AmateurRadio.com

“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!

Larry Makoski, W2LJ, is a regular contributor to AmateurRadio.com and writes from New Jersey, USA. Contact him at [email protected].

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Alex Hill, G7KSE, is a regular contributor to AmateurRadio.com and writes from Cumbria, UK. Contact him at [email protected].

The recording of AmateurLogic.TV episode 66 will be streamed live Saturday morning around 9:00 AM CDT, 1400 UTC (if I am awake). We will have the chat room up as well. Check back here for the links Saturday morning.

The live stream can be found here: Live Stream
The chat room is here: Chat Room

George Thomas, W5JDX, is co-host of AmateurLogic.TV, an original amateur radio video program hosted by George Thomas (W5JDX), Tommy Martin (N5ZNO), Peter Berrett (VK3PB), and Emile Diodene (KE5QKR). Contact him at [email protected].

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.

Jim Cluett, W1PID, is a regular contributor to AmateurRadio.com and writes from New Hampshire, USA. Contact him at [email protected].

I just put HamRadioNow episode 143 on-line. It’s mostly a conversation I had yesterday with… Joe Ham. OK, really Joe Hamm KC1BAQ. Joe’s sort of a new ham, sort of a young ham. He’s 35, and a boomerang, having been licensed in college, but letting it go when it didn’t really ignite a spark.

So now he’s back. He’s a EE, so what attracted this young engineer back to ham radio? And what will keep him?

Gary Pearce, KN4AQ, is the host of HamRadioNow.tv. If you enjoy this and other HamRadioNow programs, help keep them 'on the air' with a contribution. Contact him at [email protected].

LP-100 reading

I was on the air the other day using the MFJ loop and as I was trying to tune to the lowest SWR reading I noticed an odd thing happening! Available to me at the station are 3 separate points to view the SWR. I have the SWR reading on the K3, the LP-100 and the MFJ remote control for the loop antenna. While tuning the loop antenna I was able to get an SWR of 1.5.1 on 20m with the K3's meter this is a very decent reading. I had the same reading on the MFJ remote unit but the LP-100 was showing 2.08 SWR??? The way the meters read the SWR are as follows.....the K3 right at the radio, then the LP-100 and then the MFJ remote unit. Oh and in case you are wondering if I am SWR meter crazy, I have the LP-100 in the game plan as it also reads very accurate output power and when operating QRPp it comes in very handy. . as for the MFJ remote that just comes with the antenna package and is really used to adjust the antenna and I really don't rely on it's SWR meter. I have heard and read in the past that the remote MFJ meter should not be relied on to much. ANYWAY.............I am getting this odd reading on the LP-100 and it is on all bands that I get a differing reading from the other SWR meters. First thing that came to mind was faulty coax or faulty

K3 meter

LP-100. I bypassed the LP-100 ( I removed the LP-100 and attached the two PL-259 using a SO-259 coupling) using all the same coax that fed the LP-100 and there was no problem. I then setup the LP-100 on it's own, meaning out the K3 through the LP-100 into a dummy load and there was a perfect match. Then I simply removed the SO-259 coupling and added the LP-100 again....there was the funny SWR again. Not sure what is going on here. In my trouble shooting I tried the LP-100 on it's own into a dummy load and it worked fine. I then used all the same coax cables and bypassing the LP- 100 and all was fine. Therefore LP-100 is fine and cables are good??? Not sure what is going on here.


Mike Weir, VE9KK, is a regular contributor to AmateurRadio.com and writes from New Brunswick, Canada. Contact him at [email protected].