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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:
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? ?? Given all the features, that's a very good deal. Not sure, but I don't think Hans has released the code. Perhaps the etherkit library implements phase shifting, but even then it may take a few days to get working properly. The register of interest is the "Initial Phase Offset" for each channel, registers 165 to 170: ? ?? It is 7 bits unsigned, the LSB is one quarter of the internal VCO period, minimum VCO frequency is 600mhz. So maximum shift is 2**7 * 1/(600e6 * 4) = 53.33 nanoseconds. Shifting one of the clocks by 90 degrees, our output quadrature clocks can be as low as 1/(4*53.33ns) = 4.687 MHz. As you go up in frequency you can raise the VCO up to 900 mhz, beyond that the accuracy of the 90 deg phase shift degrades since the phase shift resolution is always 1/4 of the VCO period. Hans has found that the VCO in the si5351 works well enough below 600mhz (and up to almost 1200mhz). To get a 90 degree phase shift at 3.5mhz, the VCO would have to be down around 448mhz I don't get QRP-Quarterly, would like a pointer to the article if it exists. Here's an FDIM paper that Hans presented, including a full description of quadrature clocks from the Si5351: ? ?? In it, Hans mentions how he uses integer divides on the output multisynths, fine tuning is done by manipulating the PLL multisynth divider.? However, as the uBitx has shown, using fractional output multisynths with a fixed VCO works just fine, this is necessary on the uBitx to generate the three independent clocks. Small frequency transitions are glitch free when using fractional output multisynths, and though phase noise is?worse than would be with integer output multisynths (I believe within a factor of 2), the phase noise still far better than the typical analog VFO. There are differences? between my analysis above and his FDIM write up. He doesn't mention the issue of bringing the VCO below 600mhz. You would do well to study his writeup closely, as what he has done clearly works. If I were doing a one-off from scratch, I'd probably just put down an si5351 and a 74AC74.? At least as a first pass. Jerry, KE7ER On Tue, Nov 26, 2019 at 10:33 AM, Karl Heinz Kremer - K5KHK wrote:
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 (again, if I remember correctly - I read too much stuff and sometimes it's hard to remember where I saw something :) ) |
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Re: "A Binaural IQ Receiver" QST Mar 1999 Campbell KK7B
开云体育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 a DPDT switch to flip the channels from usb to lsb, and I encourage anyone to try that as it really simplifies the I/Q projects. 73Scott ka9p On Nov 26, 2019, at 12:33 PM, Karl Heinz Kremer - K5KHK <khk@...> wrote:
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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 it. These parts can use 3.3V supply and in this case interface directly to the Si5351 output with perfect level matching. This mixer also saves 1 transformer. Another application I tried was RTL-SDR upconverter with 5V supply and 50MHz crystal oscillator LO, also with good results. Look for bigger SOT-23-6 package. I bought some in smaller SC-70 package, these are more difficult to handle. 73, Mike AF7KR |
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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 comparing the two is dynamic range and RF performance. The SBL-1 (any diode-ring mixer) offers significantly better RF performance, dynamic range, etc. It requires more parts, more "VFO drive" and a post-mixer amplifier, but it's a sledge hammer compared to a tack hammer. Each has its place, of course. :) Regards, --Kirk, NT0Z ? Rochester, MN My book, "Stealth Amateur Radio," is now available from
www.stealthamateur.com and on the Amazon Kindle (soon)
On Tuesday, November 26, 2019, 10:00:14 AM CST, Cory KG7BBV <cory.goates@...> wrote:
From looking around online, couldn't you use an NE602 in place of an SBL-1? They're definitely cheaper.
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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 (again, if I remember correctly - I read too much stuff and sometimes it's hard to remember where I saw something :) )
Karl Heinz - K5KHK |
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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.
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Farhan gives his recipe for the transformers in the circuit description. The Bat54s diodes on the uBitx are Schottky, so half the threshold of the 1n4148's on a Bitx40, and thus only 7 dBm of power required from the VFO versus 14 dBm for the 1n4148's. (I doubt the Bitx40's si5351 + 6db attenuator gives anything like 14 dBm, but it works well enough.) The Bat54s package provides two matched diodes.? ? There are 4 diodes in the complete mixer, but only two are conducting for each half of the clock cycle. Each set of two diodes that are simultaneously conducting should be matched. The SBL-1 and ADE-1 are level 7 mixers (7 dBm of VFO energy required for optimum performance). The SBL-1 has been around for maybe 40 years, there are many (good?? bad?) clones on ebay. Hams reading old QST articles tend to buy SBL-1's (and 40673's and 811 vacuum tubes). The ADE-1 is roughly equivalent, but in a modern surface mount package. Half the price of an SBL-1 when buying at quantity 20 or more from MicroCircuits. If you want uniform performance across 1 to 500 mhz, you probably want to buy directly from MiniCircuits. If all you want is something that works at 7mhz, go ahead and roll your own if so inclined. The SA612 mixers are fine for many applications, but not a drop in replacement for a diode ring mixer. The SA612 has about 14 dB of gain (vs about 6dB of loss through a diode ring), and requires far less? energy from the oscillator.? You can use the oscillator provided on the same chip if you wish. However, the SA612 does not have nearly as much dynamic range. A good choice for battery powered equipment, often works well if there is plenty of selectivity (perhaps a crystal filter) up front to knock out strong adjacent signals that might saturate it. Jerry, KE7ER On Sat, Nov 23, 2019 at 03:38 PM, Ryan Flowers wrote:
Hi everyone, |
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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?
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strikes me as the hard way to create a quadrature clock. Could use a 7474 dual D-FlipFlop as done on the $21 Softrock Lite II:?? Requires a VFO (such as the $1 Si5351 plus a $1 microcontroller) operating at 4x the operating frequency,? Or buy the RX-Ensemble kit for $64, general coverage and includes an si570 clock source. Either one is emitting quadrature baseband audio, you could hook it up to your stereo amp for Binaural audio, instead of using a computer soundcard and decoding stuff digitally. . Jerry, KE7ER On Thu, Nov 21, 2019 at 04:50 PM, Bob Clarke wrote:
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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 higher performing :)?
73! -- Ryan Flowers W7RLF
https://miscdotgeek.com |
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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 peripherals are powered from 12 Volts D.C..? Here, I power my cable modem, wifi router and VOIP ATA from a 12 Volt backup 'box' made by Belkin.? 86'd the three wall warts that formerly powered the three.? Those 3 boxes are about 4-5 feet from my operating position and about 6 feet from the floor (to get the wifi router antennas as high as practical). Now, things are considerably less noisy, in fact, I hardly hear them if at all.? My direct ethernet cable connection from the router to the shack PC is CAT-5E cable and it's quiet without additional ferrites, so far.? There is something else that clobbers me at this location but it's coming in from the outside world on the A.C. power line drop; likely from a neighbor.? I chased one noise source for nearly a day and found a defective charger for one of my DMR handhelds to be the culprit.? Sounded like a sawmill at full song.? It got the hammer. I concur with filters on the network (and wall wart) cables but I'd first try ruling out the warts by powering the network equipment on batteries as a test.? ? Best of luck finding your interference and 73.......Steve Smith WB6TNL ? ? ? ? ? ? ? ? "Snort Rosin" |
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Re: OT: WIFI RFI?
My thoughts are with the switching power supply. Test it with a test load, anything really.? On Sun, Nov 24, 2019, 7:21 AM Bill Cromwell <wrcromwell@...> wrote: Hi Curt, --
Ryan Flowers W7RLF
https://miscdotgeek.com |
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Re: "A Binaural IQ Receiver" QST Mar 1999 Campbell KK7B
开云体育Thanks Nick.? That’s quite an ambitious project. Mike K5ESS ? From: [email protected] [mailto:[email protected]] On Behalf Of Nick Kennedy ? See AA0ZZ's article on the IQ Pro with the AD9854 in the May/June 2006 QST.?? ? ? ? 73- ? Nick, WA5BDU ? ? On Sat, Nov 23, 2019 at 10:21 PM K5ESS via Groups.Io <k5ess.nothdurft=[email protected]> wrote:
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Re: OT: WIFI RFI?
Hi Curt,
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A 3 pound sledge hammer comes quickly to mind. But then you will be without your WIFI :( Lucky me - I don't hear my WIFI in my radios. The router is halfway to the other end of the house. My radios are at either end of the house (two locations). Others have tamed the router rfi the same way I have tamed noises from some of my other computer gear. Try some ferrite chokes on external leads from the router - especially the power supply. Sometimes the beast is the power supply itself. Most are 5 volt DC power supplies and they are switchers. Hams have replaced the switchers with good linear regulated supplied. Those are much more civilized. So try filtering at or near the WIFI unit. Try relocating the router farther from your radios. And use coax with your antennas to at least get outside the house (farther away from the router). I use end fed wires that come right into the shack sometimes and they are much more sensitive to such RFI sources. Good luck with your evil router. Go tame that beast! 73, Bill KU8H On 11/24/19 6:56 AM, Curt via Groups.Io wrote:
Since this is a "tech" group, want to know if others have experienced and solved WIFI RFI. --
bark less - wag more |
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Re: "A Binaural IQ Receiver" QST Mar 1999 Campbell KK7B
See AA0ZZ's article on the IQ Pro with the AD9854 in the May/June 2006 QST.?? ? 73- Nick, WA5BDU ? On Sat, Nov 23, 2019 at 10:21 PM K5ESS via Groups.Io <k5ess.nothdurft=[email protected]> wrote:
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OT: WIFI RFI?
Since this is a "tech" group, want to know if others have experienced and solved WIFI RFI.
I own a Netgear 6300 "Smart" WIFI router that is located inside the shack on desk near the operating position.? I experience "motorboat" interference on HF, all bands.? I originally thought it was a problem in one of my older transceivers ( Triton IV ) with the audio amplifier and nearly dismantled the radio until heard it in another radio and traced it to the router. Thoughts? |
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Re: "A Binaural IQ Receiver" QST Mar 1999 Campbell KK7B
开云体育Has anyone used an AD9854 DDS to provide a quadrature LO? Mike K5ESS ? From: [email protected] [mailto:[email protected]] On Behalf Of Bob Clarke ? One alternative to phasing networks in quadrature downconverters is to use two sources with a common reference, on the same frequency but 90 degrees out of phase. You can do this with a dual DDS IC or two DDS ICs (or two fractional-N PLL/VCOs with the phase programming feature) with a bit of calibration. You can then, as Rick Campbell KK7B? does in his QST article, drive a pair of audio phase shift networks to complete the image-reject downconverter. ? Bob, N1RC (ex ADI) ? ? On Thu, Nov 14, 2019 at 11:30 PM Ted KX4OM via Groups.Io <wirehead73=[email protected]> wrote:
Bob Clarke M: 978.337.2720 |
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Re: Replacing SBL-1 with hand built mixer?
What Kirk said.
I will add: size.? Unless you have teeny-tiny fingers :-P you won't be able to duplicate an SBL-1, HA! However, for ham HF use and if assembled properly, a HB DBM will function just fine.? Proof:? Jim Kortge's 2N2/40 and 40+: <? 73.......Steve Smith WB6TNL ? ? ? ? ? ? ? ? "Snort Rosin" |
Kirk Kleinschmidt, NT0Z
Nick Kennedy
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