Nosiey USB cable #NewUser


Patrick Jackson
 

I've noticed that on occasion, but not all, when I open wsjtx I get an awful lot of noise showing up on my IC-705 spectrum scope. This primarily happens in the HF bands. I've tried putting a ferrite choke on the cable, and that helps a little, but still leaves a lot of noise. I am connecting my radio to a Macbook (M1). The cable is a basic usb-c to micro usb I got off amazon. If there was noise all the time I'd just get a new cable. But since it is intermittent I'd like to find the cause before buying another. Any suggestions on things to check or investigate would be appreciated. 

73
Patrick
KJ7NOZ


Bill Somerville
 

On 15/02/2021 03:57, Patrick Jackson wrote:
I've noticed that on occasion, but not all, when I open wsjtx I get an awful lot of noise showing up on my IC-705 spectrum scope. This primarily happens in the HF bands. I've tried putting a ferrite choke on the cable, and that helps a little, but still leaves a lot of noise. I am connecting my radio to a Macbook (M1). The cable is a basic usb-c to micro usb I got off amazon. If there was noise all the time I'd just get a new cable. But since it is intermittent I'd like to find the cause before buying another. Any suggestions on things to check or investigate would be appreciated.

73
Patrick
KJ7NOZ
Hi Patrick,

this is probably something Icom need to investigate. A USB connection has clock signals and other data signals, the rig should have sufficient isolation and filtering to stop them appearing on the received signal.

73
Bill
G4WJS.


 

USB (at least 1.1 and 2.0) do not have clocks as such. They have a synchronising data pattern every 1 ms or 125 us depending on the data rate. I have seen the latter as a carrier every 8 kHz when I had a 1 m unscreened USB cable to an SDR RSP with an attached wonderwand aerial. Disappeared when I had a short screened cable. The data will be switching at a much higher rate.

 

If there is cross-talk between the USB and RF connections inside the rig, wouldn’t it be there all the time?

 

73 Phil GM3ZZA

 

Sent from Mail for Windows 10

 

From: Bill Somerville
Sent: 15 February 2021 11:25
To: main@WSJTX.groups.io
Subject: Re: [WSJTX] Nosiey USB cable #NewUser

 

On 15/02/2021 03:57, Patrick Jackson wrote:

> I've noticed that on occasion, but not all, when I open wsjtx I get an

> awful lot of noise showing up on my IC-705 spectrum scope. This

> primarily happens in the HF bands. I've tried putting a ferrite choke

> on the cable, and that helps a little, but still leaves a lot of

> noise. I am connecting my radio to a Macbook (M1). The cable is a

> basic usb-c to micro usb I got off amazon. If there was noise all the

> time I'd just get a new cable. But since it is intermittent I'd like

> to find the cause before buying another. Any suggestions on things to

> check or investigate would be appreciated.

> 73

> Patrick

> KJ7NOZ

 

Hi Patrick,

 

this is probably something Icom need to investigate. A USB connection

has clock signals and other data signals, the rig should have sufficient

isolation and filtering to stop them appearing on the received signal.

 

73

Bill

G4WJS.

 

 


--
73 Phil GM3ZZA


Ken WB8UFC
 

Hi Patrick,

Do you have another computer you can try in an attempt to determine if the computer is the source?


Bill Ahillen
 

When you put a ferrite on the cable you may need 3 turns through as you would get 9 times the isolation. I use 31 material. 43 material for a choke is not as good for HF. If you use too many turns it becomes resonate and you loose the choking effect at some frequency ranges. If one helped try several more to test impact but more turns is a winner if that is the path.

73
Bill W9JJB

On Feb 15, 2021, at 8:53 AM, Ken WB8UFC <wb8ufc@gmail.com> wrote:

Hi Patrick,

Do you have another computer you can try in an attempt to determine if the computer is the source?


Ed W2LCQ
 

Try a high quality shielded USB cable. 

73 de W2LCQ, Ed Jones

Frankford Radio Club
BUG 204 - CWops (Life) 701 - SKCC 5474T -
FISTS 12294 - QCWA 33438 - LICWC (Life) 51 Instructor - ARRL - New York County (Manhattan) FN30AT DXCC WAS

Inscription on a photograph, ”To my illustrious friend, Sir William Crookes, (British chemist and pioneer of the vacuum tube) of whom I always think, and whose letters I never answer.”
        ~ Nicola Tesla



On Feb 15, 2021, at 11:02 AM, Bill Ahillen <bahillen@...> wrote:

When you put a ferrite on the cable you may need 3 turns through as you would get 9 times the isolation. I use 31 material. 43 material for a choke is not as good for HF. If you use too many turns it becomes resonate and you loose the choking effect at some frequency ranges. If one helped try several more to test impact but more turns is a winner if that is the path.

73
Bill W9JJB
On Feb 15, 2021, at 8:53 AM, Ken WB8UFC <wb8ufc@...> wrote:

Hi Patrick,

Do you have another computer you can try in an attempt to determine if the computer is the source?







Patrick Jackson
 

I do have another computer that I can try out so I will give that a whirl. If that doesn't cut it I'll investigate chokes and a new cable. I did find a setting on the radio to charge it while plugged into a laptop. I doubt that will have any effect but i will disable that feature so its not trying to charge the radio at the same time. 

Thanks for input!!

73
Patrick
KJ7NOZ


Williams, G (af8c) <af8c@...>
 

A good USB cable should be completely shielded end to end by being constructed using raw cable that has a shield.  Maybe find out if the cable has a shield.  Some USB cables have clear transparent insulation so you can see the shield.  We "assume" that the Macbook has passed FCC RFI requirements.

--73, Glenn, AF8C

On 2/14/2021 10:57 PM, Patrick Jackson via groups.io wrote:
I've noticed that on occasion, but not all, when I open wsjtx I get an awful lot of noise showing up on my IC-705 spectrum scope. This primarily happens in the HF bands. I've tried putting a ferrite choke on the cable, and that helps a little, but still leaves a lot of noise. I am connecting my radio to a Macbook (M1). The cable is a basic usb-c to micro usb I got off amazon. If there was noise all the time I'd just get a new cable. But since it is intermittent I'd like to find the cause before buying another. Any suggestions on things to check or investigate would be appreciated. 

73
Patrick
KJ7NOZ






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Jim Bacher - WB8VSU
 

The only USB cables I will use are Cables2Go (C2G), Tripp Lite, Dell or HP. I used to do FCC, etc compliance tests, and those are the ones I know are good. There are likely others, but I haven't seen them tested. I have crossed paths with a number of junk (RF Wise) USB cables and devices.

If a cable gets a lot of mechanical use, it gets replaced once a year.

Jim Bacher, WB8VSU
wb8vsu@...

On Feb 14, 2021, at 11:16 PM, Patrick Jackson <kj7noz@...> wrote:
I've noticed that on occasion, but not all, when I open wsjtx I get an awful lot of noise showing up on my IC-705 spectrum scope. This primarily happens in the HF bands. I've tried putting a ferrite choke on the cable, and that helps a little, but still leaves a lot of noise. I am connecting my radio to a Macbook (M1). The cable is a basic usb-c to micro usb I got off amazon. If there was noise all the time I'd just get a new cable. But since it is intermittent I'd like to find the cause before buying another. Any suggestions on things to check or investigate would be appreciated. 

73
Patrick
KJ7NOZ




Ken WB8UFC
 

On Tue, Feb 16, 2021 at 02:44 AM, Patrick Jackson wrote:
I do have another computer that I can try out so I will give that a whirl. If that doesn't cut it I'll investigate chokes and a new cable.
Yes. Better to treat the disease than the symptom - if you can.