Friday, September 30, 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  30mV 10MHz Trimble out
to 5V tt square wave 
derived from a video amplifier




  
A short shielded cable to the SMA REF improved the signal a lot
the onboard 10MHz oscillator output is open the jumper is connecting the external REF
The oscillator is not switched off  it seems to have influence to the signal    quality

When touching the open oscillator out with a very short wire the AM  hum increases strong
possible it is better to switch it off have to find out how



on top the GPS rx  giving the 1pps to the Progrock  that outputs a 10MHz  to the REF in of ADF4351a    tuned to 1296.200MHz out   the 23cm XVTR is next on the desk
the other picture is still crawling  over the internet to my mailbox.


Another test with the  ADF4351A  / Progrock / QLG1 GPS
Using the ADF  onboard 10MHz DIL oscillator
I got a clear T9 signal at 1296.185 MHz   S9 +60 and more
on the IC706 144.185  as i.f. receiver.
The  S reading drops  to about S9   10 khz  away and no AM sidebands.
With the Attenuation down to 9+40    close to the carrier the S reading drops to zero
 that seems very acceptable  roughly   60dB down

But  the 10MHz  from the Progrock clk0 out  results huge wide AM hum side-bands
very irritating sound approximate 350Hz

No difference if the 10MHz  clock0 out  is directly on the REF -IN
or over the 74AC14  Schmitt trigger ports to shape it to TTL level.

The Progrock is connected to the QLG1 GPS receiver 1pps
 Sometimes i hear a sudden jump in the output frequency  it seems regulated
But it does not sound at all like a stable tone
It is constantly drifting slowly up and down like random

Touching the 27MHz xtal  the 1296.185 frequency drifts a lot and
It was not regulated as if there is no lock.

My conclusion:
ADF with a better 10MHz signal  can give a clean output
The Progrock clock0 output does not produce a suitable 10MHz  signal for the ADF.

Now  i will have to try my Trimble GPSDO 10MHz  signal
amplify its 30mV 10MHz to a TTL shape level.
I tried an INA10386   folowed with the 74AC14 pulse shaper
  no good result the signal was 1-2V sin  but changing all the time
Or the frequency seems to be doubled distorted  and or the output went to zero

I hope that someone reading my struggle can give a hint!

 23cm XVTR DB6NT 1990 design  TX over 2W out  stable since the MSA0885 is replaced
 with the original part INA10386 as driver for the M67715

One Buck converter for 13.5 to  8V  for the PA with M67715  the buck converter is switched  to 13.5 at TX  that can give some delay before full output is reached but i did not notice any drawback yet.
If the buckconverter  is having switching mode QRM it will only be there during TX.
But sofar I have not noticed RFI from this type of sm-converters
I amusing it mobile to convert 13.6V to 8V for the 70cm mobile also RFI effects noticed yet.






btw
  sharing pictures with HTC phone is annoying slow and difficult
One drive  does not work with this blog yet
   Dropbox  is full ,  Picasa once worked nice ..
  mailing it to myself still seems the only working option

The HTC one camera once was good but now all is turning purple if not in full daylight.
Besides that opening the camera is a very slow process
Once it is active   in seconds the HTC goes standby again to save power..
 the  security patern once it is activated no way to disable it.

it seems that Technic is more and more a struggle the older i get.


I had to reboot my older Laptop Lenove X60  with W10
W10 works nice on this relative slow Laptop.
But what is slow?   when it came on the market sure it was called very fast..

W10 is running nice on it  besides some blue screens  of W10

but now it was going  very slow  had to reboot
then logged in with finger biometric as normal

sudden  there was a Cortana pop up :
Hello!   i am Cortana i am going to help you
ask any question!
 and a message about the biometric system being beta type??
huh? it worked all the time without problem

Did i catch a  bad W10 update crashing my PC?
 few reboots  with  "do not turn off while updating etc.."


 the keyboard did not work on its question input field..

the mouse was spinning around
sudden my system  was playing crazy

I remember once Word had its assistant..   "helping"   blocking your system with stupid useless answers
annoying!    never ever heard again of the assistant experiment

but now its back!   Cortana  will frustrate you hihi




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