Category Ham Radio Equipment

Sep 23 2020

The 40 Meter Wrapper Antenna

Wrap Wrap Wrap They Call Me The Wrapper! One of my favorite parts of the ham radio hobby is messing with portable HF antennas. When running QRP, I have built and tried several antenna kits from QRPGUYS.

One of my all time favorite QRP antenna kits is the QRPGUYS Tri-band vertical. The antenna kit was adapted from the original design by Joe Everhart N2CX. My first CW contact was a station in Texas. Not bad for 5 watts from Long Island.

QRPGUYS supplies the enamel wire, torroids, switches and PCB board, you supply the wire for the vertical and counterpoise(s).  Find out more about QRPGUYS kits here.

Remembering back, to some of the other portable antenna contraptions I have tried reminds me of the time I wrapped about 33’9”of wire (cut it at 34 feet and trim) around a 20 foot Shakespeare Carbon Fiber Wonderpole which I got from Amazon. Cut the same length of wire for the counterpoise. Like any other homebrew antenna contraption, the fun is to see how many contacts you can log and the distance your signal has traveled.

Wrapping 33+ feet of wire around a 20 foot pole takes a few minutes but you end up with a light weight antenna that can be leaned against a tree or lashed to a fence for quick setup.

To bring the feed point impedance to around 50 ohms, I used an LDG 4:1 BALUN that had lying around from the time I setup delta loops. I think I bought from either DX Engineering or Amazon.

The BALUN got the impedance down to around 50 ohms on 40 meters but you will still need a tuner with this setup if you want to tune other bands. Like any compromise antenna, don’t expect miracles, just have fun.

I am not taking any credit for this antenna since I got the idea from this video by VE3BF some time ago.

73 de KE2YK
Vintage Morse Code
Sep 4 2020

The Long Island CW Club Revisited

The Long Island CW Club
W2LCW – The Long Island CW Club

The Long Island CW Club (LICW) has come a long way since my first post about the club in January 2018.

I recently visited their Web site and found that the Club now has about 800 members in all 50 states and 18 countries!

As one of the original lifetime members, it’s great to see that their idea of bringing tradition to Amateur Radio has really caught on!

Among the 48 classes on their schedule, LICW now offers classes for kids and ladies. What a perfect idea to bring people together into one of the best aspects of the Amateur Radio hobby and service.

Morse Code, The Original Digital Mode

Unlike FM and SSB modes, Morse code or CW (continuous wave) only needs a narrow bandwidth to operate. Less bandwidth means space for more operators. CW transmissions can be received when band conditions are poor. Morse code was, is and always will be the original form of digital transmissions.

Are you interested in learning the most efficient, original form of digital communications?

Visit the Long Island CW Club. Check out their web site, photo gallery, videos and class schedules today!

73 de KE2YK
Ham Shack Battery Equipment
Sep 2 2020

How Long Will Your Backup Battery Last?

Somewhere in my travels across the Internet I ran into a formula for calculating transceiver usage and associated battery consumption. The formula has been a fairly accurate way to estimate my shack’s backup battery consumption. Draining 100% of a battery is obviously unworkable so transceiver run time is calculated at 75% of total battery amp hours. I have examples of the formula with both a 100 watt and 10 watt transceiver below. Plug in your own numbers and check your results.

Formula: %BAh / (((R%h x RI) + (T%h x TI)) = rt

  • %BAh – 75% of total battery ampere hour usage
  • R%h – percent of hour in receive mode
  • RI – radio ampere rating in receive mode
  • T%h – percent of hour in transmit mode
  • TI – radio ampere rating in transmit mode
  • rt – approximate transceiver run time

I keep an Optima Blue Top high performance AGM (sealed absorbed glass mat) battery on a CTEK Battery Minder Charger in the Ham Shack.

The AGM design holds the electrolyte in suspension and keeps the electrolyte in constant contact with the lead surface on the plates. AGM batteries are superior to flooded batteries in a number of ways. AGM batteries are spill proof, can be used in rugged environments, charge faster and have a much longer life to name a few.

Battery chargers are generally broken down into two general categories, smart chargers and trickle chargers. Smart chargers offer an efficient design to prolong battery life. Using trickle chargers for long term battery maintenance will actually destroy batteries because they cycle on and off which eventually overcharges and dries the battery out.

CTEK’s chargers switch to a pulse mode after the battery is fully charged. Pulse mode allows a battery to self discharge to a predetermined level and then another charge cycle is initiated. Pulse mode avoids overcharging and effectively exercises the battery as if it were in use. As a result, pulse mode greatly extends battery life.

I found that keeping my 5 year old Optima Blue Top maintained with the CTEK battery minder has done a great job in keeping my Optima Blue Top in peak condition.

50Ah battery with 100 watt transceiver

  • %BAh = 50Ah * .75 = .37.5Ah
  • T%h = 25% of hour = .25 x TI of 20 amp TX rating = 5 amps per hour
  • R%h = 75% hour = .75 x 3 amp RX rating = 2.25 amps per hour
  • 5 + 2.25 = 7.75Ah consumed hourly
  • 37.5Ah / 7.75Ah = ~ 4.8 hours transceiver run time @ 100 watts

50Ah battery with 10 watt transceiver

  • %BAh = 50Ah * .75 = .37.5Ah
  • T%h = 25% of hour = .25 x TI of 2 amp TX rating = .5 amps per hour
  • R%h = 75% hour = .75 x .25 amp RX rating = .15 amps per hour
  • .5 + .15 = .65Ah consumed hourly
  • 37.5Ah / .65Ah = ~ 57 hours transceiver run time @ 10 watts

What kind of Ham Shack backup battery system do you use?