Hi Andrey,
Parts arrived yesterday and I made modifications for the 100 kHz loop filter and tested today. The entire 900 band is below 1.5 / 5 with a good margin.
http://filebox.vt.edu/users/ttsou/http/umtrx_945mhz_4.bmp
The lower part of the 1800 is also below the target value. I was not successful at 1885 MHz, though further calibration is possible (manual calibration at each frequency takes a very long time). I will perform additional tests tomorrow.
http://filebox.vt.edu/users/ttsou/http/umtrx_1825mhz_4.bmp http://filebox.vt.edu/users/ttsou/http/umtrx_1825mhz_noise.PNG
Thomas
On Wed, Jul 25, 2012 at 9:52 PM, Thomas Tsou ttsou@vt.edu wrote:
On Wed, Jul 25, 2012 at 1:41 PM, Andrey Sviyazov andrey.sviyazov@fairwaves.ru wrote:
Hi Thomas.
Digikey part numbers links: C82 = 100pF, C83=1500pF, C84=33pF, R106=2.2k, R109=3.3k, L6=0.022uF.
But you'll remove 100pF capasitor from position C45, so you could use it for C82. BTW, how long time required to delivering from the DigiKey?
Thank you for the links. Parts are ordered. Digikey orders usually arrives in 2 days.
Thomas