Hi all, just got this stellar labs FM antenna for my NAT-03 that I’ve not connected up yet, do you think it will be adequate just placed in my roof space or should it be mounted outside?
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it will depend on proximity to the transmitter and orientation
Only real way is to try in indoors and see what reception is like !
Depending upon where you are in the world, @Mike-B or @Simon-in-Suffolk should be able to give you a steer.
I have got what you have got in a strong signal area. My Yagi is on the roof. Radio sounds great.
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Tell me your location (country and city/town/village) and I can look up whatever data is available for your country and advise
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Hi Mike,I’m in Sydney Australia, a suburb called Castle Hill.
Thanks!
g’day Mario, this has not turned so easy.
It looks like Sydney is over populated with FM transmitters and stations.
Castle Hill is well covered by the main local and national stations,
I’m not sure how your aerial will work in a roof space, thats always a lottery, especially so in Aus if you have metal roof covering.
(NB for non-Aussie’s - metal (tin) roofs are common is Aus buildings)
If you have a tin roof I would be inclined to go outside as whatever it the best location anyhow.
The main transmitter for Sydney is located at Artamon 19km and a touch north from due South East from you.
My info shows it transmits at 50kW on the main stations so your 4 element Yagi will be well suited for that.
Hope this helps, have fun
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Hi Mike, that is very helpful, our house only has a tiled roof with no metal , just timber frame with terracotta roof tiles. It’s two stories so quite high. I’m fairly handy but not happy at heights hence the question about just placing it in the roof space. Looks like I may have some chance of getting a good sound. I’ll start mucking around tomorrow.
Cheers.
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Hey again Mario, you should be OK inside with a timber & terragotta roof.
One challenge with any inside antenea is getting the direction optimised as metals such as wiring & pipes can add reflection problems.
A 4 element Yagi will have a -3dB acceptance angle of around 45 degrees so don’t a afraid to go a bit off beam direction to fit it in with the timber beams.
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Hi Mike, thanks for all the help, I did muck around with it in the roof space today and got it sounding pretty good, still need to tidy things up a bit and may eventually go the extra mile and get it outside on a post. I got the NAT-03 for quite a song, it had a dent in the outer cover which I panel beated out, paint striped the cover and had it re-powder coated in the same texture black paint. Found the plastic rivets on Amazon as a couple were missing and cleaned the lovely olive facia. Thing looks brand new!
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Good Stuff Mario, you’ve done the extra mile with the paint job and clean up.
If you do go for the outside post mount, try to get a quality coax, best for FM & UHF TV is Webro WF100, it has a ‘solid’ foam insulation that does not deform on bends with sun/heat like the air spaced cell types.
Ok Mike I will look into that, was going to use quad shield RG6 cable but will check out what you suggested. Hey I also have a Sony ES tuner that I would like to hook up so does putting a two way splitter after the antenna seriously degrade the signal going to the 03, or is the signal halfed only when both tuners are on and pulling signal?
Thanks.
G’day @Mario, I might be a little late to the party. You have received good advice. I was an RAAF Radio Tech working on F1-11s at Amberley. These days, I retired near Wonathaggi, Victoria.
Living in Sydney, do you have a particular FM Station that you wish to listen to? I can see the desirability of having the antenna inside a roof space and would check to see if the tiled roof has aluminium sisalation as colorbond tin roofs do. I am 61 years and climbing on roofs for love jobs is over even for myself. Your antenna is a directional antenna and would be required to point at the radio station you would like to receive from.
For myself I have and do employ TV technicians to mount my amateur radio antennas these days. For your purpose they have signal strength meters and can do all the hard yards. I am not flush with cash, though I prefer younger men climbing in roof spaces, running cables and the like. You will require 75-ohm coax and possibly a 300 ohm to 75 ohm balun at the antenna connection point.
Not being familiar with NAT03 could you please let me know what RF input has? I am suspecting a 75 ohm, though it may be 300 ohm or both.
Warm regards,
Mitch (ex-pat Queenslander). Well done in The State of Origin this year.
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Hi just seen this.
If you are going to use a Yagi antenna like that, it really needs to be outside in free space. It should be mounted at least a metre above the roof line or chimney to avoid compromising performance.
I can’t see if there is a Balun on the aerial. Yagi antennae are balanced, and coaxial is unbalanced, so you need a BalUn of some description to attach to coax so as not to badly negate performance of the aerial.
There is also then the impedance matching of the aerial and coax. For the NAT03 this is 75 ohm for unbalanced - ie coax. Balanced is either 110 or 300 ohm but that is quite rare these days and irrelevant as the NAT03 doesn’t support it
The Balun will typically transform the antenna impedance to that of the coax as well, ie 75 ohms.
It all sounds a faff, but actually is quite straightforward and easier done than said. Impedance and matching are important for effectiveness of the antenna and interference rejection, as well as for maximum signal pick up transfer. For a quality tuner like the NAT03 these considerations are important so as to be able to get the best from the tuner.
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Hi again, all passive splitters will have an insertion loss, and it makes no difference if the tuners are connected or pulling signal, the loss is in the splitter.
Question is will it affect your tuners sound quality, probably not if your antenna is correctly aligned and you’re located in a strong high power transmitter area as you are. But it will affect performance with distant/weak signals.
Choose a good quality item, avoid the cheap plastic types, go metal and a good known brand. Consider F Type screw connections, they are so much better than coax plugs and easier to work with.
Make sure it’s operating band is correct for FM 88-108 MHz, they are normally set for both FM and TV and will have a range of 5MHz and an upper level of something around 850 to 2500 MHz.
Beautiful, but stereo light not yet lit.
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The difference between an adequate and a great antenna on a tuner can be compared to the differences between an adequate and a great cartridge on a LP12/Ittok.
Yes, I actually ran a Basik cartridge in the LP12/Ittok for a while, and it was a lot of fun-but highly colored and unsophisticated. A Supex SM100E (one of the greatest MM cartridges ever made) was transformative.
Similarly, years ago I ran a test using my NAT-01. A roof mounted G17 antenna on a rotor vs a 5m length of NACA5 plugged into the antenna input on the 01. BOTH gave an equally bright stereo light display, as my local NPR transmitters were fairly close.
But they sounded quite different, with the NACA5 having an audible background hissssss, inspite of a near full signal strengh indicated, and the clarity and soundstaging suffered greatly.
The importance of a good quality signal cannot be overstated, because a low-quality (even if it is high amplitude) signal, will always result in a low quality sound.
The ability to reject multipath is equally as important as the gain. All Yagis I believe offer a fairly narrow acceptance angle, which is a great help-but also requires a rotor.
BTW…if you want FLAC rips of the NACA5 vs the G-17 on the NAT-01, I have them somewhere. They are quite convincing.
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Inside**, but TBF, I have LoS to Rowridge! The NAT03 works very well, but the NAT05 has the better SQ…. (other opinions are available 
}
**one day, I will get around to mounting it outside (I’ve already got the bits….somewhere!)
One day………………
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You really are not going to get much performance from the antenna like that I am afraid… it looks very close to other metal and wiring… it simply can’t work as designed. You would be likely equally well off or more likely better off with a fm wire ribbon cable or large whip aerial which you could make more discrete and shape away from wiring and metal. Your signal quality (not strength if you are close to a transmitter) will be likely be poor. This will affect the quality of the stereo decode, this not the same as a detecting the stereo carrier (ie stereo indicator light) which should not be an issue if close to a transmitter.
A Yagi needs to be in free space with any metal in the same plane as the antenna at least 2 metres, ideally further, away. Metal at 90 degrees to its plane can be closer with out interacting… hence the mounting pole and cable is at 90 degrees to the polarisation plane of the antenna.
I suspect your signal will be full of RFI, and it’s the relative strength of the wanted signal, being close to the transmitter, that is suppressing that in the tuner.
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Assuming you are roughly 20 to 30 miles from your transmitter that should work well with your tuner. Remember to get it installed at least 2 metres above your roofline or chimney… your aerial rigger should do this anyway for you un prompted… and use low loss coax, again a good rigger will likely use such low loss coax.
It’s not clear if there is a Balun with the antenna … but if not your rigger should provide… sometimes the Balun can be a coil of coax just prior to the feed point … but I think if you can it’s better to use a small low loss Balun transformer.
A Balun allows the antenna to work as designed without the coax feed between it and your tuner interacting with the performance of the antenna. It also forces the coax to act like coax, and keep interference away from the signal in the coax feed down link. Without a Balun, your coax becomes part of the antenna and can also pick up electrical noise.
Remember coax is unbalanced and a Yagi balanced.