PC/Radio Port protection from ESD and other out world gremlins...

k0eoo

I posted this comment earlier as part of another thread but thought our group might find it useful in protecting their investment from near hits and ESD....

Since my lightning strike 3 years ago which wiped out my PC and all hubs and port adapters, I searched and found an industrial grade 4 port USB hub isolator from B&B Electronics, the UHR304, it has 4kv isolation and 15kv ESD protection and can be ordered with a medical grade PS, which I did.  Its isolating the communications to my LP-100A, RC2800PX rotor controller, SteppIR controller and REA modulation monitor PC interface.  Communications has been virtually solid for those 3 years....  Its full-speed 2.0 and backward compatible to 1.1 and 1.0.  Model UHR204 will handle high-speed, but I didn't need HS for those peripherals.  There is also a 7 port version.

Al_NN4ZZ

Dennis,
I just found your previous post on ESD protection for the USB ports on the radio.  Rather than continue to post about it the "fan failure" thread I'll add my notes here.  I also wanted to get your feedback on some other less expensive models from Tripp Lite.  Now that the USB ports on the radio can be used to control station peripherals.  Here are some of the comments from the other thread.




  

Al_NN4ZZ

Dennis,
Here is info on the hub you suggested for other that may want to get one of these models.

Al_NN4ZZ

Here are the less expensive Tripp Lite models.  They have 15KV ESD protection for a lower cost. 

Al_NN4ZZ

Dennis,
It sounds like the Atolla model I have currently provides some minimal amount of  protection but the ones from B+B or even Tripp Lite would be much better.   What are your thoughts on the Tripp Lite models?

I suspect that as more folks begin using the USB ports on the radio and as more operate remotely (ie WAN using V2.0) this could become something they are interested in.  So figuring out a good and cost effective solution before we run into the problems from Lightning, ESD and power surges is not a bad idea.

Regards, Al / NN4ZZ  
al (at) nn4zz (dot) com
SSDR / DAX / CAT/ 6700 -  V 1.10.16
Win10

k0eoo

Al,

Thanks for moving over to the port protection conversation, more appropriate as you mentioned.  

The Tripp Lite model provides ESD protection but NOT the port to PC isolation provided by the B&B HUB.  ESD protection means they added MOV's to each pin of the USB port to short circuit high static voltage discharges.  Certainly this is good but the PC/Flex connected via this HUB would still be DC connected to the downstream ports.  For example, if lightning or static discharge came in via a port connection the current would follow through the ground connection of the HUB, which probably would be the PC or Flex, not good.  But if their is isolation between the PC/Flex and downstream port then the discharge ground/power path would be isolated to the port side of the HUB and not the PC/Flex side of the HUB.

That is why I went the extra yard and got the isolator instead of a HUB with only ESD protection.  

In the long run Al, disconnecting your USB ports from peripherals on the antenna cables coming into the house and disconnecting your antennas from the house all together is the BEST practice, especially in lightning prone areas like Minnesota.   This is what I do each and every time a T-storm is forecasted for our area.

By the way, if you get the Tripp Lite unit make sure you power it via the 3 wire DC block and not via the PC, this would rout static discharge return current through the external power supply and not through the PC.  Actually, without seeing a schematic of this unit I'm not sure even this would help, but oh well....

k0eoo

How fast a HUB do I need?  Do I need a USB3.0 or 2.0 or will a USB1.1, 1.0 be adequate?

For all the peripherals us hams usually have connected to our radio's, amplifiers, rotor controllers, watt meters, SteppIR antennas controllers and so on USB1.1 (full-speed, 12mbps) is more than adequate and has worked at my QTH for 3 years now.

The reason I bring this up is, the amount of input to output isolation provided by HUB's is directly affected by the data rate supported by the HUB.  At FS the B&B HUB provides 4kv of isolation but at USB3.0 data rates only 2.5kv is provided.

I might add if the ESD protected HUB is cheap and does HS (480mbps) data rates than its not ISOLATED.

Al_NN4ZZ

Dennis,
Good information, I summarized the options below.  I'll probably go with the B+B UHR304 option at some point.  I might wait to see if anyone reports any USB port failure experiences or we get any other feedback on the options. 


CLICK to see full size...


Regards, Al / NN4ZZ  
al (at) nn4zz (dot) com
SSDR / DAX / CAT/ 6700 -  V 1.10.16
Win10

k0eoo

I like your summary Al....

Al_NN4ZZ

Ordered the UHR304 hub and recommended power supply from Amazon today.   Will update when it arrives and hopefully it will be  "plug and play."





Regards, Al / NN4ZZ  
al (at) nn4zz (dot) com
SSDR / DAX / CAT/ 6700 -  V 1.10.16
Win10

Kevin N9JKP

Glad I ran across this post.  I have carefully isolated my powered speakers from my computer and I have an optical fiber link from my Flex 6700 to my but I have my Green Heron Rotator Control plugged right into my computer.
While I doubt I will ever have a remote operation setup (I have satellite for my internet connection) I do like to ensure that everything is both properly isolated and properly grounded.  The USB connection is now my weakest link.

So I have a couple of questions:
Does anyone anticipate the need for USB 3.0 connections?
What about ferrite chokes on the USB  cables?
Can I use my Astron (linear) power supply to power one of these isolation hubs or would that defeat the isolation? Ttrying to avoid switching power supplies.)

At the moment the loudest thing in my shack is the Flex.  I have 5 fans in my computer, a split A/C and one other computer and its the Flex that's noisy.  So RF and AF noise along with lighting protection have always been top priorities for me thus, this thread on the USB mad me realized I had overlooked a path that goes from my tower to my computer.
Thanks
Kevin N9JKP

Al_NN4ZZ

Hi Kevin,

Does anyone anticipate the need for USB 3.0 connections?
- I don't think any of the devices we need to control  require or benefit from the 3.0 speed.  Dennis also noted that the isolation is less for the faster 3.0 hub devices. 

What about ferrite chokes on the USB  cables?
- I don't think the USB cables are typically long enough to pick up any significant amount of RF, plus the B+B type hubs provide isolation.  

Can I use my Astron (linear) power supply to power one of these isolation hubs or would that defeat the isolation? 
- I think it would be fine, the power to the attached devices does not come from the radio side if you are using the radio USB port or from the PC side if you are using the PC USB port.  That avoids the DC path that can damage the port.   Assuming you use the Astron to also power your radio there is probably some additional isolation for the radio if you used a different power supply for the hub.  

In the case of a direct lightning hit, all of these efforts may not prevent damage.  

Regards, Al / NN4ZZ  
al (at) nn4zz (dot) com
SSDR / DAX / CAT/ 6700 -  V 1.10.16
Win10

Kevin N9JKP

Thanks Al for the spot on comments. Right now the only USB is to the Green Heron. When I get a linear amp I assume I will have a need for another USB connection.

The Astron does power the Flex radio and will power my other radios (when I get them back in service).

Seems like the B+B makes the most sense.

Al_NN4ZZ

@Dennis,
The UHR304 Isolated hub came today.  It took about 30 minutes to wire up the power, ground strap, and attach the USB cables.  They recommend grounding the case which I would do anyway and they provide a **** for the ground strap.   I used velcro to attach the power supply to the top of the hub. 

I currently use the radio USB ports to control my Bandmaster III antenna switch and Prometheus SS amplifier.  It was just a matter of moving the USB cable from my old unprotected hub to the new B+B UHR304 hub.  When I powered up the 6700 everything just worked, no changes needed to the USB setup in the 6700.

Here is a pic of the hub.  Click to enlarge.


Regards, Al / NN4ZZ  
al (at) nn4zz (dot) com
SSDR / DAX / CAT/ 6700 -  V 1.11.12
Win10

k0eoo

Great job of documenting the setup for the community Al.

k0eoo

@kevin, I just read your post from 2 weeks ago regarding adding ferrites to the USB cables on the B&B isolated HUB. 

Yes, I had to add clamp-on's to each USB cable plugged into the HUB, one full turn,  and I added same to the USB cable going into my PC with one full turn.  YMMV but when my beams are pointed toward the house and I'm running power I have RFI issues in the PC.