Saturday, July 08, 2017

Things that can't be understood

My "fancy" homebrew computer (not pictured here) has been running nicely for about 8 years. It was big and powerful in 2009, using the new Intel Core i7-920 chip, with lots of RAM and lots of cooling.  Nowadays, Gimli (as I call it) runs mostly Windows 10, with a touch of Linux.

It runs up to 8 background threads simultaneously, running up some nice statistics with BOINC -- the science "@home" brokering site. Maybe we've discovered a pulsar or two, who knows?

This was alongside my "real" work which has been operating my ham radio station -- running SDR radios, logging, digital mode operation, etc.

That was until a few weeks ago, when Gimli started failing -- stopping suddenly with no blue screen of death or software logging, just a blank screen.  I thought maybe my checkered past as an overclocking experimenter was catching up with me.  I tried going back to the absolute minimal BIOS settings just in case.

I starting checking out what I might need to buy to upgrade this "ancient" machine through Newegg or Amazon -- and the discussions I'd need to have with the XYL.  Yes, there are many new options on the market.  The biggest one might be the advent of SSD technology (Solid State Disk).

As a last stand, I thought I'd check out the computer as best I could.  It's practically impossible to find a fault of the kind I was having.  You'd just have to replace key components one by one until it started working again.

Opening the box and blowing out the dust, I started wiggling the cables and re-seating the connectors. I pulled out the two RAM modules and "cleaned" the contacts (wiping with fingers), and I plugged them back swapping their positions.

Naturally when I put things all back together, Gimli came to life and hasn't crashed for a week or so now.  Maybe we're go for another 7 years?

Or maybe we're running on fumes.

Sunday, July 02, 2017

Sad day at AA6E

My FlexRadio Systems model 6500 transceiver has gotten a serious bug, dropping frequency lock periodically.  It may arise from operating with the GPS Disciplined Oscillator -- and summertime high ambient operating temperatures.  Back to factory it will go.

The following crude video shows how this looks when listening to WWV (15 MHz).  Problem tends to develop after high duty-cycle transmission (JT65 - 50 W) for a few minutes.  It sometimes goes away if the radio is left in receive for a long while (10+ minutes).