In reply to MM0FMF:
In reply to 2E0YYY:
s interesting the choice of antenna. A colinear will produce a more squashed donut radiation pattern than a dipole, thats why it has
gain over one. But the effect of the ground will be to lift the main
lobe so it points upwards somewhat. This is fine for a house mounted
antenna where typically you want a slightly raised angle so you can
see up slightly to repeaters which are mounted in well sighted
positions. But when you are higher than most of your target QSO
partners, an antenna with a 0 or below zero take off angle should give
better coverage. This can be achieved with a pair of vertical elements
if you play about with the phasing of how you drive them.
Interestingly enough Andy, after purchasing the X-300, I decided to embark
upon some experimentation. I drove to Merryton Low, not a million miles from the Winking Man pub just outside of Leek in Staffordshire, a favourite haunt for contesters and a place I
m sure youre familiar with.
I assembled the X-300 alongside my home brew dipole, then listened to numerous qso
s on the 2m band, switching between the collinear and dipole. Now, as you are well aware, Im a big fan of the simple dipole, however, the collinear simply blew it out of the water. The improvement on receive was between two and a staggering six S points. From then on, I was sold on the X-300. From G/SP-004, I can honestly say, with I think maybe one exception, I`ve not failed to work a single call. Last Saturday, when G1STQ turned up to Shining Tor, and I handed him the mike, he was amazed at the antennas performance.
The question would be: why? The omni directional pattern means you
t need to rotate the antenna but its just wasteful compared to a
You`ve more or less answered your own question. Turning a beam back and forth, drives me loopy. The collinear scores highly in that respect.
A 2x 5/8 co-linear array has a gain of about 3dB over a
dipole no matter what the makers may claim. (Some claim gain figures
such that they must have made with Oil of Aphrodite and the dust of
The Grand Wazoo. 6.0dBd indeed for an X300… they claim it
ll cure your asthma too!) A 5 ele yagi will give about 9dBd or 6dB more than the X300. So for a nominal QSO just workable with the X300 and 20W youd be the same strength with 5W and the small beam. The small beam
can be supported on fishing rod resulting in a substantial reduction
in carried weight.
The merits of directional and vertical antennas has been done to death since the beginning of radio. At the end of the day, I guess it
s a matter of personal preference and what you as the Amateur is comfortable with. For me, half the fun of radio has been experimenting and as I said before, Ive done some pretty wacky things, however, I`ve had some very interesting results.
For me, the combination of an X-300 collinear and the FT-857 are worth their weight in Myrrh.
You could drop the battery down from 20Ahr to
something less massive and operate for a long time still at the lower
power just bumping up the power now and then.
While at the Magnum Rally yesterday, I purchased a bag full of home made cakes from the lady who had the table directly behind me AND I`m ashamed to say, I scoffed the lot. The lady asked me If I would like any more? I declined, citing the fact that they were bad for my figure. As quick as a flash, she retorted that I had no problems with my figure whatsoever. I put this down to lugging a 20Ah Slab up and down summits
If you insist on running an omni, then clone the guts of the X300. A
7m fishing rod and a co-linear made out of wire without the casing and
mounting hardware of the X300 would get the same performance for 5% of
the weight and it would all roll up and be a doddle to carry. It would
probably easier to set up too. Guy pole about 1.5m up, connect antenna
to top of pole, unroll antenna as you push up pole, attach feeder,
lock off pole. Plug in, switch on and QSO out to paraphrase a certain
T. Leary Esq.
However, you could do me an invaluable favour. Next time you go out,
do Cyrn-y-Brain instead of Shining Tor. It
s a touch more to walk and climb but nothing major, about 30mins to the top if you slouch up the track. Wander along about 50-100m past the furthest tower and operate with the X300 setup from there. C-y-B has a much better take off from that end than Shining Tor and Id like to map out your QSO results as
I did before. I used to be able to work into the Dutch/German border
area from there on 2m SSB with 10W and a 10ele beam. I think it would
be most enlightening to see if it is such a demonstrably better hill
than Shining Tor.
HA!!! You tempt me with the promises of riches beyond my wildest dreams!
Ok, I`ll be delighted to sort out an activation of Cyrn-y-Brain in the next couple of weeks or so.
In fact, for such an activation, I may even take along the X-510 collinear. For the sake of another Kilo, that should prove really interesting