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Re: Replacing SBL-1 with hand built mixer?
The NE602 also clips at a much lower input level; you¡¯ll have better performance with a passive mixer. -- Bob Clarke M: 978.337.2720
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Bob N1RC
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#330
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Re: "A Binaural IQ Receiver" QST Mar 1999 Campbell KK7B
I wrote:? "I wonder if that VCO/4 step size is by design or just a happy coincidence." I'm betting happy coincidence, perhaps a result of the tricks they play to get low jitter fractional divides.
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Jerry Gaffke
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#329
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Re: "A Binaural IQ Receiver" QST Mar 1999 Campbell KK7B
Hans, Good stuff! Table 5 of the datasheet says crystal reference oscillator on the Si5351 can be 25 to 27 MHz, but that the Si5351-C in the QFN20 with the separate CLKIN pin can take a reference
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Jerry Gaffke
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#328
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Re: Norcal 40a (testing 4.9MHz xtals)
It's good that you've found the problem. The issue with the counter affecting the source reminded me of what I saw in a counter I got from eBay. From my notes: "Hey, I noticed this after connecting it
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Nick Kennedy
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#327
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Re: "A Binaural IQ Receiver" QST Mar 1999 Campbell KK7B
Hi Jerry lowest two divider. The reason the reference oscillator frequency is involved, is that it determines the minimum possible VCO frequency specified by the configuration registers. The minimum
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Hans Summers
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#326
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Re: Norcal 40a (testing 4.9MHz xtals)
Turned out that the berg connector that the counter vendor supplied had a faulty connector. A friend of mine had the same counter and with that counter the oscillator worked just fine. Another
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Ramakrishnan Muthukrishnan
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#325
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Re: "A Binaural IQ Receiver" QST Mar 1999 Campbell KK7B
This section from Hans' FDIM writeup is key: "The MultiSynth division ratio has a minimum of 4 (for output frequencies over 150MHz). The phase offset register has a maximum value of 127. Since we are
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Jerry Gaffke
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#324
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Re: "A Binaural IQ Receiver" QST Mar 1999 Campbell KK7B
Thanks Jerry, that's what it was. The FDIM paper you linked to ended up on QRP Quarterly - just like his 2019 presentation about the design challenges of the QSX also got published in the current
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Karl Heinz Kremer - K5KHK
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#323
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Re: "A Binaural IQ Receiver" QST Mar 1999 Campbell KK7B
Hans is selling a complete Si5351 VFO with uC and display that gives quadrature clocks for $33: http://qrp-labs.com/vfo Given all the features, that's a very good deal. Not sure, but I don't think
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Jerry Gaffke
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#322
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Re: "A Binaural IQ Receiver" QST Mar 1999 Campbell KK7B
Karl is right and it¡¯s almost embarrassingly simple compared to what folks had to go thru in the old days. I built a Mini R2 a couple years ago using the phase shift feature in the QRP Labs VFO and
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Scott McDonald
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#321
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Re: Replacing SBL-1 with hand built mixer?
I tried homebrew mixers using BAT54S and BN43-2402 cores, they work just fine. For use with Si5351A? I prefer KISS mixer built on FSA3157 or SN74LVC1G3157 parts. Look for Chris N7ZWY articles about
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vbifyz
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#320
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Re: Replacing SBL-1 with hand built mixer?
Cory and the group: As mentioned, the NE602 (SA612, NE6xx, etc -- they're all the same chip) is a handy device indeed, but it's not a replacement for an SBL-1 diode-ring mixer. The biggest factor in
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Kirk Kleinschmidt, NT0Z
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#319
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Re: "A Binaural IQ Receiver" QST Mar 1999 Campbell KK7B
With the Si5351 you can actually create quadrature clock signals directly -?al least for frequencies starting in the 80m band if I remember correctly. See Hans'?writeup in a recent QRP Quarterly
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Karl Heinz Kremer - K5KHK
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#318
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Re: Replacing SBL-1 with hand built mixer?
If you want cheap and homebrew, I'd duplicate the mixers on the uBitx from HFSignals. Farhan gives his recipe for the transformers in the circuit description. The Bat54s diodes on the uBitx are
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Jerry Gaffke
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#317
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Re: "A Binaural IQ Receiver" QST Mar 1999 Campbell KK7B
Building phase shift networks or fabbing a board for some DDS chips in TQFP packages strikes me as the hard way to create a quadrature clock. Could use a 7474 dual D-FlipFlop as done on the $21
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Jerry Gaffke
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#316
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Re: Replacing SBL-1 with hand built mixer?
From looking around online, couldn't you use an NE602 in place of an SBL-1? They're definitely cheaper.
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Cory KG7BBV
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#315
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Re: Replacing SBL-1 with hand built mixer?
Diz used to sell a DBM kit: https://www.kitsandparts.com/drm.php I used a couple in project and they worked well. Although he no longer sells this kit, his design might provide some food for thought.
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Graham <colonelkrypton@...>
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#314
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Re: Replacing SBL-1 with hand built mixer?
Thank you, gents! I appreciate the assistance and understanding. Given the low-buck nature of anything I do, I'm quite alright with a hand built mixer vs a pre-made mixer, even if it is smaller and
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Ryan Flowers
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#313
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Re: OT: WIFI RFI?
Switch-mode, consumer grade power "cubes" (AKA: Wall Warts) are a menace and, to a lesser degree, any consumer grade device containing a microprocessor. Most Internet modems, routers and other network
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sigcom1
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#312
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Re: OT: WIFI RFI?
My thoughts are with the switching power supply. Test it with a test load, anything really.
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Ryan Flowers
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#311
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