[HCDX]: Beverage matching/tuning/balun

[Mauno Ritola <ritola@xxxxxxxxxx>]

Hello colleagues,
	I'm referring to an article that Guy Atkins wrote some time ago. The
article is
available on the Nordic DX website. It's about antenna matching. I'd like
to ask a few questions because there is so much talk and many different
views about baluns/antenna matchers.
	I have built a DX-cottage in the middle of woods. It has no electricity and
the nearest electric power line is 1 kilometer away. My receiver is AOR
AR-7030. I will use Beverages of 400 meters to 1 kilometer. My question is:
why should I use coaxial cable (and go to the trouble of impedance
matching). AOR as most receivers has two antenna inputs: low and high
impedance. I just take the wires straight in the cottage to the high
impedance antenna connection (well, through a switchbox) and that's all.
The minimum loss of signal is achieved and with very little trouble. I
realize that this is an exceptional situation, but that's why I built the
cottage! 
	The only reason for using coaxial lead would be to try to separate the
beginnings of the Beverages from each other to avoid them effecting to each
other. But if they are maybe ten meters away from each other, would that
make any difference? (Is the loss of directionality so dramatic without
long coaxial cables?) Anyway, I can get the wires in to the cottage from
their direction and they will be well separated all the way till the
switchbox. The
matching (balun) itself doesn't make the directionality, it's the antenna
and a long coaxial cable can improve it, because the other antennas don't
affect the used antenna so much, right?
	Is antenna tuning and matching more or less the same thing? (I'm already
afraid of having asked a stupid question!) I have for trying a tuning unit
called Howes CTU9. Has anyone used it? Wouldn't that then do the matching
as well as a self-made balun, if I put the unit between radio and antenna
switchbox and then take the signal from the ATU in to the radio's 50 Ohm
connection via coaxial cable?

	I hope someone having used Beverages bothers to answer. Below find an
earlier question asked and Guy's reply.

73, Mauno
Finland

>Wouldn't the mismatch affect the aerials directional characteristics,
>and (even worse) allow the coax cable to pick-up signal on its outer
>shield, thus negating the reason we are using the coax (to remove
>local QRM and local stations on adjacent frequencies)? 

Guy:

>I tend to agree with you about the directional loss... not so much from
>theoretical knowledge but from having DXed with Beverages for 4-5
>years with a direct Bev-coax connection, and then for the last 5 years with
>a impedance matching device in between.
>I believe that the directionality when using a 10:1 matching transformer
>(per design shown in Fine Tuning's PROCEEDINGS) has been better on
>MW and tropical bands during my DXpeditions. I have not done a direct,
>"A-B" comparison, but it is my judgement based on 20-25 Beverage
>expeditions since I started using the matching transformers. I have five
>identical "Bev Matchers" that I use on DXpeditions.
>I also like the fact that a matching transformer ensures, within reason, the
>best possible signal transfer. There *are* occasions when geomagnetic
>conditions, T-storm static, etc. are EXTREMELY quiet and favorable;
>when I seek out very weak transpacific MW DX I don't want ANY signal
>loss in my antenna system if I can help it! Noted MW DXer Patrick
>Martin in Oregon, USA, feels the same way as I do about this. Those
>who say that "because we don't transmit on our antennas means that we
>can tolerate all sorts of mis-match" must never spend their time crawling
>around on the noise floor of their receivers. Sometimes the real DX is
>WAYYYY down in the mud! I know that a 3db loss or gain of signal
>strength is barely discernable, but a Beverage antenna is not particularly
>efficient and we can use all the signal our antennas can generate.
>However, we must keep in mind that actual impedance of the Beverage
>antenna varies with frequency, wire height and size, rainy weather, and so
>on. The 10:1 transformation offers a good starting point for bringing the
>antenna's impedance closer to a nominal 50 ohms.

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