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Showing posts from October 19, 2016

external l.o. 1150MHz connected to DB6NT

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The original 96MHz  x12  chain  was at 1150.010   10kHz high  could not correct it  Also showing the usual temperature drift as most  x-tal 's have and  a bit too high in frequency I cut the 8V supply of the internal  X-tal 96MHz  x 12 3 stage part and fitted an SMA for the external l.o. the 1150 is injected trough the 1152 helical filter using a 4.7 pF coupling C  . The 10 OHm chip to the disabled tripler transistor was removed.  The signal level at the mixer is enough also with this 10 OHm left in.

My effort to replace the internal l.o. 1152MHz  using ADF4351A PLL 35 - 4000MHz demo board  or the GPS locked Progrock oscillator output did not result in a good quality signal. I decided to buy a DF9NP ready build PLL for 1150MHz switchable between 4 l.o. frequencies.       Very quick build and delivered  by Dieter Leupold.   Now with this external PLL the DB6NT  1.3GHz XVTR  is almost exact at at frequency. This PLL standalone is producing a very stable and clean signal at 1150MHz …

external l.o. 1150MHz connected to DB6NT

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Improved the DB6NT  1.3GHz XVTR  to be almost exact at at frequency.  with external PLL at 1150.00000 MHz  The original 96MHz  was 10kHz high  could not be tuned lower  Had the usual temperature drift like most  x-tal 's  a bit too high in frequency Received   this nice PLL  unit from  DF9NP   1150/1152 MHz local oscillator It is the box left very quick build and delivered   Very stable and clean signal  from this unit. using ADF4153 and TCXO  0.5ppm  -20 -- +70 C
standalone already  very stable  The weakest part is now the IC706 that needs a warmup time to become stable But this IC706 is stable enough for 144MHz WSPR so it is not that bad My ADF4351A test board is used as test signal generator 1296.200  and the 10MHz overtone at 1300MHz is still a good strong reference signal I switched off the internal  X-tal 96MHz  x 12 3 stage part and fitted an other SMA for the external l.o. The ADF4351A signal is not as clean as the DF9NP PLL And standalone with the onboard 10MHz xo it is …

external l.o. 1150MHz connected to DB6NT

Image
Improved the DB6NT  1.3GHz XVTR  to be almost exact at at frequency.  with external PLL at 1150.00000 MHz  The original 96MHz  was 10kHz high  could not be tuned lower  Had the usual temperature drift like most  x-tal 's  a bit too high in frequency Received   this nice PLL  unit from  DF9NP   1150/1152 MHz local oscillator It is the box left very quick build and delivered   Very stable and clean signal  from this unit. using ADF4153 and TCXO  0.5ppm  -20 -- +70 C
standalone already  very stable  The weakest part is now the IC706 that needs a warmup time to become stable But this IC706 is stable enough for 144MHz WSPR so it is not that bad My ADF4351A test board is used as test signal generator 1296.200  and the 10MHz overtone at 1300MHz is still a good strong reference signal I switched off the internal  X-tal 96MHz  x 12 3 stage part and fitted an other SMA for the external l.o. The ADF4351A signal is not as clean as the DF9NP PLL And standalone with the onboard 10MHz xo it is …

external l.o. 1150MHz connected to DB6NT

Image
Improved the DB6NT  1.3GHz XVTR  to be almost exact at at frequency.  with external PLL at 1150.00000 MHz  The original 96MHz  was 10kHz high  could not be tuned lower  Had the usual temperature drift like most  x-tal 's  a bit too high in frequency Received   this nice PLL  unit from  DF9NP   1150/1152 MHz local oscillator It is the box left very quick build and delivered   Very stable and clean signal  from this unit. using ADF4153 and TCXO  0.5ppm  -20 -- +70 C
standalone already  very stable  The weakest part is now the IC706 that needs a warmup time to become stable But this IC706 is stable enough for 144MHz WSPR so it is not that bad My ADF4351A test board is used as test signal generator 1296.200  and the 10MHz overtone at 1300MHz is still a good strong reference signal I switched off the internal  X-tal 96MHz  x 12 3 stage part and fitted an other SMA for the external l.o. The ADF4351A signal is not as clean as the DF9NP PLL And standalone with the onboard 10MHz xo it is …

external l.o. 1150MHz connected to DB6NT

Image
Improved the DB6NT  1.3GHz XVTR  to be almost exact at at frequency.  with external PLL at 1150.00000 MHz  The original 96MHz  was 10kHz high  could not be tuned lower  Had the usual temperature drift like most  x-tal 's  a bit too high in frequency Received   this nice PLL  unit from  DF9NP   1150/1152 MHz local oscillator It is the box left very quick build and delivered   Very stable and clean signal  from this unit. using ADF4153 and TCXO  0.5ppm  -20 -- +70 C
standalone already  very stable  The weakest part is now the IC706 that needs a warmup time to become stable But this IC706 is stable enough for 144MHz WSPR so it is not that bad My ADF4351A test board is used as test signal generator 1296.200  and the 10MHz overtone at 1300MHz is still a good strong reference signal I switched off the internal  X-tal 96MHz  x 12 3 stage part and fitted an other SMA for the external l.o. The ADF4351A signal is not as clean as the DF9NP PLL And standalone with the onboard 10MHz xo it is …

external l.o. 1150MHz connected to DB6NT

Image
Now the 1.3GHz XVTR improved stability and now almost exact at 1150.00000 MHz  not 1152.010  as the standard 96MHz  was 10kHz high and could not be tuned to exact 1150 like most  x-tal 's  a bit too high in frequency Received    PLL  unit from  DF9NP   1150/1152 MHz local oscillator It is the box left  Very stable and clean signal  from this unit. using ADF4153 and TCXO  0.5ppm  -20 -- +70 C standalone already  very stable 
My ADF4351A is used as test signal generator at 1296.200  and the 10MHz overtone at 1300MHz is still a good strong reference signal I switched off the internal  X-tal 96MHz  x 12 3 stage part and fitted an other SMA for the external l.o. The ADF4351A signal is not as clean as the DF9NP PLL And standalone with the onboard 10MHz xo it is to unstable to be used as local oscillator for 23cm but GPS locked  it is a very stable test signal.  XVTR  with Antenna relay and external 1150MHz l.o. 146  - 148 MHz  #  1296 1298MHz The l.o. is switchable  to 1152
and can shi…

external l.o. 1150MHz connected to DB6NT

Image
Received    PLL  unit from  DF9NP   1150/1152 MHz local oscillator It is the box left  Very stable and clean signal  from this unit. using ADF4153 and TCXO  0.5ppm  -20 -- +70 C standalone already  very stable 
My ADF4351A is used as test signal generator at 1296.200  and the 10MHz overtone at 1300MHz is still a good strong reference signal I switched off the internal  X-tal 96MHz  x 12 3 stage part and fitted an other SMA for the external l.o. The ADF4351A signal is not as clean as the DF9NP PLL And standalone with the onboard 10MHz xo it is to unstable to be used as local oscillator for 23cm but GPS locked  it is a very stable test signal.  XVTR  with Antenna relay and external 1150MHz l.o. 146  - 148 MHz  #  1296 1298MHz The l.o. is switchable  to 1152
and can shift - 28 or + 28 MHz for repeater use. however the DB6NT design is small band using helical bandfilters i could not get 2W on all shifts it should be possible to tune the 28 down 1122Mhz  and 1150 to have full output.