Identifying FM Es stations
Posted: Tue Jan 06, 2015 7:30 pm
Prompted by a question asked by VK3ZAZ in the iChat this afternoon (he had left by the time I got back from dinner) I thought I would answer some questions as an FM DXer.
08:04:41 VK3ZAZ VK2FEAE I am curious as an ABC tech how you know what si what, for one callsigns are not given and man multi use of freq
08:05:55 VK3ZAZ try 91.7 92.5 93.3 94.1 94.9 and best 88.9 mix all at hamillton see what you get
08:06:19 VK3ZAZ 88.9 is 60kw and runs six directional stack
08:07:17 VK3ZAZ you also have a news radio at Horsham ona 500 foot tower and you have lawloit RN on its own
08:06:19 VK3ZAZ 88.9 is 60kw and runs six directional stack
08:06:43 VK3ZAZ Mt Dundas is all 20KWx5 Mt Burr is only 10K
08:06:19 VK3ZAZ 88.9 is 60kw and runs six directional stack
For sure sometimes it is impossible to identify the location of a station, but there are a few tricks we use. For a start PNN/News Radio is a national program with no timeshift, so I can easily check it against the local MW outlet. The remote FM outlets will be usually up to a few seconds behind. So that is a quick way of confirming it is News Radio (though it doesn't tell you where from if more than one on frequency). That quickly determines if it is News Radio Horsham, or RN Lawloit (which would also be in sync with Sydney RN so again a parallel check can be made) if western Victoria happened to be in.
The ACMA produces a monthly list showing all FM stations in Australia (not including Temporary Community or other Broadcasts). That lists the official callsign though I agree these are rarely used on air except mainly by some community stations. New Zealand is a bit harder as information can be harder to come by, their version of ACMA is a lot harder to query and while we can look at frequencies it only tells you the licence owner - and if Mediaworks or similar they run multiple networks.
However FM DX by it's nature is usually not widespread but reasonably concentrated in an area (be it very local or a region). It is rare that stations from all over the place are being heard at the same time, though a couple of years ago I did have an opening to Queensland like that where the band was wall to wall stations with sometimes 2-3 stations competing on usually empty frequencies. Last week I was hearing Mackay commercial stations, so it was a reasonable bet that the ABC outlets I heard on frequencies also listed for Mackay at the same time were the ones being heard.
That also applies the other way in working out what might be possible. Immediately before the Mackay reception I heard a Triple J outlet on 97.9 (ID heard). The only one listed in Australia is 4JJJ Burketown with 10 watts, and I could hear it on peaks on the portable radio with the whip. Straight after I was hearing all Mackay outlets including ABCFM 97.9 so I suspect some sort of switching error briefly and I was hearing the much higher powered Mackay transmitter carrying the wrong program rather than Burketown which was well away from anything else logged that day (all up and down the Queensland coast). Though I would much rather claim Burketown at 10 watts than Mackay at 100 kW that said I have had 10 watt Queensland reception before but during much more spectacular openings than I have heard this season so it couldn't be immediately discounted purely on power levels.
Lastly of course Craig & myself are using a directional antenna, an 8 element Hills yagi made for 88-108 MHz so we can be reasonably confident that long hop Es will be coming from the direction we are pointing it at except in the case of short haul Es reflecting back off a cloud, something I have rarely if ever experienced.
My 5EZY logging of Murray Bridge was based on a Power FM ID heard, rather than local ads with locations or phone numbers which are of course a good giveaway if heard. A quick google of "Power FM Murray Bridge" confirmed that was their frequency and given I had been hearing Adelaide immediately before was a fairly safe guess. My first logging of 5FBI Adelaide was based on hearing a "Fresh" ID, but given Craig's previous logs and the 50 MHz paths open from Sydney on the logger I suspected that might be the direction to aim. Having lived in Adelaide before I knew Fresh FM was on 92.7, though again a quick google of Fresh 92.7 would have brought that information up.
It's not necessarily as easy as when you are given a callsign immediately by the station you are hearing, but using the scientific method we can generally work out what we might be hearing. And not spotted are the ones we can't positively ID, such as the many low power Rebel FM or ABC outlets in Queensland that could have several towns on the one channel with no local ads to help ID them and no other local markers coming in. Off the logger on the mailling list some of us are on you will often see logs for stations that are unidentified even though the station name be known.
There are ones that don't immediately make sense, for example I once heard a mining outfit in remote South Australia relaying an eastern states JJJ program (based on time calls). The signal was audible for about 20km on the car radio over dunes etc so I suspect they were running at least 10 watts from the top of the tower. I assume they had tuned a satellite receiver to it and were just relaying it around for the local workers (well away from any local radio, even MW) but that would be receivable in a good Es opening. They will be the ones we can never track down as to exactly what they were.
08:04:41 VK3ZAZ VK2FEAE I am curious as an ABC tech how you know what si what, for one callsigns are not given and man multi use of freq
08:05:55 VK3ZAZ try 91.7 92.5 93.3 94.1 94.9 and best 88.9 mix all at hamillton see what you get
08:06:19 VK3ZAZ 88.9 is 60kw and runs six directional stack
08:07:17 VK3ZAZ you also have a news radio at Horsham ona 500 foot tower and you have lawloit RN on its own
08:06:19 VK3ZAZ 88.9 is 60kw and runs six directional stack
08:06:43 VK3ZAZ Mt Dundas is all 20KWx5 Mt Burr is only 10K
08:06:19 VK3ZAZ 88.9 is 60kw and runs six directional stack
For sure sometimes it is impossible to identify the location of a station, but there are a few tricks we use. For a start PNN/News Radio is a national program with no timeshift, so I can easily check it against the local MW outlet. The remote FM outlets will be usually up to a few seconds behind. So that is a quick way of confirming it is News Radio (though it doesn't tell you where from if more than one on frequency). That quickly determines if it is News Radio Horsham, or RN Lawloit (which would also be in sync with Sydney RN so again a parallel check can be made) if western Victoria happened to be in.
The ACMA produces a monthly list showing all FM stations in Australia (not including Temporary Community or other Broadcasts). That lists the official callsign though I agree these are rarely used on air except mainly by some community stations. New Zealand is a bit harder as information can be harder to come by, their version of ACMA is a lot harder to query and while we can look at frequencies it only tells you the licence owner - and if Mediaworks or similar they run multiple networks.
However FM DX by it's nature is usually not widespread but reasonably concentrated in an area (be it very local or a region). It is rare that stations from all over the place are being heard at the same time, though a couple of years ago I did have an opening to Queensland like that where the band was wall to wall stations with sometimes 2-3 stations competing on usually empty frequencies. Last week I was hearing Mackay commercial stations, so it was a reasonable bet that the ABC outlets I heard on frequencies also listed for Mackay at the same time were the ones being heard.
That also applies the other way in working out what might be possible. Immediately before the Mackay reception I heard a Triple J outlet on 97.9 (ID heard). The only one listed in Australia is 4JJJ Burketown with 10 watts, and I could hear it on peaks on the portable radio with the whip. Straight after I was hearing all Mackay outlets including ABCFM 97.9 so I suspect some sort of switching error briefly and I was hearing the much higher powered Mackay transmitter carrying the wrong program rather than Burketown which was well away from anything else logged that day (all up and down the Queensland coast). Though I would much rather claim Burketown at 10 watts than Mackay at 100 kW that said I have had 10 watt Queensland reception before but during much more spectacular openings than I have heard this season so it couldn't be immediately discounted purely on power levels.
Lastly of course Craig & myself are using a directional antenna, an 8 element Hills yagi made for 88-108 MHz so we can be reasonably confident that long hop Es will be coming from the direction we are pointing it at except in the case of short haul Es reflecting back off a cloud, something I have rarely if ever experienced.
My 5EZY logging of Murray Bridge was based on a Power FM ID heard, rather than local ads with locations or phone numbers which are of course a good giveaway if heard. A quick google of "Power FM Murray Bridge" confirmed that was their frequency and given I had been hearing Adelaide immediately before was a fairly safe guess. My first logging of 5FBI Adelaide was based on hearing a "Fresh" ID, but given Craig's previous logs and the 50 MHz paths open from Sydney on the logger I suspected that might be the direction to aim. Having lived in Adelaide before I knew Fresh FM was on 92.7, though again a quick google of Fresh 92.7 would have brought that information up.
It's not necessarily as easy as when you are given a callsign immediately by the station you are hearing, but using the scientific method we can generally work out what we might be hearing. And not spotted are the ones we can't positively ID, such as the many low power Rebel FM or ABC outlets in Queensland that could have several towns on the one channel with no local ads to help ID them and no other local markers coming in. Off the logger on the mailling list some of us are on you will often see logs for stations that are unidentified even though the station name be known.
There are ones that don't immediately make sense, for example I once heard a mining outfit in remote South Australia relaying an eastern states JJJ program (based on time calls). The signal was audible for about 20km on the car radio over dunes etc so I suspect they were running at least 10 watts from the top of the tower. I assume they had tuned a satellite receiver to it and were just relaying it around for the local workers (well away from any local radio, even MW) but that would be receivable in a good Es opening. They will be the ones we can never track down as to exactly what they were.