Hi Ron...
I am facing the same dilemma myself for stacking a 150' tower.....And I have
to make a decision in the next few weeks...I am also agonizing between the
C3/4 and KT34XA...
First, I think that radiation efficiency is a subject which has been
overlooked in beams/yagis... I suspect the radiation efficiency of the small,
untrapped C3 overcomes the enhanced 'gain' of the TH7...
The KT34 is a more efficient trapped beam, and therefore better, than the
TH7...
The C3 has a broader main beamwidth (less gain) than the KT34XA... A stack of
either will do you just fine... Now, the devil is in the details, as they
say...
A) In contests where the desired sigs may come from many headings in a
general direction, you probably will do best with a stack of C3's... Due to
the nice fat pattern.... Gain is of secondary importance, i.e. you need just
enough gain to be able to hear the desired signals, but ANY increase in gain
beyond that merely results in a narrowing of the main lobe (undesireable)...
Also, a lower FB ratio may be helpful to snag that occasional multiplier off
the back side...
(FB ratio will be low in any stack, however, so that we need not concern
ourselves with this item...It will be what it will be...)
B) In contests where the desired signals are from a definite direction, such
as where you are working just U.S. stations, or just Zed El's, etc. then more
gain in the stack, i.e. a narrower main lobe is highly desireable... Here a
stack of longer, higher gain antennas is called for... For this the KT34XA
will be preferred over the C3...
C) For working general DX, i.e. non contest situations, a stack of 6 element
monobanders is exactly what you need...
D) In all of these scenarios, the TH7 is an also ran....
And, that's my opinion....
Rational discussion entertained ( I do a mean soft shoe )
Flames go to the curb with the kitty litter.....
Denny K8DO@AOL.COM
>From ke7gh@primenet.com (Brian Short) Sat Jul 29 19:42:03 1995
From: ke7gh@primenet.com (Brian Short) (Brian Short)
Subject: 2-Radio Band Port
Message-ID: <199507291842.LAA01275@mailhost.primenet.com>
I have wired both of my radios for use with the Top Ten Decoders as well
as the FL-7000 amplifier. This was done as an alternative to using the
LPT band info available from various programs (for several reasons):
1. CT supports only LPT1 output, making 2-radio SOP difficult.
2. Unable to utilize filters outside of contests in casual operation.
3. RTTY by WF1B contest software does not support LPT band data.
Any comments?
FT-990 8-PIN DIN TOP TEN DB-25M FL-7000 MOLEX
--------------------------- -------------- -------------
1 +13v WHITE WHITE
2 TX GND GREY GREY
3 GND ORANGE 25 SHIELD ORANGE
4 BAND A BLUE 2 BROWN BLUE
5 BAND B GREEN 7 ORANGE GREEN
6 BAND C YELLOW 8 YELLOW YELLOW
7 BAND D RED 9 RED RED
8 LINEAR BLACK BLACK
SHELL BROWN BROWN
FT-890 8-PIN MINI-DIN TOP TEN DB-25M FL-7000 MOLEX
--------------------------- -------------- -------------
1 +13v WHITE WHITE
2 TX GND GREY GREY
3 GND BROWN 25 SHIELD BROWN
4 BAND A BLUE 2 BROWN BLUE
5 BAND B GREEN 7 ORANGE GREEN
6 BAND C YELLOW 8 YELLOW YELLOW
7 BAND D RED 9 RED RED
8 LINEAR BLACK BLACK
73 de Brian
>From David & Barbara Leeson <0005543629@mcimail.com> Sat Jul 29 20:27:00 1995
From: David & Barbara Leeson <0005543629@mcimail.com> (David & Barbara Leeson)
Subject: stacking tribanders
Message-ID: <05950729192750/0005543629NA4EM@MCIMAIL.COM>
The discussion of stacking tribanders has some interesting aspects. For
starters, note that one of the best and most competitive stations in the
world, EA8EA (OH2MM, et al) uses stacked TH6/7's, so don't write anything
off. However, the problem for a station in an area with (a) lot's of
competition and (b) non-rare mult. is that your signal must stand out from
the crowd.
My own personal theory, for what it's worth, is that you lose directivity in
a loaded antenna because the pattern is broader for a shorter element, even
if lossless. It has been pointed out that if traps were really the entire
source of lowered gain, they would be hot to the touch.
The ideal would be to illuminate the entire azimuth of an intended target,
say all of Europe. This would probably dictate different beamwidths from
different distances. Since you can correlate beamwidth with antenna gain,
you could decide whether it is worthwhile to have more gain than the
simplest log periodic or tribander. For reference, my 12-el Hy-Gain LP
seems to have the 7.25 dBi gain they say it has (confirmed also with MN/AO).
By comparison, the C3 calculates out to 6.6-6.7 dBi, but has a more convenient
size because it is all active.
My experience with the KT-34XA was that it didn't have any staying power. The
reliability in my location was so bad that I traded it for some other antennas.
I also have a TH7, which has had some trap and joint problems, but has been
pretty reliable for a 20+ year old antenna (made from an old TH6).
If you use a 204BA as a standard of comparison (smallish end of the monobander
range, but works good), you would be seeing another dB over the LP and maybe
1.5 dB over the C3/TH7 (you can count on 8.25 dBi from the stock 204BA).
In everyone's experience, this seems to make a much bigger difference than
you would expect, although the reasons aren't at all clear but might be due
to ionospheric fading statistics (% of time you stand out of the crowd).
The gain difference in any antenna setup can be washed away in a minute by
using bad coax. If you are serious about antenna gain, you should be using
some form of hardline, even if only surplus CATV stuff. The same is true
of amps that don't really put out 1500 watts.
So what's the bottom line? For a US station, I believe there's reason to
try for as much gain as you can get, since the azimuthal beamwidth is going
to be wider than the target area at any DX-type distance. It is questionable
whether the KT34 is reliable enough to count on, even though it seems to
have a lot of gain. i wouldn't count out the standard of comparison (TH7)
or the longer LP's (Hy-Gain 1009). It seems that the ultimate tribander
still isn't on the market, as it should be possible to come close to the
performance of three monobanders. It is certainly the case that a close
stack of monobanders probably gives up so much that a tribander may be a
better choice. (BTW, the LP is spectacularly insensitive to adjacent
antennas, even showing SWR while only a few feet above the ground).
I'm working slowly on interleaved 40-20's and 15-10's, working for full
bandwidth, control over F/B and full gain. I'm probably halfway there.
It seems to me that the ideal tribander would be 0.4 wavelength on 20m,
and would have full-size elements and full bandwidth, with nothing given
away on 15 and 10. I'm also working on putting high-band directors on the
lower band antennas in a stack, to undo the pattern distortion you get
otherwise. I've got some good designs for 2-band antennas with LP driven
cells that make me think that the TH11 might be an interesting choice. It
would be interesting to see if things could be improved by elimating the
WARC band pieces. OE6MBG is running stacked TH11's, and getting great
result
I guess the main thing is not to believe in magic, but stick with what
works. Hope this ramble is helpful. Expect to change whatever you put
up as new antennas come on the market, and don't cut corners with coax.
73 de Dave, W6QHS
>From Richard Hallman KI3V/7 <ki3v@connectus.com> Sat Jul 29 23:05:27 1995
From: Richard Hallman KI3V/7 <ki3v@connectus.com> (Richard Hallman KI3V/7)
Subject: stacking tribanders
Message-ID: <Pine.SUN.3.91.950729150137.2005A-100000@africa.connectus.com>
I am running a stack of TH7's (102 & 55 ft). I have yet to find
a time that the stack isnt better than the lower or the upper. It is VERY
nice during contests to be able to swing the upper to VY/VE8 and have the
lower at the east coast. This has paid off in the last 2 SS Contests
for me.
The current stack will never change as far as im concerned...Works too
well!! Im sure once I play with it, Ill lose it!! ha
See ya! Rich KI3V Reno, NV
*****************************************************************
Richard Hallman Internet: ki3v@connectus.com
11870 Heartpine St IP Address:
Reno Nevada 89506 Amateur Radio: KI3V
*****************************************************************
>From Fred Hopengarten" <k1vr@k1vr.jjm.com Sat Jul 29 02:41:45 1995
From: Fred Hopengarten" <k1vr@k1vr.jjm.com (Fred Hopengarten)
Subject: Contests and Vanities
Message-ID: <301991dd.k1vr@k1vr.jjm.com>
On Fri, 28 Jul 1995 19:36:05 -0500 (CDT), "Larry Crim"
<wz4f@iquest.com> wrote:
> Any thinking on what is the most effective call-sign(s)
for contesting?
K1VR: I received K1VR in 1975. (I was W1NJL from 1956-
1975. Try it quickly on phone and everyone comes back to
W1HIL.) I liked the sense of being an old timer with my W
call, but K goes more quickly on phone. WB2OEU, you may
know him as K2TR, used to do "W" exercises before operating
20 meter phone from W2PV, as a good "W" is hard to say
quickly.
So I prefer K1 on phone to W1, and even if you must add a
phonetic, "kilo" goes more quickly than "whisky."
Victor works well with Europeans, as it is readily
recognized by English, French, German and Russian speaking
hams. I swear, however, that I must say "Victoria" if
Japanese speaking hams are to understand. I don't know why,
but I have had the frequent experience of Japanese hams
coming back to me with K1 Echo Radio, unless I say
"Victoria."
Radio works well, but when the DX comes back to "Radio??",
you get K1AR, N3RR, N4AR, WZ1R, W1RR, K2TR, and more. And
those guys are all LOUD.
On CW, I think the general wisdom is that dashes get more
power out of your amplifier. At least that's the reason
that K1GQ gave me for selecting his call (and remember, he
WON several contests with that call, as well as its
predecessor -- are you old enough to remember KH6GPQ?).
Then again, K1GQ may have been prejudiced against dots after
his youth as K2SIL. All of those favoritism of dashes
explains, of course, why K1EA does so well on CW. ;-)
--
Fred Hopengarten K1VR
Six Willarch Road * Lincoln, MA 01773-5105
home + office telephone: 617/259-0088 (FAX on demand)
internet: k1vr@k1vr.jjm.com
"Big antennas, high in the sky,
are better than small ones, low."
>From jreid@aloha.net (Jim Reid) Sun Jul 30 00:50:57 1995
From: jreid@aloha.net (Jim Reid) (Jim Reid)
Subject: Turn it off vs. Leave it on?
Message-ID: <199507292348.NAA18938@hookomo.aloha.net>
OK, what's the truth? Just had a visit out here from
a Hewlett-Packard engineer friend of ours. He seemed
concerned when he saw me shut off the rig and computer
after showing him some of the "toys" here in the shack.
Per him, at hp they NEVER trun off the PC's nor the lab
test equipment. He explained that the life of such things
is estimated by the US Gov and others on the basis of
the numer of turn-on/turn-off cycles; also that most of
it only has a life expectancy of 5 or so years anyway!
He felt strongly I ought never turn any of this stuff off.
I asked about the hard drive spinning all the time in
the computer. He said never mind, the bearings are
designed to last the expected life of the machine
anyway! Well what about the power consumed (my
computer rig is so called "green compliant", it sort
of shuts down if nothing is used for 15 min or so;
however the hard drive keeps on spinning tho
the monitor has gone dark and does take a few
seconds to come to life if the mouse is moved,
for example to wake the machine. Again, he claimed
the in-rush of current at turn-on was causing much more
harm to the components via thermal shock, that
the cost would be higher in earlier maintenace/replacement
cost, than the cost of current used were all the stuff just left
on anyway, all the time.
I know in the old days, DX'ers always left the rigs on, kept the
temperature constant, and the VFO's were, therefore, kept
more stable. But that is not supposed to be a problem with
our new solid-state, synthesized VFO's., etc.
So what do you do, leave them on or turn everything off?
Which way will all this expensive stuff have the longest
life?
Aloha and 73,
Jim, AH6NB
jreid@aloha.net
>From Mike Cizek <mcizek@CapAccess.org> Sun Jul 30 01:50:17 1995
From: Mike Cizek <mcizek@CapAccess.org> (Mike Cizek)
Subject: stacking tribanders
Message-ID: <Pine.SUN.3.91-FP.950729204211.17813A-100000@cap1.capaccess.org>
On Sat, 29 Jul 1995, David & Barbara Leeson wrote:
......<snip>..........
>
> The ideal would be to illuminate the entire azimuth of an intended target,
> say all of Europe. This would probably dictate different beamwidths from
> different distances. Since you can correlate beamwidth with antenna gain,
> you could decide whether it is worthwhile to have more gain than the
> simplest log periodic or tribander. For reference, my 12-el Hy-Gain LP
.....
W3LPL spoke about this at Dayton a few years ago. He designed his
antennas by calculating both the elevation & azimuth ranges he wanted to
illuminate, then used a formula to calculate the maximum possible gain
that could be obtained by illuminating just that area, and designed his
antennas for that amount of gain (and beamwidth). You may still be able
to get a transcript of his talk from K3LR. I think it was 93 or 94.
Mike Cizek KO7V
>From James White <0006492564@mcimail.com> Sun Jul 30 04:10:00 1995
From: James White <0006492564@mcimail.com> (James White)
Subject: Contests and Vanities
Message-ID: <00950730031000/0006492564PK1EM@MCIMAIL.COM>
.............don't, not for an instant, think of getting a callsign in a
district out of your station's physical call area! DON'T (you'll be sorry)
...that is unless you do NOT operate domestic contests....
........I have lived here in Florida since the end of the seventies. I have
suffered for over a sunspot cycle with numerous requests for repeat of my
state/section...chat's with AC1O have verified I am not the only Floridian
who has experienced this fate. I suspect other call area challenged
contesters are out there (shouldn't we get the first dibs on calls from our
own district?)
....In a contest there is without doubt an indisputable anticipation of
exchange to be received based on the call area of the station being worked,
since I hold a K1 callsign something along the lines of CT or VT or EMa is
expected as my section - it is not SFLa....
............Every Sweepstakes I am reminded of this - last year was my best
SS ever and even though I made a LOT of QSOs, and apparently was doing
something right, there had to be at least 30 or 40 requests for me to repeat
my section. I even have a keyer in paralell with the computer's key line
that has a dedicated memory programmed with my section - that's how often it
happens! Had I traded in my call for a fourth call area call when I moved
here, the new call would have been a 2 x 2...so I have have "suffered" with
this one.
...............If I only worked the CQWW contest where I am a zone 5 even
though I am portable four, then, I might keep this callsign.....I operate
too many other events though and I am willing to part with this call - with
two sunspot cycles worth of break in time - now that it looks like I can get
a "4 call"
.........The dits vs daws and what works best can be answered by personal
experience and now that we have computers - by roadtests of the callsigns
you may wanna have. Try NA in practice mode, or PED using an anticipated
choice for your 610V, try it you'll like it - or know you won't wanna sign
it 10s of thousands of times a year.
...."Phone-wise" the positive effect of "universality" of phonetics has been
pointed out by K1VR - letters with only one phonetic are the best (as in
X-Ray :-)).....there is a new tool for you to see what is useful codewise,
it has been talked about much on this reflector in the past week....it is
RUFZ - WC4E downloaded a copy for me and I found what I already knew from
past experience - when you go fast some letters are always really hard to
distinguish.
...............The enemies include: s and h, b and d (not the kinky, the
code characters!). Seeing where copying errors occur tells me what letters I
don't want in my call-I wan't my call copied right the first time, always
everytime forever! And as 'VR and others will bring up that thud in the
headphones that a dash with its surge of RF is very compelling....as N2AA
says "loud is good".
Finally, after homing in on your choice you of course delete anything that
is the same suffix as another active contester's............why should you
have to fight him - be a unique! Or is that a bad thing?
When the possible availability of vanity calls raised its head I did a quick
sort of the open calls, tried them with K8CC's NA in practice mode, and
within an hour came up with a wish list.
On a related note, at a local hamfest today there was an FCC representative
whom I questioned as to just when we might see the 610Vs - his repsonse was
rather terse and ran something like whenever "they" can make up "their"
minds on what they want and who should get them when...he was referring to
the objections the gate 2 raised by ARRL and others. Recently when N1EE
requested a 610V he was told by the FCC to: "reorder no earlier than
10/31/95." I'd guess you will have plenty of time to pick your favorite 25
calls.
Happy Hunting
Jim K1ZX (probably 'til next year)
k1zx@mcimail.com
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