Yes. That does make sense.. Depending on where I am setting up and how
ambitious I am I typically run my 50 MHz beam at approx 24 to 32 feet above
ground level while roving / operating portable. I'd like to go higher (often
to help clear near by trees) but 32 feet seems to be the practical limit for me
and often I don't go that high.
I'm also starting to think that using a free standing tripod (usually with
guys) away from the truck (vs my trailer hitch mount, or a tripod in the truck
bead) works a bit better but don't really have any actual data to support that
belief. I usually position the truck behind the beams. Most of my
operations involve beaming in one direction (from BC into the PNW) so I don't
need to move the beams much. At 50 MHz I'm not overly worried about feed line
losses.
I'd be curious to hear more thoughts from others.
73
Mark S
VE7AFZ
mark@alignedsolutions.com
604 762 4099
> On Feb 16, 2018, at 9:53 AM, David Olean <K1WHS@metrocast.net> wrote:
>
> More data....
>
> We ran a similar test using a rover station 4 element 50 MHz yagi at 12-14 ft
> vs a halo at 35 ft. This was a real test and not a quick exchange during a
> contest. The path was about 280 miles long and the halo was a definite winner
> over the low yagi for the rover station. A home station was on the other end
> of the path. The rover was W2GE/r with N2CEI and WB2ONA at the Packrat
> contest location in the Poconos in FN21. I was operating the home station in
> FN43 in Maine. Height above ground makes all the difference on 50 MHz.
>
> Dave K1WHS
>
>
>> On 2/16/2018 5:07 PM, Bill Olson wrote:
>> Hi all, This might be a good time to bring up "height above average terrain"
>> for a 6 meter beam. I'll digress here a little then will get back to the
>> point. I used to rove with the lower 6 bands. Antennas were all mounted on a
>> rotor fixed to roof racks on my truck. There were ~ 8 ft yagis and loop
>> Yagis on 2 thru 1296 BUT on 6 meters I had an old 4 element Yagi on a 12
>> foot boom. This got mounted right above the rotor so was maybe 7 feet off
>> the ground. (Yeah the ~9-10ft long 6M elements hung over the sides of the
>> vehicle a little - never was a problem with law enforcement hi). Everything
>> worked great except 6M. It had reasonable SWR and I knew the Yagi worked
>> because I had used it on the tower.. but signals were weak except when the
>> band opened for e-skip.. Well that should have tipped me off right there but
>> It wasn't until I had a talk with Pete, K9PW, who used to operate with the
>> AA9D multi-multi VHF contest station in central Illinois. They had done some
>> experiments wi
th
>> their rovers and found that just a HALO antenna at 25 feet WAY out
>> performed a multi-element Yagi at 10 feet.. Well duh, of course the Yagi's
>> pattern in the vertical plane got more and more elevated off the horizon the
>> closer it got to the ground and at 10 feet there was practically no response
>> on the horizon. I haven't done any of the math BUT just experimenting with
>> it, I arrived at about 20 feet for my rover 6M antenna. I built a 2 element
>> beam on a four foot boom. This could easily ride on the roof racks with the
>> elements pointing fore and aft. I put together a 20 foot mast and that got
>> stowed up there too.. So, yeah, no operating 6m while in motion, but with a
>> trailer hitch sort of mount for the mast, it really only took a couple
>> minutes to get the 6M beam in place.. Armstrong rotated for me, but here in
>> Maine pretty much everyone is in the same direction and with abroad pattern
>> it was pretty much set it and forget it.. The results were quite amazing and
>> all of a su
dde
>> n I worked stations on tropo at several hundred miles..
>>
>>
>> To get back to the back-packer antennas, folding up the antenna and making
>> it "packable" is one thing but then you need a 20 foot mast too and a way to
>> keep it up in those high mountaintop winds!! The gain of the antenna is not
>> doing you any good if it's peak is above the horizon and there is a null AT
>> the horizon!
>>
>>
>> just saying..
>>
>>
>> bill, k1DY in Maine
>>
>>
>> ________________________________
>> From: VHFcontesting <vhfcontesting-bounces@contesting.com> on behalf of Mark
>> Spencer <mark@alignedsolutions.com>
>> Sent: Thursday, February 15, 2018 4:22 PM
>> To: Bob K0NR - email list
>> Cc: vhfcontesting@contesting.com
>> Subject: Re: [VHFcontesting] Portable 50 MHz beam antennas
>>
>> Thanks All. I got some great on and off list responses.
>>
>> Yes I believe the 40" length limit is a reasonable one. (I have found
>> carrying 48" mast sections via backpack to be a bit awkward for me.)
>>
>> 73
>>
>> Mark S
>> VE7AFZ
>>
>> Aligned Solutions Co.
>> mark@alignedsolutions.com
>> 604 762 4099
>>
>>> On Feb 15, 2018, at 7:17 AM, Bob K0NR - email list <list@k0nr.com> wrote:
>>>
>>> Zack,
>>>
>>> I'd be interested in the 144 MHz yagi design for backpack portable
>>> operating.
>>> Its got to be compact and easy to assemble, otherwise it tends to get left
>>> at home.
>>> For me, compact is nothing longer than 40 inches.
>>> (I'm actually thinking SOTA more than VHF contesting but I sometimes
>>> combine the two.)
>>>
>>> 73, Bob K0NR
>>>
>>>> On 15-Feb-18 7:57 AM, Zack Widup wrote:
>>>> I got a design from VE3BFM for a four-element 6m beam on a 13 foot boom.
>>>> It's a great performer. Since I operate portable 95% of the time, I built a
>>>> version I could quickly assemble and disassemble at a portable site. The
>>>> boom and each element is in two pieces. I never formally wrote up an
>>>> article about how to build it, but I did talk about it at the VHF forum at
>>>> Dayton a couple years ago. Maybe I should write it up.
>>>>
>>>> I have similar portable Yagis for 144 through 432 MHz. I can assemble and
>>>> disassemble them pretty quickly. My 144 MHz Yagi has six elements
>>>> wide-spaced on a 12 foot boom. I believe the gain predicted by Yagi
>>>> Optimizer is about 12 dBd. I haven't measured it yet.
>>>>
>>>> 73, Zack W9SZ
>>>>
>>>>
>>>>> On Thu, Feb 15, 2018 at 8:23 AM, jon jones <n0jk@hotmail.com> wrote:
>>>>>
>>>>> Mark:
>>>>>
>>>>>
>>>>> Another idea is to build your own portable 6 meter beam. I have found a 2
>>>>> element yagi is easy to build, break down and re-assemble quickly. A 2
>>>>> element yagi offers about 3 - 4 dB gain over a dipole. It is easier to put
>>>>> up and take down than a 3 el.
>>>>>
>>>>>
>>>>> I use one for my VHF contest and portable operations. A picture of it is
>>>>> in the NCJ March/April 2016 pp. 32. It works... have WAC with it on 6 with
>>>>> 100 W from KS on ssb/cw.
>>>>>
>>>>>
>>>>> A plan for one is here: http://www.qsl.net/k7yo/6m2Yagi.htm
>> [http://www.qsl.net/k7yo/6m2yagi.jpg]<http://www.qsl.net/k7yo/6m2Yagi.htm>
>>
>> 6 meter 2 element yagi - QSL.net<http://www.qsl.net/k7yo/6m2Yagi.htm>
>> www.qsl.net
>> 6 meter, 2 element yagi. A simple, compact and effective antenna for 50 Mhz.
>> This antenna was built in about an hour after using K6STI's AO simulation ...
>>
>>
>>
>>>>>
>>>>>
>>>>> - Jon N0JK
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> ________________________________
>>>>>
>>>>> Hi:
>>>>>
>>>>> I finally took delivery of a suitable LiPo battery to facilitate "back
>>>>> pack portable" operation at the 50 to 100 watt level. If any of my
>>>>> Canadian colleagues are interested I can provide the contact details for a
>>>>> Canadian distributor.
>>>>>
>>>>> At this point I'm planning on simply taking my 50 MHz three element beam
>>>>> apart and re assembling it on site. In my view the beam I have isn't
>>>>> really intended for that type of use and I'm curious if anyone knows of
>>>>> any
>>>>> suppliers for small 50 MHz beams that break down and re assemble quickly
>>>>> and easily. Google searching on my part didn't turn up anything that is
>>>>> currently in production.
>>>>>
>>>>> I'm hoping to shift my focus a bit this year and actually reach the true
>>>>> summit of at least one local mountain (vs simply driving most of the way
>>>>> up
>>>>> via logging roads.) Having this ability would also have been useful
>>>>> earlier this year when I had to abort my CO81 visit during the sept
>>>>> contest. In hindsight I suspect I could have activated the grid for a
>>>>> few
>>>>> hours on foot.
>>>>>
>>>>> 73
>>>>>
>>>>> Mark S
>>>>>
>>>>> Aligned Solutions Co.
>>>>> mark@alignedsolutions.com
>>>>> 604 762 4099
>>>>>
>>>>> ------------------------------
>>>>>
>>>>> _______________________________________________
>>>>> VHFcontesting mailing list
>>>>> VHFcontesting@contesting.com
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>> VHFcontesting -- VHF
>> Contesting<http://lists.contesting.com/mailman/listinfo/vhfcontesting>
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>>> --
>>>
>>> --
>>> Bob Witte K0NR
>>> bob@k0nr.com
>>>
>>> _______________________________________________
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>>> VHFcontesting@contesting.com
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