PA0O ham radio

 na lange DX loze tijd  vandaag weer down under  decodes op 28MHz

Meanwhile  some progress made My Trimble GPSDO 10MHz output  30mV tt   amplified  a filter  followed by 3 stage amplifier then shaped by hex inverting Schmitt trigger  74AC14 a reasonable clean signal at 1296.210 Shielding and grounding and a clean 5V power are important the AM 350Hz hum side-bands are weaker -60 dB at 144.550     -40dB 1296.210 The ADF4351  REF in seems to be a straight TTL input  without analog interfacing. It  omits  a trigger circuit.  I had to  make that myself. The specs only give the maximum signal level for this REF  nothing about the shape or minimum usable  level. It does not work with  a relative weak or  sinus shape 10MHz signal. Some other types PLL chips seem to have no issue with the reference  level.  2V / division    .5 uSec /devision  10MHz signal at the ADF REF input test setup  10dB / dev. ...

Could only join  for a few hours  the CQWWRTTY  last weekend DX was possible CE3CT  40m strong  XE2CQ 40m   (heard only  could not copy me or other EU callers ) VK3JA 40m    several JA at 21 MHz A very strange issue with the K3 in RTTY at 15m   the tx switched out / on   in a  slow sequence  after some cq  calling a relay starts to click in a slow 1-2 second sequence  and the RF does interrupt to  complete zero. The TX  led is on as normal.  And first off/on off/on and then  stays at  zero out. No error message. no RFI effect observed . This is only in RTTY and only 21MHz It happend before only RTTY at 15m It is not that the CAT RTS drops i monitored that  then the TX would go off as well. it is an internal K3  issue since a relay click is heard at the moment the TX output is gone. strange things  happen sometimes Finally i tried to make a video clip...

ADF4351a   F1CJN  in a housing   update 24-4-2017  is a usefull  35 - 4400 MHz generator   locked to 10MHz Trimble GPSDO 2017 in a protective case detail:  the Arduino  LCD keypad screen buttons are accessible trough  3.2 mm drillings longer plastic shafts from other push buttons as extension under the front. The ADF4351a   uses external 10MHz reference by disconnecting the internal 10M XTO i used a 3 pole jumper to have internal or external ref. that should be an front option switch  ( to do)  The external reference is the  Trimble GPSDO 10MHz It's 30mV sinus shape is filtered and amplified to 3V3 ttl level for the ADF4351a    Have been testing the ADF4351 demo board some time now But the signal from the PLL  is very IMD distorted and unstable Useless  sofar ... Arduino Uno  controling ADF4351A      F1CJN sketch QRPLABS   Progrock / SI5351 ...

The latest test  is using a 74AC14 Schmidt trigger to shape up the 10MHz signal to the REF inout now the 10MHz is at  TTL level  about the same shape the onboard oscillator But still the 1296.200  shows -40dB  AM  tone modulated side-bands So my conclusion is this ADF4351A  can not generate a clean signal. When  I get new information maybe i will have another try. Have been testing the ADF4351 demo board some time now But the signal from the PLL  is very IMD distorted and unstable Useless  sofar ... Arduino Uno  controling ADF4351A      F1CJN sketch QRPLABS   Progrock / SI5351    and  GPS QLG1 receiver all locked the Progrock output 10MHz ttl level signal  matches the ADF REF input good output  1296.200    T9 + huge IMD  hum about 400Hz? the signal is locked  with 10MHz GPS DO but it does not sound stable at all  tuning with a 2...

Have been testing the ADF4351 demo board some time now But the signal from the PLL  is very IMD distorted and unstable Useless  sofar ... Arduino Uno  controling ADF4351A      F1CJN sketch QRPLABS   Progrock / SI5351    and  GPS QLG1 receiver all locked the Progrock output 10MHz ttl level signal  matches the ADF REF input good output  1296.200    T9 + huge IMD  hum about 400Hz? the signal is locked  with 10MHz GPS DO but it does not sound stable at all  tuning with a 23cm receiver there is a huge AM tone  IMD around the carrier When locking to the ADF onboard 10MHz  X-tal oscillator ref this AM tone IMD  is much weaker but still not clean still searching for a solution that makes the ADF4351A output clean to be useful as LO generator The Progrock output is more clean but  also showing irregularities  absolute not Xtal T9 It can not be used  ...

Have been testing the ADF4351 demo board some time now But the signal from the PLL  is very IMD distorted and unstable Useless  sofar ... Arduino Uno  controling ADF4351A      F1CJN sketch QRPLABS   Progrock / SI5351    and  GPS QLG1 receiver all locked the Progrock output 10MHz ttl level signal  matches the ADF REF input good output  1296.200    T9 + huge IMD  hum about 400Hz? the signal is locked  with 10MHz GPS DO but it does not sound stable at all  tuning with a 23cm receiver there is a huge AM tone  IMD around the carrier When locking to the ADF onboard 10MHz  X-tal oscillator ref this AM tone IMD  is much weaker but still not clean still searching for a solution that makes the ADF4351A output clean to be useful as LO generator The Progrock output is more clean but  also showing irregularities  absolute not Xtal T9 It can not be used  ...