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Showing posts from September, 2016

PLL ADF4351A Progrock QLG1 GPS

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. discrete 10MHz  booster  3 stage  and a band filter  after a lot of modifications this one can amplify the  3


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 of this strange behavior This was happening all the time after a few cq's  or when i tried to respond to a c


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