In reply to G1PIE:
Hi Mark,
I use the same antenna for home base too. Mine is is on TK brackets above the roof.
73 Mike
2O0YYY
In reply to GM4TOE:
Hi Barry,
The 2M Angus beacon is always a reasonable signal at my home qth. (Cheltenham). The 432MHz Angus beacon is just on, or slightly below the noise floor under flat conditions. During the Icelandic ash cloud period, the 2m beacon vanished for days, only returning when commercial air flights resumed. I was quite surprised that I was so dependant on aircraft reflections for beacon reception from Scotland.
73,
Frank
In reply to 2E0YYY:
smashing mike,
i live in a ground floor flat, so no antennas on the building.
so we manage.
73,
mark.
In reply to G1PIE:
Hi Mark,
You get out really well from your flat. Always a big signal to me.
I’ve stuck a picture of the X-510 on the bottom of my qrz.com page, taken when I was on G/WB-004 Titterstone Clee last Friday. There was no wind when I put it up, but as you can see from the angle it’s at later in the day, it really should have been guyed.
73 Mike
2E0YYY
In reply to 2E0YYY:
well smashing photos, max power at my side is about 25 watts more often 10.
cheers,
mark.
In reply to 2E0YYY:
Interesting these colinears. I’m thinking of making one for 2m. It might be a coaxial based colinear, swapping the core and shield every electrical 1/2 wave. I could coil this up for transport and then attach the end of it to the top of a PVC pipe that can be carried in pieces and then assembled on site. The base would be 3 metres high on an al pole where I would guy, but the colinear itself is still going to be over 4 metres high from there, so I might need a second guy point further up to secure the PVC pipe.
73 de Wayne VK3WAM
In reply to VK3WAM:
Hi Wayne,
I’ve stripped down one of my collinears and removed all of the fibre glass. There’s a little work to be done, however, it should reduce the weight considerably. Radials are a bit of a pain, though.
I’ve also looked at this design by W7LPN.
73 Mike
2O0YYY
In reply to 2E0YYY:
Do you need the radials as such, Mike? Could they be replaced with one downward pointing element as a counterpoise? Just a thought…
73
Brian GO8ADD
In reply to G8ADD:
In reply to 2E0YYY:
Do you need the radials as such, Mike? Could they be replaced with one
downward pointing element as a counterpoise? Just a thought…
Hi Brian,
I did once operate for about an hour from G/WB-003 using the X-300 Collinear without any radials. To be honest, I’d forgot to put them on!
Had no problem making contacts though. Stiperstones is not one of my favorite hills. The first time I activated it, I nearly got blown off the top.
73 Mike
20OYYY
In reply to G8ADD:
Do you need the radials as such, Mike? Could they be replaced with one
downward pointing element as a counterpoise? Just a thought…
Some of the designs that I have seen recommend the counterpoise to lower the SWR for collinears with fewer elements. For the one I am planning for 2m, I intend on having 4 1/2 wave elements, plus the elements at the bottom and the top. The whole thing will be a little over 4 metres long - plus mounted at 3 meters. Should look impressive. This also might mean I can get away without the counterpoise, but I also plan on integrating an ugly balun suitable for 2m as part of it.
73 de Wayne VK3WAM
In reply to G8ADD:
I thought the radials on these commercial VHF colinears were more to act as an isolator between the feedline and the aerial. They’re not 1/4l on the 2m antennas I’ve seen. They’re cheap to make hence their use. Some form of choke to stop currents on the coax outer is needed instead. That’s why the W7LPN design has ferrite rings or a choke balun shown.
Andy
MM0FMF
In reply to 2E0YYY:
I think that you can buy radial free colinears now! However they seem rather expensive!
For SOTA purposes I think for vertical omnidirectional polarity I will stick with my less than 5 pounds Home brew 450 Ohm ladder feed Slim Jim! I have used one for 4m FM loads and have only had to service it once! It coils up and goes very neatly into my rucksack, weighs less than 1/2 a kilo! My 2m ones gets a run out, however it is heavier due to the greater amount of coax compared to the 4m variant!
Still Mike gets excellent results, he says colinear, I say beam! At the end of the day it is a matter of personal opinion and of course what you are willing to lug/spend!
My two pence
Matt G8XYJ
In reply to G8XYJ:
At
the end of the day it is a matter of personal opinion and of course
what you are willing to lug/spend!
Absolutely Matt!
I’m following this with fascination - I like to take the light weight approach, and couldn’t bring myself to squirt the RF in all directions at once - what a waste! I’d far sooner turn a beam as often as needed. For practical beams used for SOTA, you don’t need to point it in many directions anyway to work your way round the chasers since the beam width is not that tight. But it’s tight enough to squirt the RF power in roughly the direction you want!
A 5-ele DK7ZB has a -3dB beamwidth of around 45-50 degrees, i.e. a gain of about 9dB over squirting the stuff in all directions. That’s worth a lot of battery weight to me!
73
John GM8OTI
At
the end of the day it is a matter of personal opinion and of
course
what you are willing to lug/spend!
Yes indeed, pretty much as Richard G3CWI commented further up the thread.
The other factor is transmit power. If your intention is to work as many chasers as possible, then whatever antenna you use, optimum results will be achieved if you are using the same transmit power as the chaser (assuming current receivers to be much of a muchness). I would suggest that most home based chasers use more than 5 watts.
This may not be obvious, as it is generally the activator who calls CQ, and by definition, only those who can hear him / her will respond.
If chasers often called CQ, then activators with 5 Watts might often find themselves unable to work a weak calling station.
I am only a dabbler compared to many of you, but in my few activations I have used what is to hand, eg an FT290 plus amplifier producing 20 Watts. That is around 6dB, or one S point ish over a 5 Watt handy.
I have received quite a few comments along the lines of “I don’t normally hear activations from that summit from home”
Mike takes this to the extreme, by using a high gain verical antenna, and relatively high power as necessary, and he gets great results.
It really does all boil down to what you are trying to achieve. My current aim is to have an enjoyable walk, and work at least 4 stations from the summit!
I’ll put my tuppence in the post :o)
Adrian
In reply to GM8OTI:
A 5-ele DK7ZB has a -3dB beamwidth of around 45-50 degrees, i.e. a
gain of about 9dB over squirting the stuff in all directions. That’s
worth a lot of battery weight to me!
Hi John,
Speaking as someone who has had a foot in both the vertical and beam camps, I wouldn’t go back to a beam… Just too much hassle.
Squirt RF 360° from a high gain collinear from a summit in the middle of England and you’ll be rewarded with a shed load of contacts. There is no way you will achieve the same results with a beam. Granted, the beam will find better dx, however, for sheer numbers of contacts, a collinear such as the 2 x 5/8 or 3 x 5/8 will beat it hands down.
On a number of occasions, I’ve also been lucky enough to work from a SOTA summit during tropospheric ducting with a collinear. Then the collinear performs just like a beam, only difference, it’s doing it 360°. Now you will work a serious pile-up embellished with plenty of dx.
73 Mike
2O0YYY
In reply to 2E0YYY:
What’s your view on the 5/8 wave element approach vs the 1/2 wave element approach. Could a colinear with 3 5/8 elements be better than one with 4 1/2 wave elements?
73 de Wayne VK3WAM
In reply to 2E0YYY:
Squirt RF 360° from a high gain collinear from a summit in the middle
of England
Yup - that’s a major difference - you’re surrounded by lots of folk!
Squirt the limited amount of RF power I have out in all directions from my usual haunts and very few people will receive it. I need to get the distance as well.
73
John GM8OTI
In reply to G8ADD:
In reply to G0ELJ:
A downside to a high gain vertical is that its main lobe in vertical
cross-section is compressed close to the horizon, which means that the
mast must be vertical. If you haven’t made sure that it is vertical or
if the wind slants it then there will be segments of the horizon where
the gain is reduced.
Solution I’ve had for this predicament is that (in low winds) I can let the antenna hang freely from the top of my 9m mast, and regardless of what angle the chosen mounting tree is pitched at, the radiators will be nice and vertical.
It’s also much easier to get a vertical antenna up (and down! more difficult!) through a canopy of foliage (varies by summit).
Model? Easy as cake: M0GIA’s design. You can see it here where I used it for the first time:
I have since changed the phasing elements from the wind catchers you see in the photos to coils around plastic coffee cups (nest in each other for xport). Have used it in high winter winds with much success (and me out of the wind) and those cups slide right down the pole to keep it from flailing. I’ve got pics but haven’t posted them yet. There’s a matching section, j-pole style, so no radials.
Total cost (excluding jackite pole) less than ten clams.
HL1WOU Has been working on a j-pole-less version, using a small matching box (coil/capacitor) at the feed point and ultra tight phasing coils. Thus far I haven’t been pleased with the performance. 
The only real inconvenience is dragging the support around, it collapses to only 46". Power handling depends on how large a gauge wire you use, and I swap between 50 and 5 watts, so it’s a tad bit heavier to accommodate.
In the end, I’m sold on the collinnear.
73 de HL4ZFA
Jason.
In reply to HL4ZFA:
Well, what can I say!
I went with Mike to Bardon hill on Wednesday and from the start it was clear there were normal conditions (no lift on).
But his colinear DID produce some better than expected results on 2m fm! I know the hill well and understand the kind of results to normally expect, and that day it was substantially better.
Would I cart that thing up the Cheviot? Well no, but it does make an interesting case.
All the best,
Rob
In reply to 2E0YYY:
nice to get you on NW-076 yesterday mike, from onother 3x5/8 hi, plus i was on the moonraker ht90e handheld led on the bed.
but it was plugged into the x510n with a long ext lead from the shack,
many thanks mike for points.
73,
mark.