28-01-2017, 09:46 AM
I have been doing a bit more research today and want to rescind my thought that it is primarily a Vodaphone pager on 148.6375 that is causing the triggering of VK4RBN and VK4RAX repeaters. Yes, at least one of the transmitters on 148.6375 is producing spurious but it is not the cause of the triggering....
The screen shot below, with explanatory labels, reveals that the problem transmitter is actually on 148.8125 MHz, denoted Pager 3 at the RHS in the image.
Click on the image to see in greater detail.
Hard to see but there are wandering spurious only when the Pager 3 transmitter is active.
The ACMA database search reveals only two probable sources :
Register of Radiocommunications Licences
Assignments found
Results 1 - 13 of 13 assignments.
(UNLIKELY ONES OMITTED...)
ID Frequency Emission Designator Authorisation Date T/R Client Licence Site
1341805 148.8125 MHz 16K0F2D 15/Dec/2016 T Mater Misercordiae Public Hospital (72693) 1918219/2 Mater Hospital Raymond Tce SOUTH BRISBANE QLD 4101
1341806 148.8125 MHz 16K0F3E 15/Dec/2016 T Mater Misercordiae Public Hospital (72693) 1918219/2 Mater Hill Hospital Main St SPRINGFIELD LAKES QLD 4300
Given the problem has only recently started, it could be either site BUT the likelihood that I am hearing South Brisbane at some 29.5 Km away is unlikely, that makes Springfield Lakes at 8 Km away as the probable source. I have only heard paging tones on 148.8125 yet Springfield is licenced as 16K0F3E - voice - so that makes me think that they are using it purely tone paging.
Being able to determine it as the one source will be easy if I travel to the Springfield area with a suitable receiver and look at it in close physical proximity. Alternatively, someone near South Brisbane may be able to check that one...
At least it may be easier to get it fixed rather than as with a wide area network like Vodaphone's..
More to come in due course
Doug VK4ADC
Added in 16 minutes 37 seconds:
Better view of the wandering spurs without a lot of activity on 148.5625 or 148.6375. Makes it easier to define the "culprit".
VK4RBN and VK4RAX are the signals at LHS, 148.8125 the signal at LHS..
Spurs from 148.6375 are easier to spot too.
The screen shot below, with explanatory labels, reveals that the problem transmitter is actually on 148.8125 MHz, denoted Pager 3 at the RHS in the image.
Click on the image to see in greater detail.
Hard to see but there are wandering spurious only when the Pager 3 transmitter is active.
The ACMA database search reveals only two probable sources :
Register of Radiocommunications Licences
Assignments found
Results 1 - 13 of 13 assignments.
(UNLIKELY ONES OMITTED...)
ID Frequency Emission Designator Authorisation Date T/R Client Licence Site
1341805 148.8125 MHz 16K0F2D 15/Dec/2016 T Mater Misercordiae Public Hospital (72693) 1918219/2 Mater Hospital Raymond Tce SOUTH BRISBANE QLD 4101
1341806 148.8125 MHz 16K0F3E 15/Dec/2016 T Mater Misercordiae Public Hospital (72693) 1918219/2 Mater Hill Hospital Main St SPRINGFIELD LAKES QLD 4300
Given the problem has only recently started, it could be either site BUT the likelihood that I am hearing South Brisbane at some 29.5 Km away is unlikely, that makes Springfield Lakes at 8 Km away as the probable source. I have only heard paging tones on 148.8125 yet Springfield is licenced as 16K0F3E - voice - so that makes me think that they are using it purely tone paging.
Being able to determine it as the one source will be easy if I travel to the Springfield area with a suitable receiver and look at it in close physical proximity. Alternatively, someone near South Brisbane may be able to check that one...
At least it may be easier to get it fixed rather than as with a wide area network like Vodaphone's..
More to come in due course
Doug VK4ADC
Added in 16 minutes 37 seconds:
Better view of the wandering spurs without a lot of activity on 148.5625 or 148.6375. Makes it easier to define the "culprit".
VK4RBN and VK4RAX are the signals at LHS, 148.8125 the signal at LHS..
Spurs from 148.6375 are easier to spot too.
Doug VK4ADC @ QG62LG51
http://www.vk4adc.com
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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.