Topband: Front End Filters

[Rudy Bakalov]

This is the original ask:

"What if we take it a step further, could we limit the band-with of the antenna signal with a crystal lattice for 160 meters before the receiver. 
Years ago I played  around with a single crystal at the input of an old tube type receiver. It was remarkable what I could hear on 40 meters, on what seemed to be one frequency."
I understand the proposed solution- and have used one on 80- but fail to understand the problem statement in the year 2017. Crystal from ends, Q multipliers, etc. existed at a time when RX antennas were not common and radios had poor performance. And yes, they worked really well and turned rigs like the TS530 and Heathkit SB 102/104 into amazing receivers. Personally, I will never go back to one of these solutions.
What I did find surprisingly effective is a good set of BPFs. Using a QS1R SDR I observed a material reduction of band noise, including on 20 m, at my remote VE3 location, which is already amazingly quiet. Ditto for the Icom 7300 which became an even greater pleasure to use with a set of BPFs in front of it.
Rudy N2WQ

Sent using a tiny keyboard.  Please excuse brevity, typos, or inappropriate autocorrect.


> On Dec 24, 2016, at 9:40 AM, K1FZ-Bruce <k1fz at myfairpoint.net> wrote:
> 
> Rudy,
>  
> Using topband archives.  Try going back to the beginninmg of the emails. It started with "thinking out loud", subject then someone changed the subject.
>  
> 73' Bruce-k1fz
>  
>  
> 
> On Sat, 24 Dec 2016 08:46:47 -0500, Rudy Bakalov via Topband <topband at contesting.com> wrote:
> So what problem are we trying to solve here?
> 
> 
> 73, Rudy N2WQ