[Lowfer] New to the list. A few questions re: Lowfers and longwave

[lowfer@mailman.qth.net]

> Commercial LF preamps may be available from companies like LF 
> Engineering,
> Palomar and Datong. Someone else may be able to offer advice on 
> which unit
> would be best -- I haven't ever used a commercial preamp because 
> they are so
> easy and cheap to build. As Gary, WA6DTX points out, a major concern 
> is
> overload by strong local broadcast stations. I would expect KSTP to 
> be even
> more of a problem than WCCO in the Arden Hills area. An essential 
> feature of
> a preamp will be a good low-pass filter in the front end.
> 

I have the ckt for the LF eng. preamp. uses an Opamp .
is a LF 357 and works well. I used the same chip but replaced the
input with an Audio transformer for better pref. at ELF. Is simple to
repo
and doesnt need to be tuned and if anyone wants a copy I can supply a JPG
is LF Eng. still in business  ?? The info probably shouldnt be posted on
a site

Oh the chip is by National Semiconductor
 

Bob  K3DJC