My RockMite has arrived so I will build that over the next couple of weeks when I get a free evening. In the meantime I have “bitten the bullet” and ordered an ATS-3B kit from KD1JV. They were sold out but Steve has made a few more kits this week.
Now I think at least 2 of you activators have built and use this radio. But just to know or sure, I wonder which of you have built or own one?
I have a few questions related to construction but before I bombard the reflector I thought I would see if there are more of you.
I am also curious whether using 8 x Alkaline AA’s is OK as the max spec. is 12v (it is “optimised” for 9V)… does this “overcook” the PA at all?
There is an ATS 3B Group at Yahoo.com which provides a lot of information and discussions.
I was lucky to get one of the last kits from the first batch, assembled it over new years turn and already used it for a couple of activations and portable operations. It’s a very nice radio and a great buy. I purchased a battery case for a maximum of 10 AA NiMH cells but use only 9 of them if fully charged. There are taps at each cell and so I am able to reduce the battery voltage in steps down to 6 Volts, which is the min. spec. and which will still ouput nearly 1 Watt of RF power (excellent for tuning purposes). 12 Volts won’t fry the PA at a well matched antenna, but the overcurrent detector may trip at a certain point. I am sure the radio would be doing very well at 9 Volts, too.
By the way, did you assemble using the “paste” method or
conventional soldering for the surface mount parts?
I soldered conventionally with a fine tip which wasn’t too exciting except the smallest parts like the DDS-Chip and the 0603 size resistors (to which you may easily apply too much solder) and which may result in a shortening bridge or an unsightly “teardrop” on the pad. A good pair of tweezers, sufficient illuminating and a magnifying glass are a must.
I am not sure from where the 12 V limit comes from. I would not be too worried about 13 V though the overcurrent tripping may become a problem. The trick to improve stability is to use a series resistor with the battery.
Out of interest , what did you use for preheatng the board? …and did
you then use the “hobby heater blower” that I’ve seen on
Cash Olsen’s site?
You can get a new SMD rework station for about 70 euros http://www.eurogerd.com/ . Used ones probably cheaper. For preheating I used a small racklet plate. I measured temperature curve after switching on and figured out at what intervals I need to switch it on/off to keep 100 - 140 C. Finally the soldering with paste using hot air will probably be faster than with iron.