[Elecraft] Impossible mission? USB with the 13khz filter for PSK31on Digipan

Joe Subich, W4TV lists at subich.com
Fri Jan 30 21:10:07 EST 2009



> I can only speak for Yaesu and Icom gear, but Yaesu 
> rigs specify 5Khz transmit FM in their manuals and in
> the Icom 706MKIIG service manual states FM deviation
> is adjusted for 4.5Khz.

There is a BIG difference between FM deviation and 
maximum modulating frequency (audio response).  I was 
speaking specifically to maximum modulating frequency. 

As Lyle has said elsewhere, the maximum modulating 
frequency in the K3 is limited to about 2.8 KHz - in 
all modes except ESSB - which results in an occupied 
bandwidth of about 15.5 KHz with 5 KHz of deviation 
for FM.  





> -----Original Message-----
> From: Thomas Tumino [mailto:thomastumino at yahoo.com] 
> Sent: Friday, January 30, 2009 1:33 PM
> To: lists at subich.com
> Subject: RE: [Elecraft] Impossible mission? USB with the 
> 13khz filter for PSK31on Digipan
> 
> 
> 
> 
> No, typical transmitted bandwidth for communications use - 
> including FM is about 100 Hz to 3000 Hz.  
> 
> I can only speak for Yaesu and Icom gear, but Yaesu 
> rigs specify 5Khz transmit FM in their manuals and in
> the Icom 706MKIIG service manual states FM deviation
> is adjusted for 4.5Khz.  I would assume
> this was the standard for all Yaesu and Icom gear
> at least.  Some Yaesu rigs do have a special 
> "FM-N" transmit mode of 2.5 Khz, similar to FRS radios,
> but I think that mode is the exception and not 
> the rule. 
> I think the DSP receive limit of 4Khz should at least
> be mentioned in the K3 materials (or perhaps it 
> is and I missed it?).  This bothers me as
> really I feel FM and AM are most regularly used 
> to enjoy audio of a better quality then SSB audio, 
> and a 4Khz limit cuts down on that a bit.
> 73 to all and thanks for your
>  help,
> Tom-N2YTF
>  
> 



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