Re: QSD sampling question (again)
- Gary: would you be kind enough to share the input filter design for
your 8.8MHz unit? I haven't figured out what makes those filters
tick yet. Thanks much, Ed Krome K9EK Columbus, IN
--- In firstname.lastname@example.org, "Gary Winblad" <garywinblad@...>
> It's fixed.
> My bifilar secondary windings WEREN'T somehow, rewound it.
> I works good now, no more 5.9MHz broadcast stations and at least
> good 8.8MHz reception.
> Thanks again Tony!
> --- In email@example.com, "Gary Winblad" <garywinblad@>
> > Thanks Tony,
> > That confirms I should still keep working on it..
> > I did know about the R6 change.. I had to make it something like
> > 8.5K (10K and 6K didn't do it) but its fine now.
> > The clocks look fine though I haven't checked the exact phasing,
> > holding two probes is too much for me! I do see the 2x clock
> > into the last FF though..audio?
> > Question: Could it be that the 2x response is canceled in the
> > What I am doing is sweeping RF into the ANT and scoping ONE audioout??).
> > channel only (either one looks the same, but are they 180deg
> > BUT, I found that there was a problem when I hooked the SR to anfound was
> > antenna and found nothing but AM shortwave broadcast that I
> > the 5.9MHz band.oscillator
> > I am wondering if one of the switches could be bad..?
> > Gary
> > --- In firstname.lastname@example.org, "Tony Parks" <raparks@> wrote:
> > >
> > > Hi Gary,
> > >
> > > I have recently found that the best configuration for the
> > on the 8.83 MHz SoftRock Lite is to omit C4, have C3 at 180pFand to
> > include R6 on the board at 22.1k (20k or so should be fine).amplitude
> > >
> > > Signals at 2x the clock frequency should be much lower in
> > if the QSD circuit is working properly. Please check to makesure the
> > quadrature clock signals are getting to pins 2 and 14 of U4.
> > >
> > > 73,
> > > Tony KB9YIG
> > >
> > >
- Sure Ed,
Well, I am just getting started with these filters too!
I got a good free program at www.aade.com to model Tony's
designs. Later I programmed my DDS-60 to sweep the SR input
while I scoped the output of the filter. It looks pretty good.
With the aade software, I think I could even design my own filter
now if I wanted to get to another band. Try it, is actually pretty
fun to use. AADE sells some good looking equipment on his web site
too, check it out. The DDS-60 is a great $40 RF generator too.
BTW, I am using Tony's input filter from his kit as he designed
it. I did a boo-boo in my winding of the secondary bifilar winding
but after I fixed it the kit works perfectly. It now receives 8.8MHz
and not 5.9MHz as it did originally.
I posted my analysis and results in a .doc file in Folder:
"8.8MHz Input Filter (V6.2lite)"
--- In email@example.com, "efkrome" <efkrome@...> wrote:
> Gary: would you be kind enough to share the input filter design for
> your 8.8MHz unit? I haven't figured out what makes those filters
> tick yet. Thanks much, Ed Krome K9EK Columbus, IN