[HomeBrew] Mitch Lee Receiver PDF is now on line

[Philip Atchley]

Hi Stan et al,
I built mine using a NJQRP DDS daughterboard (100 MHz clock) and PIC
controller.  I have 1 Hz tuning resolution and while I can't say it has "Zero"
drift, it is so negligible that I can't measure it with the equipment I have
on hand.  In the sharp IF position it will hang onto a carrier for hours with
no noticeable drift in the Spectran FFT program.

Actually, I built my receiver as two separate units.  The DDS and
controller/display in one steel cabinet with the rest in a second.  It was all
built in a subchassis of doubleclad PC board with individual compartments for
each IF stage (8 IF stages altogether), the RF mixer compartment, tunable
pre-amp and product detector/audio board.

73 de Phil,  KO6BB

http://users.mercednet.com/beaconeer/
DXing from the "Beaconeers Lair",
where DX begins at the noise floor, and only 938
different LF beacons have been heard since June/99.
Merced, Central California, 37.3N  120.48W  CM97sh




> I think that is quite the "thingie".
>
> I would expect the problem to be two things.
>
> 1)   Super stable DDS to maintain a signal in the 50 Hz IF bandwidth
> 2)   Setting of the mixer oscillator (NCO) to the correct frequency (GPS
> locked ?)
>
> I would love to see a picture of the receiver and also perhaps a peak at
> his monitoring log.
>
> Thanks, de Stan AK0B