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My antennas today :  - home made 2 el YAGI 3,8 MHz (total element length is about 24 m,shortened with home made coils)

                                  - home made 4 square 3,5 MHz (wire elements with toploading 13 m high,feedpoints 2 m from ground)

                                  - home made 5 element YAGI 18 MHz (interlaced 80 m)

                                  - shunt fed tower 1,8 MHz

                                  - stack of two 5 elements OP DES 14 MHz YAGIS

                                  - OFC-8010E-3K dipole antenna 

                                  - Rx : 200 m long beverage NO 

                                  - Rotary Active Rx loop ALA 1530 LNP Pro Imperium  (8 m above ground)

                                  - 'DO' rectangular rx loop


All antenna work is just a one man (me) job.....

The 80 m YAGI is up since 15 July 2017 and is sure a winner and a keeper.

I have been evaluating this antenna now since a bit more than 6 months..

In Autumm and winter so far have been working all over the globe with great signals reports and lots of nice qso's. 

Since the day i put up this antenna i worked dx every single day ( sunrise or sunset ) and comments and reports are very

promising so i conclude this antenna works real well ......

Some qso statistics :

- 3050 qso's from 15 july untill 31 december 2017

- 500 USA - 190 VE - 65 ZL - 26 VK - 30 JA - 15 YB - 26 ZS - 4 PY - 3 LU , 8P6, J69, KP2 etc...

- Rest of qso's are Europeans,Russians....

Highlighted qso's this winter so far ....: - KK6ZM,WA6DON on the longpath (extremely difficult path for both stations)

                                                              -  two real qso's (not just rst )with KH6YY 24 and 25 december 2017 short path




Radiation diagram for my 2 el 80 m yagi.

Maximum gain is 6,6 dbi (free space) and F/B is 25 db.


Home made hi Q coils OT4A

Very high Q loading coils home made are used in order to shorten elements to a practical length of about 24 m.

High Q coils are needed to keep losses at minimum. Coil design also took into account the lack of any parasitic resonance on the

HF spectrum. Q eff,ul = around 1500 of my coils (effective unloaded quality factor at design frequency).     

See below some construction details : 





Please read what Tom DF2BO (owner and founder OPTIBEAM in Germany) wrote to me after he had seen my coils: 

Hi Theo

Your coils are certainly superiour to ours.

Our coils are good, reliable and low loss, yours will have close to zero loss.

For a single personal antenna such coils are for sure the way to go, to tweak out the last per cent of


For a commercial production these coils would be too lavish, and to cost intensive.

But be assured, I love your design, the best 80m coil I have ever seen !


Very nice indeed to get these compliments from Tom, who's is know for very well designed antennas.



Below some comments from Justin G0KSC ....

InnovAntennas are well known for our fantastic and super-quiet VHF/UHF Yagis..... 

but as yet, the benefits of our HF OP-DES are only enjoyed by a few.

See below the setup at OT4A and read what you are missing out on!    What a killer antenna system.....


Radiation diagram of my stack of the two 5 el yagi's OP -DES 20 m 13 m apart bottom one 13 m high.

                                             Maximum gain is 16,64 dbi and F/B 26db.



 Rotary Active Rx loop ALA 1530 LNP Pro Imperium at 8 m high


Below the picture of my old antenna system, replaced since july 2017.....home made 4 element 40 m Yagi with stack of two KT34XA's....they were up in the air for more than 15 years and i certainly made lots of qso's with them....  







                                                See more at http://ot4a-theo.webnode.nl




















8652294 Last modified: 2018-02-15 10:18:40, 10621 bytes

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QRZ Logbook Summary for - OT4A
Latest Contacts for OT4A at QRZ.com
dedateband mode grid Country op
K3FLY 2017-11-03 80M SSB FM29hx United States JACK PEOPLES
N4ZED 2017-11-03 80M SSB EM74xg United States KEN DURAND
VE3KPV 2017-11-03 80M SSB EN93vn Canada JESSE LAWRENCE
WA3IEM 2017-11-03 80M SSB FN20dv United States KENT SHIPLEY
N5AQ 2017-11-03 80M SSB EM15hf United States BILL ROBERSON
MW0CKT 2017-11-03 80M SSB IO71vq Wales CJ
F5PBG 2017-11-03 80M SSB IN78ti France Ludovic V.
K1LTJ 2017-11-03 80M SSB FN31gk United States AL MATTHEWS
DL7ON 2017-11-03 80M SSB JO62jt Germany Fritz Littmann
NZ3O 2017-11-03 80M SSB FM29ex United States BYRON PEEBLES
K1BGH 2017-11-03 80M SSB EN21bh United States ART HAWKES
KE5EE 2017-11-03 80M SSB EM60ir United States STAN SCHWARTZ
N8ACC 2017-11-03 80M SSB EM98xr United States NATHAN SCOTT
KI4TSI 2017-11-03 80M SSB EL96va United States MITCHELL ROSENFELD
KW4GT 2017-11-03 80M SSB EM74ef United States JIM HOCUT

Book Totals: 268463 qso's   24485 confirmed Get a free logbook at QRZ.COM

United States Counties Award#7911
Granted: 2017-11-22 17:34:49   (OT4A)

  • 100 Counties Mixed
  • 1000 Counties Mixed
  • 250 Counties Mixed
  • 500 Counties Mixed
United States Award#2118
Granted: 2016-05-15 06:35:04   (OT4A)

  • 17 Meters Mixed
  • 20 Meters Mixed
DX World Award#3796
Granted: 2016-05-15 06:35:03   (OT4A)

  • 17 Meters Mixed
  • 20 Meters Mixed
  • 40 Meters Mixed
Grid Squared Award#11543
Granted: 2016-05-14 06:35:03   (OT4A)

  • 5 Band Mixed
  • 10 Meters Mixed
    15 Meters Mixed
    17 Meters Mixed
    20 Meters Mixed
    30 Meters Mixed
    40 Meters Mixed
    80 Meters Mixed
World Continents Award#12828
Granted: 2016-05-14 06:35:02   (OT4A)

  • 5 Band Mixed
  • 10 Meters Mixed
    15 Meters Mixed
    17 Meters Mixed
    20 Meters Mixed
    30 Meters Mixed
    40 Meters Mixed
    80 Meters Mixed
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