[Elecraft] K? for remote rx only

Geoffrey Mackenzie-Kennedy lx2ao at pt.lu
Fri Dec 28 15:20:00 EST 2012


David,

My XYL and I have been away, so my apology for being slow to make a comment.

If your remote Beverages are to be used on 160m, 80m and 40m, and a remote 
TRF is used on each band to provide selectivity and gain, then unless their 
outputs are combined before up-conversion then obviously you would require a 
home-to-remote site link to band-switch the TRFs.

Of course I have no idea as to the level of BC signal(s) etc your Beverages 
would present to the TRFs, but as you know the size and mix of all Iron/ 
Ferrite cores used in the system (including the combiner's) must be chosen 
with care to prevent "Core Generated IMD" becoming a "problem".

Another difficulty which might arise in an up-conversion scheme is the 
generation of intermodulation products, either by the up-converting mixer or 
by any subsequent stage.  This makes me wonder whether it would be better to 
run the 160m, 80m and 40m TRFs continuously, and view their combined outputs 
as "Baseband".  Then use this "Baseband" signal to Angle Modulate (FM or PM) 
the microwave transmitter at the remote site.  At the home site the 
recovered baseband from a FM/PM receiver would be the 160m, 80m and 40m 
bands.  Of course a home-to-remote link would not be required.

Here I must put my hand up, because it has been a -long- time since I 
designed any microwave kit, and I cannot recall if a "Baseband" extending to 
7.2 MHz is feasible.

Best wishes to you, David, to all on the "List", and to everbody at Elecraft 
for the New Year when it comes!!

73,

Geoff
LX2AO


On December 22, 2012 at 2:40 PM, David Cutter wrote:

>I want to place Beverages at remote sites (for rx only), for 160m (useable 
>on 80 and 40m), but it's not viable to use a K0 at each site.  Is there a 
>way to use a simpler system: perhaps a TRF on each band, up-converted to, 
>say, 2.3/2.4GHz then down-converted to each band for my K3 at home.  The 
>transmit antenna will be at home and listen in diversity mode.
>
> I can see various issues like image and sensitivity cropping up, but I 
> just wonder if this has be done.  It would be nice if there was a lower 
> cost K series simple remote receiver available.



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