Results

It is notoriously difficult, and expensive, accurately to measure HF antenna performance, hence I have not attempted to make accurate field measurements. Predictions, using the NEC+ modeling tool, show good performance, commensurate with the radiator modes described, and with the electrical characteristics measured.

Results “on-the-air” have exceeded even my expectations; I show below some examples. I am on a good, elevated rural site. However, it is also interesting to note a comparison made, on 80 metres, with an antenna product from a popular manufacturer, comprising a 25 feet long elevated multi-band vertical radiator, with no traps and with elevated short radials, which I happened to have available, and which appeared to be operating, as designed, on 80 metres. While this is, clearly, not intended to perform on a par with a full quarter-wave vertical, I was surprised to find that DX reports were some 20 to 25 dB down as compared with the DX – Low-Band Vertical!

I may add results, of further comparisons with other antennas, from time to time.

559 from VY2ZM on 160m near Mid-day!

I was heard by VY2ZM, in Canada, at 559 on 160m at 11:15Z (note the time!), on the morning of 4th November 2006. We then went on to have consecutive two-way contacts on all bands 80m through 20m, with reports to me of between 579 and 599, all near midday! (It is very unusual to have trans-Atlantic contacts, at this time of day, in the low part of the HF spectrum). I was using 400w on all bands except 20m where I used 100W.

Some G4DBL log extracts are shown below. All incoming reports appear to the right, and were with 400 Watts transmit power at the antenna, except where shown otherwise.

Log excerpts show:

YearMonthDay - Time(Z) – Frequency (KHz) - Mode - My Call – RST report sent by me – Call worked – RST report received by me – Comments

160m:

2006-11-28 2055 1830.0 CW G4DBL 559 K1GUN 559 Ten mins before his sunset.

2006-11-26 1320 1823.0 CW G4DBL 5”9”9 LY7A 5”9”9 CQWWCW Contest

2006-12-18 2154 1969.0 LSB G4DBL 58 MM3RDQ 59+ John, Perth. My signal running 26 watts: 59+20 I was "by far the strongest of the group" of half a dozen south-east UK stations.

Excerpt from ON4KST chat page during an evening in early November: “2006-11-04 K1GUN: Not an Eu signal to be found Tim u are the CHAMP….” This was twenty minutes after he gave me 559!

80m:

2006-01-06 2330 3800.0 LSB G4DBL 59+ K1LZ 59+ I'm "booming signal, strongest signal in (big Eu) pile-up"

2006-11-22 1945 3799.0 LSB G4DBL 47 K2RR 47 Richard Very early! (He running 1500w 1/4 vert and ~500 radials).

2006-11-21 0520 3799.0 LSB G4DBL 59+20 K2RR 59+20 Richard again

2006-11-18 0023 3799.0 LSB G4DBL 59 5A7A 59 Through HUUUUGE Eu pile!

2005-10-22 2335 3795.0 LSB G4DBL 56 VA7XX 57 Pat very early! (He running 1Kw 4-square vert dipoles). Shell, CT1IZU, running 600w and “very crude 2 ele” got RS 56; Pelle SM7EHU, running1 Kw and 4-square vertical dipoles, got RS 58, from Pat.

40m:

ARRL DX CW 2006 single-band 40m high-power contest: leading UK entry

ARRL SSB DX 2006 single-band 40m high-power contest:

Max rates:

2006-03-04 0105Z - 4.0 per minute (1 minute(s)), 240 per hour by G4DBL

2006-03-05 2316Z - 2.6 per minute (10 minute(s)), 156 per hour by G4DBL

2006-03-04 0200Z - 1.7 per minute (60 minute(s)), 102 per hour by G4DBL

Total on time: 6.25 hours for 295 Qs + 5 dupes, 885 points and 47 states/Canadian sections.

Calling CQDX on SSB DX one week-day evening on 7.095 in mid March 2006, netted the string of the

following contacts; the reports, on my signal, are on the right, followed by brief descriptions of the contacted stations:

2006-03-14 2043 7095.0 LSB G4DBL 57 VE9DEN 59+ Den 100w + dipole

2006-03-14 2052 7095.0 LSB G4DBL 59 ZB2BU 59 Chris Gib. ARC 100w dipole.

2006-03-14 2100 7095.0 LSB G4DBL 549 KB2IXT 59 Fred Albany NY. 50w dipole

2006-03-14 2110 7095.0 LSB G4DBL 45 KC2TE 57 Mike Puerto Rico? 150w

2006-03-14 2116 7095.0 LSB G4DBL 45 JG0TCL 55

2006-03-14 2120 7095.0 LSB G4DBL 58 KP4FL 57 John sunset due ~ 6:30 local. 700w dipole

2006-03-14 2122 7095.0 LSB G4DBL 56 WP3BH 59 Joakin FT840 75W hy-gain 35' vertical

2006-03-14 2139 7095.0 LSB G4DBL 35 VE5PM 53 John Been hearing me for1 hour i.e from 5 hrs before his sunset!!

2006-03-14 2146 7095.0 LSB G4DBL 59 OH8FAL 59+ ? Ollu 50w 80m loop

2006-03-14 2156 7095.0 LSB G4DBL 45 F1VFH 59 Robin 500w 80m loop

2006-03-14 2206 7095.0 LSB G4DBL 59 VE3RZU 59+ Rudy 150w dipole @~28'

2006-03-14 2242 7095.0 LSB G4DBL 58 VK6WC 58 John 2ele delta loop

2006-03-14 2255 7095.0 LSB G4DBL 35 YC2OSE 59 Yon

30m:

I haven’t spent much time on 30m, but when I do the results are pleasing:

2006-11-28 0805 559 from a string of JAs I can hardly hear!

20m:

Computer log drop-out has lost many results on 20m. However, a trans-Atlantic test, on my 5Watts SSB, with a number of North-American stations, showed the DX – LBV to be heard around 4dB stronger than an 8 metres long GAP Titan vertical antenna.

20060816 1844 14146.0 USB G4DBL 59 9J2BO 59 Brian

20060816 1846 14146.0 USB G4DBL 56 C5DXC 59 Noz, coast

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	Introducing the DX – LOW-BAND VERTICAL from DBL Antennas