[AK-VHF] [Magic Band EME] VP8DMH 6m from Antarctica

[Edward R. Cole]

Lance,

Yes, with no trees and nothing to stop the wind, so a temporary 
antenna makes lots of sense in Antarctica.
---------------------
Today, we got the 6m antenna raised to its permanent position at 
20-feet and swung around to pointing az=120 looking for Es openings 
from the west coast.  The telescoping mast is a bit light-weight for 
a 30-foot long antenna.  3/16 inch guy wires carry the main force 
(the mast-to-boom clamp is about 34-inches above the guy ring because 
I added two 4-foot angle braces to keep the antenna rigid in a 
horizontal plane).  The strain relief uses Phillystran which keeps 
the 2-inch aluminum boom straight.

I bought the nylon rope since it is locally available (cheap) and it 
will be tied and untied repeatedly as the antenna is turned for 
pointing.  So any stretch will be taken up frequently.  It is being 
used for tag lines on front and rear of the booms, but will also help 
secure the antenna during storms (normally occurring fall-winter).

The biggest question will be if the set up is survivable in our 
winters which see winds up to 65mph.  At least we know the prevailing 
wind comes from the NE so the antenna can be tied in that direction 
during winter months when there is little or no Es.  Of course it 
will be swung to look at moon-rise (az=040-090) and moonset 
(az=280-330 during high positive declination days).  I will scope out 
tie-out locations for common azimuth headings where I will set some 
short tie-out posts.  The main guy posts are 6-foot in the 
ground.  the weak point will be at a point right above the guy ring.

I have the feedline temporarily run across the lawn to the shack (it 
will eventually be buried in 2-inch pvc conduit).  Line loss is 1.55 
dB so some sections will be replaced with lower loss cable once I 
receive some L5NM connectors in the mail.  My goal was 0.85 dB loss 
from the amplifier, but the used sections of 7/8-inch line may not 
measure up to spec.  Finding good used cable is difficult in AK.  New 
cable is astronomical in price due to shipping costs.  Running 125w I 
see absolutely no reflected power 50.000-50.700 MHz (in part due to 
the high cable loss).  SWR is 1.0 from 50.180-50.350 MHz as measured 
on the MFJ-269B.  Z=51+j0 at 50.250 MHz.

I took some photos of the antenna that will be added (later) to the 6m webpage:
http://www.kl7uw.com/6m.htm

Specs for the antenna along with element spacing/lengths are on a 
link titled "6M6UW":
http://www.kl7uw.com/6M6UW.htm

I have some home projects that need attention and participation in 
field day this weekend.  I will be looking to make some 6m contacts 
during FD from home.

Then I will get working on the 50vdc PS and Harris PA. That will be 
mixed with some time testing my 2m-8877/HVPS and 1296-eme 
station.  Baring any problems with the 8877, I plan to QRV on 2m-eme 
within a couple days.

73, Ed - KL7UW
6m-eme/ms line up:
6-element yagi (Hpol) 13 dBi, manual az rotation (no elev), K3 with 
ARR P50VDG preamp, Mirage A-1015G (125w), Harris Platinum PA* (up to 
1100w), JT-65, JT6M, ICSAT, FSK-441A and CW/SSB for non-eme. *under 
construction

At 03:40 PM 6/23/2011, you wrote:
>Howdy Ed,
>
>On 6/23/2011 11:23 PM, Edward R. Cole wrote:
>>
>>Nice to have access to workplace equipment. Down on the treeless snow-covered
>>Antarctic plain it becomes more than a nicety. His antenna has a 
>>few more lines than
>>mine will but there is some resemblance to the image.
>
>Yes, of course it is VERY windy in Antarctica and the 6M8GJ is 43' long.
>
>I plan to raise the antenna to
>>20-feet today and set the permanent guy wires. The 1-1/2-inch mast 
>>is a little light
>>to support a 30-foot yagi but will have two nylon guide lines 
>>attached at each end so
>>hoping that will survive high wind.
>
>Nylon stretches.  I recommend the very affordable Kevlar lines or use Dacron.
>
>I have added 4-foot long diagonal braces to the
>>boom back to a point 34 inches below the antenna boom, but the mast 
>>is guyed directly
>>below that point so the antenna is not supported by anything other 
>>than guide ropes
>>and mast. The original installation called for using a 3-inch dia. 
>>support mast.
>>
>>I am hoping the replacement section of LDF5-50 (7/8-inch) hardline 
>>will be good and
>>get installed early next week when I expect delivery of new 
>>connectors. I should have
>>a photo or two later today.
>>
>>73, Ed - KL7UW
>
>GL and VY 73, Lance
>>
>>
>>73, Ed - KL7UW, WD2XSH/45
>>======================================
>>BP40IQ 500 KHz - 10-GHz www.kl7uw.com
>>EME: 50-1.1kw?, 144-1.4kw, 432-100w, 1296-60w, 3400-?
>>DUBUS Magazine USA Rep dubususa at gmail.com
>>======================================
>
>
>--
>Lance Collister, W7GJ
>(ex WA3GPL, WA1JXN, WA1JXN/C6A, ZF2OC/ZF8, E51SIX, 3D2LR, 5W0GJ)
>P.O. Box 73
>Frenchtown, MT   59834-0073
>USA
>TEL: (406) 626-5728
>QTH: DN27ub
>URL: http://www.bigskyspaces.com/w7gj
>Windows Messenger: W7GJ at hotmail.com
>Skype: lanceW7GJ
>2m DXCC #11/6m DXCC #815
>
>Interested in 6m EME?  Ask me about subscribing to the Magic Band EME
>email group, or just fill in the request box at the bottom of my web
>page (above)!


73, Ed - KL7UW, WD2XSH/45
======================================
BP40IQ   500 KHz - 10-GHz   www.kl7uw.com
EME: 50-1.1kw?, 144-1.4kw, 432-100w, 1296-60w, 3400-?
DUBUS Magazine USA Rep dubususa at gmail.com
======================================