Topband: Need antenna advice

[Charlie Young]

Mike, W0BTU said: 


> Am I expecting too much with just 100 watts? I don't think so; I've heard of many hams working DXCC without an amplifier. It was my intention to get a transmitting antenna working well at the 100 watt level, and then building a legal limit amplifier.
> 

 

The primary problem could be that 100w is not enough power to fulfill your expectations. 


Being new to Top Band (Nov 2008), I am a regular reader of this forum but seldom a contributor.  A new QTH along with retirement created the opportunity to start from scratch with ham radio, after several years of inactivity. When starting out on 160, I had no performance expectations. One of my friends, W8TN, had worked DXCC over a couple of seasons on 160 with a simple inverted L and a single elevated radial.  To get on the air, I decided to try a very simple, quickly erected, tree supported L, similar to but not exactly like what Clark W8TN used.  

 

With no antennas for 40 and above, I focused on working 160 meters last season.  My first inv L was installed over a tree, with the vertical portion of about 50' running down the tree trunk and perhaps offset 2 or 3' from it. The horizontal portion was tied off to another tree.  This antenna was 130' long, directly fed with 50 ohm coax and it used two elevated radials which were installed about 6' from the ground, high enough to keep the deer out of them.  The radials were floated; no ground rod was installed at the feed point. I trimmed the 1/4 wave radials to achieve a good match without using an antenna tuner.  My first antenna differed from Clark's in that his only had one radial and used a coax balun at the feedpoint. My antenna had two in-line radials and no balun.  Working alone, it took about 2 hours to install and adjust the first inverted L. 

 

I knew that a balun should have been installed at the feed point and that more radials should have been used. The antenna could have been made longer and a capacitor used to resonate it. However, I just wanted to see how the most simple configuration would work, performance-wise.  No doubt, this antenna left many db on the table, but it does not get any simpler than this, if one has the space. 

 

Running legal limit power, it was quickly obvious that anything which could be heard could be worked, using this simple antenna.  Not only could the DX be worked, but the thing was sometimes competitive in pileups, depending on propagation variations. I was amazed! 

 

A group in WVDXA (West Virginia DX Association) became active about the same time last season on 160 meters. Several folks installed variations of this simple inverted L. W8HC just completed working 160 DXCC a couple of weeks ago with his antenna, starting last season. W8OP put up one for this season and is I think around the 60 or 70 country level already.  KC8UHE, who has only been licensed a handful of years, put up one and is also around the 60 or 70 country level.  Rip, K3XO over in the eastern panhandle, is one of the few not running power to his L. Not sure of Rip's country total, but I heard him working lots of DX.  

 

I have tried to work some DX with 100 watts with this setup.  Given that many of the received signals are just above the noise, the ~10 to 11 db gained by running an amplifier is most of the time the difference in working stations or not.  I am not saying you can't work DX or make DXCC with 100 watts; it has been done many times.  It would just be harder to do and take longer, particularly with compromise transmitting antennas. In your case, with good receive antennas and a quiet location, you will be able to hear far more DX that will be able to hear you with 100w to a simple wire antenna. 

 

I don't have the patience to run 100w on 160, but admire those who do.  My first season on 160 was the best time ever in ham radio for me, but it would have been one of the most frustrating times if I were limited to 100 watts. Maybe picking up a few db by optimizing the transmitting antenna would mitigate somewhat the performance difference between power levels. 

 

With my simple antennas and legal power output, 165 countries and 34 zones have been logged since Nov 3, 2008.  In calendar 2009, 140 countries were logged.  To do this, it was necessary after about 60 days to install some simple receiving antennas (short beverages).  The current station performance remains limited by the receiving capability, even with these simple transmit antennas.   The results from here and for some of my friends using simple inv L antennas are given to encourage others who have not tried 160 to throw up some wire in a tree and give it a shot.  You will be amazed at what can be worked.  Running some power makes it much easier!! 

 

The location also makes a difference.  W0 probably is tougher for a 100w station to be successful than my location would be.  I am about 30 miles from the southern Ohio border, about 170 miles directly south or even a couple of degrees west of Cleveland.  

 

Guess you can tell I am not a QRP kind of guy!! 

 

73 and good luck 

 

Charlie (Chas) N8RR 

 

  


 
 		 	   		  
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