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For those of you wanting to do Manhattan construction. You want to plan ahead as much as possible. And not spend a lot of time being an artist. I found that if I use a membership card for a gated community that has the lanyard hole already in it, it works to easily place and draw pads on paper with a pen or pencil. Possibly use an expired credit card and use the hole punch and make the hole sizes you need. Punch through the magnetic strip and card numbers for security. And I just draw a from pad to pad with a centered space with the part number, i.e. R1, and I don't have to spend a lot of time drawing outlines for resistors, caps, etc. Does not have to be to scale and you adjust as you build. dit dit -- chuck adams, aa7fo QRP WAS 17m started Apr 2, 2025 WAS-17 QRP --> TX,FL,SC,GA,OK,AR,KS,AL,AZ,MN PA,CA,CO,WI,NE DXCC W,VE,JA,PY
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Encyclopedia of Electronics Vols 1-6
11
Gang, Probably, most of you know about the Graf series of books titled "Encyclopedia of Electronics" with volumes 1 through 6. Just about anything you are looking for may be in there. Crystal oscillators to sirens. Amplifiers of all types and the list goes on. All six volumes are on archive.org and are downloadable. If you are looking for something to do, then you should consider spending the next three or four months reading these in your spare time. You wont have any spare time when you start. Been there. Done that. Or read them in place on the web. FYI chuck, aa7fo
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LTSpice vs ngspice vs DeepSeek vs ChatGPT
4
It's a different environment today for simulation. I can't run LTSpice on my ARM based Orange Pi 5 Plus like I can on the 32 processor Intel. But I can run ngspice for circuit analysis just fine. But, for grins, I asked DeepSeek to give me the tuning range for the values KD1JV was using for the ADC-40 receiver BPF in the front end. That's reason for the order for trimmers. Was getting different values than the BOM (which is changing daily and the reason I don't like doing one until the project is complete). So, the point, no more cranking up simulation and for getting the slide rule out for some things. Just type in a simple question and out comes the analysis and the values. Try this on the AI of your choice. Given L=12 micro Henry. What is the resonant frequencies for C=30pF and 5pF? For DeepSeek I'm impressed. It shows each step. Kids in the engineering and the sciences don't have to do homework anymore. Didn't try the others. Also, I use the turns calculator for toroids on KitsAndParts.com and compared with DeepSeek and results were slightly different, but good enough for starting assembly. FYI -- chuck adams, aa7fo WAS started Apr 2, 2025 at 5W. WAS-17 QRP --> TX,FL,SC,GA,OK,AR,KS,AL,AZ,PA,MN
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Jim, Thanks, I've used them before. When do we start getting hit with the tariff charges? Can I get an order in soon enough? I went ahead and ordered the Honbay trimmers, as I get them today and I can get the ADC-40 project back on track. So, let me take one for the team and I'll run an analysis and report back to the group at large, if they don't mind. I got KS yesterday around 0000UTC, so I'm willing to get on your frequency of 18.080MHz (the same one I start out on almost every day :-) ) today and we'll try to hook up. I'm up to nine states in 4 days with my one element beam at 4m. I've hit Japan twice in the last two days grey line. Hoping for KL7 and KH6 at the same time. Funny story. I had fired up the rig and heard N6TR/7 (the most famous contest op in the world IMHO) Tree working VT. So OR and VT to get in 15 sec. (*&(*)(*#$ My patented AA7FO Bencher paddle failed to operate. Pic attached. It has been sitting on the shelf for decades. I had run paper between the silver plated contacts. But, the ground is connected through the four pointy contacts and dust/corrosion/rust... had made a high enough resistor to not trigger the keyer. Got the N3ZN paddle and by that time they were gone. I'll be running my old QCX+ from QRP-Labs and I have a QCX-mini to build when I can get the ADC-40 project off the workbench. Did you know the QCX-mini has sold over 16K units. They are used a lot for POTA and SOTA ops as far as the YouTube videos seem to show. I got AZ yesterday with a ham 2km away in the same gated community. Didn't know I had any one on HF in the same complex. Funny. See you this afternoon buddy, -- chuck adams, aa7fo WAS-17 QRP --> TX,FL,SC,GA,OK,AR,KS,AL,AZ
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Trimmer Capacitor Kits on Amazon.com
5
Choices are Honbay or Acxico. Any preference or experiences with either or both? -- chuck adams, aa7fo WAS-17 QRP --> TX,FL,SC,GA,OK,AR,KS,AL,AZ
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This is a new one for me. I copied a couple of old sources for ft testers but some of them just vanished from the hard drive. One was a real nice PNP/NPN with a VFO and meters. 1960s. You could test common base or common emitter max oscillator use. Alpha Test or something. An old VHF manual had this in it. Was trying to squeeze it into an altoids tin but moving interrupted that build. I wonder where it is.... At the time, I was looking for a small variable cap 1 to 100pf. Just may go with a multipole mini rotary..... There is this one from techlib https://techlib.com/newprojects.htm Ft tester and included is an LTspice file. This could be automated with a micro, 5351, a couple of diodes, and a display. Maybe add the DC beta test, and the BVcbo, BVceo, BVebo and .... mission creep. The test is done at about 10 mA. The CAL and OUT points would typically connect to a scope, preferably through coax terminated with 50 ohms at the scope, but 50 ohm resistors and scope probes should work, too. Other measurement devices will also work. The user plugs in the transistor and adjusts the frequency of the signal generator (set near 10 dBm out or lower) until the signals at CAL and OUT are equal in amplitude. F is 20 times that frequency ND6T made a simple tester from an absorption wave meter from a hamfest. http://www.nd6t.com I have only text, the images didn't come through
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Solder expring
4
In the post earlier today about tariffs there was mentioned the pricing of solder. I have had good luck with picking up mostly full rolls of solder at garage sales or when the shop at work has to dispose of it because it "expires". I am sure many of you are familiar with similar industrial practices that adhere to strict shelf life requirements. I have used and or tested many of these rolls of solder, and they often work just fine. So the question is: Does it really expire, or more precisely, go bad? And yes, I am certainly familiar with the rosin vs acid core varieties and the leaded vs lead free. I do pay attention to that fact when picking up said items at garage sales. Sometimes I do want the acid core solder because I use it in the garage for different things. -Albert KI4ORI
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Worked a critter yesterday and he said he was sending a QSL card to confirm QSO. Went looking for online source/printer and not having any luck since we lost W4MPY. Any ideas? tnx -- chuck adams, aa7fo WAS-17 QRP --> TX,FL,SC,GA
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1. Screenshot... New Manhattan layout diagram for an AA7FO Noise Generator /w values 2. 1698.jpg How I mount a transistor with 3 legs on pads. Compact. IMHO. 3. 0614.jpg Note diode and resistor lower right have leads soldered to ground plane. 4. 0617.jpg This is what I do when I have multiple leads going to a pad. I wait until I have all leads in place and then solder. Saves expensive solder. On the layout diagram. The dark circles are pads with leads soldered to them. The leads with multiple circles drawn represent the lead is soldered to the ground plane. The resistors are mounted in vertical position. And 1037.jpg shows what parts mounted end up look like, even though this is with a Muppet board that K7QO used to make for me. I have not shown in the layout the specific details on attaching the 9V battery. I used the snap on critter that I got in quantity from ebay. For the output I solder the ground lug to the ground plane and it serves to give a good solid support to the BNC connector. Think outside the box for your own. FYI. Just wanted to clarify for the new Manhattan builders for now and in the future. Download the photos so you don't have to go looking for them. I hope 1037.jpg looks OK. It did with one viewer, but enlarged for view with thunderbird for some reason. -- chuck adams, aa7fo WAS-17 QRP --> TX,FL,SC,GA
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For some things that I test on a receiver, I find the following to be of great use around the lab. It uses the fact that a zener diode will generate a lot of random noise. Let's not nit the pink vs gaussian vs exponential vs white vs .... types of noise. 1. Use it at the build of each stage in a receiver, if you start with the audio amp first as in the series of videos I'm doing. 2. Use it after a build or even for working rigs to test the IF filter. Requires an audio analysis computer program that shows a spectrum plot. I'm currently looking for an ARM based SBC program since most non-free software binaries run only on Intel/AMD base computers. Open source would be great. 3. Irritate the neighbors. Attached: 0084.jpg original prototype using on two stages on PCB done toner transfer Screenshot... showing Manhattan layout drawn by C program I wrote I will come back and change the call sign. :-) Schematic lost in the dark caves of large SSDs and to be recreated at some later date. But you can reverse engineer the layout to a schematic. You've been there and done that many times before. BOM: R1,R3,R5 1.2K 1/4W resistors (not too critical) R7 680ohms 1/4W resistor (drives the final stage harder) C1,C2,C3,C4 10nF mono or disc caps (.01uF if you prefer labeled 104) D1 6.8V 1/2W zener diode Q1,Q2,Q3 2N2222, 2N3904 or 2N4401 NPN transistors (just about anything) The part values are not critical. You can use what you have in the parts depot in the closet and it's more fun to experiment. I think I got everything. Exercise for the student(s). This critter will be used pretty soon in the ongoing videos and there after many times. FYI -- chuck adams, aa7fo WAS-17 QRP --> TX,FL,SC,GA
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VHF QRP project/building
8
Good afternoon gents. I have a project that I would like to work on and would appreciate some input. Most of the QRP stuff I see is HF related, and I was looking for ideas and resources for a VHF project. I have always wanted to build my own "walkie-talkies". I have a reproduction military BC-611 case, and what I would like to do is build two different chassis, one each for 6m and 2m FM that will fit/slide into this housing. I would like to keep the project pretty basic in features, with repeater split and CTCSS tones about as feature rich as I want to go. I have dealt with microcontrollers before, but have not really dealt with RF. I was figuring that one of the DDS modules and/or the programmable oscillators might be the place to start with this. Links to websites, books, other hams, and whatnot is appreciated. Also, I know this is an outlier for this group, so if this question is better presented somewhere else please let me know. Thanks, Albert KI4ORI
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Hi Everyone The uDCR2 worked so well I thought I'd have a go at an SSB version. It uses the phasing method of image rejection. The PCBs are here and I've started building. This is the filter response: It is actually easier to build compared to the uDCR2 because the mixer is SOIC. Cheers, 73, Ian VK7IAN
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A must watch
7
Please. You have to watch this video I just did. Please. Pretty please. <https://www.youtube.com/watch?v=qkwBw5dR_gs> This is a test to see if you really really understand parts of a superheterodyne receiver. The video is 8 mins long. At one min you see the change in the signal from the previous videos. Sorry about the speaker wires for a little bit, but you can tell what is going on and the wires move away. Then a little after 4 mins you get a quiz. Let's see if you just memorized stuff for your electronics amusement. :-) Thanks for the time, it is appreciated. This is getting exciting for those of building the transceiver. ciao dude, chuck, aa7fo
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BOM
Here is updated from several viewers. Check one more time for effect. The X1 in the transmitter will be renamed X5. The original was named X1 due to being on the one page for the transmitter. thanks in advance, chuck, aa7fo
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Gang, I uploaded two new videos to @aa7fo on the ADC-40 project. For the 6 of you following. Will be on hold for three days to allow you to catch up. I have to put up an antenna this afternoon and get on 17m to start and complete WAS by the end of the year. Look for me, please. Love to do it all qrptech guys and gals. I'm still made at HRO for charging me $20 freight charge on two hamsticks that I bought in store. Not a good business model in my opinion. Waiting on K7DD to get back to me. Challenge: I have accepted the DC receiver challenge build from SolderSmoke that is being run by Mike, Pete and Dean. This will take me three days or so and it's hunker down time. I'd love to see some of you do it also and show some group pride. Heat up the irons and let's get to work. chow, chuck, aa7fo
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VE3DNL Marker Generator
2
Remember the VE3DNL generator from the qrp-l mail reflector? Used 5.12MHz crystal with a divider to generate signals every 5, 10, 20 and 40KHz. Kitted by NorCal and others a long time ago. K7QO came up with a similar critter using a 4.000MHz crystal and a Microchip 12F508 8-pin DIP uP in 2009. I was using it in the #006 video posted today. Handy when you don't have a working crystal checker. :-) See the video for a good laugh. I bought two Raspberry Pi Pico critters to try the same thing. Have to order a micro-USB cable to program 'em. In the meantime, one of you experts want to do it for fun? The group would appreciate it. Any SBC with GPIO ports can be programmed to do it, I'm sure. Just an idea for your consideration. chuck, aa7fo
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Updates
BOM for the ADC-40, Version 1.0 attached. Do not use. Do not put anywhere. We need some people to double check it. ASCII file. Not cross referenced yet or spreadsheet format. Typo 101. Here is the deal. Those of you about to build it Manhattan style or waiting until I release the boards (which will happen after I build one), please printoff the list and print a copy of the schematics previously reverenced in previous postings. Highlight components one by one in both the list and the schematic and see if you come out even. If not, then send me an email off list to chuck.adams.phd@... and let me know where I screwed up again. 17m WAS: one state down. K=5, but I managed three stations in TX. RBN spots me only in TX. Hoping for better results as we go along. Built another section on the ADC-40 PCB. Video at 11 later. Got the BOM for the DC receiver made up and the audio board planned. Audio transformer coming via amazon tomorrow. Moving along down the road. ciao, chuck, aa7fo
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The QRPp Journal of the Northern California QRP Club, Volumes #1 to #11 [long]
14
Gang, From 1993, the year in which the NorCal Club was formed, until 2003, Doug Hendricks, KI6DS, expended considerable energy, time and expense to provide a quarterly publication so indicated in the title of this posting. I personally, and I'm positive (like a proton), that I am not the only one that considers the work one of his best works. Consider herding cats. That would be much easier than getting a bunch of ham radio guys and girls to sit down and write about their adventurers using, building and reviewing everything known to mankind to be published. Well, related to radio stuff and the hobby. Being an early member of the club and a devote hoarder I bought and saved every issue. A few years after the publication stopped I wanted to be very sure that the work could be preserved. I scanned in, as best I could with the equipment that I had, every issue. I then gave the work to Doug and he had it on the home page of the club. He gave up the club to a committee (as clear as my feeble mind can remember) and left everything in their hands. The page was last updated 2019 as shown there. I recently discovered the work has disappeared from the home page. The link is broken. I contacted Doug and asked his permission to put the work on archive.org for posterity. Archive.org is a valuable resource and I hope and I pray that their work will continue forever. So, if you go to <https://www.archive.org> and search for 'QRPp Journal', you don't need the whole string you will find my postings and you will also find some uploaded by another individual that you may find useful. I am not a fan of the grey contrast myself. It is there for the non-commercial use of the audience and not for transfer to other sites. Besides, the files are huge. Feel free to download them to your drive(s). One of the things that archive.org is it uses ABBY Fine Read 9.0 to do OCR of PDF material and creates a file thereof. I started a long time ago and tried to create a table of contents for all 11 years. It was too much for me. But now, with the ASCII text, maybe some hero can come forth and create same by selective cut and past of the text files. There will be some typos, I've found no OCR program on the Earth that is 100%. None. Not even AI could do it. If you get bored, if you want to look at history, if you are looking for adventure or you are looking for a Manhattan Project, either easy or hard, then the above 11 volumes could be a goldmine for you. Let us know. ciao, chuck, aa7fo, NorCal #40 P.S. I want to thank Wayne Burdick, N6KR, and the club for naming a rig after me. :-) P.S.S. If you have a better scan of one or more of the issues, please, please, put it up on archive.org or send it to me and I'll make sure it gets there.
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2SC5706 from Kits and Parts
8
I notice that Kits and Parts have a good quantity of the through-hole version of the 2SC5706. I think the through-hole version of this transistor is now obsolete, which is why I'm interested. I'm attempting a scratch-build of a 2N2 for 20M, and wondering if this transistor would be a suitable replacement for the 2SC5739 final? Either way, it looks as if it could be useful for QRP PA's. Dave AA7EE
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I am sure many of us have built the cheap crystal checker/counter available in kit form from China. I have previously used them twice before for receiver frequency displays. They use a PIC16F628A in a circuit that I think originated with DL4YHF. A couple of months ago I ordered a couple more of these kits intending to use them in upcoming projects. When they arrived I quickly built one up intending to use it to help with some software development I was working on. It did not work. Annoyed I checked my construction. You get no circuit with the kit but the circuit is pretty simple. I quickly realized that the time base oscillator (20MHz) was not working. I found that the crystal was okay so I put the PIC chip in my programmer thinking that it may not be programmed and found it didn't meet the device ID for a PIC16F628 and didn't pass any other tests as a PIC chip. Okay I thought maybe I had received a dud. The PIC16F628 from the second kit also acted the same way. I left a bad review on the sellers site and ordered another kit from a different vendor. I am sure you have already guessed I had the same result with the PIC chip from this new kit when it arrived. I tried to obtain some PIC16F628 chips locally but my normal suppliers have deleted the DIP version. I did manage to get a SMD version and soldered this to an SMD to DIP adapter board. I managed to prove that this was the problem but during the process destroyed the kit's PIC's socket with the thicker adapter board pins. Finally some PIC' chips arrived from www.futurlec.com. After programming at last they gave me working counters. I am very aware of fakes from China but thought that kits would be okay. I just can't understand the logic of someone supplying fake chips in a kit. They will just destroy the market for those kits. Even if whoever put the kits together was sold fakes by someone else it has to mean that they have no quality control process in place. So I thought I would put this out there in case others have also fallen for these fakes. The good news is that the rest of the kit seems okay so if you replace the fake chips with real programmed PIC16F628 chips you will get a working counter. 73 Mark VK6WV
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