don’t think longer cables change how much current the Raspberry PI needs and a bigger power supply on the source end won’t change the current the Raspberry PI needs. ?

My solution is to use a 5.2v regulator and a six inch cable to the USB-c plug.? There are a host of inexpensive (< $20) variable output, 8v to 37v input, adjustable output supplies out in the world.? DROK makes a good one which actually has a variable voltage output into a USB-A socket and that’s the one our local radio club uses.? We like that the PI comes on when the radios are powered up.? Having the PI powered up whenever the radios are on is a good thing.? Having the radios powered and the PI not powered can be bad because voltage enough to start up some of the PI’s peripherals can show up on connections between the radios and those peripherals.? So if the PI is powered down and the radios are up, you can get bad glitches in the peripherals. ?

The point is, you need 5.2v at the Raspberry PI.? You can measure the voltage at the 40-pin AUX connector.? Wires drop voltage when the current draw is > 0.? Longer wires drop more voltage and higher current draw causes more voltage drop.? Thinner wires also cause higher voltage drop. ?

So, ?if you have a voltage need, and a current need, and length of wire you want to keep the voltage high enough, the length short enough and the wire thick enough. ?

? ?Tadd

On Jul 12, 2021, at 10:15 PM, dwfunk4475 <dwfunk@...> wrote:

Measure the voltage and current at your Pi, don't guess.?

And FYI, power supplies according to? require 5.1 volts.

-david

On Mon, Jul 12, 2021, 16:15 Jeremy Utley <jerutley@...> wrote:

Hi all in the group!

?

Been doing lots of Google searches, and while years ago I found this kind of info for the old micro-USB cables, I haven’t found similar information for USB-C – and I figure the Pi Ham Radio group is my best bet.

?

I’ve got a Pi-4 8GB model, with an Argon One M.2 case and Samsung SSD as the boot device.? I’m building out this device for portable logging/digital mode usage when I’m on POTA activations – either by VNC from a tablet, or a small portable screen mounted in my radio case.

?

So the problem I have is with voltage drop – I power the Pi via a PowerWerx USB-Buddy – which provides 5v DC @ 3A, connected to a Bioenno LiFePo4 battery.? In my testing here at home, using a 1ft long USB-A to USB-C cable, it works without any problems.? But, I wanted a longer cable, so I went to a 3ft cable from the same maker.? Once I used that cable, I was immediately getting low voltage warnings – so obviously I’m getting voltage drop on the longer cable.? But I’m having trouble finding heavier USB-A to USB-C cables to avoid voltage drop across that length.

?

Anybody have knowledge of any good cables that fit the bill???

?

Thanks!

?

Jeremy, NQ0M

The acid test for all this is whether the Raspberry PI complains about under-volt.? If the PI doesn’t complain, EVER, you are probably in great shape. ?

Measuring the voltage at the PI makes sense.? Measuring the current doesn’t help much since the PI will draw what it draws. I don’t think longer cables change how much current the Raspberry PI needs and a bigger power supply on the source end won’t change the current the Raspberry PI needs. ?

My solution is to use a 5.2v regulator and a six inch cable to the USB-c plug.? There are a host of inexpensive (< $20) variable output, 8v to 37v input, adjustable output supplies out in the world.? DROK makes a good one which actually has a variable voltage output into a USB-A socket and that’s the one our local radio club uses.? We like that the PI comes on when the radios are powered up.? Having the PI powered up whenever the radios are on is a good thing.? Having the radios powered and the PI not powered can be bad because voltage enough to start up some of the PI’s peripherals can show up on connections between the radios and those peripherals.? So if the PI is powered down and the radios are up, you can get bad glitches in the peripherals. ?

The point is, you need 5.2v at the Raspberry PI.? You can measure the voltage at the 40-pin AUX connector.? Wires drop voltage when the current draw is > 0.? Longer wires drop more voltage and higher current draw causes more voltage drop.? Thinner wires also cause higher voltage drop. ?

So, ?if you have a voltage need, and a current need, and length of wire you want to keep the voltage high enough, the length short enough and the wire thick enough. ?

? ?Tadd

On Jul 12, 2021, at 10:15 PM, dwfunk4475 <dwfunk@...> wrote:

Measure the voltage and current at your Pi, don't guess.?

And FYI, power supplies according to? require 5.1 volts.

-david

On Mon, Jul 12, 2021, 16:15 Jeremy Utley <jerutley@...> wrote:

Hi all in the group!

?

Been doing lots of Google searches, and while years ago I found this kind of info for the old micro-USB cables, I haven’t found similar information for USB-C – and I figure the Pi Ham Radio group is my best bet.

?

I’ve got a Pi-4 8GB model, with an Argon One M.2 case and Samsung SSD as the boot device.? I’m building out this device for portable logging/digital mode usage when I’m on POTA activations – either by VNC from a tablet, or a small portable screen mounted in my radio case.

?

So the problem I have is with voltage drop – I power the Pi via a PowerWerx USB-Buddy – which provides 5v DC @ 3A, connected to a Bioenno LiFePo4 battery.? In my testing here at home, using a 1ft long USB-A to USB-C cable, it works without any problems.? But, I wanted a longer cable, so I went to a 3ft cable from the same maker.? Once I used that cable, I was immediately getting low voltage warnings – so obviously I’m getting voltage drop on the longer cable.? But I’m having trouble finding heavier USB-A to USB-C cables to avoid voltage drop across that length.

?

Anybody have knowledge of any good cables that fit the bill???

?

Thanks!

?

Jeremy, NQ0M

Hi all in the group!

?

Been doing lots of Google searches, and while years ago I found this kind of info for the old micro-USB cables, I haven’t found similar information for USB-C – and I figure the Pi Ham Radio group is my best bet.

?

I’ve got a Pi-4 8GB model, with an Argon One M.2 case and Samsung SSD as the boot device.? I’m building out this device for portable logging/digital mode usage when I’m on POTA activations – either by VNC from a tablet, or a small portable screen mounted in my radio case.

?

So the problem I have is with voltage drop – I power the Pi via a PowerWerx USB-Buddy – which provides 5v DC @ 3A, connected to a Bioenno LiFePo4 battery.? In my testing here at home, using a 1ft long USB-A to USB-C cable, it works without any problems.? But, I wanted a longer cable, so I went to a 3ft cable from the same maker.? Once I used that cable, I was immediately getting low voltage warnings – so obviously I’m getting voltage drop on the longer cable.? But I’m having trouble finding heavier USB-A to USB-C cables to avoid voltage drop across that length.

?

Anybody have knowledge of any good cables that fit the bill???

?

Thanks!

?

Jeremy, NQ0M

Dave. Certainly 5.5v wont hurt the pi. But he has a voltage drop because his powerworex is only at max of 3a unit with the 3 ft cord.? Also what I would do if it were me. I would ohm out the 3 ft cord from one end to the other. And see how much resistance there is? That way you can calculate the drop in current by Ohm's law pretty easy. So I don't think it's his USB cord. The cord is only amplifying his situation...? 73

*Jeremy, You got a Powerwerx USBbuddy? 5v 3a???

It looks like Powerworx does sell/have a 4.8a round model (Panel mount dual usb 4.8a)? But first. Have you tried the 3ft cord at home with a 5v wall wart??? I say this because most pi kits come with a 5v 3a wall wart and a 3 ft cord attached? Mine did when I bought the pi kit.? Raise the voltage it will increase the current

On 07/12/21 3:56 PM, Dave R via wrote:

How do you "up your output current" in this situation??

Maybe raise the Voltage to get same power on a given conductor? 5.5Vdc won't hurt anything. Beware of smart USB sockets that limit power. 73

On Mon, Jul 12, 2021, 14:42 Vince A <vince@...> wrote:

Hello Jeremy

My first question is:? Where did you buy the USB cord?

Also 5v 3a is right close to being not enough current for your pi-4. 4-5a would be better. I mean by the time it reaches your pi its at max 3a. I don't think it's your cord. 3ft should not* be enough to shortchange you. That to me would not be that much of a voltage* drop. Current yes by all means. 3a at 3 feet. That's quite a lot. So up* your output current for the loss of voltage from your 3ft cord.

Now have you tried to power this at home with a 5v wall wart with that 3 ft cord?? I don't think it's the cable. Your right at the edge of your current with the Powermax 5v 3a supply. Get my drift?? Up your amperage and try again...

HTH? 73

On 07/12/21 3:13 PM, Jeremy Utley via wrote:

Hi all in the group!

?

Been doing lots of Google searches, and while years ago I found this kind of info for the old micro-USB cables, I haven’t found similar information for USB-C – and I figure the Pi Ham Radio group is my best bet.

?

I’ve got a Pi-4 8GB model, with an Argon One M.2 case and Samsung SSD as the boot device.? I’m building out this device for portable logging/digital mode usage when I’m on POTA activations – either by VNC from a tablet, or a small portable screen mounted in my radio case.

?

So the problem I have is with voltage drop – I power the Pi via a PowerWerx USB-Buddy – which provides 5v DC @ 3A, connected to a Bioenno LiFePo4 battery.? In my testing here at home, using a 1ft long USB-A to USB-C cable, it works without any problems.? But, I wanted a longer cable, so I went to a 3ft cable from the same maker.? Once I used that cable, I was immediately getting low voltage warnings – so obviously I’m getting voltage drop on the longer cable.? But I’m having trouble finding heavier USB-A to USB-C cables to avoid voltage drop across that length.

?

Anybody have knowledge of any good cables that fit the bill???

?

Thanks!

?

Jeremy, NQ0M

-- 
73, de Vince KD7TWW
In what year did the FCC mandate the 1500 Watt PEP limit for amateur radio station
power output? - Motorola Corp was formally named
"Galvin Manufacturing Corporation" (1928–1947)

-- 
73, de Vince KD7TWW
In what year did the FCC mandate the 1500 Watt PEP limit for amateur radio station
power output? - Motorola Corp was formally named
"Galvin Manufacturing Corporation" (1928–1947)

Hello Jeremy

My first question is:? Where did you buy the USB cord?

Also 5v 3a is right close to being not enough current for your pi-4. 4-5a would be better. I mean by the time it reaches your pi its at max 3a. I don't think it's your cord. 3ft should not* be enough to shortchange you. That to me would not be that much of a voltage* drop. Current yes by all means. 3a at 3 feet. That's quite a lot. So up* your output current for the loss of voltage from your 3ft cord.

Now have you tried to power this at home with a 5v wall wart with that 3 ft cord?? I don't think it's the cable. Your right at the edge of your current with the Powermax 5v 3a supply. Get my drift?? Up your amperage and try again...

HTH? 73

On 07/12/21 3:13 PM, Jeremy Utley via wrote:

Hi all in the group!

?

Been doing lots of Google searches, and while years ago I found this kind of info for the old micro-USB cables, I haven’t found similar information for USB-C – and I figure the Pi Ham Radio group is my best bet.

?

I’ve got a Pi-4 8GB model, with an Argon One M.2 case and Samsung SSD as the boot device.? I’m building out this device for portable logging/digital mode usage when I’m on POTA activations – either by VNC from a tablet, or a small portable screen mounted in my radio case.

?

So the problem I have is with voltage drop – I power the Pi via a PowerWerx USB-Buddy – which provides 5v DC @ 3A, connected to a Bioenno LiFePo4 battery.? In my testing here at home, using a 1ft long USB-A to USB-C cable, it works without any problems.? But, I wanted a longer cable, so I went to a 3ft cable from the same maker.? Once I used that cable, I was immediately getting low voltage warnings – so obviously I’m getting voltage drop on the longer cable.? But I’m having trouble finding heavier USB-A to USB-C cables to avoid voltage drop across that length.

?

Anybody have knowledge of any good cables that fit the bill???

?

Thanks!

?

Jeremy, NQ0M

-- 
73, de Vince KD7TWW
In what year did the FCC mandate the 1500 Watt PEP limit for amateur radio station
power output? - Motorola Corp was formally named
"Galvin Manufacturing Corporation" (1928–1947)

Interesting, so all the?usb3 SSD issues and issues with usb3 high speed bus like using a coral are related to usb2 compatibility issues? Got any data to back it up? Or this is just the Texas chip in intel radios? Anywhoo im trolling so I will leave it at that.?


Excuse typos and brevity, sent from a mobile device.

On Monday, July 12, 2021, 9:44 AM, N5XMT <dacooley@...> wrote:

Not faulty, just not 100% backwards compatible with USB2.0

On Jul 12, 2021, at 09:16, "Kelly Keeton via " <yahoo.com@ target=_blank>kellykeeton=@> wrote:

the pi4 usb3 is faulty

Not the radios issue it’s the pi defect?


Excuse typos and brevity, sent from a mobile device.

On Monday, July 12, 2021, 7:44 AM, Jim Darrough <jim@...> wrote:

Try using a black USB port on your Raspberry Pi. For some reason, the IC-7300 and IC-705 ports don't work with USB 3.0.

73 Jim KI7AY