From N5XTR
3/17/2008 11:12:24 PM (2 comments) 
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I have had a lot of emails about my HF antenna, so here is a brief description.
I operated mostly mobile and only 10m and up from my home. After discovering PSK31 and other digital modes I wanted to relocate my ft-857d to the house and connect to my PC. The change wasn't really that difficult until I moved to a cheaper QTH...an apartment. All of my hf wires had to come down and I designed the fan out of my hamsticks. I would say the outcome was better than expected.
I went to Home Depot and bought a piece of 3/16" x 1 1/2" flat steel. I bent it into a square and drilled holes for a U-bolt and 3/8 X 24 antenna lugs. I had to bend it by hand so it's not perfectly square but it works. Next was the phasing box. I bought the aluminum enclosure at Radio Shack for 3 dollars and drilled holes for 5 so-239 connectors. I ran 12 gauge power wire to each center of the connecters and grounded the shields to the box. I also made 4 1 foot jumpers from rg-8x to feed the antennas and a 50' line of rg-213 to the rig.
Having all the lines run and connected and no shorts found I began to tune the antennas. First was the 75m stick which I removed the factory stinger and used a k40 stinger which was longer and trimmed it to 3.580 for 80m psk31. Next was the 40m stick adjusted to 7.050 so I could cover 070 and 035 psk frequencies both with 1.1:1 swr. 20m element next tuned to 14.070 and then 10m stick to 28.120. The trick is to tune one stick and check all frequencies as you go. I had to re-adjust the 20m element after tuning the 10m element and it took some time to get them both right on. You see, all of these hamsticks are phased together and they will all transmit but the most rf will come out of the most efficient antenna.
Now I have an antenna that is roughly 14' across and very little wind load capable of operating on all HF bands with my LDG AT100pro tuner. The band with the highest swr is 17 meters with the highest swr of 4.5:1, which is easily tuned although not very efficient. The hamsticks used my 30' mast and an 8' ground rod as a counterpoise. So this is a much cheaper antenna than the N1GY version in Dec.07 QST which uses 2 sticks per band. At $30 per hamstick it can get very pricey when using more bands.
Here are the SWR details:
160m - 2.5 to 2.1 across the band (see note 1)
80m - 1:1 at 3.580
60m - 2.3 at 5.373
40m - 1:1 at 7.050
30m - 1.6 at 10.125
20m - 1:1 at 14.070
17m - 4.2 at 18.110
15m - 3.3 at 21.100
12m - 1.9 at 24.920
10m - 1:1 at 28.120
6m - 1.9 at 50.350
All of these swr are within the capabilities of the autotuner.
Note 1 - On the 160m band I can add a ground wire from the support mast to a cold water pipe to get an SWR of 1.3 at 1.990 and 1.1 at 1.805, 1.2 avg swr across the whole band and have made local and stateside contacts. The problem is that the water pipe is across the walkway and some foot traffic is present so I have to be careful. When we got snow are really good rain, I didn't need the extra ground wire and reading the same swr as with the wire.
Hopefully this will help with the questions I have been getting. Anything I haven't covered can be commented on or email @ N5XTR@ARRL.net
73
