Managed to get the 10.5m vertical connected with the broadband pre-amp
Also included a common-mode filter directly at behind the pre-amp.
After stopping the DGPS band recording, I realized, that only one, rather thin (half inch copper pipe of 1m) is not a real good RF-ground - so the vertical has no good counterpoise...
Does active antennas require good RF-ground?
Of coarse! The broadband pre-amp takes care of mainly broadband impedance matching without loading the voltage at the antenna too much (input impedance of 1MOhm or more!), so losses are very small.. HOWEVER !
Without good return pass (RF) for the RF-current of the vertical, the pre-amp will introduce a lot of noise, which comes from the antenna return currents flowing in anything, but in a good counterpoise (the fence nearby, the coax cables , anything which is metal, etc..). So to prevent this really uncontrolled situation, I installed today a radial system. This will be used for the recording of coming night!
One thing what I already at noontime realized: Local NDB's up to 300km are louder than before. Also the total efficiency of the antenna is higher - more antenna voltage. Even more...
So a real challenge for the pre-amp. So far I have not seen any IM-products at all, either IM2 (second order) nor IM3... incredible!
The mediumwave band produces -10dbm Signals almost on all frequencies - fortunately there is not real local station, as both France and dutch part of Belgium stopped mediumwave transmissions.
So it will be interesting, what happens with the radial system in place
I installed elevated radials - 10pcs of 10m long all arround the circle... so it would be a good 40m transmission vertical...
Here are the logs from last night, without the radial system (only ground rod) and with a good common-mode filer (100n caps to ground at antenna side plus 700uH common-mode choke in series on all cables):
Brazil could be true, as it is not a buzy frequency here in Europe:
Cabo de Santa Marta Grande Lt - 310kHz
Sonntag, 11. Februar 2018 22:44:47
Sonntag, 11. Februar 2018 22:44:54
Sonntag, 11. Februar 2018 22:45:23
Sonntag, 11. Februar 2018 22:45:30
Count ID ref1 ref2 kHz Baud City Country Lat Lon km Deg
2 745 000 130 308,0 200 Pedra Branca (Horsburgh) Singapore 1,339 104,409 10.689 80
4 269 466 466 310,0 100 Cabo de Santa Marta Grande Lt BBrazil -28,606 -48,824 10.163 224
13 644 688 689 302,0 200 Hachijo Shima Lt Japan 33,088 139,869 9.803 35
7 614 628 629 295,0 200 Shitang China 28,267 121,617 9.387 51
38047 652 704 705 302,0 200 Ose Saki Japan 32,622 128,614 9.344 44
81 806 012 013 289,0 100 Driver, VA United States 36,963 -76,562 6.262 289
60 847 058 059 301,0 200 Annapolis, MD United States 39,018 -76,61 6.116 291
2 844 094 095 324,0 200 Hudson Falls, NY United States 43,272 -73,542 5.621 293
9 935 334 335 312,0 200 Western Head, NS Canada 43,993 -64,67 4.990 289
84 936 332 333 319,0 200 Point Escuminac, NB Canada 47,075 -64,8 4.817 293
678 940 338 339 315,0 200 Cape Race, NL Canada 46,661 -53,075 4.058 287
4364 944 342 343 310,0 200 Cape Norman, NL Canada 51,509 -55,831 4.016 295
155 342 484 485 308,0 200 Horta Azores 38,533 -28,617 2.814 254
211 414 628 629 289,5 100 Raufarhofn Iceland 66,45 -15,957 2.080 336
4 403 603 001 304,5 100 Outokumpu Finland 62,683 29,017 2.066 39
2853 405 605 001 314,5 100 Marjaniemi Finland 65,033 24,567 2.042 29
3 513 793 823 286,5 200 Skomvaer Lt, Rost Norway 67,419 11,883 1.950 11
50 005 005 005 311,0 100 Shepelevskiy 2 Russia [Eu] 59,983 29,15 1.944 47
58 408 608 001 290,5 100 Kokkola Finland 63,833 23,167 1.903 31
15432 406 606 001 287,0 100 Klamila Finland 60,5 27,433 1.880 44
1170 531 841 001 295,5 100 Narva Estonia 59,467 28,04 1.865 48
8111 407 607 001 292,5 100 Haarajoki Finland 60,517 25,167 1.771 42
3370 462 724 001 289,0 100 Jarnas Sweden 63,486 19,655 1.753 28
7 355 510 001 303,5 100 Rota Spain 36,633 -6,383 1.712 210
1546 400 600 001 293,5 100 Porkkala Pilot Station Finland 59,981 24,403 1.705 43
901 401 601 001 287,5 100 Mantyluoto Finland 61,599 21,475 1.675 35
11436 404 604 001 301,5 100 Turku Finland 60,442 22,224 1.630 40
25674 340 480 481 311,5 200 Cabo Carvoeiro Lt Portugal 39,365 -9,411 1.573 223
4373 530 840 840 307,0 100 Ristna Lt Estonia 58,945 22,058 1.533 45
1057 464 728 728 307,5 100 Kapellskar Lt Sweden 59,719 19,087 1.442 38
44 463 726 001 299,5 100 Skutskar Sweden 60,617 17,433 1.441 33
5936 454 715 716 287,5 100 Torshavn Faroes 62,023 -6,841 1.425 339
17431 468 734 734 298,0 100 Nynashamn Sweden 58,946 17,958 1.338 39
57 360 520 001 297,5 100 Cabo de la Nao Spain 38,733 0,233 1.320 191
1872 465 730 001 297,5 100 Hoburg Sweden 56,928 18,156 1.222 48
482 361 522 001 294,5 100 Cala Figuera Balearics 39,465 2,528 1.220 182
71 363 526 001 286,0 100 Castellon Spain 39,967 0,017 1.188 193
2275 470 738 001 288,5 100 Otterbaecken Sweden 58,867 14,1 1.171 33
7901 482 743 744 301,0 100 Rozewie Poland 54,84 18,337 1.135 59
17679 445 685 695 291,5 100 Sumburgh Shetland Isles 59,869 -1,276 1.086 347
11015 444 684 694 295,5 100 Butt of Lewis Lt Scotland 58,526 -6,27 1.083 330
46347 500 780 810 310,5 200 Faerder Lt Norway 59,034 10,533 1.067 23
12994 460 720 001 292,0 100 Holmsjoe Sweden 56,433 15,65 1.062 46
13760 469 736 001 296,5 100 Goteborg Sweden 57,617 11,967 985 32
476 351 502 001 289,0 100 Cabo Mayor Spain 43,4 -4,417 968 219
89 366 532 532 313,5 100 Cabo San Sebastian Spain 41,883 3,2 950 180
9755 451 700 701 289,5 100 Hammerodde Lt, Bornholm Denmark 55,31 14,779 950 51
8125 453 710 711 296,0 100 Skagen West Lt Denmark 57,761 10,605 949 28
3 432 665 666 293,0 100 Loop Head Lt Ireland 52,568 -9,942 933 290
6305 435 670 671 288,5 100 Tory Island Lt Ireland 55,267 -8,25 932 310
9767 503 783 813 304,0 200 Lista Lt Norway 58,116 6,572 883 13
11524 446 686 696 297,0 100 Girdle Ness Lt Scotland 57,142 -2,056 820 338
15212 001 850 851 295,0 100 Obristvi Czech Republic 50,301 14,484 805 87
12936 491 761 721 308,0 100 Gross Mohrdorf Germany 54,367 12,917 795 53
16965 443 693 001 285,5 100 Stirling [Earls Hill] Scotland 56,067 -4,067 787 325
4 336 466 466 310,0 100 Cap Ferret France 44,567 -1,25 730 208
15058 496 766 766 313,5 100 Mauken Germany 51,717 12,817 692 74
8977 495 765 765 314,5 100 Bad Abbach Germany 48,933 12,033 662 101
479 452 705 706 290,0 100 Blavandshuk Lt Denmark 55,564 8,085 660 28
10788 442 682 692 297,5 100 Point Lynas Lt Wales 53,427 -4,292 607 306
14663 441 681 691 306,0 100 Lizard Lt England 49,966 -5,202 594 268
2674 332 462 462 308,5 100 Pont de Buis France 48,3 -4,083 573 248
139 334 464 464 307,0 100 Les Sables Olonne France 46,517 -1,8 566 222
28560 492 762 001 298,5 100 Helgoland Germany 54,183 7,883 528 36
17729 493 763 001 303,5 100 Zeven Germany 53,283 9,25 527 51
17751 449 689 699 309,5 100 Nash Point Lt Wales 51,401 -3,552 480 286
18360 447 687 697 290,5 100 Flamborough Head Lt England 54,126 -0,091 465 333
11833 494 764 001 293,5 100 Iffezheim Germany 48,833 8,117 401 114
18517 439 691 001 291,0 100 Wormleighton England 52,208 -1,374 370 304
35020 428 655 656 294,0 200 Vlieland Lt Netherlands 53,3 5,067 346 22
7969 330 460 001 299,0 100 Heuville France 49,7 -1,267 323 257
16125 490 760 001 302,5 100 Koblenz Germany 50,367 7,583 316 90
15405 440 680 690 307,5 100 St Catherines Point Lt England 50,581 -1,306 313 275
38036 425 650 651 312,5 200 Hoek van Holland Netherlands 51,992 4,123 187 22
38047 426 652 653 302,0 200 Gilze Rijen Netherlands 51,617 4,933 183 43
18159 448 688 698 299,5 100 North Foreland England 51,38 1,457 157 313