Friday, September 18, 2020

Modifying KA Band LNB for 24GHz ATV

 I have been experimenting with a Triax Twin KA TKT001 LNB.

The normal frequency coverage is 19.7GHz to 20.2GHz

I started out by measuring the DRO oscillator cavity size Outside Dimensions.
and then sanding down the whole dicast housing.

 

 
Then when I had removed close to 1mm I then moved onto the DRO puck,
Which I then proceeded to sand down thus raising its frequency of resonance.

Below is a picture of the PCB with the puck removed from the green circle with the red dots.
I used Nail varnish to re-attach the Puck to the board
 

So basically I made the cavity it sits in smaller and the puck thinner, in the hope of being able to recieve a 24GHz ATV signal generated with a Gunn oscillator.



I also took a scalpel blade and cut down the mixer tuned lines by about 1mm or so.
I also attacked the filters in the front end, however I am not sure how much improvement it gave me, I may be better to remove the filter altogether by overlaying with some copper tape.
Sadly I have no test gear to verify any of this its purely a trial and error modification.
I did not have to adjust the tuning screw that sits above the DRO in the cavity.

Here is the picture of the mods I made, if you make the same mods and have the capability of measuring the results? please please let me know.



Again this is purely a bodge attempt so do so at the risk of trashing the LNB.
Cheers for reading

Mark G0NMY

As requested here is a photo of the full LNB pcb, this is one I scrapped after experimenting with and zapping the front end devices.





And here is an image of the 24GHz ATV received in the shack using an analogue sat rx and the modded LNB





Due to health issues I havent moved this project forward yet sorry.

1 comment:

spec said...

Do you have photos of entire LNB board? Any further progress on this project?