开云体育

Hi Colin

Thanks for the update, you are the first person to report having completed
the construction of the Arduino kit. Although you are also the only one to
have yet received it, as there is a gap in the shipping and the next
shipping date is 27'th May 2013!

Regarding the transistors - note that 2N7000's are used in the Arduino kit,
as in the earlier QRSS/Ultimate kits. You can use BS170, they are a more
powerful transistor apparently. If you do that though, you have to remember
to rotate them 180-degrees compared to the 2N7000, since the pinout is
reversed.

For more power you could put more transistors in parallel with Q3, though
there isn't board space for this, so you'd have to be creative. You could
also disconnect the +5V end of the FT37-43 and connect it to a higher PA
voltage. Put some heatsinks on Q3 for that. Just various ideas for
modifications, in case you are inclined! :-)

73 Hans G0UPL




On Sun, May 19, 2013 at 12:53 PM, dd5cf_colin <jobaco@...> wrote:

**


Hi to all members of the group,

I have just finished the QRSS Arduino shield for 40m, all went well the
instruction manual was a usual excellent and the PBC well made, I am only
able to get 50 mW output at 40m I can get 60mW but the transistor get too
hot, I am txing on ca 700645 Hz any reports would be appreciated:
jobaco@...

Vy 73 Colin DD5CF / G1ZOS

Hi Colin

I am not a programmer and have only just started with aurduino uno I have
had a look at the sketch but cannot see where to change the frequency

The Arduino QRSS shield output frequency is controlled by the crystal on
the shield board. To change the frequency you have to adjust the trimmer
capacitor.

if you are referring to the amount of shift between the key-up and the
key-down frequencies: it's these two lines shown below:

#define FSK_HIGH 160 // Analog value for when FSK is high
#define FSK_LOW 100 // Analog value for when FSK is low

You can experiment with other values between 0 and 255. If the "height" of
the FSK produced is too high, you can bring these numbers closer together.
If the FSK is too small, you can make the two numbers further apart e.g.
reduce the FSK_LOW number.

It is unlikely, but if you find that the amount of FSK you observe is too
big or small to be adjusted by FSK_LOW and FSK_HIGH, then you have to
change the value (a.k.a. length) of the C3 "gimmick" capacitor.

the callsign was easy, I take it I can add stuff like 73 and my locator or
is there a limit to the size?

You can add 73 and your locator. I am sure there is *some* limit to the
size, but it's plenty more than you'll need!

73 Hans G0UPL