[Premium-Rx] Siemens CHR-531

[Karl-Arne Markström]

The reason for using such a low IF is that it is very much easier to
get optimal passband and pass/stopband transition shapes in mechanical filters at low frequencies.

On the downside, it places much higher demands on the first IF filter, as it has to suppress
the second IF image response at a narrower frequency spacing.

Operationally, I don't think there would be any differences between a last IF of 30 kHz (such as in i.a. the EK47 and CHR531) or 200 kHz (such as in the CR91 and E1800) unless you use the receiver to receive a
modem waveform with exceptional requirements for passband flatness and group-delay characteristics.


73/

Karl-Arne
SM0AOM

----- Original Message ----- 
From: "Ahmet Gundes" <ahmet-m at usa.com>
To: "Premium-RX" <premium-rx at ml.skirrow.org>
Sent: Friday, January 14, 2005 6:08 AM
Subject: [Premium-Rx] Siemens CHR-531


> 
> Hello all.     
> 
> I would greatly appreciate getting comments on the Siemens CHR-531
> from those who use(d) this HF receiver, especially in comparison to 
> some other sets such as the R590s, Telefunken E- series, 
> Racal 6790s... etc.  I heard it has an IF of 30KHz !.. Does this
> offer any technical advantage ?  What are its pros and cons ?
> 
> Thx for your time.
> 
> Ahmet
> 
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