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“Hey, Dad …… do you have a meter that will read really small voltages and tiny amounts of current?”, my son Joseph asked the other week.

“Joey, I’d better! I’m an Amateur Radio operator, and I was an electronics technician for 22 years.”, I replied.

And so began the 2014 8th grade Science Fair project. My son decided to see how the pH of a fruit or vegetable would affect its ability to generate electricity. His hypothesis – the more acidic the fruit/vegetable, the more power would be generated.

The materials were an apple, a lemon, a pear and a potato. A head of red cabbage was procured to act as a pH indicator. Zinc screws and 3 inch pieces of #10 gauge copper wire served as electrodes.

Before we began generating electricity, my wife boiled some leaves from the cabbage in a pot of water. The resulting liquid would act as our litmus paper.

I stuck a screw and a piece of the copper wire into each piece of produce. The positive lead from the meter went to the copper wire and the negative lead was attached to the zinc screw. We measured both voltage and current, to be able to calculate Watts.

A teaspoon of the cabbage water was put into four glasses. Juice from each piece of produce went into the purple cabbage water. If the cabbage water turned blue, it would indicate a base. If the water stayed purple, the pH would be neutral. An acidic pH would turn the cabbage juice pink.

From lowest output to highest were – potato, pear, apple, lemon.
And in turn, the potato had the lowest pH, while the lemon had the highest. The voltage and current readings followed the pH indications. It seems my son’s hypothesis was correct!

Now all Joey has to do is make a graph, print out the pictures we took and write up an explanation of what was observed. The really neat thing was that he had a good time and really enjoyed himself. I’m not sure what he wants to be, someday; but something in the scientific or electronics field would not be so bad.

72 de Larry W2LJ
QRP – When you care to send the very least!

Tim, W3ATB and I took an extraordinary hike to Knox Mountain this afternoon. We walked along the brook enjoying the music and scenery of the spring day. I worked Italy, Spain, and Portugal. Tim worked Illinois and took some fantastic photos.

Barely a quarter of a mile from the pond we came around the corner and found a pile of rubble in the middle of the trail. “It’s a landslide!” said Tim right away. And it was. Tim estimates nearly 100 tons of the hillside (mostly clay) had slid down the hill… some of it reached the brook.

We crossed it easily, although we had mud covered shoes by the time we reached the other side.

It’s always a treat when the pond and cabin come into view after the hike.

The day was warm… perhaps 65F. The black flies have just started to appear, but they’re not biting yet. Tim tossed his line nearly 50 feet over the branch of the large cherry tree near the cabin. He pulled up a Par End Fed for 40 and 20 meters. I chose a smaller maple and used a 33 foot wire sloping toward the south. I was running the KX3 set up on 17 meters. Right away I worked IK2SND, Dan in Italy. Conditions weren’t great, but good enough for solid copy both ways. Meanwhile Tim was working K9MY, Jerald in Illinois with the HB-1B on 20 meters.

Next I worked ED5URL in Spain and CT7/RC2A in Portugal both on 17 meters. Then I switched to 15 meters and worked EA8NC, Manuel… again in Spain. I don’t think the propagation was very good because I didn’t hear many stations. And the ones I worked weren’t that strong.

Tim and I packed up and headed back down along the brook. It’s a day to be savored in memory. Blue skies, warm weather, a hike through some of the most beautiful country anywhere and some wonderful radio contacts… not just across the small pond at Knox Mountain… but across the Big Pond… all the way to another continent.

Not much special going on lately. Worked some SKCC members, spent some time on 6 meters and worked my first station over 3000 km there. My weather station always seems to be in need of repair and my website’s CMS needed upgrading. Oh yes, there is the daytime job, too. Busy, busy, busy.

But, my wife was so nice to bring me a 2.6 meter telescopic whip from one of her trips to China. And so, last Saturday afternoon, while my little girl was horseback riding, I took the KX3 and MP1 with the new whip for a spin. The longer whip proved okay, although now the loading coil is much too large. Without the coil the whip needs to be shortened to be resonant on 12 meters and lower. I made four QSOs: HL0HQ (the KARL HQ station), JD1BLY (from Ogasawara), 7M2ALZ and JL1NMB. The resident ostrich took interest in my setup and decided the counterpoise set was a nice toy to play with and so he took it from me. Who said QRP is not dangerous? Power levels may be low, but those beaks do have a lot of force in them.

A curious ostrich interested in my counterpoise set.

Took a drive down to Superior WI yesterday May 3rd to take part in the A.R.A.C.  Swapfest in Superior Wisconsin. Got up at 5 am, picked up Wayne VA3WRL and Clarence VE3WCW and we proceeded for our 3.5 hour tour down the lake-shore. Stopped in Two Harbors for breakfast before heading into Duluth MN and then over the bridge to Superior. Had rain/drizzle from Thunder Bay to Two Harbors but was sunny after that. Arrived at the fairgrounds on Tower Ave. and went into the building to see what was on the tables for grabs. Lots of vintage radio gear, computer parts, hand helds, coax and almost anything that folks have been collecting in their garages that they wanted to get rid was there. There were having hourly draws as well for prizes. Had a chance to talk with lots of the folks that I have not seen in a while and the Thunder bay group had a good showing at the swapfest as well.

73 Fred VE3FAL

Thunder Bay, Ontario

While this may not be a surprise to those with electrical engineering backgrounds, this is a first for me — never seen this sort of thing before. While the effect is very cool, it’s potentially very dangerous and you shouldn’t go jumping the fence at the neighborhood 50kW shortwave station to try it out.

Wikipedia on plasma speakers:

Plasma speakers are a form of loudspeaker which varies air pressure via a high-energy electrical plasma instead of a solid diaphragm. Connected to the output of an audio amplifier, plasma speakers vary the size of a plasma glow discharge, corona discharge or electric arc which then acts as a massless radiating element, creating the compression waves in air that listeners perceive as sound. The technique is an evolution of William Duddell‘s “singing arc” of 1900, and an innovation related to ion thruster spacecraft propulsion.

The effect takes advantage of two unique principles. Firstly, ionization of gases causes their electrical resistance to drop significantly, making them extremely efficient conductors, which allows them to vibrate sympathetically with magnetic fields. Secondly, the involved plasma, itself a field of ions, has a relatively negligible mass. Thus as current frequency varies, more-resistant air remains mechanically coupled with and is driven by vibration of the more conductive and essentially massless plasma, radiating a potentially ideal reproduction of the sound source.

After doing some looking around, I realize that I’ve seen a similar phenomenon in the past while visiting the Boston Museum of Science — the singing Tesla coil!  Here is a fun example:

(via Reddit)

Here’s a video by Dennis Blanchard, K1YPP who is also the author of “Three Hundred Zeros”

Dennis hiked the Appalachian Trail, among other places and has lived to tell us all about it.  If you haven’t read his book, then you’re missing a good read.  While there’s not a whole lot in devoted to Amatuer Radio, it is a good read nonetheless, and inspiring, too.

72 de Larry W2LJ
QRP – When you care to send the very least!

Paul Signorelli W0RW posted this to QRP-L yesterday. It is entitled “Top 10 Steps for QRPttF Operation”.  This is SO good that it needs to be shared with those who might not subscribe to QRP-L. Paul has spent many a year operating outdoors, particularly pedestrian mobile.  Paul has a wealth of tribal knowledge built up here and this is good – very good, but often overlooked advice.

Here are the Top Ten Steps that I take for successful QRP Portable operation:

1. Propagation and Band Activity.
When you operate portable you want to work as many people as possible so the band conditions must be good. This means that you have to keep track of the propagation conditions before planning an operation. I try to look for propagation predictions for the band I plan to operate on but they are not very reliable. I check the QSL Net propagation site at <http://dx.qsl.net/propagation/>

The flux is always changing, so before I pick a date to operate, I monitor the bands at the same time that I plan to operate. The Absorption Index is also a key factor, I never operate when the “A” Index is above 6. I also use the NCDXF beacons see: <http://www.ncdxf.org/beacon/beaconschedule.html>

Trenton Military (15034 kHz) or CHU (14670 kHz) for 20 Meter propagation checks. Coastal stations might use WWV/WWVH on 10, 15 20 and 25 Mhz.

20 Meters is best for day time country wide propagation. 40 and 80 Meters are good for night time operation. I always try to avoid contests and other busy periods. Checking the QST Contest Calendar helps to insure the band is going to be clear. Check your desired frequency in advance, you don’t want to pick a frequency that is used for nets, traffic handling or RTTY.

2. Weather Conditions.
The weather forecasting is really good, so this is easy.
Try <http://www.wunderground.com/>
I look for warm temperatures and no wind. If it is going to rain don’t get too far away from a shelter.
Check your local web cam.

3. Honey Doo Items.
Always check the XYL’s honey doo list and make sure you have a valid Pass for the day.

4. Location and Road Conditions.
Try a your local National Park <http://www.nps.gov/findapark/index.htm>, If you are an Old Timer you can get a lifetime Pass. Always check the road and site conditions before going out in the field. You don’t want to drive hundreds of miles to find out that the Capulin Volcano road is closed by snow. Canyon roads can have snow or land slides, Pick an open space operating site, canyons are not good for QRP operating. If you are going to operate Pedestrian Mobile with a whip you will want to find trails that don’t have a lot of over hanging, antenna eating branches.

5. Equipment Readiness.
You need to check out your equipment right before you head out to your operating site. This prevents leaving behind some critical item. Needless to say, you should have your antenna all pre-tuned before you leave. My radio is always mounted to a backpack and is always ready to go. The LiIon battery is always charged but I always take a spare. I just need to put the back pack into the car, with the antenna and counterpoise. The accessories should also be checked: microphone, earphones, key, SWR meter, pen, log, watch, hat, gloves, coat, etc.

Make an equipment checklist.

It is good to charge or have a spare accessory batteries for your computer, keyer, SCAF, HT’s, etc.,
and a spare radio, clip leads and duct tape for contingencies.

6. Vittles.
I take water, lunch (GORP) and my VHF HT in a fanny pack.

7. Operating Announcements:
I try to post my operations on the reflectors a day before the operation. When you post too far in advance, people forget and when you post right before the operation, some people don’t get get the notice until after your are finished. I always try to be on my exact posted frequency (or alternate) at the exact time so people don’t get stood up. Posting your operating times gives you more Q’s. It is no fun running your battery down calling CQ with no responses. QRPspots, HFnow, GORC, QRP-L, SOTA Summits are good places to list your operation, as appropriate.

Post your schedule in GMT (Universal Time/Zulu time) as well as your local time.

Also post details about your operating location, links to pictures, trail maps, QSL Information, will be helpful, etc.

8. Prep Your Vehicle.
Put gas in your tank !

9. Initial set up.
When I arrive at my operating site, I set up my rig , attach the antenna, and check power and my operating frequency. When operating Pedestrian Mobile, I tune my whip and dragwire, put on my backpack and I am ready for the trail.

10. Safety.
Always be prepared for adverse conditions. You might need rain gear, snake proof boots, a map, GPS, etc. Always give someone your travel plans. Take your cell phone or an HT that will hit a repeater.
Be safe !
————

For more detailed information on Portable and Pedestrian Mobile operation get WA3WSJ’s Amateur Radio Pedestrian Mobile Handbook. He has made his First Edition Handbook free at: http://w3bqc.homestead.com/W3BQC-Library-Contents.html

That’s it, the Top Ten Steps for QRP portable operating. If you are addicted, you can consider this your 10 Step Program.

Paul w0rw

Thanks for sharing your wisdom and knowledge, Paul!

72 de Larry W2LJ
QRP – When you care to send the very least!