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...other than unplugging it!? My USB keyboard is causing quite a lot of interference to the Softrock.? I have tried different USB ports, but still have noise.? I also used a couple of snap closed ferrite chokes.? This helps, but if I keep adding them, soon there won't be enough wire left for the keyboard to be of any use.? I just wondered if maybe there was something I could add to the inside of the keyboard which might suffice.? Thanks!
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Unplugging it isn't necessarily tragic. You could replace it with an old school PS/2 keyboard (most desktop computers still have a port for those that can accept either a keyboard or a mouse), a wireless keyboard with a USB dongle, or a Bluetooth keyboard (you might have to buy a Bluetooth receiver). On Mon, Jun 7, 2021 at 11:36 AM JonI via groups.io <ji425bt= verizon.net@groups.io> wrote: ...other than unplugging it! My USB keyboard is causing quite a lot of
interference to the Softrock. I have tried different USB ports, but
still have noise. I also used a couple of snap closed ferrite chokes.
This helps, but if I keep adding them, soon there won't be enough wire
left for the keyboard to be of any use. I just wondered if maybe there
was something I could add to the inside of the keyboard which might
suffice. Thanks!
|
Hello Joni,
Have you tried another keyboard?
I spent much of my work life with EMI problems and FCC part 15 compliance. (Retired now) FCC part 15 only says it will not interfere with NORMAL home entertainment electronics. Amateur radio receivers are vastly more sensitive and not protected. Much of electronic junk from China fails pretty bad if tested. The FCC has no teeth & not enough staff to catch it. Your keyboard may not even meet FCC part 15 requirements which are not strict enough to protect amateur receivers.
Ferrite sleeves & clip-ons come in many flavors. (NOT chocolate, Vanilla & Strawberry) Most of my compliance headaches were in the 30 to 500MHz area. A lot of the Ferrites are optimized for that region, not HF. I used a lot of ferrites from Laird so I am familiar with them. I got engineering lab parts through Digikey. Not endorsing either as there are many other good suppliers as well.
Laird materials:
LF good from 2 to 30 MHz. Not available in clip-ons Hi permeability of materiel will not handle slight gap of a clip on.
28 good from 30 to 500MHz. Most common but less effective below 30MHz.
HF good from 300 to 2000MHz. Has virtually no effect at HF radio range of 3 to 30MHz. Poor choice of alphabet soup of part numbers.
It also may pay to put filters or ferrites on the softrock cables. The outside of a coax shield can be an undesired "Antenna"! Power cable often couple in noise & filters often help there. Sometime separating cables in a bundle make problem go away or get worse.
The clip on ferrites can be less effective if there is any contamination between the 2 chunks of ferrite where they meet.
If the hole in a ferrite is big enough, running cable through 2 x with a loop around the outside sometimes helps. At lower frequencies 2 passes gives 4 times the impedance. At higher frequencies 2 passes are often WORSE.
A toroid core such as Digikey 240-2286-ND with USB connector looped through 4 or 5 times may help.
Troubleshooting this type problem often seems like black magic or worse.
Another odd note: I have a daughter named Joni who is almost 40 & still kayaks off of waterfalls. Playing with radios sounds safer!
Bruce NT4RT
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-----Original Message-----
From: softrock40@groups.io [mailto:softrock40@groups.io] On Behalf Of JonI via groups.io
Sent: Monday, June 7, 2021 11:36 AM
To: softrock40@groups.io
Subject: [softrock40] ways to tackle USB keyboard interference?
...other than unplugging it! My USB keyboard is causing quite a lot of
interference to the Softrock. I have tried different USB ports, but
still have noise. I also used a couple of snap closed ferrite chokes.
This helps, but if I keep adding them, soon there won't be enough wire
left for the keyboard to be of any use. I just wondered if maybe there
was something I could add to the inside of the keyboard which might
suffice. Thanks!
|
You mentioned the other day that you are using an indoor loop.
Fifteen to twenty years ago I used indoor loops for LF/MF with no problems, a Wellbrook loft mounted on a rotator and a Palomar tuned active ferrite loop mounted right alongside my then PC served me very well, but nowadays the the amount of self generated interference in the average domestic dwelling makes this far more difficult, if not impossible.
You also asked about an indoor mounted Wellbrook loop vs an outdoor active vertical.Not knowing about individual circumstances can make answering such questions a bit hit and miss, but if you do have room for an outdoor antenna I would recommend the Wellbrook over an active vertical, I do use both though and would always suggest experimentation where possible, and would also recommend mounting anything as far away as possible.I know this may not be practical but, by way of example, not so long ago I found it necessary to mount a Wellbrook some 15 to 20 metres away from the building in order to adequately reduce the LF interference generated by the electronic ballast of a modern fluorescent light.Ok, so the light is in the process of being scrapped but this is just one example of the problems we now face.
Ironically one of the worst examples of wall wart switch mode noise I've come across was from an Icom PSU supplied with one of their wideband receivers, another recommendation would be to always use linear PSUs where possible.
Of? course do all you can to reduce USB interference etc, but if it's still reaching your softrock via the indoor antenna, rather than via the cabling, then it's quite likely you could be fighting a losing battle.
Just a further thought re the USB keyboard, for several years now I've used Logiteck K260 wireless kits for keyboard and mouse, connecting via a small dongle plugged into a USB port on the PC.
The wireles link, I believe, is at 2.4GHz, but either way it certainly doesn't interfere with my radios, nor with wi-fi when I was using it.I think I paid somewhere between ?10 and ?20 per kit, and whilst this kit might be obsolete now I'm sure there will be similar available.
I just bought them for the convenience of? being cable free but something like that might help reduce your USB problems.
Nigel GM8PZR
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-----Original Message-----
From: JonI via groups.io <ji425bt@...>
To: softrock40@groups.io
Sent: Mon, 7 Jun 2021 16:35
Subject: [softrock40] ways to tackle USB keyboard interference?
...other than unplugging it!? My USB keyboard is causing quite a lot of
interference to the Softrock.? I have tried different USB ports, but
still have noise.? I also used a couple of snap closed ferrite chokes.?
This helps, but if I keep adding them, soon there won't be enough wire
left for the keyboard to be of any use.? I just wondered if maybe there
was something I could add to the inside of the keyboard which might
suffice.? Thanks!
|
Jon,
Interference to Softrock comes in 2 different flavors.
1. Interference coming through the audio connection ("ground loop") shows up as a symmetrical center hump, or some other symmetrical picture on the waterfall. USB devices typically show up as spikes at + and -1kHz for keyboards, and +-8kHz for higher speed devices. These humps/spikes don't move when tuning the VFO.
2. Interference coming through the RF input is typically periodic spikes, often widened, on the waterfall. Not symmetrical, but repeated every 11..18kHz (solar panel inverters, variable speed votors), 62..64kHz (PC and other switching power supplies), or some other step. These spikes move with the VFO change.
Which one do you think you are experiencing? The methods to fight the interference depend a lot on whether it is AF or RF.
73, Mike AF7KR
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Hi Mike,
Well, when I unplug both the monitor and keyboard, the most of the offending "birdies" go away.? I had just hoped to be able to keep the keyboard plugged in.? Others are suggesting a wireless and I may go with that.? Just as an experiment, I lined the non-key inside of the keyboard today with sticky aluminum foil, then stuck foil around the USB cable leading from the keyboard to the USB connector on the desktop.? Did not make much difference.
I guess I can just turn off the monitor as I'm using RDP anyway and controlling everything from the laptop.? Of course, would still like to solve it.? I started using ferrite chokes on the monitor cable with success, but ran out of chokes.
There are a couple of other sounds I get from about 3- 5 Mhz. Not at the spike so I think it's RF, but not sure if it's coming from me.? I will try and video and post those. ? I was able to null the loudest one out by turning the loop.
Jon
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On 6/7/21 5:06 PM, vbifyz wrote: Jon,
Interference to Softrock comes in 2 different flavors.
1. Interference coming through the audio connection ("ground loop") shows up as a symmetrical center hump, or some other symmetrical picture on the waterfall. USB devices typically show up as spikes at + and -1kHz for keyboards, and +-8kHz for higher speed devices. These humps/spikes don't move when tuning the VFO.
2. Interference coming through the RF input is typically periodic spikes, often widened, on the waterfall. Not symmetrical, but repeated every 11..18kHz (solar panel inverters, variable speed votors), 62..64kHz (PC and other switching power supplies), or some other step. These spikes move with the VFO change.
Which one do you think you are experiencing? The methods to fight the interference depend a lot on whether it is AF or RF.
73, Mike AF7KR
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Jon,
A couple thoughts.
The USB section of the SoftRock RXII is supposed to be electrically (DC ground and +V buses) isolated from the rest of the circuitry. There are optocouplers and a transformer to accomplish this. The “ground” of the USB section should have very high DC resistance to the “Ground” of the main board. If that isolation is compromised somehow then noise on the USB lines will get coupled into the AF/RF circuits.
There are add-on USB filters sold to clean up USB noise. I have never used one but know they are sometimes helpful depending on the situation.
See e.g.
Roger
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On Jun 7, 2021, at 2:40 PM, JonI via groups.io <ji425bt@...> wrote:
Hi Mike,
Well, when I unplug both the monitor and keyboard, the most of the offending "birdies" go away. I had just hoped to be able to keep the keyboard plugged in. Others are suggesting a wireless and I may go with that. Just as an experiment, I lined the non-key inside of the keyboard today with sticky aluminum foil, then stuck foil around the USB cable leading from the keyboard to the USB connector on the desktop. Did not make much difference.
I guess I can just turn off the monitor as I'm using RDP anyway and controlling everything from the laptop. Of course, would still like to solve it. I started using ferrite chokes on the monitor cable with success, but ran out of chokes.
There are a couple of other sounds I get from about 3- 5 Mhz. Not at the spike so I think it's RF, but not sure if it's coming from me. I will try and video and post those. I was able to null the loudest one out by turning the loop.
Jon
On 6/7/21 5:06 PM, vbifyz wrote:
Jon,
Interference to Softrock comes in 2 different flavors.
1. Interference coming through the audio connection ("ground loop") shows up as a symmetrical center hump, or some other symmetrical picture on the waterfall. USB devices typically show up as spikes at + and -1kHz for keyboards, and +-8kHz for higher speed devices. These humps/spikes don't move when tuning the VFO.
2. Interference coming through the RF input is typically periodic spikes, often widened, on the waterfall. Not symmetrical, but repeated every 11..18kHz (solar panel inverters, variable speed votors), 62..64kHz (PC and other switching power supplies), or some other step. These spikes move with the VFO change.
Which one do you think you are experiencing? The methods to fight the interference depend a lot on whether it is AF or RF.
73, Mike AF7KR
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Hi Mike,
I took special note of your comment below about the USB interference, asone of my student designs <> had some annoying problems with this USB type interference.? It was significantly better with the super-cap USB smoother than without it, but it was still present, (lines in the waterfall about 1 KHz apart).? Thanks for your comment.
73,
Rob
KL7NA
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On 6/7/21 2:06 PM, vbifyz via groups.io wrote: CAUTION: This email originated from outside the Walla Walla University email system.
Jon,
Interference to Softrock comes in 2 different flavors.
1. Interference coming through the audio connection ("ground loop") shows up as a symmetrical center hump, or some other symmetrical picture on the waterfall. USB devices typically show up as spikes at + and -1kHz for keyboards, and +-8kHz for higher speed devices. These humps/spikes don't move when tuning the VFO.
2. Interference coming through the RF input is typically periodic spikes, often widened, on the waterfall. Not symmetrical, but repeated every 11..18kHz (solar panel inverters, variable speed votors), 62..64kHz (PC and other switching power supplies), or some other step. These spikes move with the VFO change.
Which one do you think you are experiencing? The methods to fight the interference depend a lot on whether it is AF or RF.
73, Mike AF7KR
--
Rob Frohne, Ph.D. P.E.
E. F. Cross School of Engineering
Walla Walla University
100 SW 4th Street
College Place, WA 99362
(509) 527-2075
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For the price of a logitec wireless mouse and keyboard combo you can eliminate 2 usb wires and their ferrites and the rfi they bring to the game. Less clutter and more flexibility for operating position too. I use them on all my rpi and computer rig controls. As long as mobos and consumer perpherals continue fo ignore the pin 1 problem I think this is at least a simple and partial alternative to unintentional usb antennas in the shack.
AB1VL Chuck in MT
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You may also try to replace the cable with a well shielded one. Some of the 2005-2010 stuff before the massive cost cutting era we are in now.
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I just did that, and the price at Wal-Mart for this combo is only twenty bucks. On Tue, Jun 8, 2021, 8:31 AM Chuck Yahrling <ab1vlqso@...> wrote: For the price of a logitec wireless mouse and keyboard combo you can
eliminate 2 usb wires and their ferrites and the rfi they bring to the
game. 73, Mike W0BTU
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I guess I can just turn off the monitor as I'm using RDP anyway and controlling everything from the laptop. I have a sketch of a HDSDR plugin and a tiny server to run on an Android phone, so you don't need to run a laptop. to stream the Softrock RX IQ output onto a local network. Currently it works only with an Peaberry SDR aka Omnia Basic. There is no official support for direct access to USB sound card on Android, one has to implement an USB sound card driver in user space oneself. However I am considering to try to add a support for Behringer UCA222, which is based on PCM2902. This chip work similarly to the USB interface of the Peaberry, it locks to the 1ms poll interval of the USB interface, thus the interface is simple to implement, at each USB frame the same number of bytes is handled.
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After some adjustments yesterday, I have it now set up where I won't even need a keyboard.? A setting in Win RDP without password allows this.? Now if in the event I do need one every now and then, I can borrow the wireless one I use for my main desktop. That problem has been solved.
Before I leave keyboard comments, I decided to make one of these yesterday just as an experiment:
I didn't have the ferrite bead specified, so tried a couple I had in my parts boxes of around the same size.? I could never get it to work correctly.? Trying to plug in the USB keyboard, the three lights would blink every time I touched a key, but no response on screen.? Only way it works is if I disconnect the capacitors in the circuit.? If even one is still connected, the keyboard functions as I describe.? I'll bet I need the bead specified or one close is the reason.
Monitor was creating some interference, but easy to keep that turned off as I control remotely most of the time.
There is still a big noise around 5 Mhz.? I think this is coming from something outdoors as when I turn the loop, at certain spots I can null it out.
I also still have "birdies" with fairly even spacing, but varies depending on band.? These are more of a nuisance than a reception stopper as I can use HDSDR's filters to notch them.? However, would still be nice to locate the source.? With the monitor and keyboard eliminated, might be the desktop power supply.
As far as ground loops, I think they're gone.? Center spike is pretty narrow.? Can get a bit wider at higher frequency, and on some bands it hardly appears at all, so satisfied as far as that goes.
I will try and video the remaining noises today and post.? It will take some time.? I'm trying to find free screen capture for Win 7 that also allows audio.? If not, I can use the videocam.
Jon
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Shirley Dulcey KE1L
Rob Frohne (KL7NA)
Chuck Yahrling
W0BTU