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SMT/Solder Paste Question
I am planning the build of an Ensemble RX and I am thinking of trying the griddle-heat gun reflow method to install the SMT parts. As far as blocking out time to apply the solder paste and place individual parts, how long can one let the applied parts stand without reflow? I would like to break the placement process up over several days but I am worried that the solder paste will separate or otherwise degrade if I don't place all the parts and reflow them in the same session. Can the process be broken up over a period of days or even a couple of weeks without ruining the already placed parts??
John Stockman, KC2THY |
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Re: Introducing the Hermes-Lite
Sid Boyce
开云体育Thanks Steve,
After I posted I realized it was the FPGA Register Transfer Level code. 73 ... Sid. On 15/04/14 07:13, steve@... wrote: ? -- Sid Boyce ... Hamradio License G3VBV, Licensed Private Pilot Emeritus IBM/Amdahl Mainframes and Sun/Fujitsu Servers Tech Support Senior Staff Specialist, Cricket Coach Microsoft Windows Free Zone - Linux used for all Computing Tasks |
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Re: Ensemble II RX problem
Alan
Original Message -----
Subject: Re: [softrock40] Ensemble II RX problem Just an update... Tony checked out the board and all was well. When I received it back I tried using a cheap (VERY CHEAP) USB soundcard and while not optimal the RX at least worked. So it appears that the soundcard on my ASUS which uses a REALTEK ALC1150 was at fault all along. I will continue my search for a better USB soundcard. Thanks to all for their suggestions.Looking at your first post I cannot see how the soundcard could be responsible for only getting reception below 10MHz. The REALTEK ALC1150 has the potential of being a reasonably good system. I suggest trying again, maybe digging into it's configuration. It is a complex device and wrong settings can make problems with SDR. 73 Alan G4ZFQ |
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Re: Advice re best program for weak signal work
Alan
Original Message -----
Subject: [softrock40] Advice re best program for weak signal work I recently built the 2m Rx SDR and have everything working fine. I am using HDSDR and WinRad software. Tried to download SpectraVue but had issues.Charlie I've never checked between software because none of them really have any deficiency in showing weak signals. If after adjusting the brightness and contrast of the waterfall there is no improvement I'd think that insufficient signal was reaching the Softrock. Does the noise floor rise when you connect the Softrock? Any software program should produce equal, or usually, better results than a conventional receiver. 73 Alan G4ZFQ |
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Re: Ensemble II RX problem
John Williams
开云体育Creative Xfi is my choice...sometimes avail on Creative website as a refurb - what I bought...John - ke5ssh On 4/13/2014 8:05 PM, tng5737@...
wrote:
? -- John Williams KE5SSH - ham since 2007 WQKA523 - GMRS for family use on the farm |
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Re: Ensemble II RX problem
Just an update... Tony checked out the board and all was well.? When I received it back I tried using a cheap (VERY CHEAP) USB soundcard and while not optimal the RX at least worked.? So it appears that the soundcard on my ASUS which uses a REALTEK ALC1150 was at fault all along.? I will continue my search for a better USB soundcard.? Thanks to all for their suggestions. |
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Re: Introducing the Hermes-Lite
Sid Boyce
开云体育Hi Steve,
One question I forgot to ask elsewhere - Is the Hermes RTL code referred to the Hermes code for the RTL-SDR dongle and HF upconvertor? 73 ... Sid. On 13/04/14 23:17, steve@... wrote: ? -- Sid Boyce ... Hamradio License G3VBV, Licensed Private Pilot Emeritus IBM/Amdahl Mainframes and Sun/Fujitsu Servers Tech Support Senior Staff Specialist, Cricket Coach Microsoft Windows Free Zone - Linux used for all Computing Tasks |
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Introducing the Hermes-Lite
Hello List, I have been working on a lower cost variant of a DDC/DUC transceiver which I am calling Hermes-Lite. All the details are at? I would like to eventually have something that is similar in price to the RXTX ensemble.?The design is entirely open source and open hardware. The cost of all materials (including the BeMicro SDK board) is around $150. No sound card is required. The FPGA firmware is a port of the Hermes RTL and is compatible enough to work with existing Hermes software. The ADC/DAC is the AD9866 12-bit integrated device intended for cable modems which I have repurposed as a 0-36 MHz transceiver. RX/TX tests of my prototype show good performance. The github site has instructions for listening to the receiver online. ? I had hoped to have a more polished project before releasing, but I am starting a new job tomorrow and will have limited time for this project. Any help on this project or derivatives is welcome. 73, Steve KF7O |
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SR Combined Lite 2 and K3 SMD crystal
Hi,
I started building SR Combined Lite 2 for K3 from kit I have bought a long time ago. I got the 32.768MHz crystal from Tony years ago and it is SMD type. It didn't have any info about the pad pinout. How should I mount it to the two holes which are for conventional crystal? I searched the group and noticed that some have used resistor leads to help fitting the SMD part to the holes. That sounds like a plan but I have no idea which pads I should connect. A crystal spec sheet would help but I couldn't find any from the internet. It says 32.768M 6619A on top of the xtal. BR, Juha OH6XX |
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Re: Advice re best program for weak signal work
I compared the Softrock 144 MHz Ensemble II with my FT290RII, which is known to be a little deaf. They compared favorably in receive sensitivity. I'd recommend adding a low-noise preamp with 20 dB or better gain. 73, Zack W9SZOn Sun, Apr 13, 2014 at 4:21 AM, <charlie@...> wrote:
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Advice re best program for weak signal work
Hi all, ????? I recently? built the 2m Rx SDR? and? have? everything working fine.? I am? using HDSDR and? WinRad? software.? Tried to? download SpectraVue? but? had issues. ? Anyway? my? question is as follows....When? listening? to? local? 2m? stations? everything seems OK? but the intended? use of my? SDR? was as a Panaoramic display? on my? EME? station.? I use 2m? IF's? for my? transverters? and? used a splitter? network? to? inject the Rx? signal? into the 2m? VHF? Ensemble?SDR. ? I was hoping to be able to "see"? activity on the waterfall display? but? I cannot? see any? sign? of? stations? even? when they are quite? loud? on my? "analogue"? Rx.?? ? So? injecting? very? low? level? signals? (Circa -130dBm)? into? the? SDR? directly? and? I can? see them? clearly. I am using? predominately? HDSDR?? and? I am? connected? through an? external? Sound Blaster XiFi? unit. ? The? exact? question is? what? is the current? BEST? "free"? software? out there for? seeing? very? weak? signals.? I? was? under the? assumption that I would? typically? see? traces? of a signal? well before I could "hear it"? on my? Analogue Rx.....At? least? that? was my? impression? with? Spectran? and? WSJT? digital? modes.......... ? Any? help? and? advice? appreciated.....?? 73 Charlie VK3NX |
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Softrock Lite II defective crystal, and an interesting result...
I recently built the 20M version of the softrock Lite II and enjoyed monitoring CW on 20M. I no longer have an HF station, so this little unit is how I get my "fix". Between one use and the next it stopped working. I've spent 3 days, off and on, troubleshooting and have finally determined that the crystal is defective.
This decision was reached after replacing the two LO transistors, pulling several resistors out of the circuit to test them, etc. Finally I swapped out the 20M crystal for the 30M crystal included in the kit. I reasoned that if the 20M crystal were defective I should be able to see at least some sign of life after the switch. The difference was dramatic. Voltages at the LO test points leapt to their listed values. Some were better than when I first completed the kit. More important, when I hooked up to the sound card program (Quisk on Linux) I was able to monitor and record a very clear RTTY signal and a CW signal. This was while using only a 2M/440 mag-mount antenna, by the way, since I have no HF antenna either. The short of it is that I need to get a new 20M crystal for this rig. I've sent a note to fivedash.com so I assume I'll hear back before long. Just thought it was an interesting outcome to a few days of frustration. |
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Re: Crystals in Softrock LTE combined kit
Should you want to eliminate the subharmonic sampling, you can use an ICS501 with the crystal that came with the kit.? If you look in the files section, June 26 2007 I have an article called
Softrock-Lite with ICS501M.pdf Also can be found on my webpage In the article are some photos.? I actually "dead bug" wired the few parts on top of the PCB.? More recently I have used 8 pin SMT adapter boards or custom PCB's.? The parts are inexpensive, really easy to use and directly interface to the softrocks. Also can be found on my webpage I recently bought some 501's from Mouser, so they are still available. Mouser # 972-501MLFT? 1 @ $1,58 Dick K9IVB |
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Re: Crystals in Softrock LTE combined kit
Alan
Original Message -----
Subject: [softrock40] Re: Crystals in Softrock LTE combined kit Many thanks for discussing this issue. From my egoistic point of view, using this “sub-harmonic” mode has not only a financial advantage. I’ve remarked that spurious trying to "escape" from the receiver -antenna circuit- on the fundamental frequency (I mean the Xtal/4 when using tayloe mixer the “traditional” way) are less important when using a sub-harmonic mode. That’s an important point when you are dealing with the high amplification levels of an I.F., even if you are using a high isolation coupler to pickup the signal. The softrock –and other direct conversion SDR using digital mixing devices- are definitely not “clean”.Marc, I have used this technique for a pandaptor at 47.05MHz As you say, there is no LO in the middle. But surely in the normal mode Softrocks this can be sufficiently reduced, the Z1000 (is that right?) has very good isolation. I'm not sure about any RX/TX combination. You have to interface a digital program with the radio, be it SDR or conventional. Most digimodes use SSB, unless you really want FM modulation is there really any point in making it more complicated? 73 Alan G4ZFQ |
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Re: Crystals in Softrock LTE combined kit
Hi Shirley, Mike et All Many thanks for discussing this issue. From my egoistic point of view, using this “sub-harmonic” mode has not only a financial advantage. I’ve remarked that spurious trying to "escape" from the receiver? -antenna circuit- on the fundamental frequency (I mean the Xtal/4 when using tayloe mixer the “traditional” way) are less important when using a sub-harmonic mode. That’s an important point when you are dealing with the high amplification levels of an I.F., even if you are using a high isolation coupler to pickup the signal. The softrock –and other direct conversion SDR using digital mixing devices- are definitely not “clean”. Have your measured the same results on your rigs ? The reason of my interest of this subject is that I’m trying to modify an almost conventional superhet transceiver, and I’m wondering if putting an xtal driven Softrock in the IF (for receiving AND transmitting) would’nt be a nice solution. This would addd new modulation schemes (FM, psk, rtty etc… ) to a “SSB/CW only” rig in RX and in TX. This approach would also give the ability to offer a free (as in beer) bandscope/spectrum-waterfall display to a analog transceiver. Nothing new in fact. I wonder if it would be smart to use the so called “subharmonic” mode? during receiving, and working on the fundamental during transmission (just switching the active xtal with a TX/RX signal, or changing a Si570 I2C word to do the same thing). A kind of “6.2 Lite” working in duplex mode for 10.7 or 9 MHz in other words. Stupid thoughts ? 73' Marc f6itu ? ? |
Warren Allgyer