NSW RFS Test Transmission

RFS, SES, SLSA, VRA, SJA
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Mike Alpha
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NSW RFS Test Transmission

Post by Mike Alpha » Fri Jan 18, 2019 3:46 pm

A possible test transmission popped up this morning on 420.2125Mhz - that control channel type sound.

Still going at 3:45PM. At one stage an RFS transmission broke in.

Very strong signal in Sydney South West. I suspect off Horsley Park. Not listed on any Sydney site.

Mike

citabria
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Re: NSW P25 GRN - Site Listing (current)

Post by citabria » Fri Jan 18, 2019 3:50 pm

It sounds a lot like one of the standard test patterns - I'll compare a few and report back!

EDIT:-

OK, so the noise is the "Standard Tx Test Pattern (formerly CCITT V.52)". You need a service monitor to read the resulting BER but it shows that they're doing coverage testing. At my location I get the signal with a 0% BER.

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Mike Alpha
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Re: NSW P25 GRN - Site Listing (current)

Post by Mike Alpha » Fri Jan 18, 2019 4:32 pm

I think it's a RFS PMR test. That frequency appears as belonging to the RFS on other country sites. Might be the same as what they use on 420.200Mhz off Kurrajong Height - hence the test.

With the BER you're getting Citabria, do you think it's coming off Kurrajong Hts or Horsley?

Mike

citabria
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Re: NSW P25 GRN - Site Listing (current)

Post by citabria » Fri Jan 18, 2019 4:57 pm

Initially thought it was Kurrjong because of the strength (it's very high), but then I checked and it turns out that I have line of sight to the licensed allocation at Narrow Neck, even though I am definitely in the Sydney Basin!!!

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Mike Alpha
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Re: NSW P25 GRN - Site Listing (current)

Post by Mike Alpha » Fri Jan 18, 2019 5:29 pm

It seems like it's at Hosley Park for me. I'm receiving it on a portable indoors and fairly strong mobile near Bankstown Airport.

Mike

citabria
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Re: NSW P25 GRN - Site Listing (current)

Post by citabria » Fri Jan 18, 2019 6:16 pm

Don't underestimate just how high that site is - here is the path from Narrow Neck to Bankstown Aerodrome:-

Yes, it's LOS too..

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Mike Alpha
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Re: NSW P25 GRN - Site Listing (current)

Post by Mike Alpha » Fri Jan 18, 2019 8:07 pm

Hmmm. You may be right.

There was an RFS weather report broadcast on 420.200Mhz this arvo and with 20 dB attenuation, the 100% signal from Kurrajong dropped to about 80%, but the test transmission on 420.2125 dropped from 100% to about 30% with attenuation.

20dB attenuation on anything from Horsley Park barely makes a difference.

Mike

matthewn1983
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Re: NSW P25 GRN - Site Listing (current)

Post by matthewn1983 » Sat Jan 19, 2019 8:32 am

It was coming up with a NAC 211 last night with Blue Mountains RFS traffic, and NAC211 belongs to the Blue Mountains Digital PMR Vote. However doesnt appear to be a channel assignment in the codeplug for it, ill have a closer a look.

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