ZL special antenna

K1IU at ids.net K1IU at ids.net
Tue Apr 12 14:13:46 EDT 1994

   I've been on internet for 1 week and it's great to see so many
friends on here.
   I plan to put up a ZL special aimed south for 40 and 80 meters
and would like to feed them with coax. Has anyone put up one using
coax and a balun ? My existing antennas 2 ele. yagi at 100' on 40 meters
and the 4 square vertical array on 80 meters are too low angle for
the Carribean and central america. I think ZL specials at 50' would
be just right for the distance.
                                 73, Jeff k1iu at ids.net

>From kiddi at marel.is (Kristinn Andersen)  Tue Apr 12 19:59:13 1994
From: kiddi at marel.is (Kristinn Andersen) (Kristinn Andersen)
Date: Tue, 12 Apr 94 18:59:13 GMT
Subject: Suggestions for QRP rigs/kits?
Message-ID: <9404121859.AA04781 at marel.is>

Summer is on its way (even up here at the 64th latitude north!) and soon it 
will be time for backpacking and field operation.  Can anyone suggest a 
"good" rig, kit or homebrew HF construction costing within, say, $150-200?  
Desirable features (not necessarily a complete wish list):

        Around 5W output
        Stable VFO
        Efficient power usage (RX and TX)
        One-bander/Multiband depending on complexity
        CW-only will probably be just fine
        Reliable design (dependable specs)
        Rugged construction (suited for the glaciers...)
        Overall good performance

I could go ahead and just order a kit from one of the radio outlet places, 
but I'd prefer some real operating evaluations first.  I guess a good source 
of information, in addition to you seasoned contesters, may be some of the 
QRP associations/clubs around, but I don't have any addresses there.  
Anything that
leads to FAST results (say, FAX/phone numbers) would help, in addition to 
your own comments.

Please send responses directly to me:   "kiddi at marel.is"
and I'll summarize the results on the reflector if it looks like worth it.

Thanks - 73 de Kris, TF3KX

>From H. Ward Silver" <hwardsil at seattleu.edu  Tue Apr 12 20:26:59 1994
From: H. Ward Silver" <hwardsil at seattleu.edu (H. Ward Silver)
Date: Tue, 12 Apr 1994 12:26:59 -0700 (PDT)
Subject: Rating System respondees
Message-ID: <Pine.3.07.9404121259.D29273-9100000 at bach>

Thanks to all who wrote and requested the full system.  Remember, it's the
"gears and levers" and not meant to be particularly easy reading, just a
formal description of how the thing is envivionsed to work.  I will
respond to some of your replies after I get back from Visalia where I will
get an earful, no doubt!
73, Ward N0AX

>From Roy Hradilek <73374.2465 at CompuServe.COM>  Tue Apr 12 21:03:14 1994
From: Roy Hradilek <73374.2465 at CompuServe.COM> (Roy Hradilek)
Date: 12 Apr 94 16:03:14 EDT
Subject: Who Needs Front-to-Back?
Message-ID: <940412200314_73374.2465_DHS49-1 at CompuServe.COM>

I agree  with KM9P  that front  to back optimization for yagis is
not necessary. Here in Texas, I have never had a problem with QRM
from the  Pacific while running Europe. Running JA, it is GOOD to
have South Americans answer off the back of  the beam, especially
when I  need zone  12. The  main QRM  problem is  the unruly East
Coast, which is in the same direction as Europe.

I have been setting the F/B priority of YO to zero for some time.
You optimize  only for forward gain and SWR bandwidth. It simpli-
fies things. Any beam with an F/B of better than  30 db  gives up
about a  full db  of forward  gain. Even most of DX Engineering's
optimized product line advertises such a  high F/B.  High forward
gain antennas  operate by squeezing signal out of the side lobes,
not off  the back.  The optimized  beam with  the highest forward
gain will  have the  narrowest BEAM  WIDTH, and an F/B under 20db
(even as low as 10db).

So who needs front to back? I haven't a clue as to  how the bands
sound from  the East Coast in a contest, and can't understand why
anyone up there should worry about  whether somebody  west of the
Mississippi is S9+20 or only S9. They're going to blow us off the
run frequency anyway, right? Such a luxury it must be  to have 1,
2 &  3 Land  in your skip zone! When 10 or 15 are packed wall-to-
wall on an EU opening, all run frequencies are grabbed before the
sun  touches  the  central  time  zone.  Frequencies near you are
aggressively defended  against  western  riffraff  by  other East
Coast buddies  you may  not even  hear. And  then, Europe is loud

So then, does  anybody  need  front  to  back?  Maybe  in Western
Europe, with  so many  dirty QRO signals further east. Perhaps it
is  important  to  ANTENNA  MANUFACTURERS.  Back  before  antenna
modelling, all commercial beams advertised flat SWR, high F/B AND
enormous gain - but we couldn't MEASURE the gain! We all have SWR
meters. We can swing the beam back and forth and get F/B measure-
ments from our S-Meter or friends. We can COUNT the elements, and
the new  antenna sure beat the heck out of the old trap vertical.
We were happy, but without another  beam  to  compare  it  to, we
couldn't tell  if the  antenna had maximum gain. Antenna manufac-
turers were free to  make any  claims they  wanted -  and did. We
were impressed by the NUMBER of elements, a flat SWR, a high F/B,
and a high CLAIMED forward gain. This sold antennas. A lot of the
commercial beams  that come  configured on  YO optimize better if
you REMOVE an element and use the same  boom (eg:  the 205CA). So
then, is Front-to-Back Ratio an important design priority?

                Opposing viewpoints are welcome.

                     de Roy - AD5Q, Houston.

>From Peter G. Smith" <n4zr at netcom.com  Tue Apr 12 21:33:28 1994
From: Peter G. Smith" <n4zr at netcom.com (Peter G. Smith)
Date: Tue, 12 Apr 1994 13:33:28 -0700 (PDT)
Subject: Last call for KH6IJ memories
Message-ID: <Pine.3.85.9404121328.A6957-0100000 at netcom6>

After an initial flurry of activity, the reminiscences about KH6IJ have 
pretty well dried up.  If you would like to add to the collection of 
messages that will be passed on to Katashi Nose's family, please do so 
before the end of this week.  Send them to me and I will see that they 
are appropriately packaged and passed on to them.

73, Pete
n4zr at netcom.com
NOTE: New Address

More information about the CQ-Contest mailing list