Yes, rabbit ears are 1.6 m wingspan when fully extended in a line… The one I’m using stays tightly on the RF connector, hasn’t come loose once. It’s just this one from Bunnings.
Yagis are great for some stations, but will miss the “sweet spot” for others, some for which i need to tilt the ears. And it’s a lot more fun moving the ears around and finding two (or even more) stations on the same frequency).
And the TEF is great for one handed DXing. I can walk around, hold it on my right hand and tune and change volume, and wave the rabbit ears around with my left hand, listening using headphones. Helps that I’m right handed too since the controls are on the right hand side of the radio.
Lots of enhancement today. Mackay 98.7 received with RDS from the north plus enhancement from south as well. Driving was interesting with RDS on both Zinc and triple J on 96.1 switching between stations depending on location. So with the RDS might have listed triple J the music was classic hits
The more I read all your stories about the TEF, the more I’m convinced that I unfortunately got a dud unit. Antennas don’t connect well, and I don’t get the sensitivity of distant signals anywhere near what you guys are reporting. It’s a good portable (when I can get the antenna to connect), but that’s as far as I’d go.
I’m thinking of swapping the omni on the roof (which is pretty useless as well) for a 3 or 4-el yagi. Anyone have any recommendations on the best ones? That way I can plug the Sony or the TEF into that, and maybe with some directionality on the antenna I can try and avoid the worst overload from the local blowtorches. I generally just stick with the car radio if I’m DXing while out and about anyway.
Yeah it’s cool to see how radios deal with that, my car is the same when those two clash.
There’s a sweet spot on the M1, just as you cross the Logan River at Beenleigh, where Zinc 96 comes in with RDS whenever there’s a hint of enhancement. It will flip from saying ‘triple j’ to ‘ZINC96.1’ then you drive a bit further up and it flicks back again.
Yeah I bought some adapters at Jaycar to connect it to the rooftop aerial (F-type to BNC to SMA). I shouldn’t complain, as it’s probably about as sensitive as the Sony comparing with the same aerial, but a bit worse at rejecting adjacent channel noise (which is everywhere on the dial here in Brisbane) and it has some bad images - 91.7 here is just a mess of local images on the TEF, but I can hear Gold Coast on the Sony plugged into the same antenna.
Also heard a weak Hit93.1 Wagga (heard Listnr app mentioned), plus Goulburn ABCs on 89.5 and 90.3 as well as Power 104.3 from the Bay and 2ST 106.7 from Ulladulla. All except Hit Wagga were first time catches with the TEF None with RDS though, and reception was variable.
And I had a chuckle when I heard the following on 90.7… "At the roundabout, take the first turn right and exit onto… " obviously in car FM transmitter being used nearby… that faded out and JJJ SW Slopes returned.
@Radiohead & any others that have a TEF, a friend has bought one & asked me what a couple of things on the screen mean/indicate, neither he nor I can find an English manual that says what everything is so I’m only guessing.
In that last pic & by deduction on reading the chip manufacturers specification document, the 151kHz at the top of the screen is the channel bandwidth filter, it’s manually tunable to Narrowband or Wideband across various bandwidths or set in auto mode.
On that station in the pic, 151kHz would only just be a full 100% modulation channel bandwidth, so it’s possible some of the channel info (audio/RDS sub-carriers, etc) maybe filtered out & in that case I wonder why the tuner auto chose that filter bandwidth, unless that station isn’t hitting 100% modulation? Am I on the right track with that reading?
Also the S & M bar graphs, I would’ve said they were Signal strength & Modulation graphs, but on that pic the M bar has red dots at around the 80% mark, which I can’t see why 80% modulation or higher would be indicated bad?
Also Radioheads TEF has V2 firmware, my friends has an earlier version firmware & it’s S graph goes to +40 & at a higher signal level gives a lower level on the bar graph.
This brings me to the question of exactly how accurate are all these measurements on screen?
In the 2 screenshots he’s sent me one of Coast FM & one of WSFM you can see the difference in the S graph but also the channel filter bandwidth in which WSFM is quite wide (max I think) as it obviously over modulates so the used channel bandwidth is greater.
Yes, I have similar questions… your guesses sound pretty logical though.
Interesting though, on your friends radio, the first image has the frequency and some text in yellow, in the 2nd, they are in green… I’ve not seen them show different colours like that before… mine has yellow, but I think I prefer the green (unless it’s just the camera angle making it look more green). Green would probably be better for battery life too.
Looks like your friend is in Sydney judging by the 68.9 in the WSFM image on what appears to be the signal strength indicator… which is similar to what I get on the local Newcastle stations and Central Coast commercials.
And how did your friend find out about the TEF radio?
Correct with Signal Strength & Modulation.
My memory of RF modulation level theory for various types of modulation getting hazzy now, so won’t bother commenting.
I don’t honestly trust all the readings, especially SNR on low level FM signals & maybe the BW setting could effect those readings too.
You mention 151kHz BW. That’s just one of several available BW’s on FM BCB Wideband.
Manually selected BWs range from 56 - 311kHz on FM BCB (Yellow Button)
The auto BW select will choose BW upon signal strength levels, (or at least on that one criteria, not sure if also modulation maybe another ? Maybe??)
As for decoding RDS in theory on low modulation levels one needs BW opened up to at least 118kHz. On higher modulation levels, thus wider bandwidth, a wider BW filter should be required to decode the RDS at its best. In practice using this receiver I’ve decoded RDS around the 84 or 97kHz BW settings, which in theory shouldn’t be possible, but with this radio it is, be it with a much attenuated RDS subcarrier. One would think this might be due to poor shape factor filters, but the BW filtering ‘appears’ reasonably sharp.
With 311kHz upper BW limit on FM BCB it does limit the fidelity of wide BW stations such as KIIS 106.5 in Sydney with it’s 400kHz of BW, but given the small speakers one isn’t buying the radio for fidelity.
True, I’ve never seen the TEF go higher than 236 khz Bandwidth… but it still sounds quite decent using good headphones on mine with the V5 hardware upgrade, which apparently includes a better audio chip than earlier models.
I don’t have one in my hands just yet, but a difference I’ve noticed with the TEF6686 blue radio models is the bands covered differ. See pics.
Also, if anyone is wanting to test the https://list.fmdx.pl/ remote access software that has been linked here, but doesn’t want anyone connecting directly to their IP, a possible free solution is “AWS EC2 free tier” Sydney server (be aware of the free tier limits).
Following the instructions from the link here AM and FM DX - #8922 by mrwish7 it took me just minutes to get it up and running including opening up the required ports.
Obviously I can’t yet test it 100% without the radio, but it looks promising, if someone wants to be the first in Aus to try it.
Some tropo dx about out west this morning.
Pulling RDS from all available Orange RDS stations, including 107.5 Orange FM
(See RDS list).
Bathurst in with 92.3 2MCE & Orange 94.7
Also noting 92.7 2ZOO Dubbo. Appeared to be a mix of two stations on 93.5, guessing Goulburn & Dubbo.
93.9 very weakly I suspect Young was in too briefly.
Interesting your comment about the auto BW filter choosing depending on signal strength, that’s logical I guess, as a low signal strength would cause more hiss, so you’d want a narrower BW to filter that & hone in on the strongest part of the audio.
It doesn’t really matter what sub-carriers you have on the FM baseband, mono or stereo with RDS, for FM modulation in this situation (FM Radio), theoretically & to licence specifications, 100% modulation will give you a plus & minus deviation of 75kHz or total 150kHz channel BW, with the remaining 50kHz in the 200kHz BW FM channel being for a buffer between adjacent channels, (or space to over modulate, lol).
To modulate mono only audio at 100% the audio will have more punch power in it, everything else you put on the baseband takes away from everything else.
FM Licence conditions in the USA allows for a stereo station to modulate at 100% & 75kHz deviation, if they add RDS to that baseband, to overcome what the RDS takes away from the mono & stereo audio, they are then allowed to modulate to 110% & go over the 75kHz deviation, in Australia we aren’t, we still have to stick to 100% modulation & 75kHz deviation, so we loose a bit from the audio.
Theoretically you being able to decode RDS with 84 or 97kHz BW filter shouldn’t be a problem with a strong signal to start with, the filter will cut down on the total BW of the modulated carrier before decoding back to baseband, not what’s on the baseband, but if you cut down the overall BW of the modulated carrier, what’s on the baseband will be weaker.
Don’t forget the overall modulation of the carrier & thus total channel BW will vary with what’s on the baseband, it’s Frequency Modulated not Amplitude Modulated, so it doesn’t matter how loud the audio is on the baseband, but it will vary with the actual audio, speech will vary the modulation & channel BW a lot more to a lower level than say rock or pop music which won’t vary much at all, a full power RDS sub-carrier with no audio on the baseband will still Frequency Modulate the carrier, but it’ll be very low, & the actual used channel BW will be very small (narrow) also, but if you have a strong signal level of that modulated carrier, you’ll still be able to decode the RDS.
With FM the transmit power & coverage aren’t dependant on the modulation level, they stay the same whether it’s at 20% modulation or 120% modulation, but the channel BW will change in that situation.
Ended up being a big fizzer last night and today in the west. Middle level widespread rain and thunder was hard to predict, therefore the tropo forecast was off.
