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Date: Fri, 09 Jun 2006 15:39:27 +0200
To: rsgb_lf_group@blacksheep.org
From: Rik Strobbe <rik.strobbe@fys.kuleuven.be>
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Subject: Re: LF: Re: IC706 vs TS850
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Bryan,

if only (the lack of) selectivity is a problem and not sensitivity I would 
recommend to insert a (passive) bandpassfilter in front of the RX.
QRM/QRN level at 136 kHz is that high that even a few dB insertion loss 
won't do any harm.
With my Kenwood TS440 and a tuned inverted-L antenna (12m high, 22m long) I 
could insert  a 30 dB attenuator and the band noise was still a lot 
stronger than the RX noise.

73, Rik  ON7YD / OR7T

At 08:40 9/06/2006 -0400, you wrote:
>In a message dated 09/06/2006 12:35:12 GMT Standard Time, 
>captbrian@ukonline.co.uk writes:
>Thanks for that.  It certainly helps _me_.   I have a 706/2/g but no 850.
>
>The front end of my 706 is so wide it recieves all the world at the same
>time !  but I am only one mile from a MW broadcast station .
>
>   I can see I need at least a V.  narrow tuned pre-amp.  Any ideas where to
>find one? [ Newbury Rally next week ]
>
>Hi.
>
>The G3YXM / G0MRF pre-amp is fairly narrow. It certainly offers good 
>rejection of MW.
>But it is 50 ohms ish in and out.  - I think some simple response tests 
>are listed on the web site.
>
>Another possibility would be a tuned input FET which could be made a 
>higher Z input.
>
>73
>
>David  G0MRF
>
><http://www.g0mrf.freeserve.co.uk>www.g0mrf.freeserve.co.uk


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<html>
Bryan,<br><br>
if only (the lack of) selectivity is a problem and not sensitivity I
would recommend to insert a (passive) bandpassfilter in front of the
RX.<br>
QRM/QRN level at 136 kHz is that high that even a few dB insertion loss
won't do any harm.<br>
With my Kenwood TS440 and a tuned inverted-L antenna (12m high, 22m long)
I could insert&nbsp; a 30 dB attenuator and the band noise was still a
lot stronger than the RX noise.<br><br>
73, Rik&nbsp; ON7YD / OR7T<br><br>
At 08:40 9/06/2006 -0400, you wrote:<br>
<blockquote type=cite class=cite cite><font face="arial" size=2>In a
message dated 09/06/2006 12:35:12 GMT Standard Time,
captbrian@ukonline.co.uk writes:</font>
<dl>
<dd>Thanks for that.&nbsp; It certainly helps _me_.&nbsp;&nbsp; I have a
706/2/g but no 850.<br><br>

<dd>The front end of my 706 is so wide it recieves all the world at the
same
<dd>time !&nbsp; but I am only one mile from a MW broadcast station
.<br><br>

<dd>&nbsp; I can see I need at least a V.&nbsp; narrow tuned
pre-amp.&nbsp; Any ideas where to
<dd>find one? [ Newbury Rally next week ]
</dl>&nbsp;<br>
Hi.<br>
&nbsp;<br>
The G3YXM / G0MRF pre-amp is fairly narrow. It certainly offers good
rejection of MW.<br>
But it is 50 ohms ish in and out.&nbsp; - I think some simple response
tests are listed on the web site.<br>
&nbsp;<br>
Another possibility would be a tuned input FET which could be made a
higher Z input.<br>
&nbsp;<br>
73<br>
&nbsp;<br>
David&nbsp; G0MRF<br>
&nbsp;<br>
<a href="http://www.g0mrf.freeserve.co.uk">www.g0mrf.freeserve.co.uk</a></blockquote><BR>
<BR>
<FONT FACE=3D"Arial" SIZE=3D2>Disclaimer: <A HREF="http://www.kuleuven.be/cwis/email_disclaimer.htm">http://www.kuleuven.be/cwis/email_disclaimer.htm</A> for more information.</FONT>
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