As this is an Irish website, it seems only fitting to have the 'Guinness Book of Records'-style listing of the biggest, the fastest, the tallest and the best in Contesting listed here.

If you know of any more records, don't hesitate to tell me....

Highest QSO rate Every Recorded

457 QSOs - N5TJ operating at P40L in CQWW SSB. The record for humans (and those without N5RZ yelling at them to go faster) is lower. There have only been a few other verifiable hours over 400 reported, and several dozen over 350. CW record was somewhere around 235 while I [K1DG] was actively tracking them, although I have a vague memory that CT1BOH had one absurd hour around 250 in the past few years.

Highest Antenna AGL

My data is a bit out of date, but I think the KC1XX 80M stacked delta loops at 300 and 150 feet (100 and 50 Meters) are at the top (so to speak). There also used to be an 80 M inverted Vee at W1MX (MIT club station) at the top of a 300-foot building (the Green Bulding, for alums) back in the 70s, but I'm not sure if it is still there. That antenna was used by WA1CQW and WA8WNU (now W1FV and K8RX, respectively) who took turns winning the 80M single-band category from MX for several years.

Largest Array ever used

This is tough to qualify. Let's start with element counts.

KC1XX's 10-meter array is pretty impressive (8-stack of 4-element yagis), and is probably the most HF elements in one array. The KC1XX 10M system also includes some fixed beams South, one low long-boom monster fixed on Europe (its nickname, required of all legendary antennas, is the "Autobahn", because there's no speed limit when you run Germans with it), and 3-stack of beams fixed on JA (I think they're 7 elements each). That gives a total of somewhere over 60 elements on 10 meters.

It's beaten in element count by the AA6TT stack of 6-meter beams (8 x 10-element yagis, dismantled in 1993).

Stacked full-size 3- or 4-element 40-meter beams (K3LR, W3LPL, the old W2PV, and several others) probably include more aluminum, and there are a few 80M rotary yagis out there.

N6BT and VA7RR once loaded up the curtain array at the Far East Broadcasting Corp. on Saipan, and reported a substantial improvement from a tribander (like 30 dB or something really scary - but not bad for a "wire antenna"). Various hams have also fired up the giant dish at Arecibo for moonbounce now and again, or used rhombics originally installed for government or military applications. These don't count as ham antennas, though.

Highest SO LP QSO rate

I think several people have done in the mid-200s LP, and maybe even 300 in an hour.

Biggest Quads

Yuri UA9CI once had a system of 3 band(20-15-10) quads in H configuration. That was 4-4 over 4-4. The system was installed on the roof of a 9 storey residential building using 26 meter tower. He had to take the antenna due to moving to another flat but now has plans to restore it possibly next summer. Another big antenna he had up was full size 4 el 40 meters quad. That was a real "killer" on 40 meters during the day hours when he could hear what nobody else could because of "no propagation"

Biggest array on 20m

The OH8OS 20M array 6-6 over 6-6 over 6-6 probably beats KC1XX's 32 on ten for most HF elements. I think the highest 6-6 was 180 - 200 feet. Maybe it wasn't really amateur since it was built for a University project, but it was on 20 meters.=20

That nomenclature indicates (for those unable to think THAT big) that the array had three pairs of side-by-side 6-element beams. Many hams referred to that station as OH8 "Only Signal", because it often was the only signal from Europe coming through.

Biggest array on 10m

Bill, K4XS's 10m stack is bigger than KC1XX. He's got 6/6/6/6/6/6 on 10m, for a total of 36 elements, all phasable.

Conventional wisdom from W1 suggests that 6-element beams are too narrow for coverage of all of Europe in a contest, but now that the challenge has been issued, I imagine Matt [KC1XX] will want to upgrade.

Biggest antenna on 80m

The biggest I've heard of is 7J4AAL's 5 element 80m yagi, 59 metres high! You can see some photos + text in Japanese here, or you can click here for a pre-translated page.

Tallest Towers

Tom, N4KG comments on this question:
W8JI has a 300 ft high tower with some 160M wire antennas on it. There are several 200 ft amateur towers, mostly at big contest stations like KC1XX, W3LPL, N4AR, plus others I'm sure, plus several 160 ft towers at single op contest / DX stations, and LOTS of 120 ft amateur towers.

The highest TV towers I know of are 2000 ft. Many big cities have them.

Other Notable Stations

Lets not forget NO8D. He's got a 200 foot rotating tower with Six DX Engineering Experimental Log Periodic Antennas. Each antenna has 16 elements on a 42 foot boom. You can see photos on the ArraySolutions page. The XX Towers page mentions his stack of 3ele 80m beams, too!

Thanks to K1DG, N2NL, UA9CDC for the postings to the CQ Contest reflector.