Topband: Beverage working

Sun Jan 1 13:52:40 PST 2012

Gentleman, 

  Happy New Year. 

I want to take this time to let everyone know that my efforts to install a Beverage have met with success and thank all those who took the time to aid in my efforts. One person in particular John G3PQA spent a large amount of time working with me via email.  His efforts wont soon be forgotten.  Now for what I found. 

In the way of a refresher the antenna I installed is a two wire 490ft long system. I used the canned transformers described by ON4UN but it didnt seem to perform correctly nor did the SWR flatten out. After some measurements I decided that the Receiver end transformers were working and matching fine but that it was the termination transformer that was outta wack.  

With this in mind I constructed a special transformer.  It was the one similar to the one described by ON4UN but had taps on the ground end of the secondary. I connected the ground to the taps in turn until the SWR flattened out.  Why did this happen.. Heck I dont know but I suspect that it had to do with the ground resistance. It could be that my ground was either lower or higher than normal. My money is on higher and at one time I considered adding extra ground rods but unfortunately there are way to many tree roots to bury connecting wires and leaving it on the ground would have been a hazard to the deer.  

Anyhow it works great now.. Tomorrow I will run the second cable out to the receiver end so that I have boths directions for direct comparison and front to back measurements. 

This is what makes this list great. Thanks Tree for your efforts and to those who help with oppinions, technial knowlege and encouragement. 

Again many thanks..   
Jim WA3MEJ 

----- Original Message -----

From: topband-request at contesting.com 
To: topband at contesting.com 
Sent: Tuesday, December 27, 2011 3:01:09 PM 
Subject: Topband Digest, Vol 108, Issue 79 

Send Topband mailing list submissions to 
        topband at contesting.com 

To subscribe or unsubscribe via the World Wide Web, visit 
        http://lists.contesting.com/mailman/listinfo/topband 
or, via email, send a message with subject or body 'help' to 
        topband-request at contesting.com 

You can reach the person managing the list at 
        topband-owner at contesting.com 

When replying, please edit your Subject line so it is more specific 
than "Re: Contents of Topband digest..." 

Today's Topics: 

   1. Re: K2AV 160m Folded Counterpoise Antenna (Charles Moizeau) 
   2. Update Information Sought: "Topband Bad Frequencies" OpAid 
      (Jeff Maass) 

---------------------------------------------------------------------- 

Message: 1 
Date: Tue, 27 Dec 2011 00:31:49 -0500 
From: Charles Moizeau <w2sh at msn.com> 
Subject: Re: Topband: K2AV 160m Folded Counterpoise Antenna 
To: Topband <topband at contesting.com> 
Message-ID: <COL123-W43807CACD137AA7F26C1EA9BAF0 at phx.gbl> 
Content-Type: text/plain; charset="Windows-1252" 

I should like to offer comments on and some alternative 
recommendations for the described construction of the 66-foot long FCP. 

It has already been pointed out that the commercially 
manufactured ?450-Ohm open-wire line? is not suitable for the counterpoise.  That is indeed true.  A yardstick will quickly show that with less 
space for ?windows? than ?panes? that black stuff measures 58 percent 
closed.  Hardly ?open-wire?!  The surge impedance is around 390 Ohms dry 
and less when wet.  ?Nuff said. 

I homebrew my open-wire feedlines, using #14-gauge solid 
copper wire, either enameled, or bare wire that is roughened and then painted 
gray.  Spaced 2?, the surge impedance is 
very close to 500 Ohms.  I use solid 
copper wire, not copper-clad steel. 
First because my feedlines are not under mechanical stress and therefore 
steel?s greater strength is unnecessary. 
Second, and importantly, because one antenna when used on multiple bands will almost 
certainly have standing waves on its feedline, and it has been my experience that, with standing waves present, 
the feedline suffers permeability losses if itsr conductors contain iron or 
steel.  In fact, I have also experienced permeability losses when using steel or steel-cored conductors in matching stubs.  And I would expect similar losses in any impedance transforming device, balun, transformer, etc. 

Please spare me any lectures about skin effect and how the rf just whizzes along without attenuation.  Let me assure you that when an rf conductor, 
albeit with its unquestioned skin effect, is in intimate contact with another substance 
it WILL BE affected.  For example, it 
is perhaps not widely known that the intimate contact between pvc insulation and house wire will 
change the velocity factor of a single conductor (although to a much lesser 
extent than does the insulation of a coaxial cable).  And  just as with a conductor?s 
insulation,"intimate contact? 
certainly prevails between a conductor's surface and its core.   

Therefore, in your FCP use solid copper wire, bare or 
enamel-insulated, not stranded (which has higher losses because over time an outdoor environment 
will change the Ohmic relationship of the individual strands to one another, and thereby may also intensify the inductive effect of the spiraled strands).  By all means avoid copper-clad steel. 

14-gauge wire is perfectly adequate; the extra expense of 12 
gauge is not warranted, nor is the extra weight desirable. 

One does not need spreaders made out of small diameter pvc 
tubing with end caps and weep holes. 
The weight, bulk and expense of such spreaders is not justified.   

I have read, but not verified, that bamboo has a more 
favorable strength-to-weight ratio than steel. 
Regardless, it is wonderful stuff for making open-wire spreaders.  At an Asian food market I bought 200 bamboo 
chopsticks for five dollars.  Snooping 
around I?ve found bamboo skewers in various lengths and diameters for very 
little money.  For 14-gauge wire I use 
bamboo skewers that are about 3/16? diameter. 
I look over the chopsticks or skewers and discard the misfits, about 
10-15 percent of the lot. 

Here?s how I make my spreaders for the 500-ohm feedline 
mentioned above: 

I measure 2.5? lengths. 
At the cut marks I use a compact tubing cutter to scribe a groove all 
the way around the skewer.  I cut with a 
fine tooth hand saw.  Using a divider 
set to 0.25? I make a prick mark at that distance from each end.  I use a naked hacksaw blade to cut a slot to 
a depth of 0.25? in one end of the spreader. 
Placing a piece of cardboard in that slot, and with the spreader in a 
bench vise, I visually align my hacksaw blade at the spreader?s other end with 
the cardboard, and again cut to a depth of 0.25?.  In this way I achieve a spreader with two parallel slits.  At the base of each slit, I use a #50 drill 
bit secured in a pin vise to make a circular hole through the sawn slit.  I then widen only the slit using a couple of 
naked hacksaw blades taped together and/or a small file.  The slit should be just wide enough to 
tightly pass the 14-gauge wire and the hole should grip it tightly when the 
slit ends of the spreader are pinched together. 

Spreaders are baked in a <180 degree oven for 24 hours, 
and while still warm dipped in diluted gray exterior latex paint. 

I stretch the two parallel 14-gauge wire conductors between 
two trees.  For bare wires, I rough up 
their surface by running a piece of coarse sandpaper along them.  The Eastwood Company also sells an acid etch 
that would probably do the same thing. 
I paint the bare wires with the same gray paint used on the 
spreaders.  Then I snap the spreaders on 
to the wires and adjust their spacing, which can be anything between 9 and 15 
inches.  I secure the spreaders using 
50-lb. test Dacron kite line with a constrictor knot at each spreader?s 
tip.  Another technique is hot glue 
applied with a gun and then pinching the spreader tips with spring clamps while 
the glue sets.  After the spreaders have 
been fastened, I paint them thoroughly with gray latex paint. 

If you wish to have the described 4? spacing for the 
160m folded counterpoise, you should start with 4.5? long bamboo skewers. 

73, 

Charles, W2SH 

------------------------------ 

Message: 2 
Date: Tue, 27 Dec 2011 09:07:11 -0500 
From: "Jeff Maass" <jmaass at k8nd.com> 
Subject: Topband: Update Information Sought: "Topband Bad Frequencies" 
        OpAid 
To: "Topband Mailing List" <topband at contesting.com> 
Message-ID: <004201ccc4a0$d51757b0$7f460710$@com> 
Content-Type: text/plain;        charset="us-ascii" 

Topbanders: 

Seeking the collective experiences from you. 

Some years ago, I assembled an OpAid for myself providing guidance in 
selecting operating frequencies on 160 meters. In building it, I asked (on 
this Reflector and others) for input on bad frequencies in various areas of 
the World, and general band usages. Eventually, it was published online.   

It's been revised a few times with input sought again on Reflectors, the 
last time three years ago. It has been suggested to me that it is time to 
update this "Topband Bad Frequencies" OpAid once again. 

You can review the current version at: 

  http://www.k8nd.com/Radio/Planning/CQWW160/TopbandBadFreqs.pdf 

Please look it over, and provide me with corrections/enhancements. The "Bad 
Frequencies" should be those affecting others over a large area, not your 
neighborhood-generated noise. Broadcasts, beacons, birdies, and other band 
noises that make a frequency difficult or impossible to use should be 
included in your report. 

The band allocations notes are broadly general: there are many exceptions, 
and there may have been some changes. Please provide corrections to these if 
something is incorrect that might affect operating decisions on the band. 

And while there is no formal "DX Window" recognized any more, I leave it 
noted as many still respect the 1830-1835 range as a reserve for working 
stations in other continents. 

You may send your corrections/comments to me directly. I may seek 
confirmations here on the Reflectors once I accumulate some changes. 

Thanks! 

73,  Jeff  K8ND 

------------------------------ 

_______________________________________________ 
Topband mailing list 
Topband at contesting.com 
http://lists.contesting.com/mailman/listinfo/topband 

End of Topband Digest, Vol 108, Issue 79 
**************************************** 