I have built vertical HF9V for 8 bands (80-10m) on the roof of block of flats in height 25m between lift wells. Height of antenna is 8m, guying with silon ropes in 2 floors. On the last picture is detail of connecting antenna base to lightning conductor rope.
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Antenna LW 60m for 160m band. Bottom end is on lamp at height 4m, top fixative point is near roof at height 25m. Antenna finishes into windows by ATU. |
Antenna LW 30m for 80m band. I am again "make the best of" with success lamp public lighting, hi.
Wire finishes into windows by ATU with antenna current meter. Only on this antenna myself me nice contacts to JA, JT, BY a VK4 on 80m with QRP!
Yagi antennas for the band 50MHz (5el),
144MHz (4el) and on the top for 432MHz (7el). Rotary equipment is KOPEK AR 1002.
Antennas are 30m above the ground.
All my aerials are switched by home made switch, it is made from tin can sheet material. The antenna switch is directly connected into resistive SWR meter.
Vertical HF9V modified and tuned for 60m band
I have a multiband vertical HF9V - version installed on the roof of an 8-storey block of flats OK1DLA which has capacitors from coax - the heel of the vertical is at a height of about 30 m and I have a star stretched system of quarter-wave radials, which are placed directly on the roof - for each band 2 pcs. Radials have a length of lambda / 4 x 0.92, I counted them in the CW
parts of the bands:
80 m - 4 pcs = 19.43m
40 m - 2 pcs = 9.83 m
30 m - 2 pcs = 6.80 m
20 m - 2 pcs = 4.91 m
17 m - 2 pcs = 3.81 m
15 m - 2 pcs = 3.27 m
12 m - 2 pcs = 2.77 m
10 m - 2 pcs = 2.45 m
Copper radials I just cut it with wire, unwrapped on the roof and I didn't anything else. I was just fine-tuning vertical according to the tuner resonance on all bands. I have installed the antenna since 1995 and beyond those years I found that walks unbelievably well, all QSOs I did with a power of 5 W or less. I use HF9V from 40 m upwards, at 80 m I have a better LW of 30 m and a
sloper and the vertical is very narrowband even though it has an excellent SWR of 1: 1.2 in resonance. According to the OK1UFC modeling, the antenna thus installed on the roof of the high concrete panel house probably behaves as if it were in free space. In addition, my QTH is about 100 meters above the city of Zilina. In the 40 m band the vertical works great, so I thought of tuning it to the 5MHz band. The vertical has total height of almost 8 m and it could still work quite well in the 60 m band. I already have a permanent license for the 60m band, the 15kHz
segment is narrow which is ideal for short vertical due to good SWR in the whole frequency band. It occurred to me that it might be possible to short the pair of coil turns for 80 m and get into the 5 MHz band. First I translated the two known points with a straight line and according to the graph it turned out that I should short-circuit spool for 80 m on the eighth thread, but I knew it would be a different curve. I mounted relay 15N59914 in a small plastic box - relay parameters on picture - with antiparallel Si diode and 22 nF capacitor (after the first winter snowstorm
they were destroyed - diode and capacitor - to short circuit so switching so I simply clicked them with pliers and so far it works so well).
I dropped the switch cable from the roof +12 V, in case of rig there is a switch with fuse 1 A, ground goes on coax shielding - I connected to the radials. Box with Al stirrup - the stirrup is attached to the switched contact of the relay - I hung up to the last coil thread for 80 m and second switched relay contact on a cable with a small clamp I connected to the eighth coil thread from above. After measuring the resonance, I got the third point of the curve so I adjusted the curve to an elliptical rounded and at the required resonance at 5358 kHz I now got the fifth thread from the top. The final graph is in here:
So again climb the roof - already in the dark with the headlight - and connect the caliper to the fifth thread. It fitted perfectly, the vertical did not detune in any band - except for the 40 and 80 m band of course - and in the whole segment of the 15kHz band of 5 MHz SWR is 1.4. At 60 m I did not add any radials, modificated vertical and box with the relay is on the picture:
After final assembly, I painted the stirrup with AUTOBIT protective wax. I drilled two 4 mm diameter holes in the box from the bottom to make any condensed water could drain away. At night I finally started hearing US stations well and I finally did VP2MDL on CW on the second call - I tried to call him from three days at 60m on LW and sloper as well they didn't hear me. Gradually I did 6Y0HM, V5 / DK7PE, 3C0W, 8P9AE on CW and FT8 (that's now main mode at 60m) OX3XR, VE1VOX, WP3UX, NP2Q, C5YK, HI8PLE, CO8LY, 5X8C, XT2AW, 9X2AW, ZS4TX, BH4IGO, WP4JLU, HH2MK, T6AA, P40AA and the first SA station PP5XA - so even in the 60m band, the switched vertical HF9V works great. Even me VK7BO and DP0POL from Antarctica also spotted a few times on Hamspots.net in FT8 mode.
I would like to draw your attention to a few important construction details that I am in 25 years with the vertical HF9V found. I installed the antenna and anchored it according to the recommendation - anchor on two floors, each floor with four anchors. I used various nylon ropes and cords as anchor ropes for laundry. Well, it wasn't a good choice, after years on the roof in winter and summer, the ropes degraded, they became brittle and gradually began to tear. During one summer windstorm in ilina, the ropes did not last, the antenna broke in the central nylon insulator and I only found a mess on the roof torn cords and bents and broken duralumin pipes. Terrible look, eyes only for crying.
I made a new insulator, pipe couplings and rebuilt and tuned the antenna. Now I am but added a THIRD lower anchorage floor in place of the new nylon insulator. I ordered a 100 m MASTRANT anchor cable with a diameter of 3 mm and I decided when I completely replace those anchors. I've been lazy by age ... Eventually life solved it for me, it was necessary to replace the roofing on the roof of the block of flats so I was forced to completely dismantle the vertical and that was the right time. After repair the roof I built vertical for the third time, tuned in and MASTRANT
proved to be perfect, to this day I didn't have to adjust a single anchor. The vertical heel, even with radials, is connected to the system lightning conductor metal ropes on the roof, it saved the antenna to keep it completely in a storm did not blow from the roof. I don't even want to guess what could happen in such a case. It also protects the antenna and cables from static electricity but a direct lightning strike would guess it completely destroyed - melted. When assembling the antenna, I first painted all the screws with Vaseline, even after In twenty years, it is possible to disassemble the joint normally because rust will not fit into the thread. After the final tuning of the antenna, I painted all the connections with AUTOBIT plastic wax or RESISTIN ML and I repaint them every few years. It is also necessary at least once to year to check the antenna when there is too much wind on the roof in a storm so the radials can be blown in one direction or fall over the edge of the roof which neighbors do not welcome much. The vertical MUST be constructed tuned to a minimum SWR! If we wanted a vertical with bad SWR to fine-tune while the antenna tuner on the end of the coaxial in the hamshack so that's the worst thing we can do. We will tune vertical and cable as system and to an antenna on request can only get a fraction of the power supplied. That's how I ran when i didn't do well tune HF9V in the 30 m band - SWR 1: 4 - and I caught up with him at the radio at the end of a 30m coax L-tuner. Although I achieved SWR
1: 1, but I couldn't get on no better DX to call. So I went to tune again and only after shortening the side coil I tuned the HF9V by three threads to SWR 1: 1.3 and that day I called at first call to South Shetland HF0POL. And I wasted it evoked for weeks. So the committee vertical tuning is really important, especially when running QRP. I have a tuned vertical on all bands to CW segments with the worst SWR 1: 1.5 and I don't use any antenna tuner.
To this day, I remember the beautiful CW QSO with Vrata 3D2KT in the 18 MHz band because I didn't have coils on the WARC bands 18 and 24 MHz yet, but sometimes I retuned and discovered the bands I put him in wonderful strength with a nice pile up. So I couldn't resist even though the vertical was 17 m at the end of coax SWR1: 6 !!! and I called and called ... until I finally called to my amazement and Vrata took me! I don't know how many milliwatts the antenna really radiated to Fiji, but really the ionosphere used to walk.
Technical documentation HF9V for download:
73 Igor OM3CUG G QRP club 5976