OK1DFC 8m offset - feeds

26/11/2021
Septum feed with collar W2IMU for offset F/D 0,457. VLNA G4DDK 0,2dB N/F and 36dB gain. Feed in feed point. So far I'm still 4dB short of the expected maximum Sun noise level, but the weather is not good for outdoor work and measurements. Today it is already snowing and we have 0C outside. I now need to accurately measure the focal point and place the feed in the correct position. Looks like I'll be busy enough for next spring again.
23/11/2021
I finished production of septum feed with collar W2IMU for offset F/D 0,457. VLNA G4DDK 0,2dB N/F and 36dB gain. This weekend I will install the feed into the dish and test the antenna finally properly illuminated. It's just a shame that the sun is at a very low declination this time of year.
03/11/2021
Today I brought the W2IMU copper collars for feedhorns in 2320 and 1296 MHz bands. Now I have to finish the feeds for F/D 0,457 and make measurements and final antenna calibration.
30/10/2021
For the new offset antenna it is necessary to produce new W2IMU collars to the currently used feeds for 1296 and 2320 MHz bands. I first calculated the collar dimensions and then designed a square-circle transition for the actual implementation of the 1296 and 2320 MHz feeds. The material used was copper 0,6mm thick.

The lower images show the calculated values for the dish with F/D 0.457 and the upper copies of the DXF files for the laser burning machine.

I expect the final semi-finished products for feed production on November 2nd.

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