29-01-2017, 09:55 AM
The fun never stops here. The results this morning have been a little more definitive given the connection of the 10 element 2M yagi in lieu of the omnidirectional discone. The bearings from my QTH to Mater at Springfield are about 320 degrees, the Mater at South Brisbane around 12 degrees.
The following images were obtained from SDRsharp using the SDR dongle with the variable attenuator in line set to 10dB to prevent total pager overload.
The first one is with the yagi at 320 degrees (TN (True North)) and the VK4RBN and VK4RAX repeaters (LHS) have clearly been triggered by the pager signal at RHS. No travelling spurii are noticeable.
Click on the image to see more detail.
The second image is with the yagi at 12 degrees (TN) and, again, the VK4RBN and VK4RAX repeaters (LHS) have clearly been triggered by the pager signal at RHS. The more obvious travelling spurious emissions are shown sweeping across the 2M band in a couple of places. Given the higher signal strength in this direction, that places the South Brisbane transmitter as the probable culprit.
pager8 12deg.jpg (Size: 198.53 KB / Downloads: 1,618)
Click on the image to see more detail.
It still needs to be confirmed by someone close to South Brisbane but at least the details are becoming clearer.
Added in 31 minutes 34 seconds:
By looking at the 2M FM band rather than just the top end near the pagers, it appears that VK4RCC at Ocean View on 146.625 TX, 146.025 Rx, is also being triggered.
The following images were obtained from SDRsharp using the SDR dongle with the variable attenuator in line set to 10dB to prevent total pager overload.
The first one is with the yagi at 320 degrees (TN (True North)) and the VK4RBN and VK4RAX repeaters (LHS) have clearly been triggered by the pager signal at RHS. No travelling spurii are noticeable.
Click on the image to see more detail.
The second image is with the yagi at 12 degrees (TN) and, again, the VK4RBN and VK4RAX repeaters (LHS) have clearly been triggered by the pager signal at RHS. The more obvious travelling spurious emissions are shown sweeping across the 2M band in a couple of places. Given the higher signal strength in this direction, that places the South Brisbane transmitter as the probable culprit.
pager8 12deg.jpg (Size: 198.53 KB / Downloads: 1,618)
Click on the image to see more detail.
It still needs to be confirmed by someone close to South Brisbane but at least the details are becoming clearer.
Added in 31 minutes 34 seconds:
By looking at the 2M FM band rather than just the top end near the pagers, it appears that VK4RCC at Ocean View on 146.625 TX, 146.025 Rx, is also being triggered.
Doug VK4ADC @ QG62LG51
http://www.vk4adc.com
This Forum is only going to be as interesting as the posts it contains.
If you have a comment or question, post it as it may trigger or answer the query in someone else's mind.
http://www.vk4adc.com
This Forum is only going to be as interesting as the posts it contains.
If you have a comment or question, post it as it may trigger or answer the query in someone else's mind.