Wednesday, 6 September 2017


Just a small update on the progress.

Last weekend was spent with my family and birthday celebrations so no work with this project at all.
The time schedule is somewhat delayed due to some problems on the way.
Finalized the rotor setup last week but had some problem with the HH-12 in the bottom of the Big RAK rotator.
Some friction caused a 0.2-0.5 degree hysteresis going from one direction to the other.
Seems difficult to sort out so I will have to live with it for now.
When going in one direction its rock solid and end up at the exact correct position all the times so the absolute encoding is correct it is just when alter direction the indication occasionally drags.
The problem was different depending on where in the turn the rotor was and I elaborated a lot with the coupling between the encoder and rotator.
The magnetic clutch is totally slip free and solid so no problem there but it seems difficult to make a coupling between the clutch and the HH-12 in a way where there is no friction or flex.

My version of the K3NG rotor controller.

Will elaborate with including PWM control of both rotators so I can use slow start and stop so the movement will not be so dramatic when tracking.

Got the transverter kit last week to and the customs did their job and an invoice was a part of the delivery.
Was quite simple to finalize but had some issue with the original oscillator but its on burn in now to see if that will affect the performance before I start to modify it.
I will use a separate reference locked oscillator anyway so its not a major issue but as it should work with the original one, I will make it operate as intended.
Measured Nf on the input chain and got approximately 1dB but that with the adjustable capacitors at their end positions.
Have not yet investigated if it was at min or max but will do so later in order to optimize it.
It will have little effect of the total system performance of the RX chain but if there is something that can be improved why not do it.

When assembling the 1.75m. vertical antenna bars for the antenna mounts on the 6m. horizontal boon I discovered that the boom was not fully in line resulting in the 4 vertical bars did not aligned.
It was twisted like a cork screw so I need to correct that this week.
The weather forecast for the week and weekend does not comply with outdoor work so I have to spend the time working indoors.
Fortunately I have a lot of space in the barn so I can work with up to 14 meters long mechanical structures inside if necessary.
Although the barn is large the roof is in sheet metal so no antenna tuning can be done there.

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