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[azqrp] AZ ScQRPions Meeting and the Superstition Hamfest
A bunch of us are going to the Longhorn Steak House on Alma School between Southern and US60. Address is 1434 S Alma School Rd, Mesa They have lunch specials on Saturday including a $9 chicken sandwich and a $10 cheeseburger, both very excellent. Normally kind of expensive, but for lunch (including Saturdays!), a good deal these days. (They also have some salads on lunch special if you are into those.) It opens at 11AM and is 1 mile from the hamfest. See you there!!! Wish you could join us, Mike! :-( 73, Scotty WA2DFI
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Fixing the PTO on a Direct Conversion Receiver
I thought the qrp-tech group be interested in this very simple fix to a very simple direct conversion receiver PTO: https://soldersmoke.blogspot.com/2023/03/fixing-tuning-problem-in-high-school.html Background on the project here (keep scrolling down -- there are about 28 posts!): https://soldersmoke.blogspot.com/search/label/TJ%20DC%20RX 73 Bill N2CQR
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File Notifications
#file-notice
The following files and folders have been updated in the Files area of the [email protected] group. * /K8IQY Home Brew 15-Meter Direct Conversion Transceiver/DC-HB Rx Front-EndV1-Schematic.pdf ( /g/qrp-tech/files/K8IQY%20Home%20Brew%2015-Meter%20Direct%20Conversion%20Transceiver/DC-HB%20Rx%20Front-EndV1-Schematic.pdf ) *By:* Jim Kortge <jim.k8iqy@...> *Description:* This is the schematic for the Front-end filter and RF pre-amp for the 15-Meter home brew transceiver using a direct conversion receiver. It consists of a classic, double tuned set of resonators followed by a J310 JFET RF Amplifier. It is designed to drive the 1500 Ohm input impedance of the SA612 mixer in the front-end of the direct conversion receiver. It has a gain of about 15 dB. Jim, K8IQY March 13, 2023 --- The following files and folders have been uploaded to the Files area of the [email protected] group. * /HB-RxFrontend-LogSweep.bmp ( /g/qrp-tech/files/HB-RxFrontend-LogSweep.bmp ) *By:* Jim Kortge <jim.k8iqy@...> *Description:* This is a Spectrum Analyzer plot of the 15-Meter Transceiver front-end filter- RF amplifier. Jim, K8IQY March 13, 2023
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File /K8IQY Home Brew 15-Meter Direct Conversion Transceiver/DC-RxMixer-AudioV2-Schematic.pdf uploaded
#file-notice
The following files and folders have been uploaded to the Files area of the [email protected] group. * /K8IQY Home Brew 15-Meter Direct Conversion Transceiver/DC-RxMixer-AudioV2-Schematic.pdf ( /g/qrp-tech/files/K8IQY%20Home%20Brew%2015-Meter%20Direct%20Conversion%20Transceiver/DC-RxMixer-AudioV2-Schematic.pdf ) *By:* Jim Kortge <jim.k8iqy@...> *Description:* Receiver schematic for the home brew 15-Meter transceiver that I am building. It is complete, except for the Audio AGC section. The first version that I tried didn't work at all well, so back to the drawing board. I'll figure something out eventually. In the mean time, this much works just fine. Without the front-end filter section, I can copy signals on any of the ham bands, just by setting the VFO to the correct frequency. I've tried 80, 40 and 20 meters, and a quick foray to 15 MHz for WWVB. I'll update and release the PCB that I built it on when the Audio AGC issue is resolved. Jim, K8IQY, March13, 2023
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[qrptech] [qrp-tech] Added Folder /K8IQY Home Brew 15-Meter Direct Conversion Transceiver
#file-notice
Hi Alan, Here: </g/qrp-tech/files/K8IQY%20Home%20Brew%2015-Meter%20Direct%20Conversion%20Transceiver> ( /g/qrp-tech/files/K8IQY%20Home%20Brew%2015-Meter%20Direct%20Conversion%20Transceiver ) Nothing in that folder at the moment, but I'll try to get some stuff there before the end of the day. I've got the receiver board almost done, so I'll get it and the front-end filter (already built) stuff there soon hopefully. 72/73 and thanks for your interest, Jim, K8IQY
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Added Folder /K8IQY Home Brew 15-Meter Direct Conversion Transceiver
#file-notice
Jim Kortge <jim.k8iqy@...> added folder */K8IQY Home Brew 15-Meter Direct Conversion Transceiver*
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Availability of a New MagicBox Design
Good morning everyone, Today, we are announcing the release of a new MagicBox V2.5 design. The K8IQY/KU4QO MagicBox V2.5, is an updated version of the project designed by K8IQY in 2013 and kitted by the 4 State QRP group. In the prior version, the MagicBox could be used to connect a receiver and a transmitter together to operate as a transceiver, with all of the RF switching and Audio Muting handled by the MagicBox. It used a programmed microprocessor to control the functions within the box. The updated version provides all of the RF Switching and Audio Muting functionality of the original, along with the addition of an internal, speed adjustable, CW Keyer, power control for transmitters requiring an external power source to be switched, such as a Tuna Tin 2, and a redesign of the PIN diode RF Switching circuitry to handle higher transmitter power levels. This version can handle transmitters up to 20 watts, with very low loss. In addition, the CW keyer part of the system can be used as a standalone code practice oscillator or keyer for a rig not having that feature. This version uses an Arduino Nano clone for control, so that operational changes can be made by the builder. All of the project documentation lives on GitHub, <https://github.com/ku4qo/MagicBox2.5> ( https://github.com/ku4qo/MagicBox2.5 ) and is in the public domain, including the Gerber files for PCB manufacturing, Bills of Material, 3D printing file (STL) for the case, along with other useful documentation. Builders are encouraged to team up to acquire PCBs and parts for this project, and support each other. 72 and have fun, Jim Kortge, K8IQY and Mike Maiorana, KU4QO designers 03/25/2022
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Excess Parts, CA3039 Gone
All, Anyone who missed the first round of parts also missed the CA3039s; they're all gone. There's still plenty of PNP Transistors left though. Same request as before: 1. Email me your mailing address. 2. When the envelope arrives, try the parts. They're old and haven't been stored for ESD, so try them out. 3. If you like them, put 2 single dollar bills in an envelope, fold them into a piece of paper to make them more opaque, and send them to me to cover costs. 4. If you don't like them, don't send anything. You're not out anything. -- -- Bill Lazure W2EB On 1/25/2021 at 3:46 PM, "Bill" <bill@...> wrote: >All, > > I don't do paypal and don't want to, so let's try it this way: > >1. Email me your mailing address and which parts you want. >2. When the envelope arrives, try the parts. They're old and haven't been >stored for ESD, so try them out. >3. If you like them, put 2 single dollar bills in an envelope, fold them into >a piece of paper to make them more opaque, and send them to me to cover costs. >4. If you don't like them, you're not out anything. > > By the way, I estimated poorly; there's only a couple hundred of the >CA3039. > > Finally, the cost and hassle of sending these overseas makes this deal >prohibitive for me. US destinations only. > > P.S. To whoever sent me a paypal without asking first, I don't want to >sign up for Paypal. Take your money back and send me your mailing address and >we'll give the USPS some business. > >-- >-- >Bill L >W2EB > >On 1/23/2021 at 2:11 PM, "Bill" <bill@...> wrote: >>All, >> >> My employer tossed some old parts. I grabbed a box that contains >several thousand each of CA3039 (6 matched diodes, low capacitance, low >forward voltage) that might be useful for mixers, and MPS6518 (PNP General >Purpose in TO-92 package, compared to 2N3906). >> >> If you need some send me buck and I'll put some in a padded envelope for >you. >> >> My address is good in QRZ. >> >>Bill >>W2EB >> >> >> > > > >
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Excess Parts, next attempt
All, I don't do paypal and don't want to, so let's try it this way: 1. Email me your mailing address and which parts you want. 2. When the envelope arrives, try the parts. They're old and haven't been stored for ESD, so try them out. 3. If you like them, put 2 single dollar bills in an envelope, fold them into a piece of paper to make them more opaque, and send them to me to cover costs. 4. If you don't like them, you're not out anything. By the way, I estimated poorly; there's only a couple hundred of the CA3039. Finally, the cost and hassle of sending these overseas makes this deal prohibitive for me. US destinations only. P.S. To whoever sent me a paypal without asking first, I don't want to sign up for Paypal. Take your money back and send me your mailing address and we'll give the USPS some business. -- -- Bill L W2EB On 1/23/2021 at 2:11 PM, "Bill" <bill@...> wrote: >All, > > My employer tossed some old parts. I grabbed a box that contains several thousand each of CA3039 (6 matched diodes, low capacitance, low forward voltage) that might be useful for mixers, and MPS6518 (PNP General Purpose in TO-92 package, compared to 2N3906). > > If you need some send me buck and I'll put some in a padded envelope for you. > > My address is good in QRZ. > >Bill >W2EB > > >
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Excess Parts
All, My employer tossed some old parts. I grabbed a box that contains several thousand each of CA3039 (6 matched diodes, low capacitance, low forward voltage) that might be useful for mixers, and MPS6518 (PNP General Purpose in TO-92 package, compared to 2N3906). If you need some send me buck and I'll put some in a padded envelope for you. My address is good in QRZ. Bill W2EB
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Happy New Year 2021
2020- wow, what a year. My Happy New Years wish is for 2021 to be much better for everyone. My special thanks to all who ordered my e-book. Prior to covid-19 I procured my breathing medicine for $10 to $20 a month. With all the travel and shipping limitations due to covid I am forced to procure the meds in the USA at $98 a month. Your orders have assisted that without cutting my food budget. Hopefully that will continue in 2021. See more at QRZ.com /db/W4BWS So Happy New Year 2021 and for to all have a more healthy, secure and prosperous 2021. I will be looking for everyone on slow key night December 31 and during January 1. 72/73 Dr. Don W4BWS SKCC # 81C God Bless All "Basic Wire Antennas" my new book available for $5 sent to my email address via paypal friends. More info at W4BWS on QRZ.com.
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PCBs for NorCal 2N2/XX Rig
All, After a lot of discussion with close associates and thinking through all of the issues with making the PCB available for the NorCal 2N2/XX rig, I've decided not to do it. Here are the main reasons why. That PCB is really dense, so much so that many of the support issues I had to deal with came down to builders putting the parts in the wrong place. In addition, there are 300 parts needed for that PCB, many of which are no longer available, and some of them were quite expensive like the 10-turn tuning pot at nominally $10.00 per unit. It is obvious to me that a substantial amount of time would be required to find suitable replacements for the extinct parts; I have neither the time nor the inclination to do that for a design that is now 11 years old. Additionally and realistically, since I was the designer of the rig, most of the support questions would come to me; I've moved on and can't get back into that mode. When the kit launched, support issues took over my life for most of a year. I'm going to be selfish and not let that happen again. Finally, all of the documentation for the 2N2/XX is on my web site: www.k8iqy.com ( http://www.k8iqy.com ) so you can get the docs, build any of the 3 bands Manhattan-style, like I did originally, or make your own PCB using DipTrace or KiCAD with the changes you see fit (like DDS tuning and Digital Display) on a PCB sized to your liking. So, I hate to disappoint all of those clamoring for 2N2/XX PCBs, but for the reasons above, (and a lot of other unspoken reasons) it won't be happening. 72/73 to all and enjoy the upcoming holidays, Jim, K8IQY PS....thanks to all who offered to help out with making boards available, I truly appreciate your support.
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New Group Created: [email protected]
Hello everyone, I have created a new group at [email protected]. Please do join. You all might not know me because I use joined, but owning groups of various types is something I've done a lot of. Thank you for allowing this message through moderation, Chuck. 73! (or 72, if you prefer) -- Ryan Flowers W7RLF https://miscdotgeek.com
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EOL
OK, proved my point that there is nothing left for this group to accomplish technically. Going to moderated mode and postings will be left to die after 14 days in the queue. End of this group. Take discussions to qrp-l and may the electromagnetic force be with you always. Everything up to this point will be left as is until groups.io decides to start charging fees.... Please do not migrate files to other groups. They were put here by the owners and they have all rights to same. ciao, chuck, k7qo
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QRPGuys DSB Digital Transceiver
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Gang, We are pleased to offer the QRPGuys DSB Digital Transceiver kit. It includes three easily changed FT8 band modules for 40/30/20m. The kit uses all thru hole components. Price is $40. We are also offering bare band module pcb's for those wanting to experiment with different bands and modes, 4 for $10. Come by and see it at <https://qrpguys.com/digital-transceiver>. ken - wa4mnt www.qrpguys.com
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Phasing SSB Transceiver: Homebrew w/o a scope?
10
Hello everyone, This is my inaugural post here in the QRP-Tech group. I have done a lot of hacking on the BITX40, and feel that i understand it fairly well. I also have homebrewed a DC receiver. I've written about that all on my blog in case anyone cares to read it, https://miscdotgeek.com. I followed the digital DSB thread with great interest, and if you read my site you'll see I've written on the subject. Part of the discussion that piqued my interest was a post in which it was explained how a simple SSB transceiver could be built using phasing. I don't fully understand phasing (the math in EMFRD is waaaay over my head) but it looks like if one does the math right (using online calculators?) it would be simple enough to design and construct. And thus my question emerges. I don't own a scope although if intend to eventually. But lets say I don't, and I want to homebrew the simplest SSB transceiver design: A direct conversion receiver with a phasing filter to the audio amp, with the same filter used in reverse to strip the sideband going to the PA. Allison (Who I am hoping will shed some light on this subject!) mentioned it would be pretty simple, which I understand to be a very relative term :p What designs exist, and could they be built without a scope? That is my question. -- Ryan Flowers W7RLF https://miscdotgeek.com
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QCX-40 Working...Sort of...
4
Finished the assembly and started the tuning and adjustments. Connect power -- No Smoke! Adjusted contrast -- OK Started at step 3.71 Did the "Select Band" step, OK Pressed "Left Button", OK Pressed "Long Press" and NADA... Tried a few things like touching up solder joints and checking parts, no change. I'd plugged in a straight key with mono plug. Was trying some things and noticed the DL was getting warm. (Output BS170s barely warm) Pulled the key plug and keyed with the switch -- OK. Plugged in Paddle; both levers straight key. Checked the manual -- Straight is default mode! Plugged in a straight key with a stereo plug; OK. Not being able to adjust or change anything except frequency, here's the condition of the functions. o Power off then on, comes up 7020. Easily adjusted/tuned to other frequencies o Measured the output power - 3.5 W, looks "clean" with the small Hantek 2C42 O'scope. o Rx sounds good: To my ear, noise level and sensitivity sound about the same as my FT-847 o Side tone is pleasant, a clean sine wave. o Right button seems to do what its supposed to, a/b menus etc. o Morse is decoded accurately both TX and RX, didn't like it when tuned to a pile-up though... ;-) At this point, I could use the rig quite nicely to make QS. But missing the benefit of all the other features and functions, of course. Some serious trouble shooting in order to see what I did wrong with the left button circuits. If that's where the problem is anyway. Here's some results from the RBN at 3.5 W output. K2DB W5USJ 7055.1 CW CQ 10dB 14wpm 0939z 31 Oct KM3T W5USJ 7055.0 CW CQ 4dB 14wpm 0938z 31 Oct KM3T-2 W5USJ 7055.0 CW CQ 4dB 13wpm 0938z 31 Oct K1TTT W5USJ 7055.0 CW CQ 2dB 14wpm 0938z 31 Oct KO7SS W5USJ 7055.0 CW CQ 14dB 14wpm 0938z 31 Oct VE6WZ W5USJ 7055.2 CW CQ 17dB 14wpm 0938z 31 Oct W8WWV W5USJ 7057.0 CW CQ 20dB 13wpm 0937z 31 Oct KO7SS W5USJ 7057.0 CW CQ 18dB 13wpm 0937z 31 Oct VE6WZ W5USJ 7057.2 CW CQ 18dB 13wpm 0937z 31 Oct Fun Stuff... Chuck, W5USJ (ex K2OFN) ARCI 5422, SKCC 19956 EM22cv, Rains Co., Texas
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Wilderness NC40A sked?
9
This is cross-posted in a few IO groups, just FYI. I have a virgin Wilderness 40A Rev C and want to start sea trials with another 40A. Whether it is a qrp-tech 40A, a Norcal version, or a Wilderness kit, all are good in my mind. Anyone with a 40A interested in a sked around 1000 or 11oo zulu? Thanks all, Mike N6MST
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Hello. I am working on an ATtiny power / SWR meter, basically a smarter replacement of the famous Tayloe SWR bridge. It will be a 1W to 5W (maybe a bit higher, up to 10W) QRP resistive bridge with 6 LEDs analog-like baragraph, with the intensity being interpolated between two successive LEDs enhancing the baragraph resolution to at least 4x6 levels (I can easily recognize 1 LED illuminated from 2 LEDs equally illuminated and 1 LED illuminated significantly stronger than the other). I have the baragraph electronics and code prototyped, it works quite nicely. The electronics (ATtiny13A driving the 6 LEDs) will be powered from a 3V low drop low low quiescent current 16V max input linear regulator, and the linear regulator will be powered with a 1:2 or 1:3 transformer from the radio RF power, rectified by a single 1n5711 shottky diode (the diodes will be used in the bridge anyway, so to reduce the BOM complexity). Look ma, no batteries. There will be a larger capacitor at the input side of the regulator, so the microprocessor will have couple of seconds to perform additional tasks after key up, that is to show the input power with quite a high accuracy. So there will be no button: SWR will be shown during key down, and power will be shown after a second or so after key up. I feel quite confident with digital design and programming, but I am not quite sure about the RF side. Namely, what transformer should I use to feed the linear regulator? These are my back of the envelope calculations: On the transceiver output, when loaded with an open resistive bridge (all three resistors 50 Ohm), the SWR is 2:1 and the voltage at the transceiver output is 1.3333 * of Vpeak (assuming 50 Ohm output impedance of the transceiver). Likely the maximum voltage will be lower as the output impedance of the transceiver PA is not resistive. These are the maxima: 10W -> 42.16V Vpeak at SWR 2:1 7W -> 35.28V Vpeak at SWR 2:1 6W -> 32.65V Vpeak at SWR 2:1 5W -> 29.81V Vpeak at SWR 2:1 The minimum Vpeak at 1W transceiver output with the resistive bridge shorted (again producing SWR 2:1 at the transceiver) will be minimum 8V assuming the transceiver PA output is resistive. If not, the output voltage will be closer to 10V peak. Now the digital circuit requires a minimum 3.1V at 1.5mA DC before the linear stabilizer, and the power will be rectified with a single diode, but the micro will likely work happily down to 2V even if the linear regulator just passes the voltage unregulated, as the micro may use its internal 1.1V voltage reference for measurements. Operating the micro unregulated sounds unusual, but it may be a viable option if tested, especially if the input voltage will be stable enough due to the large capacitor before the regulator. Now my question is: 1) Should I use a 1:2 or 1:3 transformer? Using the 1:2 transformer may require additional zener diode and likely a resistor before the linear stabilizer if the input voltage could exceed 16V peak. 2) What will be the tiniest / cheapest ferrite and how many widings will be optimal? I suppose this decision will be strongly dependent on the bands supported. My personal goal is a 40m-20m EFHW tuner. And also: Will there be an interest for a kit? Through hole or SMD? It may be a nice "introduction to SMD" kit as the number of parts will be pretty low. What bands? What power range? Should it contain an EFHW tuner? My personal preference would be a "NJQRP Rainbow Tuner" like setup covering 40m-20m with a T50-6 transformer, mica compression capacitor trimmer, jumpers to select the primary winding with another jumper to add a capacitance for 40m coverage. Thanks and 73, Vojtech OK1IAK (former AB2ZA)
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Dead (or seriously-ill) FeelTech FY3200S
Maybe some of you have had this same problem. After about a year of non use, I fired up my Feeltech FY3200S and was greeted with a lit-up but otherwise blank LCD, and a constant howl from the on-board annunciator. No pushing of buttons or turning of knob did anything. BTW, I've already removed the leaky power supply it came with and I'm using an external one for the +5 and +/-12V power. As far as I can remember, it was working fine after I chucked the bad supply (to be clear, it was working fine on the factory-installed supply, but I was disturbed by reports of AC on the BNC grounds). I've checked and triple-checked the supply voltages, and removed the main board from the case for close examination. Even under magnification, all looks okay. The thing's too cheap to spend much more time on, but has anyone on the group had a similar experience? Any solutions? 73, Todd K7TFC
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Sat 8:39am
Sat 8:39am