Dear LF Group, I am currently (0120) running some tests on about 503.5k using DF6NM's Chirped Hellschreiber mode - any reports welcome if anyone is still up. I am testing a new HF - LF/MF transverter
Dear LF Group, Thanks for the reports - am now closing down (2316utc). Very noisy here tonight - earlier I saw/heard some kind of data signal on about 503.6kHz with a bandwidth of about 100Hz, but di
Dear Graham, LF Group, Try searching under "envelope elimination restoration" or "Kahn modulation transmitter" - should get you several hundred thousand hits, but I haven't yet found a good general r
Dear Gary, Graham, LF Group Thanks for the screen shots of the Chirped Hell sigs. The "speed" used during the tests was intended to be viewed with the same spectrogram settings as QRSS 3 I will be ou
Dear Gary, LF Group, At the moment (1952utc), noise levels are low - I'm getting nearly 100% copy at the peaks of the fades, and nothing at all in the dips. Will keep it running for a while. Cheers,
Dear John, LF Group, Up to 1836utc you were getting up to a reasonably readable s3 level on the peaks of the fades - now you are down to a faint line on the spectrogram display. Cheers, Jim Moritz 73
Dear Jay, LF Group, Rather a lot of QRN here tonight - GI4DPE is quite strong and trying to call WE2XGR/6 at the moment (2304), and GW4HXO is going up and down in the QSB on 502kHz. Nothing seen/hear
Dear Chris, Graham, LF Group, Thanks to G3XIZ earlier this evening for a nice RTTY QSO on 503.5kHz. I used MMTTY with 85Hz shift, and everything worked fine - mind you, Chris is not far from me, and
Dear Graham, For a CW output, as Alan said, it isn't a square wave - or any other wave really, apart from a tiny amount of RF ripple. For the class E, and the usual "current switching" Class D circui
Dear John, LF Group, I would favour sticking with the "no formal band plan" arrangement that we have at the moment. The reason for the current informal band plan getting out of date is not really to
Dear Graham, Gary, LF Group, Nil here since about 1950utc or so ... since I sent my last e-mail in fact! I assume Gary has shut down - the fades seemed to go in cycles of about 5 - 10 minutes, so I s
Dear LF Group, I have written up an article describing my transverter with EER PA for 500kHz. It runs to 7 pages with circuit diagrams etc., and the pdf file at 180kB is too big for the reflector as
Dear LF Group, I have sent the file to all those who have requested it so far - if it doesn't turn up with you very soon, I may have missed you, so please let me know. Cheers, Jim Moritz 73 de M0BMU
Dear Gary, LF Group, Yes - quite consistent sigs now, I reckon I am copying your "quick brown fox" message with only a few errors on about 60% of the transmissions - It looks like a QSO would be prac
Dear Mal, LF Group, Has hard Certainly you should be getting better than 80% for a reasonable class D or E design at LF or MF. I find about 90% is typical for a "good" design - it is actually quite h
Dear Hartmut, LF Group, Thanks for the report on the PSK31 test sigs - shortly after, G3YKB came up on the frequency and we had a quite long QSO - We have previously worked in digital modes on 136k s
Dear LF Group, W4DEX has kindly added the EER transverter article to his web pages at: http://www.w4dex.com/projects/transverter_linear_lf_mf_by_m0bmu.htm This is an updated version, containing some
Dear Gary, LF Group, The attachment shows a spectrogram of the last hour or so of your test, up to around 2251utc - earlier periods were similar. The upper trace is G0MRF's beacon, which is quite loc
Dear John, LF Group, If the RX noise level is the same as the antenna noise level, then when you connect the antenna to the receiver, the noise at the RX output should increase by 3dB - this would pr
