[Elecraft] Antenna considerations (what to do?)

Sat Dec 13 06:34:01 2003

Dave,

I don't think you should assume no tuner losses.  The LDG is a fine little 
tuner, but it would take a XL of +530 ohms to tune the antenna on 
160.  Even with toroid coils, that's proportionally a lot of wire loss.  I 
was able to improve the efficiency of the over all system on a 45' vertical 
on 160 by using both linear loading and a top hat loading.  Cuts down the 
necessary Xl to load it, and the antenna R should go up a bit.

At 08:26 PM 12/12/2003, [email protected] wrote:
>Dick,
>
>you could use an LDG RT-11 remote water proof tuner mounted at the antenna 
>base. This is $179 US in a kit and $211 assembled. Here is the simulated 
>input impedance over perfect GND:
>160M   3.3 -j530 ohms
>80M     15 -j164
>40M    142 +j254
>
>A ground consisting of eight 15 meter radials will give an equivalent loss 
>resistance of about 20 ohms. The approximate radiation efficiency and 
>input impedance over actual ground with 8 radials will be (assuming no 
>tuner losses):
>160M   14%   32 -j530 ohms
>80M    43    35 -j164
>40M    88   162 +j254
>
>I believe the LDG will tune this nicely.
>
>Not the best on 160M but all right on 80M and quite good on 40M. I use a 
>similar homebrewed antenna (self supporting vertical) that is 12 meters 
>tall. It is for 160M and has an efficiency of 25% but is not multiband. 
>Your Titanex will even work well on 30 meters. On 20 and above high angle 
>lobes develop. So, you would have an effective 160-30 meter antenna with 
>quick remote tuning.
>
>    Dave WX7G
>
>
>-----Original Message-----
>From: [email protected]
>[mailto:[email protected]]On Behalf Of Dick Hissink
>Sent: Friday, December 12, 2003 2:19 PM
>To: [email protected]
>Subject: [Elecraft] Antenna considerations (what to do?)
>
>
>
>Hello Elecraft community,
>Well my K2 works flawlessly and it is time now to bother about the
>antenna's before the frost gets into the ground.
>I like to set up a vertical next to my G5RV antenna, and found very nice
>verticals made by Titanex in Germay ( see their site www.titanex.de
><http://www.titanex.de/> ) The antenna I set my eye on is the 8030
>vertical. And now, here comes the big question. Titanex advises to use a
>tuningbox close to the antenna to make it operate at different bands.
>This is a very expensive box, and made for more than 1KW of power..not
>exactly QRP.  My question is, can I feed the 8030 directly with coax and
>use the KAT2 to tune the antenna? If not, why not, and what options do I
>have? I really want to put up a vertical to experiment with, burry
>enough radials etc. Ok gentlemen antenna guru's who makes me
>Happy and gives me an affordable solution to coupling my K2 to the 8030.
>Thanks Dick PA3CW K2#3724
>
>
>
>
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73, Chas,  W1CG
K2 462b, 3571 