[600MRG] RAK front end

[lstoskopf@cox.net lstoskopf@cox.net]

TRF. No LO radiation for someone to DF. Great selectivity at that freq. Great design!  N0UU

> On April 4, 2018 at 8:05 PM "Kenneth G. Gordon" <kgordon2006 at frontier.com> wrote:
> 
> 
> On 4 Apr 2018 at 18:32, Dave Riley wrote:
> 
> > How low to go is the question here.. The SDR-IQ goes down to low audio...
> > 
> > I see this RAK as the ultimate BPF throughout it's range... Why have
> > AGC? The thing can take about +40 or so...a 150 db dynamic range is
> > not so shabby.. Intermod??
> 
> I've never, ever experienced any. I used one for several years to receive the Navy VLF 
> stations. I also used an RAL (the HF version) as my main and only station receiver for at 
> least 12 years before switching to something more modern.
> 
> And the researcher I mentioned earlier used many RAKs. He never, apparently, 
> experienced any intermod either.
> 
> They are a TRF with two 6D6 (equivalent to the 6K7) RF amps, a 6D6 regen detector and 
> two stages of audio. There is a sixth tube, a 41 (equivalent to the 6K6) configured as a 
> switchable output limiter, which the manual calls an "AVC" but it isn't.
>