East – since that seems to be the weakest direction of the antenna and there are no stations to the east of where I am to DX (unless New Zealand stations come in). Before it was pointing north-ish towards Artarmon.
It might just be that the roof antenna is in a null or bad spot for those particular stations (even the Sydney stations like Nova have distortion on the SDR) - either that, or the SDR’s sensitivity just isn’t as good. Here are those stations you mentioned on my car radio just outside my house. They all come in clearly, most with RDS, even though the car’s antenna is much lower than the rooftop antenna:
Note: The noise on the ABC Classic stations is from the camera, not the radio. Those broadcasts were very soft and the noise is from the microphone gain.
Also, just outside my house and around my area, Rhema and Today’s Country generally dominate over Power and Pulse.
Orange and Bathurst stations come in well around the Hurstville area provided you have LOS. Must be a good path through the Cox’s River/Lake Burragorang gap I reckon. The Orange stations were the bane of my existence when trying to get Es or tropo. 101.9/102.7/104.3 at least 2 bars on the XDR even aiming away!
I don’t escape Orange down here either; if anything it’s stronger than back at Oatley. Easily receivable on just a portable.
Here’s mine
Matchmaster UHF is for Kurrajong Heights. Kingray amp for splitter loss, just running very low gain.
FM antenna from memory came from academy tv/ebay. 2 way split to Sony XDR (garage) and Onkyo FM/DAB amp loungeroom. Don’t have an amp on FM (doing so boosts noise too much). Both tuners have no problem pulling in Orange nationals permanently. Dab works flawlessly. Like the match master omni FM, it has a null to the sides, in this case east/West despite being advertised as omni vertical/mixed.
Hi @matt86
Thanks for the pic.
I have never seen a folded FM dipole constructed like that.
I’m guessing it’s a variation of the 45 degree slant that exhibits both vertical & horizontal properties.
Normally, if my memory serves me correctly, a 45 degree slant antenna receives both horizontal & vertical polarised signals but at only a 3dB loss.
I can’t figure what advantage it would have over a folded dipole that is mounted in a 45 degree slant configuration other than not having to buy the right kind of mounting clamp. Very interesting in any case.
From memory some NZ FM tx antennas are 45degree right hand slant.
Is your antenna mounted as left-hand slant?
You’re correct that a 45 degree slant receive antenna is only -3dB, (from Liner Vertical or Liner Horizontal), but it depends on the transmit antenna, you’d have no theroetical loss on a slant receive from a mixed transmit antenna.
Sydney main TX FM panel arrays are in a square shape elements, Newcastle FM panel array at BAI site is X shape elements, most side mount antennas are of the X type these days, but some, such as NEWFM side mount is more like a + shape.
We call our TX antennas Mixed Polarisation in Australia, but most of the rest of the world call them Circular Polarisation antennas, & the electrical characteristics of the wave generally spin in a right rotation, so a Vertical, Horizontal or 45 degree slant (either way) receive antenna, won’t have any theoretical loss, as at some point in the cycle, the transmitted wave will match the receive 100%.
Pics top to bottom:
NEWFM Sidemount
Artarmon Main FM Array
NXFM Sidemount
ABC’s Newcastle BAI Site
Artarmon Community Sidemount Before Installation
That Looks like the Fm antenna that Laceys sells, they claim it has 2.1db gain.
With the nulls to the sides east / west would the mast be responsible for some of that?
Port Stephens, Newcastle and Manning River stations enhanced into Sydney at the moment.
Here’s Triple M Newcastle on 102.9 (usually 2ST at my location):
I’m staying at Chatswood tonight, and I’m not really noticing much enhancement here. It could be overload from the Artarmon TX that is preventing it for me, as I am 700 metres from it and can see it from my accommodation, 26 floors up.
On the way down this morning, I stopped at Westfield Hornsby and parked on the roof (as you do when DXing), and got 98.7 ABC Classic from Taree/Port Macquarie.
Ditto for me at present.
Hepburn Maps predict some coastal ducting right along the coast improving until just after sunrise.
I’ll take another look early morning.
I never realised tropo could be so localised that parts of Sydney are getting enhancement but not others.
Here’s my Manning River and Port Stephens reception at the moment:
Yeah can be. Just in last recent minutes now getting 97.1 & 98.7.
Using the FM Co-channel canceller I can receive another station underneath 2ST 102.9, but too weak (presume Newcastle). 102.1 & 106.1 stronger now than usual.
Something detectable there on 101.5
Using co-channel canceller, I can get 2RPH Newcastle under 2RPH Sydney on 100.5. Seems to be slightly delayed over Sydney.
Triple J on 102.3 also coming in (presumably Central Western Slopes).
Today’s Country now also on top of Pulse, coming in with RDS.
Lots of enhancement inot Brisbane tonight but nothing too far. Notable are 99.9 Bay FM Byron; 2MW 104,1 over the top of usually dominant JJJ. Wide Bay stations also enhanced.
Just checked here nothing to get excited about with only slight enhancements from the north and south. Newcastle commercials and Eagle fm just above the noise floor. 2ST enhanced so no sign of Triple M Newcastle.
Surprisingly Classic Middle Brother is weaker then normal (no signal) so it looks like the signal is being reflected away, or there is a very shallow duct going through the more coastal suburbs of Sydney. I am approx 40km inland.
Yes. I’m accomplishing the same . Never previously thought to try - thanks for that.
Maybe I need to get a Software Defined Radio for myself one day, because it seems like you can do some half decent DXing with those!
You can also record a whole chunk of the spectrum (e.g. 8 MHz on my SDR) and tune to any frequency within that block afterwards.
Yes they have so many features that standard radios don’t & so much fun to play with.
Briefly had Rhema 99.7 come up above the noise when FM co-channel canceller used on 99.7 2SSR, a couple of minutes ago