Sorry mouser electroncs. On Wed, Dec 2, 2015 at 8:10 AM, Herbert Poetzl <[email protected]> wrote:
> On Tue, Dec 01, 2015 at 08:33:05PM -0500, paul swed wrote: > > Digikey was a strike out with 1 filter for 86 cents but > > order was 1000 units. > > Sorry, but could you point me to the filter in question > please, I couldn't find anything on digikey, but probably > I was searching for the wrong keywords. > > Thanks in advance, > Herbert > > > Mouser however has a wide assortment very reasonable and > > by the single units. > > > Hardest thing will be soldering them. > > > Regards > > Paul > > WB8TSL > > > > > > On Tue, Dec 1, 2015 at 8:29 PM, paul swed <[email protected]> wrote: > > > > > Hello to the group have indeed done the 1575 down to 35.42 to 75.42 and > > > upconverter trick. > > > Thats what I used for 2-3 years now and thought it was time to move > beyond > > > that approach. Especially due to the earlier conversation on old > receivers > > > and that they should still work just fine if you do not care about the > date. > > > > > > I actually have 2 versions of the 35 to 75 converter. One using an > odetics > > > down converter and another using a starlink gps receiver. Both have > 35.42 > > > MHz IFs. Old stuff you can get a soldering iron into. > > > > > > No intention to put this on the tower and mini-circuits makes a good > BPF > > > for the 75 MHz IF. Since I will believe the actual antenna has a 1571 > > > filter in it I was thinking of skipping it down in the shack. > > > > > > Will see what digikey and mouser has in the way of filters and if > > > inexpensive may buy one. I keep thinking I may actually have one also. > > > Thanks again everyone. > > > Paul > > > WB8TSL > > > > > > On Tue, Dec 1, 2015 at 7:53 PM, Alex Pummer <[email protected]> wrote: > > > > > >> for 70MHz it does not hurt to match the cable to the filter at the > > >> antenna unit [down converter] end and also match the filter at the > > >> receiver upconverter end, the cable will pick up enough noise to > overdrive > > >> the 70 something receiver's input [ the "outside" field will drive a > > >> current in the cable's shield, but not in the center conductor, that > > >> current causes noise voltage between the two end of the cable's shield > > >> which will end up at the input of the receiver, therefore it need to > be > > >> filtered out before it hits the mixer......also the down converter's > LO's > > >> reference is sensitive to the noise which the cable will pick up [ > will > > >> cause phase noise ], therefore it needs to be filtered ..... > > >> That down up converter system is an interesting project but it is not > > >> that simple as it looks > > >> 73 > > >> KJ6UHN > > >> Alex > > >> > > >> > > >> On 12/1/2015 2:57 PM, Bob Camp wrote: > > >> > > >>> Hi > > >>> > > >>> Here’s sort of a backwards look at it: > > >>> > > >>> Do you *need* an IF filter in the downconverter? By that I’m asking > > >>> about a > > >>> filter better than a simple LC tank. Did they put the filter in the > > >>> downconverter > > >>> or in the main box? I would think that putting a fancy filter up by > the > > >>> antenna > > >>> would have been a less likely thing to do than putting it down in the > > >>> main box. > > >>> > > >>> Bob > > >>> > > >>> > > >>> On Dec 1, 2015, at 9:48 AM, paul swed <[email protected]> wrote: > > >>>> > > >>>> Thanks everyone. The Meinberg is nice and maybe available from Ebay > by > > >>>> Alex's link. But its 35.42 much as the Odetics down converter. I am > > >>>> looking > > >>>> to create a 75.42 Mhz IF. > > >>>> Mini-circuits makes just the right parts. But had several IF > bandwidths > > >>>> available. > > >>>> So will go with the 2 or so MHz filter as suggested. > > >>>> > > >>>> I have the typical GPS better quality high gain antenna 1/2" Heliax > > >>>> feed to > > >>>> a low noise gain block that makes up for the loss of a 8 X splitter. > > >>>> I may add a 1575 filter ahead of the 10 db amplifier and then hit > the > > >>>> mixer. I think I have a filter. I actually question that I need the > > >>>> filter > > >>>> or 10 db amp. May build without it to see what happens. Can easily > add > > >>>> it. > > >>>> The LO will be a mini-circuits dsn-2036 followed by a 10 db amp to > drive > > >>>> the mixer another mini-circuit DBM. The IF drives a bpf-a76+ and > then > > >>>> will > > >>>> follow that with 30 db of gain at 75 MHz. > > >>>> At least thats my thinking. > > >>>> Regards > > >>>> Paul > > >>>> WB8TSL > > >>>> > > >>>> On Tue, Dec 1, 2015 at 1:36 AM, Magnus Danielson < > > >>>> [email protected] > > >>>> > > >>>>> wrote: > > >>>>> Hi, > > >>>>> > > >>>>> This is a side-track to Pauls original question, but maybe a nice > > >>>>> little > > >>>>> point to make now that Peter touched on the subject. > > >>>>> > > >>>>> To elaborate a little on C/A and multipath surpression. > > >>>>> The multipath surpression of the receiver depends on code rate, > > >>>>> bandwidth > > >>>>> and correlator spacing. P-code is able to surpress more, and the > C/A > > >>>>> code > > >>>>> errors look about the same as the P-code, but scaled accordingly. > > >>>>> Increasing the bandwidth helps to reduce the C/A errors, but > taking the > > >>>>> next step of using narrow correlators further reduces the error. > This > > >>>>> is > > >>>>> shown already in the classical Spiliker book, but further readings > from > > >>>>> Novatel could be nice. > > >>>>> > > >>>>> Increasing the bandwidth and narrowing the early and late > correlator > > >>>>> taps > > >>>>> both have the effect of reducing the time over which energy goes > into > > >>>>> the > > >>>>> E-L difference, and hence reducing the impact of multipath into the > > >>>>> solution. > > >>>>> > > >>>>> Cheers, > > >>>>> Magnus > > >>>>> > > >>>>> > > >>>>> On 12/01/2015 06:00 AM, Peter Monta wrote: > > >>>>> > > >>>>> What should the IF pass band bandwidth be? > > >>>>>>> > > >>>>>>> > > >>>>>>> For GPS C/A with wide correlator, about 2 MHz; if you want > Galileo > > >>>>>> BOC and > > >>>>>> (eventually) GPS L1C, or legacy C/A with narrow correlator, about > 8 > > >>>>>> MHz; > > >>>>>> for GPS P code about 20 MHz. Books on GNSS software receivers > will > > >>>>>> detail > > >>>>>> the many tradeoffs available---if you're starting out with a > > >>>>>> proof-of-concept lab receiver, go for 8 MHz. > > >>>>>> > > >>>>>> Cheers, > > >>>>>> Peter > > >>>>>> _______________________________________________ > > >>>>>> time-nuts mailing list -- [email protected] > > >>>>>> To unsubscribe, go to > > >>>>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > >>>>>> and follow the instructions there. > > >>>>>> > > >>>>>> _______________________________________________ > > >>>>>> > > >>>>> time-nuts mailing list -- [email protected] > > >>>>> To unsubscribe, go to > > >>>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > >>>>> and follow the instructions there. > > >>>>> > > >>>>> _______________________________________________ > > >>>> time-nuts mailing list -- [email protected] > > >>>> To unsubscribe, go to > > >>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > >>>> and follow the instructions there. > > >>>> > > >>> _______________________________________________ > > >>> time-nuts mailing list -- [email protected] > > >>> To unsubscribe, go to > > >>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > >>> and follow the instructions there. > > >>> > > >>> > > >>> ----- > > >>> No virus found in this message. > > >>> Checked by AVG - www.avg.com > > >>> Version: 2016.0.7227 / Virus Database: 4477/11098 - Release Date: > > >>> 12/01/15 > > >>> > > >> > > >> _______________________________________________ > > >> time-nuts mailing list -- [email protected] > > >> To unsubscribe, go to > > >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > >> and follow the instructions there. > > >> > > > > > > > > _______________________________________________ > > time-nuts mailing list -- [email protected] > > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > and follow the instructions there. > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
