Message-ID: <00df01cb7863$13d235f0$0201a8c0@Clemens04>
From: "Clemens  Paul" <cpaul@gmx.net>
To: <rsgb_lf_group@blacksheep.org>
References: <4CCAED49.6030007@o2.ie> <4CCC2277.9040801@o2.ie> <045201cb7844$ca1df020$0201a8c0@Clemens04> <006b01cb7857$f564e870$4001a8c0@lark>
Date: Sat, 30 Oct 2010 20:48:38 +0200
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Subject: Re: LF: RFspace SDR-IQ
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Hi Alan,

>you seem to impute that there are no shortcommings in direct
> sampling! :-))

Not at all,I just meant to emphasize the difference between the two
common SDR architectures,i.e.between the direct samplers and the
IQ mixer concepts.
The message was:
If SDR, then direct sampler.

>and I do
> own a couple very good conventional receivers

Here too.
If you're interested I can send you an audio file demonstrating
the reciprocal mixing on a E1800 and an Icom IC-7800
compared to Perseus (which doesn't show any RM in this setup).

73
Clemens
DL4RAJ


----- Original Message -----=20
From: "Alan Melia" <alan.melia@btinternet.com>
To: <rsgb_lf_group@blacksheep.org>
Sent: Saturday, October 30, 2010 7:04 PM
Subject: Re: LF: RFspace SDR-IQ


> Hi Clemens, you seem to impute that there are no shortcommings in=20
> direct
> sampling!
> :-))    I suspect there are, but they are just "different".  You may=
=20
> be
> right about the units mentioned, but it is just as easy to make a=20
> poorly
> preforming DSP radio as to make a poor analogue one. We are in=20
> danger of
> being conditioned to accept that "digital" is the magic dust that=20
> solves all
> problems......it is definitely not so!
>
> Having said that, the performance of some units is quite remarkable=
=20
> and I do
> own a couple very good conventional receivers.
>
> Alan G3NYK
>
> ----- Original Message -----=20
> From: "Clemens Paul" <cpaul@gmx.net>
> To: <rsgb_lf_group@blacksheep.org>
> Sent: Saturday, October 30, 2010 4:11 PM
> Subject: Re: LF: RFspace SDR-IQ
>
>
>> Tony,
>>
>> the most important difference between SDR-IQ/-IP(from RF Space)
>> or Perseus and the $200 SDR on
>> http://www.lazydogengineering.com/LD-1A_SDR.html
>> is that  the latter is no direct sampling receiver.
>> It uses a downconverting technique with a number of=20
>> shortcomings,e.g.
>> phase noise of the LO and others.
>> I would go for a direct sampling SDR like those e.g. from RF space=
=20
>> or
>> Perseus.
>>
>> 73
>> Clemens
>> DL4RAJ
>>
>> ----- Original Message -----=20
>> From: "Tony" <ei8jk@o2.ie>
>> To: <rsgb_lf_group@blacksheep.org>
>> Sent: Saturday, October 30, 2010 3:49 PM
>> Subject: Re: LF: RFspace SDR-IQ
>>
>>
>> > Thanks guys.
>> >
>> > You have just tipped the balance for me and I shall be placing an
>> > order
>> > for one on Monday morning.
>> > It's about time I joined the 21st century, but it will be
>> > interesting to
>> > compare it to my beloved FT 102 rx.
>> >
>> > Tony, EI8JK.
>> >
>> >
>> > On 29/10/2010 16:50, Tony wrote:
>> >> Hello group.
>> >>
>> >> Has anyone any experience with this SDR ?
>> >> It looks interesting and I'm a bit tempted, especially as it=20
>> >> works
>> >> full spec down to 500 Hz and "usable" to 100 Hz.
>> >> But as I have never used an SDR, I haven't got a clue if it's=20
>> >> any
>> >> good
>> >> or not.
>> >>
>> >>
>> >>
>> >
>> >
>>
>>
>> -------------------------------------------------------------------=
-------
> ------
>>
>>
>>
>> Eingehende eMail ist virenfrei.
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>>
>>
>
>


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