[HomeBrew] direct conversion

[R. Blackman]

Hello again to all.
I really appreciate the reply's to my questions.

here is a filter example using the 14 MHz bandpass filter on my radio.
There is a bandpass for 80m,  40m,  20m,  17 / 15m  and 12  / 10m
they are switched by relays  as directed by the PIC / LCD  frequency
readout.


 50 ohm-------5uH--25p------------------25p--5uH-------------- 50 ohm
                                            |     |
                                            |     |
                                    33uH    4200p
                                            |     |
                                            |     |
 ---------------------------------------------------------------------

I used ELSIE to design the filters, they look good on paper.
I do not have enough experience to calculate losses yet, I'm still a learn'n
homebrew'n amateur.

I like the idea of a broadcast band notch filter, before  ( and after?? ) a
receive preamp.
Also, although noise is also amplified,  more audio gain may help as well.

 just for fun, here is a youtube video from about 3 months ago during some
very early testing
It uses a W1FB DeMaw receiver, not the MRX-40 but the results are the same.
I do not have the bandpass filter board built yet in the video
http://www.youtube.com/watch?v=go6NbBu8CIE

I'll try to post a video in a few days of  the TXR as it sits now,  with the 
transmit / receive board and the bandpass board. Much cleaner, and without 
the batteries and jumpers.

cheers

Richard VA3NDO