Very good MW and LW reception on Triax folded dipole

Medium & long wave antenna discussion
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Alex Cator
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Joined: 26 Dec 2014 14:53
Location: East Harling, Norfolk, England (QTH JO02LK)
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Very good MW and LW reception on Triax folded dipole

Post by Alex Cator » 23 Sep 2015 14:46

Hello all, (I am off school today with a very bad cold)
I have just hooked up my Triax folded dipole (which is designed for FM and was part of my erstwhile, now broken FM3) to the external antenna socket of my Grundig G5. By the way, a wire broke between the ferrite rod aerial and the AM section when fitting the 110 kHz filters, so there is no LW/MW reception anymore without an external antenna, even though BBC Five Live (693 in my area) can be heard very faintly on full volume in the 'narrow' and 'DX' settings.
The Triax folded dipole appears to work really well on MW and LW, so maybe it would be a good aerial for TA DX? I managed to get Smooth on 828 and the London station on 1035, which the car radios and the bare 390 struggle with sometimes.
Reception of Lille 1377 is very good too. Nordkirchen 549 was quite weak but listenable (maybe the aerial was badly positioned for this?). On LW, reception of Allouis 162 and Droitwich 198 (the latter is my local as I live in the UK, and Allouis' signal is usually local-like) was very good. Felsberg 183 and Clarkstown 252 were weak but listenable, presumably also due to wrong antenna position. There is also some unknown noise on a few LW and MW freqs.

Alex Cator
East Harling, Norfolk, United Kingdom
Home: Sony ST-SB920 (modified), Sony XDR-S10HDiP, Onkyo T-4970, Ford 5000 RDS, horizontal Triax FM3
Mobile: Ford Fiesta (Style, 2013) and Ford Focus (2012) car radios
Portable: Tecsun PL-390, Grundig G5 (2 x 110kHz), Etón G8

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Julian Hardstone
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Re: Very good MW and LW reception on Triax folded dipole

Post by Julian Hardstone » 23 Sep 2015 17:04

I have noticed this too, Alex. It was not clear to me whether the vertical folded dipole was acting as a loop at MF or as a unipole (vertical rod).

It's worth noting that with correct matching (high and capacitive reactance) the length of a vertical which is sufficient to receive background noise at MF is about 2", so provided you have got the matching right there is no point in going any longer for an MF vertical! The PA0RDT mini whip active antenna is about this height and is widely used as a receiving aerial for MF/LF amateur dx. If the folded dipole is acting as a vertical whip it will be omnidirectional.

There's a nice project for someone, to make two PA0RDT whips mounted 10 or 20m apart, and combine them with a phaser for a steerable cardioid pattern at MF

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