Re: Diversity Receiving Antennas
Posted by
Bill W4ZV on
Jul 27, 2009; 2:24am
URL: http://elecraft.85.s1.nabble.com/Diversity-Receiving-Antennas-tp3331122p3331589.html
Dave Van Wallaghen wrote
So my question to the group is, for those using diversity reception (or
separate receive antennas), and using a K9AY - does it perform well on
the HF bands for this purpose? I would also like any input from those
who have both Beverages and K9AY for comparison. And, does it make sense
to use the setup as I described? Since I can only run Beverages in a
couple of directions, I thought the K9AY use in the other directions
would cover a lot of bases.
I've never used a K9AY but I know it's S/N is several dB inferior to a decent Beverage. There's a good comparison of RX antennas below:
http://www.w8ji.com/receiving.htm (scroll down to comparison chart)
Another comparison in in ON4UN's Low Band DX-ing (4th edition) on page 7-97.
The short answer is...the K9AY is better than nothing, occupies little space and can be switched in 4 directions...but it's not in the same ballpark as a good Beverage. I'm also not sure how well the K9AY works on the higher bands, but you might want to consider a RX 4-square which can be comparable to a good Beverage in 4 directions and which can be used up to 30 MHz. DX Engineering and HiZ Antennas both make broadbanded RX 4-squares that work well at HF:
http://www.dxengineering.com/Sections.asp?ID=117&DeptID=12#Tophttp://www.hizantennas.com/These systems are not cheap but should work much better than a K9AY.
BTW, it's really doubtful your Beverage is actually working correctly. Both ends should be terminated in the characteristic impedance (~500 ohms) to work correctly, so you need a non-inductive 470 ohm resistor on the far end and a 9:1 matching transformer on the feed end. Transformers can be made to work well up to at least 20m (maybe even 15m) but require some care in construction.
This is not the place to go into a Beverage tutorial but there is a wealth of information on W8JI's website and in ON4UN's 4th edition (or you can wait for his 5th edition which should be out next year).
73, Bill W4ZV