Results of pulsar receptions with 3m dish

First tests I made on 1294 MHz, bandwidth was 2MHz with a RTL-SDR, observation time 5 hours.
oe5jfl_3m_dish
After maybe 10 observations with negative result, I finally  detected the pulsar also with my 3m dish at home, which I use mainly for terrestrial contacts.
The antenna is placed on top of a building with no obstacles around. This is good for operating tropo, but worse for observing pulsars, because I pick up a lot of RFI.
It was a nice experience to see that it is possible to detect a strong pulsar even with moderate sized antenna without large bandwidth.

b0329_3m_dish

b0329_23cm_3m_dish

 

As a next step I added a 70cm feed to the dish. It is a dual-dipole feed with a square reflector, made of mesh.

In the middle is a hole of 30cm, so that the 23cm feedhorn can look through.

This sort off feed combination is widely used for EME, although the system suffers from some loss in efficieny on both bands compared to single band feeds.

      Observations were made on 420MHz using this antenna, 2-stage preamplifier up at the feed, 4-pole interdigital filter followed by both a RTL-SDR (2MHz bandwidth) and an Airspy SDR (10MHz bandwidth).
   






See below the results of a 6 hours observation of B0329+54, using different software and bandwidth for folding.
         2 MHz bandwidth, software IW4BHY

2 MHz bandwidth, software Presto




 
 10 MHz bandwidth, software Presto






To detect other pulsars beside the strong B0329+54, more bandwidth than 2 MHz is necessary.
I could detect some more on 70cm using the Airspy SDR with 10 MHz bandwidth.


B0950+08



420 MHz, 10 MHz bandwidth


B1642-03



420 MHz, 10 MHz bandwidth


B1929+10



420 MHz, 10 MHz bandwidth

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