Workbench: Screw Terminal Adapters and Lever-Nuts

Having collection of connectors with screw terminals or lever clamps is very useful.  In a pinch you could do a field-repair on a headset, a rig interface, or resurrect a broken power cord with just a pocket knife and a screwdriver.  Here are some of my favorites:

DC Barrel Connectors - these can be used to make a quick disconnect (in lieu of a switch) or an extension cord.  If you just want the plug to match an existing device, you'll have to measure the outer diameter and inner pin.  Most of the time the outer dimension is 5.5mm, and the inner pin is either 1.7mm, 2.1mm, or 2.5mm.

2.1 x 5.5mm paired DC Barrel Connectors
http://amzn.to/2bEavs4

TRS "Phono" Connectors - these are really useful for building test cables or attaching a rig interface to the ADC port on an Arduino or ESP8266.  When you get to the mountain for a SOTA activation and realize your 5 year-old has yanked the end off your headphones, you'll want one of these.

1/8" (3.5mm) Tip-Ring-Sleeve "phono male" plug
http://amzn.to/2bjqfOS

1/8" (3.5mm) Tip-Ring-Sleeve "phono female" jack
http://amzn.to/2bj6JVy


For pocket tools, I prefer the Leatherman ES4 Squirt.  (http://amzn.to/2bEe5lV) It's a ham's dream tool, with a wire stripping jaw, knife, scissors, file, and a screwdriver bit that works well on these screw terminal adapters.

Other interesting stuff....

Wago Lever-Nuts - these are really useful for quick repairs or experiments where you want to easily connect and disconnect wires.  You can use them to quickly add sections of wire for tuning dipole antennas.  Lift the lever, slide in a wire (or wires plural) and drop the lever - done.  Made a mistake?  Lift the lever, change, drop the lever.  They'll handle up to 400 VAC and 20 amps, so they can be used for household electrical repairs or rig power cords.  I keep a handful of these in my field bag, some my glove compartment, and a bunch on my bench.  I prefer the newer 221 Series because the lever is wider and easier to manipulate.
http://amzn.to/2bEcNY3

BNC Female w/ screw terminal - these are 75 ohm, designed for CCTV installs, but for receiver testing or low-power transmit they'll work OK.  Be aware that some adapters like this actually have baluns, which you don't want for RF testing.
http://amzn.to/2bE9Yq1

RJ45 screw terminal plug - kinda bulky, but it's great for designing cables on a bench.  When I'm done and have a working design, I build a real cable using CAT6 and an RJ45 crimper or a punch-down terminal block.
http://amzn.to/2bJ6pxr

Field Day is here!

Every year the amateur radio community conducts Field Day - one part contest, one part public outreach event, one part campout & BBQ, and four parts awesome.  Bay-Net hosts a Field Day each year, operating as K6SRA.  For the past few years we've been setting up in a parking lot of the Almaden Quicksilver Park in San Jose CA - and this year is no exception.

For some Field Day is serious stuff - massive operations running 24 hours through the day and night, generators and amplifiers and stacked Yagi antennas, with operation coordinators whose sole purpose is to encourage the radio ops to work stations and log faster.  This does not sound like fun to me.  K6SRA Field Day often devolves into an impromptu technical session where the radios sit idle while we pore over the details of some homebrew project.  Our Field Day operation has jokingly been called "Hot Dogs and Radio - in that order".  For many of our members, busy as they are with work in the always-hectic Silicon Valley, Field Day is a chance to relax and catch up.

This year we plan to shift one of our HF stations from phone to digital on a station created via the excellent Raspberry Pi hacking skills of +Beric Dunn.  I figure the kids will like this better, since it's a keyboard and not a microphone they'll probably be less reluctant to get on the air.

Field Day 2012 is almost here!

Getting ready for next weekend.  Are you attending Field Day?  Check the ARRL Field Day locator for a site near you and join us!

Summer Es - Sporadic E season

In the past week we've seen some increased solar activity; solar flux peaked at 74 and that led to some interesting band openings. I worked LY1000A in Lithuania late last night (20-May-2009) on 20 meters -- an opening to Europe near midnight local time certainly qualifies as "interesting".

The summer sporadic E season (often referred to as "Es") kicked in today with reported 10 meter openings from the west coast to the east coast. I worked KJ7OX in western Washington state just before midnight local time; solid copy on him and after I signed off he was still going strong.

Given that 10 meters was pumping I also listened up on the 11 meters CB band. As expected they were going strong too; I was hearing a lot of AM stations down below channel 23 and I also learned that apparently CB channel 38-LSB (aka 27.385 MHz) is the popular sideband DX calling channel. It was good to see the hams having as much fun as the CBers for a change.

There was an interesting study done on Es propagation by Art KA5DWI; compiled over four years of PropNet monitoring data it shows that "sporadic E" may not be so sporadic after all. One noteworthy finding; Es propagation during ARRL Field Day weekend is typically poorer than the preceding and following weeks.