Hi Riccardo,
yes using the default of -92dBm.
73 Dick N4HAY
On Thu, Dec 31, 2015 at 11:15 AM, Riccardo Montaguti <ricky451@xxxxxxxxxx>
wrote:
Thank you Dick,
I’ve already changed to a new AD8307 and I get the same reading -57dbm by
connecting the si570 (terminated in the same manner of the sweeperino
schematic) and I get -92dbm with all disconnected. I’ve tried to connect
the pin 1 of the AD8307 to ground using a 100nf capacitor instead of
shorting it to ground; with this setting I get +17dbm reading with the
si570 connected and -66dbm with everything disconnected. In your code which
value of WB_POWER_CALIBRATION do you use? the default -92dbm?
Il giorno 31/dic/2015, alle ore 17:03, Richard Hayter <
richardshayter@xxxxxxxxx> ha scritto:
Hi Riccardo,
not sure why the plot did not save for the -14.2dBm case. Here attached
again. My apologies.
73 Dick N4HAY
On Thu, Dec 31, 2015 at 10:53 AM, Richard Hayter <richardshayter@xxxxxxxxx
wrote:
Hi Riccardo,
I bet your system is working! The exec only plots to 0dBm! Attached are
two plots from my prototype.
1) Shows the plot with the Si570 terminated with a 50Ohm terminator and
the Power Meter also terminated with 50Ohms. This shows the noise floor.
2) Shows the Si570 output connected to the Power Meter but through a 20dB
attenuator. This shows a plot at -14dBm. Thus the Si570 is showing +6dBm.
Now bear in mind that this is a Squarewave so the calibration is probably
not correct. There is literature out there indicating that you cannot
calibrate the AD8307 using a Squarewave to establish the Slope and the
Intercept point.
I plan to use a filter to calibrate my PM. But that is a whole different
and interesting discussion.
Try with a 20dBm attenuator. I look forward to hearing the results.
73 Dick N4HAY
On Thu, Dec 31, 2015 at 9:43 AM, Riccardo Montaguti <ricky451@xxxxxxxxxx>
wrote:
Dick thank you very much! I have received the program and it fixes the
crash problem! however after connecting the com port and doing the sweep I
get nothing on the plot. The specan gui tells me that the com8 is
initialized then when I start the sweep tells me “busy” and finally “ready”
again.
For the problem in the dbm reading I’m using the exact original
schematic maybe could be a defective chip? Or could be a problem of
calibration? Could you please check when you can what is the dbm reading
when the si570 output is connected?
For the 7ppm fix I’ve manually changed the registers that handle the
frequency changes in the Si570 library replacing the previous 7 to 12 with
13 to 18, I could post the modified library if could be useful to someone
else!
Riccardo
Il giorno 31/dic/2015, alle ore 15:14, Richard Hayter <
richardshayter@xxxxxxxxx> ha scritto:
Hi Riccardo
I sent you a link to my Google Drive. Did you receive it?
73 Dick N4HAY
On Thu, Dec 31, 2015 at 9:02 AM, Richard Hayter <
richardshayter@xxxxxxxxx> wrote:
Good morning Riccardo,
congrats on the fix. I would be very interested in how you fixed that
one?
I have a version of the exec that works. However my GMAIL will not
allow me to send it as an attachment. This works for me on my Windows 7
machine. I will have to figure out a way to send it to you. Will try to put
it on GOOGLE drive.
Regarding the power meter. I will revert with more information on this
issue. First let us get the exec working.
73 Dick N4HAY
On Thu, Dec 31, 2015 at 4:02 AM, Riccardo Montaguti <
ricky451@xxxxxxxxxx> wrote:
Good Morning,
Finally I was able to get the sweeperino working with the 7ppm version
of the Si570!
Now I have just tho problems:
when I start the Specan.exe file the program opens but when I try to
select the COM port of the sweeperino the program crashes all the time!
I simply put the folder downloaded from github in the program folder,
my operating system is Windows 7, I also tried to run it as a compatible
program of windows vista and XP but I can’t get it working. what am I
doing wrong?
The other problem is that the power detector gives me the correct
-92dbm when disconnected but when I connect it to the Si570 output I get a
reading of -57dbm but the Vpp measured of the Si570 are 1.44V, It is an
error or I have to calibrate it from the sketch?
Thank you for your kind attention
Best regards and best wishes for the new year!
Riccardo
<N4HAY2_Sweeperino_Proto1_Generator_Connected_to_PM_plus_20dB_attenuator.bmp>
