An Electro-Static Bandaid to Protect Sensitive LCD Displays

After the big East Coast blizzard,  the atmosphere in my ham shack became very dry.  I sit in one of those desk chairs with little plastic wheels.  The shack is carpeted.  So when I roll from operating bench to workbench,  the chair, the carpet, the dry air and I all become a kind of Van de Graaff generator.  Yesterday, my hand brushed against the 16X2 LCD display on my new R2 phasing receiver.  The pretty glowing numerals in that display disappeared in a small spark, never to return.

I swapped out another display I had, so all is well.  But the repair was a pain in the neck, involving the soldering of some 16 LCD pins, so I don't want to do it again.  I consulted with Pete Juliano N6QW who told me that this kind of LCD carnage is quite common in dry environments.  He said he had cured the problem by placing a small piece of Plexiglas in front of his displays. 

This got me thinking about those static protective bags that Digikey uses when shipping many of its components.  Might the material from these bags prevent the loss of another display? 

I retrieved a couple of these bags from the garbage and did a little test:

First, I rolled across the shack in the chair with a small screw-driver in hand.   At the other end of the shack lies my well-grounded DX-100 transmitter.  I moved the screwdriver close to the metal on-off switch.  SPARK!  It was visible, and quite audible in the AM broadcast receiver nearby. 

Next I taped a small piece of this material over the switch and repeated the ride in the chair.  No spark. Nada.  I repeated this several times and always got the same result.

It appears that the material in the bag helps dissipated the static discharge over a wider area, preventing the spark.  I quickly taped a piece of this material over the two LCD screens in my shack.  It's not pretty, but it is temporary, and cheaper than a humidifier.

I'm not going to try this on the actual screens, but I do think these small pieces of material will help prevent another accidental frying of an LCD display.

Here is the Wiki on anti-static bags: https://en.wikipedia.org/wiki/Antistatic_bag

And here is the data sheet on the bags that I am using:
http://documents.staticcontrol.com/PDF/Static_Shielding_Bag_1000_Series.pdf

1936 Shortwave Listener QSL card

I found this today while rummaging around in the shack.  It is starting to fall apart so I figured I better digitize it before it turns into dust.

July 24, 1936.  7 am in Central Germany.  29.0 degrees Centigrade.  Clear skies?  German Shortwave Receiving Station DE 2518/F monitored W5AIR's contact with Irish station EI7F on 20 meter CW. The receiver was an OV2 Schnell tube (almost certainly a regen) fed by a 38.5 meter long antenna.  

Conditions must have been pretty good -- they were approaching the peak of sunspot cycle 17.

In 1954 W5AIR was assigned to Garold D. Sears.  He was probably the operator.

Listen to My R2 Phasing Receiver (formerly known as "The Frankenstein" )

I really like this receiver.  Thanks to all who helped. 

Blizzard Prep Priorities: Protecting the 160 meter L network!

I'd been meaning to build a proper cover for my improvised 160 meter L network. The approach of Winter Storm Jonas pushed me into action yesterday afternoon. 

First I mounted the variable cap (from an old Johnson rig) and the roller inductor on a suitably sized piece of wood:

Then I put the tuner inside an old cooler.  I drilled holes in the bottom for the coax and the antenna wire and the ground.

Here it is at the feed point.  Pretty cool, don't you think?

And here it is 24 hours later:

The blizzard has been quite impressive.  Early this morning it featured lightning and thunder!

Some Inspiring Phasing Philosophy from KK7B

KK7B holding his original Mini-R2

Rick Campbell KK7B concludes Chapter 9 of "Experimental Methods in RF Design" with these inspiring words:

"An amateur who has built up a phasing receiver, looked at the I and Q channels on a dual trace oscilloscope, and tweaked the phase and amplitude adjustments while listening to an opposite sideband signal drop into the noise acquires a depth of understanding far beyond that of most wireless graduate students and many of their professors. The best part is that understanding of phasing systems comes from experimenting with simple circuits and thinking -- the tinkering comes first -- then the understanding. In this area the amateur with his simple workbench; primitive test equipment; and time to contemplate, has a profound advantage over the engineering student with a computerized bench and exam next week, and the professional engineer with a million-dollar lab and a technician to run it."

N2CQR Frankenstein R2 showing I and Q audio outputs

(No exam next week for me!)