With some recent serious study lately for FD planning, including an HFTA
study based on the actual site used (yeah a serious contester took the
time), you may also discover that 'common' thinking isn't always correct
about dipoles over dirt.
Based on that review, with as little as 1/4 wavelength above dirt, good
things start to happen beyond NVIS (straight up) activity, the takeoff
angle falls. At ~3/8 wave, the radiation angle of a dipole comes down
remarkably, almost to the magic 2 deg level (best chance of DX or longer
openings). At about a half wave up, the advantage is less for the extra
height (less return on the 'investment'), improvements came slower per
altitude change. The same can be said of beams but with the added gain
(Yagi, enhanced dipoles). At another point, the advantages start to
reverse too. It was an interesting study.
If you can get the height and afford the line losses in QRP, great. But
if you can't, get the dipole at least 3/8 wavelengths above dirt.
You might consider the JT modes. While extremely s_l__o___w they do
very well with minimal received signals (note I didn't say low transmit
power). I just can't bear the 15 Q/hour maximum rate (5 minutes to
complete one exchange). ;-)
73,
Rick nhc
On 6/21/2016 12:38 PM, Vic Rosenthal wrote:
A dipole-type antenna should be at least 1/2 wavelength high for decent DX
performance and preferably a full wavelength. An inverted V is not as good as a
dipole. And the high bands are poor now in the summer and as the sunspot cycle
declines. So that's one strike against you. You are running low power. Strike
two. And you are trying to use SSB. You're out.
If you don't like CW, I would suggest PSK, which seems to get out well with low
power. If you really want voice and DX then you should consider both raising
your antenna and increasing power.
Vic 4X6GP
On 21 Jun 2016, at 21:31, Eballina <[email protected]> wrote:
I am feeding it with about 80 ft of coax. Barry I would never dream of asking for the
"secret recipe"!😜
Sent from my iPhone
On Jun 21, 2016, at 2:28 PM, Barry LaZar <[email protected]> wrote:
SSB at QRP levels can be a bit challenging. I do have a KXPA100 and use it.
However, I only run QRP seriously for Field Day with a group who are doing the
same with KX3s. We do very well at 5 Watts, but we do have a few acres of
antennas. I have found two things that make a very big difference, antenna
height and minimizing antenna system loses.
You say you are running a fan dipole. You don't say what you are feeding it
with or how long your feed line is. I have a dipole up 40 feet and feed it with
open wire to a good 4:1 current balun where I transition to LMR-400 to come
into the house. You may not need a 4:1 balun for a fan dipole, but a good 1:1
balun. And, this is only needed if you have a fairly long run or want to
extract the very last milliwatt out of your system. I would tell you what we do
for Field Day, the extremes we take, but that would give away our competitive
secret. ;-)
73,
Barry
K3NDM
------ Original Message ------
From: "Eballina" <[email protected]>
To: "Barry LaZar" <[email protected]>
Cc: [email protected]
Sent: 6/21/2016 2:12:55 PM
Subject: Re: [Elecraft] KXPA100- How impactful to making contacts?
Thanks Barry, up about 30 feetr al top of
of inverted V. Ends of antenna up about 25 ft. SSB phone preferred but did
pick up PSK31 Signalink but prefer voice.
Sent from my iPhone
On Jun 21, 2016, at 1:54 PM, Barry LaZar <[email protected]> wrote:
You don't say how high your antenna is or what modes you are using. However, If
you aren't already there, I would get my antenna up at least about 35 feet, 60
feet would surely be better. At QRP power levels, I would focus on CW or PSK31,
or one of the other weak signal modes. The exception is 10 or 15 meters where
anything that can be radiated seems to work. The problem is 10 and 15 aren't
open all the time meaning you are going to need to do a lot of listening on
these bands if you want to be successful. There is a trick you might want to
employ, using the beacons that are there and knowing their schedule. Just leave
your receiver on on one of them, and when you hear it, you know the band is
open to that part of the world.
73,
Barry
K3NDM
------ Original Message ------
From: "Road Runner" <[email protected]>
To: [email protected]
Sent: 6/21/2016 1:08:06 PM
Subject: [Elecraft] KXPA100- How impactful to making contacts?
Have had my KX3 for a couple of weeks and love it. Biggest issue I have is even
at 15 watts, unless conditions are right, I am having issues making DX
contacts. The KX3 is connected to an Alpha Delta 80-6 meter fan dipole. I have
been thinking about getting the KXPA 100 but wonder whether it will be enough
of a bang for the buck. I use this at a summer cottage, at home I started with
a Kenwood Ts-590SG and eventually upgraded the rig with an Ameritron 811H to
get more punch. I have no problems getting picked out of pileup so now...
So my question is for those of you that have gone the upgrade path to
KXPA100... Did you get enough punch or are you wishing you had gone with more
power? I am not really too crazy about going all the way to the KPA500...
Sent from my iPad
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