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ATS QRP Builders--Ham Radio |
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kc7fys (a group admin) says:
11 Dec 07 - Welcome to the flickr side of the YahooGroup "AT_Sprint. Most of the action takes place over there, at , but this group is meant to supplement that discussion with photos in a format that allows more interaction. Please add yours.
11 Dec 07 - Welcome to the flickr side of the YahooGroup "AT_Sprint. Most of the action takes place over there, at , but this group is meant to supplement that discussion with photos in a format that allows more interaction. Please add yours.
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About ATS QRP Builders--Ham Radio
This is a flickr group for all AT Sprint builders/owners and those who aspire to be. You can post advice to builders and help others new to surface mount technology. You can tell us of modifications and share your photos. Also it's a place to post stories of adventures you've had with your ATS. I hope you enjoy this forum and use it as you wish according to your needs. VY 72, Jonathan Haynes KC7FYS/7J1AWL Also, Steven Weber gives his personal history of the ATS series in his own, inimitable ergot: The ATS series started out as a SMT project in an attempt to build a trail friendly rig into an Altoids tin. It was built on two boards which plugged in together, was a dual band 20/40 meter rig with relay switched filters. The PA was a NPN SOT-223 device with a fairly low Ft, so power out wasn't very good, even at 12 volts. Maybe 2 watts on 40 and 1 watt on 20. Besides the low power output, the most serious problem was mechanical. The two boards were the same size and had common connections along both edges of the boards. Both boards had to be connected together for anything to work, so it was very difficult to trouble shoot if something wasn't working right. Longish jumpers had to be soldered between the boards so they could be placed next to each other, instead of being stacked so it could be worked on. Dispite this, I put picutres of the rig on my then new web site on qsl.net. It wasn't long before I was getting requests to kit the rig. Since what I had wasn't real practical to kit or build, I went back to work on it. The breakthrough which made the ATS rigs possible was the invention of the square wave, logic gate driven 2N7000 PA. At last I had a PA which was simple, took up little board space, was effiecent, had consistant power output on different bands, worked at low voltages and used common, inexpensive parts. The second innovation was to use the now familer band filter module boards. I was now able to fit everything on a single board, dispite using mostly 1206 sized passive parts. As for functions, it only had the basics, because the processor used was an Atmel 90S2313 with only 2K of memory. It had RIT, keyer with one memory, Tune up mode, the push button tuning and frequency annunciation. Only about 50 of the original ATS rigs were produced. A year or two later, some new parts became available, or I became aware of them, like the low power AD9834 DDS chip, the TI MPS430 processor and LM4808 low power headphone amplifier. I decided to try these new parts in a new ATS design to see if the current consumption could be significantly reduced. The ATS-1 drew some 50 ma on receive, which was a significant amount of current. Thus, the ATS-2 was born. With the new parts, receive current dropped to a much more modest 25-26 ma, half of what the ATS-1 took. I also made the board much larger and put it in a plastic box which could also hold AAA batteries. The larger board allowed parts to be spaced farther apart, making it easier to build, adding a few slide switches and little volume control. With more memory available in the MPS430 processor, DFE mode was added, along with XIT and the calibration modes. 80 meters was also added, making it a 4 band rig, instead of just the three bands the ATS-1 did. (40/30/20) About 100 of these were produced. I might have did more, but the plastic box which was supplied had the front silk screened. This I did myself, which turned out to be a mistake. Most of them turned out okay, but not great. It was a lot of work. I resolved to go back to the Altoids tin formate. While some liked the larger form factor of the ATS-2, most still wanted the smaller Altoids size rig. Besides, the KX1 came out about then and I wanted to have the smallest, lightest rig there was. So, back to the Altoids sized rig with the ATS-3, followed by the 3A and finally the 3B, each which had incermental improvments from things learned from the previous design. 72, Steve, KD1JV "Melt Solder" White Mountains of New Hampshire kd1jv.qrpradio.com |
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