[Lowfer] Remote loop tuner

[Zack Widup]

OK thanks John.  I think I can come up with some timy relays and maybe use 
a ULN2003 or something similar (whatever I have in my junquebox) to drive 
them.

I have a strong signal from MY Alma Mater (WILL-AM) also on 580 here. The 
antennas are about 5 miles away. I didn't think about that.  That may be 
why the MVAM109 tuning diodes are giving me trouble. Something is causing 
WILL or noise from it to be all over the LF part of the spectrum with the 
diode tuning circuit I am using.

73, Zack W9SZ


On Mon, 29 Sep 2008, John Andrews wrote:

> Zack,
>
> I have avoided diodes for switching for two reasons. First, my "alma mater" 
> on 580 kHz has a FS of about 600 mv/m at my QTH, and mixing products are 
> easily generated. Second, PIN diodes are usually characterized for operation 
> at HF and above. I'm not sure how effective they are at LF.
>
> The W1VD preamp ( http://www.w1tag.com/pix/W1VD_Preamp.jpg ) is excellent at 
> MF and below, assuming that you want 50 ohms in/out and around 20 dB of gain.
>
> John A.
>