Netbook/other alternatives for contest software? Also RFI causing USB devices to quit
I ran the June VHF contest from my place in EN39 this year. Along with me for the run was my laptop, an external monitor, external mouse, and external keyboard.
I ran N3FJP software and put the log file remote on a USB flash drive. I also ran the voice keying part through N3FJP's software (which I accidentally found it had) with the .wav file loaded remotely off the same USB flash drive as the log file.
I also had a 10 year old or so RigBlaster Plus (serial) with a USB-serial converter as my interface.
The set up was the laptop was on the table to my right, off the operating table, and all my accessories were remoted via 10' cables (VGA for the monitor and a USB extension cable for the others, with 2x 4-way USB hubs daisy chained - flash drive on one and the second hub with the mouse, keyboard, and USB-serial adapter for keying the RigBlaster). The reason I did this was so I could split up the user interface of the computer. My laptop has an 18" screen and takes up too much space on the operating table, so by splitting everything it was a lot easier to make fit - monitor on the upper corner and a real small keyboard and mouse on the desk top. That part worked GREAT!
My problem is two fold.
First off, I was getting a lot of RF back on the audio from the computer to the RigBlaster, and consequently the transmit audio was garbled a lot of times on the air. I put ferrite cores on the audio cable - one at the computer end and one at the RigBlaster end. I also grounded the RigBlaster to the rig, and this helped quite a bit - more so than the ferrite.
My second problem was that the high RF caused my USB devices to quit working. Sometimes it was just the mouse when the rig was transmitting, sometimes it was both the mouse and the keyboard when the rig was transmitting, and occasionally I would get an error message pop up on the computer telling me that "Some USB devices have malfunctioned. Please reinsert and if the problem persists replace them", or something to that affect. So I would unplug the second 4-way hub with the mouse and keyboard on it, reinsert it, and everything would load up fine and the cycle would repeat.
My question here is - what can be done to mitigate the RFI, if anything? Would eliminating the extension cables and running everything integrated on the computer be the best route?
Getting back to the first topic in my thread title - what alternatives are there for compact computers capable of running the contesting software that have USB ports on them? I am assuming a netbook is what I am after. I would like the keyboard to be functional in that I can adequately type on it, but be as small as possible so as to not take up too much space on the operating desk. It would be nice for the computer to be Internet capable (not necessarily built-in WiFi either, I have USB's), but in terms of horsepower enough to run the contest software and Open Office would be plenty.
I'd start with ferrite beads around each of the peripheral device cables.....mouse, keyboard, etc. sometimes it helps to have beads around boTH ends of each cable. Also be sure there are no line currents on your transmission line....if so, you need to work on your antenna balun or feedline layout.
Originally Posted by KC8QVO
"The more you know, the less you don't know."
Is there ANY physical ground between your computer and the radio? It sounds to me like RF is feeding back to your computer via a ground lead.
On my system, I have eliminated the ground on all the signal lines between my computer and radios:
For rig control, I use an RS-232 isolator: http://www.amazon.com/HEXIN-RS-232-O...s-232+isolator
To isolate the audio, I use something like this: http://www.amazon.com/Raptor-GL15-Gr...+loop+isolator or http://www.amazon.com/Kensington-Red...+loop+isolator
I also had problems with RF freezing up my USB to serial adapter and with RF in my audio system; this didn't fix the audio problem 100%, but it did prevent the radio from locking up my USB devices.
What antenna are you using?
Be sure to listen for my beacon on 28.278.8 MHz
The antenna I was using is a 5 element beam fed with about 65' of 1/2" LDF4-50A heliax, 100 watt rig.
The only ground between any of the radio components and computer is the shield on the audio cable. Maybe the USB-serial adapter has a ground wire too? Anything grounded to the rigblaster would have been grounded to the computer as well as I grounded the case of the rigblaster to the ground lug on the rig.
The Rigblaster *should* be isolated. My NoMic is. The way to check though is to use a multimeter. There should be NO DC Ground between your radio and your computer (except through the power outlet.)