external l.o. 1150MHz connected to DB6NT
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 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.