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A few weeks ago, I started building a 2N2/20 from a kit and ran into a problem with what appears to be a lack of gain somewhere in the receiver. I couldn't figure out where the problem lay. As a result, I thought that if I scratch-built a 2N2/20 using the same schematic as the Norcal kit version, I'd have a working unit with which to make measurements and comparisons. I've been wanting to scratch-build a 2N2 rig for years now anyway, so this was a good opportunity. I wasn't going to post anything until it was completely finished and fully operational, but I'm running into a small snag, so thought I'd share my progress so far and share the info, in case anyone can shed some light. The picture shows the state of the build as of 2 days ago. Everything seems to be working normally, based on simple tests touching wire antennas to the inputs of the various stages, and listening to the sounds from the speaker. The only abnormality is a slight instability in the IF amp stage immediately following the main 4-pole crystal filter. I have circled this stage in the second picture and also in the schematic. It manifests itself as a scratchy noise in the speaker. When I bring a finger in close proximity to the toroidal transformer T11, or either the 100 ohm resistor R36 or 01.?F coupling capacitor C46 that feed the input of the MPSH10 transistor, the noise stops, but the gain of the receiver strip is not affected. It just kills what sounds like some kind of parasitic oscillation. I replaced the 0.1?F cap C46, suspecting a noisy component, but that wasn't it. I may end up rebuilding the stage. We'll see. Anyway, the debugging process is engaging, and it gives me something to do when I get up in the morning. In other news, I've had the pleasure of two very brief QSO's with Chuck on 17M in the last few days. QSB was working against us, but I'm happy with brief exchanges anyway. Chuck and I are only about 600 miles apart, so it's not too challenging a haul for a couple of QRP'ers. Dave AA7EE Dave AA7EE

Did get two chances to work Dave, AA7EE, on 17m. He called me once and I called him once. Time of day when you are 599 and 15secs later you are gone. Nil. Nada. Zilch. Thanks Dave. Attached is the audio amp board about ready to go. Not as neat as Daves work, but it is sure fun to build. I had to start this project his morning and I'll have it done by sunset. Using the same size board, but sheared into 3 parts, I'll build the other three sections. Then the plan is to attach them to the back of this board, thus coming up with what may be the smallest form factor or all. I'm not in the same league as Dave, AA7EE, and Jim, K8IQY, but I do enjoy working the technique. I recommend it for anyone who has a small project to learn with. Just do it. The Manhattan Madness continues. FYI -- 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,ID,IL,NC DXCC W,VE,JA,PY

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

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

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

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

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

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

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

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