ATS-3 HIJINKS: LIGHTWEIGHT SIZE, HEAVY PERFORMANCE ATS-3 HIJINKS: LIGHTWEIGHT SIZE, HEAVY PERFORMANCE

December 2005

I have a real attraction to small rigs and Steve Weber's little ATS series and especially the ATS-3 is a fantastic rig. It is lightweight in size but heavyweight in performance. One aspect to this hobby is seeing how light you can make a rig for the trail, yet still have it be functional. The Spartan Sprints are the perfect practice for experimentation. I have been tinkering with this rig for over a year now and still have a ways to go, but this is my attempt to document what I have done to date.

My first plans were to use the ubiquitous Altoids tin. There are several ways to prep the tins but the method I found easiest is to burn the paint off with a torch. Makes a nice patina finish to the metal, sort of an antique look. Another enclosure is the sardine tin. It’s lighter than the Altoids but smelly for my tastes. Lately I have been using a plywood / balsa box that is just as light as the sardine can and surprisingly sturdy.

The box is 1/32” plywood for the top and 1/8” balsa wood for the sides and bottom. Carpenters glue was used for construction. A picture of the box accompanies this story.

As you can see, this is a weight of 3.0 ounces with 2 of the band modules.

Other areas of weight savings are the battery and key and headphones. To be competitive in the sprints you must use a Lithium Polymer battery and make your own key. The LiPo batteries take some special handling and you must use care in charging them. Please read the instructions before using them.

These LiPo batteries are in many cell phones sold today and the R/C hobby uses them extensively. They come in many capacities, so judicious selection can help in weight reduction. AeroMicro is one supplier of batteries and chargers.

Your key can be anything from two wires to something more elaborate. I am using two switches (similar to the switches in the ATS-2) glued together with a short pigtail cable to a stereo plug. My key is on top of the box in the picture.

As far as headphones go, get several and weigh them, then use the lightest pair. My current favorites are Sennheiser MX-550s. You could even cut off one of the pair to make a mono earphone.

There are several other ideas such as plastic screws, carbon fiber enclosure, solder all external connections to eliminate jacks and plugs – even remove some components from the main board that aren't strictly needed for CW operation. I won't be doing the more extreme modifications, as I never know how long a rig will stay in the fold and want to preserve resale value.

By the time this is published, 2.5 ounces (0.156 lb) should have been broken in the December Spartan Sprint. I look forward to hearing other lightweight rigs and operators in the future. So get your rigs on a diet and get on the air on the first Mondays of the month. Even if you don't want to do the weight competition, get on the air with any rig – it is a blast!
* * * * * * * * * *
Michael Harnage, W1MT, is a QRPer who likes minimalist operating. He lives in Woodbridge, VA.



	ATS-3 HIJINKS: Lightweight Size, Heavy Performance
		By Michael Harnage, W1MT Special to The ARS Sojourner
December 2005 I have a real attraction to small rigs and Steve Weber's little ATS series and especially the ATS-3 is a fantastic rig. It is lightweight in size but heavyweight in performance. One aspect to this hobby is seeing how light you can make a rig for the trail, yet still have it be functional. The Spartan Sprints are the perfect practice for experimentation. I have been tinkering with this rig for over a year now and still have a ways to go, but this is my attempt to document what I have done to date. My first plans were to use the ubiquitous Altoids tin. There are several ways to prep the tins but the method I found easiest is to burn the paint off with a torch. Makes a nice patina finish to the metal, sort of an antique look. Another enclosure is the sardine tin. It’s lighter than the Altoids but smelly for my tastes. Lately I have been using a plywood / balsa box that is just as light as the sardine can and surprisingly sturdy. The box is 1/32” plywood for the top and 1/8” balsa wood for the sides and bottom. Carpenters glue was used for construction. A picture of the box accompanies this story. As you can see, this is a weight of 3.0 ounces with 2 of the band modules. Other areas of weight savings are the battery and key and headphones. To be competitive in the sprints you must use a Lithium Polymer battery and make your own key. The LiPo batteries take some special handling and you must use care in charging them. Please read the instructions before using them. These LiPo batteries are in many cell phones sold today and the R/C hobby uses them extensively. They come in many capacities, so judicious selection can help in weight reduction. AeroMicro is one supplier of batteries and chargers. Your key can be anything from two wires to something more elaborate. I am using two switches (similar to the switches in the ATS-2) glued together with a short pigtail cable to a stereo plug. My key is on top of the box in the picture. As far as headphones go, get several and weigh them, then use the lightest pair. My current favorites are Sennheiser MX-550s. You could even cut off one of the pair to make a mono earphone. There are several other ideas such as plastic screws, carbon fiber enclosure, solder all external connections to eliminate jacks and plugs – even remove some components from the main board that aren't strictly needed for CW operation. I won't be doing the more extreme modifications, as I never know how long a rig will stay in the fold and want to preserve resale value. By the time this is published, 2.5 ounces (0.156 lb) should have been broken in the December Spartan Sprint. I look forward to hearing other lightweight rigs and operators in the future. So get your rigs on a diet and get on the air on the first Mondays of the month. Even if you don't want to do the weight competition, get on the air with any rig – it is a blast! * * * * * * * * * * Michael Harnage, W1MT, is a QRPer who likes minimalist operating. He lives in Woodbridge, VA.