here is my scan of a 40 mhz filter. (see the spur hump). - f On Wed, Sep 10, 2014 at 5:30 PM, Joe Rocci <joe@xxxxxxxxxx> wrote: > Farhan > > You asked for the motional parameters and I quoted from memory. I was a > wee bit off, but for the most part, very close. > > As I said previously, when embedded a single xtal in a 20 ohm test bed, > loss was about 1.6 db, BW3db was approx 3300 hz and Fp was approx 50 khz > above Fs. From these, we can derive the following > > Lm = .002387 > Cm = .00663235 pf > Q = 50,000 > Rs = 10 > Cp = 2.8pf > > Please note as I said earlier, I did no sorting or matching. I just > grabbed 8 xtals out of the bag and it worked right out of the gate. > > > ----- Original Message ----- > > *From:* farhanbox@xxxxxxxxx > *To:* joe@xxxxxxxxxx ; minima@xxxxxxxxxxxxx > *Sent:* Tuesday, September 09, 2014 8:22 PM > *Subject:* [minima] Re: New Crystal Filter > > joe, > > while developing the minima, i did try a 40 mhz ssb filter. i will send > the scan to you as soon as i get to my laptop. i had three issues with them: > > 1. these are not available in the local market. > > 2. they had a number of spurious responses. trya full hf scan to see if > you get them too. > > 3. not more then 60 db stop band. > > your filter does look very good. what are the motional parameters? > > - f > > ------ Original message------ > > *From: *Joe Rocci > > *Date: *Wed, 10 Sep 2014 05:40 > > *To: *minima@xxxxxxxxxxxxx; > > *Subject:*[minima] Re: New Crystal Filter > Steve > > Made by ECS and others...sold by Digikey, Mouser and others here in US. > These are thru hole parts, about a 1/2 size low profile HC49. Should be a > drop in replacement on the existing PCB. > > > > > Sent from my tablet > > > > -------- Original message -------- > From Steve VK2SJA > <%3Cvk2sja@xxxxxxxxxxx> > Date: 09/09/2014 7:22 PM (GMT-05:00) > To minima@xxxxxxxxxxxxx <+minima@xxxxxxxxxxxxx> > Subject [minima] Re: New Crystal Filter > > > Joe, > > Great news! > > Higher frequency fundamental crystals for the filter at or above 30 Mhz > was one of my first thoughts. But when I went looking, and I looked > reasonably hard I thought... (obviously not), I couldn't find any crystals > to suit. > > Can you give us a supplier name and part number? > > Are these crystals SMD? What package style? > > Thanks! > > Steve. > > PS. First day back at work after being knocked out of action all last > weekend with the flu. So no further mixer building/testing has happened at > this QTH. Have been following the ongoing experiments with great interest. > > > > > > > > > > >
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