|Three Speaker Night||Summer Picnic||Park Activations|
|Why Would Anybody Do This||KX3 Portable PS||Spot Welding Batteries|
We have a tremendous show set up for you this coming month! We have collected some of the forums presented at the QSO Today Ham Expo held in August. The topics comprise a variety of talks which interested our selection panel. The forums run under 30 minutes each. Since we cannot have the speakers present a Question & Answer session, we have brought in some of our club's expertise to help with that task.
Be sure to join us at the RANV meeting on September 8. The meeting will
be on Zoom, with the session opening up at 6:30 and the meeting starting
at 7:00. If you do not know how to attend a zoom meeting, contact W1SJ
or any RANV officer.
The RANV Picnic and Kamp Kill Kare State Park activation was a
tremendous success. The picnic was small, as we knew it would be,
allowing a lot of room for everyone to space out safely. We quickly
built a single station using a multiband dipole up 40 feet and we were
on the air a bit after 12. Bob and I did all the operating. Conditions
on 20 meters appeared dead, but we had no trouble running a good rate
for the first 2 hours. We knew that the NA QSO Party would start at
2:00 and we'd get blown out by the QRM. However, the opposite happened
– we found a clear frequency and ran great rates, working mostly people
in the contest. I tried to go to 40 meters to work the close-in guys,
but the high noise level made things very difficult. Then I noticed a
bunch of spots of east coast stations on 15 meters, so I gave a quick
listen and found a lot of activity. We moved up there and maintained a
tremendous rate for over 90 minutes. There was a good deal of short
skip out to MD and VA, but nothing closer in. For a single radio
operation, where I didn't expect much more that 200 QSO's, we worked 521
stations in 44 states and 3 countries in 5 hours (wow, a sustained 100
rate!) We worked Alaska twice, but no one in NY. Hmmm. K1BIF gets the
gold star for working us on all 3 bands - impressive because we weren't
on 40 meters for very long. KK1L got us on 2 bands. WX was perfect -
nice temp, reasonable humidity and no wind. And few people in the park.
No video, but here are a couple of pix.
AB1DD, W1SJ and K1BIF activated Grand Isle State Park. https://www.youtube.com/watch?v=rPLcy36gtrY
W1SJ, AB1DD, KB1FRW,and K1BIF. Lots of fun and 825 QSOs. https://www.youtube.com/watch?v=VUYCDhkOD4c
CVARC is hosting a radio fox hunt on Saturday, September 19th starting
at 9AM. All are welcome to participate! Please see:
Put your name forward as a candidate to be a club officer, that is simple. I offered to serve as club secretary because it gave me a chance to get better acquainted with people who know tons of stuff about amateur radio and who support our club in a big way. Of the three positions, secretary is no doubt the easiest. Take minutes and write an article for the newsletter. Oh, and show up.
In addition, being a club officer is a way to support and shape our
exceptionally active club, to support amateur radio in general, and to
acknowledge the contributions of those who have gone before. For the
past two years I've put together our little election ballots. Every
year, our president, Bob KB1FRW, mentions that it has been many years
since we've had a contested election. So I'm putting it out there: if
you think you would like to be more involved in the support of our club,
feel free to throw your hat in the ring for the position of club
secretary. I will be on the ballot and hope to win. But if someone
else gets elected, no worries: I will continue to attend the Steering
Wheel meetings and, of course, support club activities whenever
My main goal was to build a power supply (13.8v) with enough energy to last for a day of radio fun on my Elecraft KX3. I decided to use high drain 18650 lithium power cells. To get to the desired nominal voltage, I need 4 cells (3.7v X 4 = 14.8v). The nominal voltage is not the fully charged voltage, that is 4.2v, and 16.8v for 4 cells. The current for each cell is 2600 mA-hour, or 2.6 A-hour. If I make 2, 4-cell series in parallel, that would double the current to just under 5 A-hour. I used easily attainable (Amazon) battery holders,
I spot welded nickel strips (https://tinyurl.com/yb687nk5), connecting four in series, and both sets of 4 in parallel. Each positive (at 3.7v, 7.4v, 11.1v and the full 14.8v) are welded together for the battery charge controller https://tinyurl.com/y7f2o9vo The battery charge controller regulates the charge/discharge cycles to assure all 8 batteries remain at the same voltage, + or -, a small amount at up to 20 amp hours. It also provides overcharge, overcurrent and short circuit protection; all for under $10. I use Kapton tape for electrical protection of the charge controller and anywhere the battery cells are vulnerable.
Remember, the fully charged battery pack puts out 16.8v at about 5 amps.
To get it down to 13.8v, I use a buck converter rated at 20 amps
(https://tinyurl.com/ycdm4lx8). They are small, and almost fit into the
cases handed out at the last few Hamfests. The input voltage can be up
to 36 volts, and can be regulated down to 1.25v (it's adjustable). So,
I have a battery pack for my QRP station that will last all day. Yes, I
have operated for 7 hours with it, up to the full 15 watt KX3 output.
The battery pack and buck converter weigh 1 pound.
As a follow up to the article about building a lithium battery pack for QRP operating, I will now provide a brief article describing how to spot weld batteried in series, or parallel. Searching the net for a spot welder, I discovered lots of devices that would work well for $200 to $600. That will never do. Then I refined my search for spot welding 18650 batteries. Now, that's more in line with my budget. On Amazon and EBay there are many choices, most look the same a nd all are made in China; probably at the same factory. I bought one from Amazon (at the time it was cheaper than those on EBay) https://tinyurl.com/y8j6k68d . I mounted it in one of those cases given away at the last Hamfest in Colchester.
I bought a pack of nickel strips ( https://tinyurl.com/yb687nk5) to bond the positive to negative battery terminals together to make 16.8V from four 4.2V batteries, then put two 16.8V packs together in parallel.
The spot welder board ultimately relies on a 2.2 farad capacitor. The
charge builds up in a few seconds, then discharges through the two
probes, melting the nickel strip and the battery terminal together in a
small spot weld. I soon discovered that it takes the amperage of a car
battery to produce enough of a charge to weld anything of substance, and
it takes a heavy duty (6 gauge wire) to carry that current efficiently.
Once all the details were figured out, it works quite well. There are
absolutely no instructions for the spot welding board, and little help
from the reviews.