Does your utracer "hang" more often then you would like?

[Never Mind]

I find the uTracer such a good tool that I have forgiven a number of shortcomings it has.

One of those shortcoming in my experience is a tendency for the utracer to "get stuck" and need a power cycle to working again.

Many times I have mumbled under my breath unkind things about software in general.

I have lately been testing a lot of tubes looking for matched sets. 

The result was also a lot of power cycling of my utracer6.

Finally I though this needs to be investigated.

So I careful watched each test looking for when a "hang" would happen.

I found that the "hang" seemed to be when the utracer was left for some time between tests before the next test was done.

A time out? What was this?

I used ping to see exactly when the uTracer6 would stop talking while left between tests.

It kept working. Rats...I switched off the analogue bench power supply I use for filament power in frustration and the utracer stopped talking...Hummm...

After a power cycle the uTracer6 talked again.

I power cycled the filament bench supply while pinging the utracer6. 

Every now and then the uTracer6 would stop responding when the bench supply was powered off. 

Ok what was this as nothing else on the bench including a few computers and bunch of other equipment was bothered by the bench supply being shut down.

Then I remembered the "old" days of early micro processors on large two layer circuit boards and EMC induced processor resets.

I pulled the bench supply apart. 

Inside I found a very nice mains power switch with nothing but two wires from the main transformer and fuse holder going to it. 

No snubber network to control switch arc or EMC when the power switch is opened at the "wrong time" in the power mains sin wave cycle.

I added a 0.22uF in series with t a 75 ohm non-inductive resistor across the mains switch. It is important to only use safety rated capacitors in this application!

Putting every thing back together now my utracer6 no longer hung when left for a while between tests (during this "while" I had shut off the filament supply it seems)

I could turn on and off the bench supply many times now with no hang in the utracer6.

I pulled the covers off a number of pieces of my lab equipment only to find "naked" mains switches in several for them. 

Capacitors cost money and bean counters hate to letting engineers spend any.

So if your uTracer hangs oddly for "no reason"  look at the surrounding bench equipment for a possible generator of EMC spikes that may be hanging your utracer.