Dear Stefan, thank You for your proposal. But I am not sure if my three taps will exactly meet the requirements according to your labels. They will just give me some means to change the match. 73 Ha-
Dear all, the different efficiency of a typical radio amateur LF aerial between winter and summer is due to the frozen ground in winter, causing lower ground loss. Therefore I have employed a matchin
Dear all, I feel with Bill concerning the loss of his preamplifier, but in general I would like to raise the question whether it makes really sense to connect a preamplifier for an VLF loop directly
Dear Daniele, At my locaton in eastern Bavaria I am using such a vertical broadband loop pointing north from 10 kHz to 500 kHz since several years and have also made experiments with a horizontal loo
Dear all, Mal in special, if the cable to the rx would really be the antenna for the active aerial, only local qrm would be received! The screen of the cable has to be grounded bfore entering the hou
Dear Mal, thank You for gaining interest in active antennas. As several points have to be answered, I put the answers into the same paragraph where these points are located: As long as an active ante
Dear Daniele,I guess the information You want is also contained in my email, at least indirectly.A german receive-only radio amateur has built such a ferrite antenna by cut and try only and finally s
Dear all, as most electric power nets at that time were direct current, tapping the tram wires carrying 500 V DC had been a possibility to get higher plate voltages for tube transmitters than the loc
Dear all, on the website of SAQ www.alexander.n.se there ist a notice that they had been unable to get the speed control working, and they excuse for this situation. OK? 73 Ha-Jo, DJ1ZB "Alberto di B
Dear all, from my memory I would like to support the view of Andy concerning a linear system. On one occasion around 1975 I also had to design an automatic tuning system for a transmitter tank circui
Dear all, compared to CW signs in the earlier years of radio, with powerful tubes in the oscillator, the OH6DC device sounds rather regularly. HW? 73 Ha-Jo, DJ1ZB "Scott Anderson" <[email protected]
Dear John, concerning your measurements I would like to know the earth resistance of each of your three ground wires separately. When paralleling different earth grounds for LF I have often found tha
Dear Horst, in the internet I have read that DK8KW, Holger Kinzel at Peine, also has a DEBEG 7121 transmitter, including its full documentation. He had also used it for the the beacon he had operated
Dear all, this would remember many operators of the old way 500 kHz had been used, of course. But to recommend an easier way of modulation, a small FM deviation for the carrier (F2) modulated with 50
Dear all, a real audion receiver usually contains an adjustable rf feedback so that the rx can oscillate. Therefore a pitch of 800 Hz should be obtainable without the reception of any other transmitt
According to the state of the art at that time the Titanic had used a spark transmitter, emitting a frecuency band of at least 100 kHz! 73 Ha-Jo, DJ1ZB
Dear Stefan, this is the first time I tried to copy You on LF. Your signal is clearly audible in JN68GN, eastern Bavaria, S-Meter showing S3, even during thunderstorm crashes. 73 Ha-Jo, DJ1ZB
Dear Stefan, just heard You at 21.57 UTC in normal CW calling cq on 476,5 kHz RST 559 some QSB. It will take some time until I will be QRV on MF; I have not expected the german administration to reac
Dear all, the only parts I have bought so far for MF (still beeing engaged in other developments) are two crystals: 6,5536 MHz and 7,0200 MHz, to be mixed with each other. The mixer is another bipola
Dear Stefan, in eastern Bavaria (JN68GN) I have copied your signal and that of DF6NM on 472,5 kHz at around 00.35h local time. Copy had not been a pleasure because of qrn. I have not heard DF0WD, thi
