?

All

My email box is full of millions of emails and so I thought, to clarify all my and your thinking, one big post should list it all out. Summarise where we are with it all. If I am missing anything, please let me know.?

Enhancement requests: firstly, there are a number of new requests (other than the GPS and 10m issues, of which more later). I'll attempt to put as many as I can in the v2.02 firmware version. These are as follows:

1) Support for the WSPR-15 mode (useful for LF WSPR)

2) Adding 1 digit to the GPS Baud setting, so the kit can be used with 115kbps (also requested for an Ultimate1 v1.09 enhancement)

3) Allowing the / character in messages for FSKCW, QRSS, DFCW, CW modes

4) Removing the 42.5MHz (approx) upper frequency limit

5) Fix a couple of occasional cosmetic bugs appearing in the Time-setting menu item

6) Move the Time setting to the front of the menu items, as it is used more often than any others when using the WSPR mode and everything is already set up (e.g. for correcting the time, when no GPS is being used).

New shop items requests: I have had requests to add the following items to the shop:

1) Selling BS170 transistors separately to the main kit

2) Sell the 4-pin headers and sockets separately to the main kit

3) Make available LF band modules for 475kHz and 135kHz?

10m etc issue: The summary of this issue is that it appears that there may be an arithmetic precision issue in the code for setting the DDS frequency word, which becomes apparent when the amount of shift is small in relation to the output frequency. So I need to change that part of the code which deals with calculating the DDS frequency word. Although, it remains considerably confusing because some people appear to have had some 10m WSPR spots. Perhaps they were lucky to choose frequencies which happened to work.

GPS issue:?There appears to be an issue with some GPS modules which worked in U1 but not U2. There have been some reports of people using GPS with no trouble, with Ultimate2. My current theory is that the short pulse width from some GPS modules is interfering with, or being interfered by, the incoming serial data stream. So I need to look at the differences between how I did the GPS work in U1 and U2.

Other comments:

1) People have remarked on the frequency switching transients when the DDS frequency changes. I think this is a minor thing which if all else was well, should not interfere with kit operation or WSPR decode etc. However, I checked in this area of the code and I did actually find that I think the frequency is being briefly set to zero before the new frequency is set, and that this might be making the short frequency glitch longer than necessary. So in v2.02 I will attempt to tidy that up.?

2) Regarding the blue potentiometer on the DDS module. When the modules arrive from the manufacturer, it appears that the blue potentiometers are not set up - that manifests itself as no output squarewave from the comparator. Before packing the kits, I individually tested every single one of the 200 DDS modules. 29 were discarded as their stability was found to be unsuitable. The rest of them, the potentiometer was adjusted for best output on 30m. So I thought that it should not need further adjustment by kit builders. However, it is possible that the setting on 10m might be more critical, or different, from the optimum setting on 30m - as some constructors have found out and advised.?

3) Someone mentioned that the maximum output frequency of the comparator is only 1MHz. However I don't think that this is correct. The specification of the DDS module from the manufacturer sometimes says that the squarewave output is valid up to 1MHz. But the DDS module output is straight from the comparator output pin of the AD9850 DDS chip and I don't see anything in the AD9850 datasheet about any upper frequency limitation.?

4) Feedback on the question of whether to reverse the BS170 transistors in the new PCB, or reverse the silk screen, or leave as is - was rather (surprisingly) mixed. So I still have to consider that one.?

?

5) I had some delay with ordering all the components, because PayPal rather unreasonably decided they should block my account to make sure I'm not a money launderer. That's all resolved now so I can continue with ordering the remaining components for the next set of 200 kits.?

I think that's about it. Let me know if I have missed anything out.

73 Hans G0UPL

Hi Andy

Yes yes, I saw the file - I get a notification as soon as you uploaded and
happen to be online to see it immediately. I think things start to add make
sense to me now. With your observations, and my trawling through the code,
it seems to be getting more clear, what is going on (and indeed, how to fix
it!).

Thanks for all your help (and patience!)

73 Hans G0UPL

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

All

My email box is full of millions of emails and so I thought, to clarify all
my and your thinking, one big post should list it all out. Summarise where
we are with it all. If I am missing anything, please let me know.

*Enhancement requests: *firstly, there are a number of new requests (other
than the GPS and 10m issues, of which more later). I'll attempt to put as
many as I can in the v2.02 firmware version. These are as follows:
1) Support for the WSPR-15 mode (useful for LF WSPR)
2) Adding 1 digit to the GPS Baud setting, so the kit can be used with
115kbps (also requested for an Ultimate1 v1.09 enhancement)
3) Allowing the / character in messages for FSKCW, QRSS, DFCW, CW modes
4) Removing the 42.5MHz (approx) upper frequency limit
5) Fix a couple of occasional cosmetic bugs appearing in the Time-setting
menu item
6) Move the Time setting to the front of the menu items, as it is used more
often than any others when using the WSPR mode and everything is already
set up (e.g. for correcting the time, when no GPS is being used).

*New shop items requests:* I have had requests to add the following items
to the shop:
1) Selling BS170 transistors separately to the main kit
2) Sell the 4-pin headers and sockets separately to the main kit
3) Make available LF band modules for 475kHz and 135kHz

*10m etc issue:* The summary of this issue is that it appears that there
may be an arithmetic precision issue in the code for setting the DDS
frequency word, which becomes apparent when the amount of shift is small in
relation to the output frequency. So I need to change that part of the code
which deals with calculating the DDS frequency word. Although, it remains
considerably confusing because some people appear to have had some 10m WSPR
spots. Perhaps they were lucky to choose frequencies which happened to work.

*GPS issue:* There appears to be an issue with some GPS modules which
worked in U1 but not U2. There have been some reports of people using GPS
with no trouble, with Ultimate2. My current theory is that the short pulse
width from some GPS modules is interfering with, or being interfered by,
the incoming serial data stream. So I need to look at the differences
between how I did the GPS work in U1 and U2.

*Other comments:*

1) People have remarked on the frequency switching transients when the DDS
frequency changes. I think this is a minor thing which if all else was
well, should not interfere with kit operation or WSPR decode etc. However,
I checked in this area of the code and I did actually find that I think the
frequency is being briefly set to zero before the new frequency is set, and
that this might be making the short frequency glitch longer than necessary.
So in v2.02 I will attempt to tidy that up.

2) Regarding the blue potentiometer on the DDS module. When the modules
arrive from the manufacturer, it appears that the blue potentiometers are
not set up - that manifests itself as no output squarewave from the
comparator. Before packing the kits, I individually tested every single one
of the 200 DDS modules. 29 were discarded as their stability was found to
be unsuitable. The rest of them, the potentiometer was adjusted for best
output on 30m. So I thought that it should not need further adjustment by
kit builders. However, it is possible that the setting on 10m might be more
critical, or different, from the optimum setting on 30m - as some
constructors have found out and advised.

3) Someone mentioned that the maximum output frequency of the comparator is
only 1MHz. However I don't think that this is correct. The specification of
the DDS module from the manufacturer sometimes says that the squarewave
output is valid up to 1MHz. But the DDS module output is straight from the
comparator output pin of the AD9850 DDS chip and I don't see anything in
the AD9850 datasheet about any upper frequency limitation.

4) Feedback on the question of whether to reverse the BS170 transistors in
the new PCB, or reverse the silk screen, or leave as is - was rather
(surprisingly) mixed. So I still have to consider that one.

5) I had some delay with ordering all the components, because PayPal rather
unreasonably decided they should block my account to make sure I'm not a
money launderer. That's all resolved now so I can continue with ordering
the remaining components for the next set of 200 kits.

I think that's about it. Let me know if I have missed anything out.

73 Hans G0UPL

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