AM and FM DX


The wind has alternated between SW’ly and SE’ly here most of the day, indicating that the maritime air is pretty shallow (too shallow for tropo). A deeper SE’ly push came just before sunset, however, which is probably why tropo has lifted. The airmass above is still fairly cool, originating from Bass Strait.


Adding a little further info to my post above:

Coastal ducting often peaks in the early evening. This is because the seabreeze inversion layer deepens- going higher in the atmosphere- as daytime heating decreases. The inversion layer readily reaches a height of 1000 m in the early evening; witness Mount Boyce at 1080 m cooling rapidly under a light easterly breeze. Unless the synoptics prevent it, the inversion holds until the morning hours and often gets stronger until solar energy is sufficiently strong to break it (happens quickly in summer, obviously).

In the cooler months, radiative cooling under high pressure systems can result in nocturnal and morning tropo because the surface cools faster than the atmosphere above. Foggy mornings generally feature strong inversions and can be quite a good indicator of tropo.


Might be a little off topic for this thread. But I would just like to ask, where is Grant Broadcasters Ballarat (Power FM, 3BA) Transmitter? Is it in the Pyrenees Ranges? At Buninyong? Couldn’t find a suitable website.


Mount Warrenheip, just to the east of Ballarat


Thanks. Didn’t think that hill was high enough for Power FM to be heard clear into Melbourne.


Not only that, but the antenna is highly directional towards the west. The opposite direction to Melbourne


It’s something like 700+m ASL there, so not overly shabby in terms of elevation

Does anyone know how far west their signal actually goes? I know it reaches into parts of Geelong and Melbourne with relative success, but haven’t really ever checked out west towards Ararat etc. I’d imagine 20kW should get that far reasonably well?


Great reception into Ararat, RDS, the lot. It’s on a good ridge, Bendigo received equally as well. Melb signals are just above the noise threshold, obviously better with an FM antenna.

Ballarat reception continues further west to Great Westen etc but I didn’t bother much on the few days I was there: wine, olives and sightseeing the Grampians took priority.


I have found another case of IMD, this time in the Southern Highlands with 2ST.

2ST is over deviating from 102.9mhz to 102…7Mhz and also onto 103.1 MHz anywhere within LOS of the Gib.

My car radio was able to seek on both frequencies either side of 102.9Mhz. It made reception of Hope 103.2 very difficult in both Mittagong and Bowral.

Also the audio quality of 2ST Bowral was equivalent to how 2LT use to sound from Wentworth Falls with breakups in the audio feed of their programs from Nowra. I am not sure if it is a faulty landline as that was the problem at Wentworth Falls, and this sounds exactly the same.


wine, olives and sightseeing the Grampians took priority

Perfectly fair enough too! But thanks for the info, I haven’t been out that way in years

Come to mention it, I remember as a kid we were hiking up near Halls Gap somewhere, and I could pick up K-Rock et al from Geelong on one of the peaks just on my walkman (which I had with me on every car trip back in those days). I was amazed at the time what a bit of elevation could do


I’ll be heading from Geelong to SA for Christmas and will have a handheld on the bus so will see how far it gets out


Victoria is a pretty flat state once you get west of the Macedons, so it’s no surprise that Mount Warrenheip, despite a fairly modest elevation by Great Dividing Range standards, gets out well to the west and south. The Grampians are basically a chain of Mount Canobolas’s or Mount Dowe’s : ex volcanic ‘peaks alone’. Mount William would be a good place to DX from; it’s over 1000 m ASL and way above its average terrain.


And that there are no other high power services operating from the Grampians to cause overload.


Which is a surprise, Western Vic along the A8 axis needs a high power signal for FM ABC services.


Good Geelong signal in Ararat too. So do the Ace stations from Colac I think I recall. I was there over a weekend and it was wall to wall automation and duplication wherever we drove from Horsham, Hamilton, Warrnambool and Colac signals. Boring stuff, good there’s a few different operator’s signals in the area.


You’re right cranky. The issue I suspect is lack of infrastructure at the top of Mount William. And probably no appetite to put in towers etc given it’s in a national park.

Telstra has its old microwave site at a much lower elevation on the north side of range. Can’t remember the name of the spot. But not much use for wide-area broadcasting.


Indeed, a compromise site by the former high standards of what would’ve been the PMG when it was installed.

Western Vic is a strange area for communication infrastructure, it really goes low scale the closer to the border you get. Be it radio, TV or comms. It’s like original planners didn’t want any overspill to SA instead of realising the market value of SE SA.


I reckon it’s more a legacy, most of Western Vic was covered by Lookout Hill, with only infill translators needed to service other areas like Warrnambool, Hamilton, Portland etc. Also bear in mind there aren’t many major population centres outside of these cities that aren’t covered by the main site or one of these translators, hence the lack of anything major west of Lookout Hill

Had Ballarat TV/FM been originally based out of a medium-high powered site closer to the city, say Mt Buninyong or Mt Warrenheip, things might have been very different, as there would have been a need to cover those areas further west with a high-powered site. But I guess those in charge at the time thought one major site to cover the lot was a better way to do it


There is Mt Dundas near Hamilton.
It has the full suite of ABC stations at 80kw.


Yes, Mount Dundas is a wide coverage site.

A bit off topic, but since we’re on Western Victoria I thought I’d give it a mention- does anyone know when 3ABCFM Portland went off the air? It used 88.1 MHz and was on air at least as recently as 1999. There may have been a push for LPONs I guess, but this flies in the face of the policy framework which prioritises broadcasting-rather than narrowcasting-services.

JJJ and Classic from Mt. Dundas get into Portland OK, though. NewsRadio, Local Radio, and RN continue to be repeated via Mount Clay into Portland.