Re: LF: Big signal with hum...

[MarkusVester@aol.com]

Hi Wolfgang,

for a quick comparison, I set up SpecLab's generator for 100 Hz squarewave FM, 170 Hz shift. The first five lines on either side were nearly identical to those in the observed EFR spectrum. Bandlimiting (or shaping) sets in at 600 Hz, with something like 10 to 15 dB down at 1.1 kHz offset. I think those hard transitions are also present on DCF39.

As the operational data bursts will appear only every 10 seconds or so, the impact on straight CW may finally be not that bad. Get nine characters, drop one :-(

73 and regards
Markus

In einer eMail vom 12.09.2006 21:42:54 Westeuropäische Sommerzeit schreibt dl4yhf@freenet.de: 

> Hi Markus and all,
>
> I heard the signal today and wondered why it's so broad - don't they 
> apply amplitude shaping to the baseband signal before modulating it, or 
> what do you think ?
> I couldn't record the signal when I heard it but it sounded very harsh 
> to me, almost like deliberately to produce broad sidebands.
> Still I don't like the idea to have to use a 'puter to get rid of this 
> on 136.5 in CW ;-)
>
> 73,
> Wolf DL4YHF