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Some  431 Mhz drift scan tests with  my 8x21 elements yagis


Equipment was :

8 times 21 elements 432Mhz yagi, 4 horizontal by 2 vertical stacking.
Polarisation is linear, horizontal.
Calculated antenna gain is 24.5 dbd/26.65 dbi
Horizontal beamwidth is about 5° at -3db, and vertical beamwith is 8° at -3db
Phasing lines and connections lines loss of 1db or so.

Mast mounted low noise amplifier of  33db gain and 0.4 db of noise figure

Receiver is a LT70s transverter (432Mhz to 28Mhz), followed by a kenwood R5000, modified for having agc off possibility.
Receiver mode is AM, with a maximum of 6 Khz bandwith only.

Software is the free radio-skypipe.

Local geographic position is  21°14'30.47"S -  55°20'9.85"E

You can play with a sky chart software to see what part or object of the sky is moving inside the main antenna lobe.

I also made some 11Ghz tracking with a 1.8m dish on the ground, but lost the files... so bad!
The results were interesting, even if the main trouble was  the T° stability of the head source (a simple TV satellite head).
I could clearly see  the drift effect of day and night T° on the charts... It needs to be T° controled.

I could have some slight pointing error on some charts, as i later found the rotator having some play in the gear.

These were only tests, just to check the possibility of radio-astronomy in the 400Mhz region with amateur radio equipment.
I had no time to really make it as seriously as i wanted. So i decided to give it a try and collect data, with no other goal, as first step.

Clearly the 400Mhz region shows interesting things... I'd like to go further. But my array has been destroyed.
So i'm a bit on the bad side now...
13 august 2007_431,562Mhz_290°azimuth_45°elevation_30s integration.
16 august 2007_431,562Mhz_220°azimuth_36°elevation_30s integration.
19 august 2007_431,563Mhz-am_226°azimuth_23°elevation_30s integration.
22 august 2007_226°azimuth_23°elevation_30s integration.
23 august 2007_431,563Mhz_226°azimuth_23°elevation_120s integration.
25 august 2007_431,057Mhz_206°azimuth_38°elevation_antenna pointing towards the Great Magellanic Cloud. See the BIG peak, probably some local noise i guess.
25 august 2007_431,057Mhz_160°azimuth_23°elevation_60s integration.
29 august 2007_431,057Mhz_355°azimuth_23°elevation_30s integration.
20 september 2007_350°azimuth_30°elevation_r5000amw_60s integration.







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