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ATS-3B - Builders/Users?


#1

Hi All

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?

Look forward to your replies.

73 Marc (nearly back to) G0AZS


#2

In reply to G0AZS:

Hi Marc,

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.

HTH
Bernhard


#3

In reply to G0AZS:

Hi Marc,

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?

I think there are some HB9s who own this radio. My photos are in

Unfortunately I did not have much time to use this radio in activations so far.

The problem with 8 x Alkaline AA’s is the additional series resistance due to the battery holder. But the output power is more than the 2.5 W I have used with FT817ND.

During the operation if the overcurrent protection trips, you will see ‘E’ on display. After that you need to recover the normal operation mode by pressing ‘menu’ button.

73, Jaakko OH7BF/F5VGL


#4

Thanks Bernhard and Jaakko… useful information.

By the way, did you assemble using the “paste” method or conventional soldering for the surface mount parts?

As for the power, maybe a small 11v LiPo would be a nice option. I would assume this might avoid the overcurrent tripping whilst still keeping the power up around 4w out?

That’s 3 folks I now know on here that have one.

73 Marc G0AZS


#5

In reply to G0AZS:

11.1V LiPo cells are over 13V when charged ISTR.

Andy
MM0FMF


#6

In reply to MM0FMF:
Aha… OK thanks Andy. Maybe not such a good idea.

73 Marc G0AZS


#7

In reply to G0AZS:

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 put a detailed picture on here (256kB):

http://www.mydarc.de/dl4cw/P3136709.jpg

From what I’ve heard the “paste method” will be easier to handle and provides more consistent results. Next time I’ll give it a try…

73
Bernhard


#8

In reply to G0AZS:

I used solder paste

http://groups.yahoo.com/group/AT_Sprint/message/2542

http://groups.yahoo.com/group/AT_Sprint/message/2600

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.

73, Jaakko OH7BF/F5VGL


#9

In reply to F5VGL:

Just to remind myself: I still need to clean the solder flux from the boards!

72, Jaakko OH7BF/F5VGL


#10

In reply to F5VGL:
Hi Jaakko

Well the ATS-3B kit arrived today… Oh my word those SMD resistors are small!

I’m still trying to decide whether to go with conventional or paste soldering.

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?

BTW For the power supply, I’m now thinking that 8 x AA NiMh will be the best bet for optimum weight and voltage/current consumption. Anyway I have to build the radio first!

73 Marc G0AZS


#11

In reply to G0AZS:

Hi Marc,

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.

73, Jaakko OH7BF/F5VGL