At around 0630 EDT on June 7, 2025 I heard K1OA calling CQ on 7030 kHz CW. This was exactly where I had a crystal. I called him, but he didn't hear me. I sent him an e-mail. We tried again -- he heard me calling him and I heard him responding by calling me, but I don't think we succeeded in exchanging signal reports. It was close, but no cigar.
I had to walk the dog. Scott and I agreed to meet on 7030 kHz at 0730 EDT. Arggh. There was a QSO there. I thought we might have to try to change frequency, but this would have been tough because both of us were crystal controlled on transmit. Fortunately, the contact on 7030 kHz wrapped up. Scott called me, I responded, and we were able to exchange signal reports. I was so excited that I almost forgot to hit the record button on my phone. But I caught the last minute or so. See above.
This was really something. This really goes to prove what Dean and I have been saying all along: this receiver is not a toy! It can be used for real ham radio contacts. And now we have had these receivers on both ends of a contact. For transmit, Scott was using a KA4KXX transmitter with about 3 watts output. I was on my Tuna Tin 2 at about half a watt output.
Thanks Scott! And thank you Walter!
Inspired by K1OA and KA4KXX, I put the SolderSmoke DC receiver to work on the CW portion of 40 meters. At first I used a very (perhaps overly) simple "Ten Minute" transmitter. On June 4, 2025 I worked N2WJW in New Jersey. But the transmitter drifted as it got hot. So I switched to the more robust Tuna Tin 2 (TWO transistors!) and worked W2XS in NY and N9FGC in Indiana on June 5. With both transmitters I was "rock bound" -- crystal controlled. Power out was always less than 200 milliwatts. Antenna was a low to the ground dipole. The receiver was powered by our beloved 9V battery. The transmitter had a second 9V battery. Some observations: First, even if you CAN hear other signals, the different tones allow your brain to seperate them out (this has long been known to CW operators, but might not be readily apparent to newcomers). So even if the DC receiver is broad in frequency response and even though it IS also receiving the other side of zero beat, you can make CW contacts (unless, of course, another station is on a frequency that produces exactly the same tone as the one you are trying to work), even at very low power . Second, you don't always really have to be right on the other station's frequency. Here's why: If he is looking he can see you in his waterfall! So that SDR waterfall is now a friend to crystal-controlled HDR operators. Who would have thought? Above is a picture of the my station with the Ten Minute transmitter. See the notes I wrote on the QSO with N2WJW.
This goes to prove what we have been saying all along: this receiver is not a toy! It is capable of operating as part of a real 2-way ham radio station. Hall of Fame member Scott K1OA has paired his receiver up with a Merry Christmas transmitter designed by Walter KA4KXX and has been making CW contacts with it (see above). Walter supplied the crystal and many of the needed parts. Scott has already worked WA9RNE, N4HAY and W3RJ, and has tried making contact with Walter but no luck yet. He has gotten RBN reports from Germany and New Zealand. All that with just 3 watts.
This is not the first time this receiver has been out to use. I made one contact with it using a "Ten Minute" QRPp transmitter that I had intended only to use for test purposes:
https://soldersmoke.blogspot.com/2023/02/first-qso-with-high-school-receiver-100.html
HoF member Aaron ZL1AUN used his receiver with an SSB transmitter to make contact using his receiver:
https://soldersmoke.blogspot.com/2025/02/soldersmoke-direct-conversion-receiver_23.html We understand Aaron's article about the receiver has been published in "Break-In" magazine -- we hope to get a copy (electronic would be fine!)
And who can forget HoF member Nate KA1MUQ who turned his "frying pan" direct conversion receiver into a double sideband transceiver and used it to make phone contact with Idaho from California:
https://soldersmoke.blogspot.com/2025/03/nate-ka1muq-turns-his-frying-pan-dc.html
If anyone is aware of other contacts made using this receiver, please let me know.
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A question this morning from Scott KQ4AOP caused me to Google this old book On page 59 I found the article about my first transmitter. Someone has put a copy of the entire book on the interenet. Here it is:
BTW. MXM stand for 1990, the year Bruce started his kit adventures. I worked Bruce on the first beta build of the transceiver Denton TX to Smithville TX on 40m during the day.
Thought you would appreciate a recent project inspired by the fabulous EMRFD. This started as a test bed W7ZOI universal tx to evaluate my stock of RF BJTs and employ some FT-243s in the shack. That was interesting by itself but the 16-32 dBm output (choice of device really matters!) did not reach the intended targets using my 40m dipole. So, add a W7EL RF PA and a nifty, clean 7W emerges after damping output from Q2. The final is pleasantly efficient and needs only a modest heatsink to survive key down for 60 seconds. KFS then reported S7-9. Success. Time to box it up and go XTO, add a meter output at 30dB down and an RF driven LED indicator. Left room to add an ATtiny85 CQ keyer but ran out of time. Had to move house and knock down my 40-6m antennas. That was the most painful part of moving. So this rig sits while I find a new place to hang antennas. Eventually, the TX will get a RX mate when it is possible to box up a 40m DC RX with Si5751 and OLED display. Am still trying to solve how to mount an OLED display cleanly in an aluminum box. First, I have to reconstruct my workbench.
Keep up your good work, and that is no April Fool’s joke.
73,
Chuck KE5HPY
Click on schematics for a better view
I picked this transceiver up at Winterfest for one dollar. 40 meters. Superhet receiver with 455 kc ceramic filter and 2 NE602s. Crystal controlled one watt transmitter on 7039.5 kc. I emailed Jeff KA2BKG and asked him to slide up a bit to my freq. I am glad he did. Thanks Jeff.
This post has a definite San Francisco vibe.
Hamilton KD0FNR appeared on the SolderSmoke blog way back in 2011. Perhaps he should join forces with N6ASD who lives quite close to him in SF, and seems to share radio interests. Also in their area is the esteemed Bay Areas blogger and homebrewer Dave AA7EE ; Dave recently sounded the CBLA alarm, alerting us to the presence of an intruder on 3579 kHz. In the process, Dave mentioned the Pt. Reyes Web SDR, the presence of which came as welcome news to Hamilton. Finally, Dave and Hamilton mention the KPH Web SDR, which brings to mind Dick Dillman W6AWO who has been on the SolderSmoke blog several times.
Hamilton and his kids have their rig (a Rockmite and a Tuna Topper in a Dole Pineapple can) mounted at the feedpoint of their dipole (in the red shopping bag above). They link to it via WiFi and Bluetooth. FB. Thomas Witherspoon has a nice presentation (by KD0FNR) of the TouCans project on his blog: https://qrper.com/2023/12/field-radio-kit-gallery-kd0fnrs-rockmite-20-and-tuna-topper/
Hamilton KD0FNR writes:
At the moment, the kids whose dad I am, better known as the gang—12, 10, and 8 year-old Diaze, Mota, and Tawnse.. all internet aliases—are big into 20 meters QRP CW with Project TouCans, a Rockmite coupled to a Tuna Topper. The radio and the amp that popped us out of QRPp to plain-old QRP are both housed in a Dole Pineapple can with a tuna can as a cover and antenna mount. The whole rig is still very much mounted in our half-wave dipole!
Project TouCans consists of a Rockmite feeding a 5 Watt Tuna Topper, all of which is housed in our dipole antenna. The Rockmite has a single crystal bandpass filter on it's rx input. That makes it a pretty wide reciever which is fine, but it's particularly sensitive to its tx frequencies, 14075.5 and 14058 kHz AND—for some reason I have yet to understand—10459 kHz. By watching the SDRs that now—thanks Dave—envelope us here at our home QTH in San Francisco, we can see the frequencies of incoming signals. That information keeps me from responding to 14059 kHz signals in vain.
And now, the headphone repeater: TouCans is completely wireless with respect to the ground. That means there's no power line, no feedline, no keyer lines and no headphone line. Keyer controls are handled via wifi to a Raspberry Pi Pico-W on the rig while audio is brought back to my headphones via Bluetooth. Power is provided by a USB-C battery pack that lives in the rig which is mounted above us in the antenna. (Yes, all of this is becuase I thought feedlines matches and baluns were too mystical and hard to understand years ago. Yes, this has probably all been more work than a balun. Yes, I am still totally enamored of my original design decision. :) ) Anyway, the bluetooth range is about 50 feet and the wifi range is shorter than that. The short of it is—pun not intended—that I can't quite use the rig while I'm in my office. But, I can send CQ to the rig every half minute or so via a memory keyer, then turn on the SDR in my office, and then sprint a bit closer to the rig when someone calls back. (It helps that houses in SF are a bit tiny.) So, SDRs are kinda an integral part of our QTH setup and it's awesome to learn about a new—to us—one! Thanks again!
-- I got a couple of books: "Weekend Projects" 1979 from ARRL, and "A History of QST -- Volume 1 Amateur Radio Technology 1915 - 2013" 2013 from ARRL.
-- On top of the Weekend Projects book you see a "Crystal Holder" from Gross Radio of New York City. W1UJR has some good history on this company: https://w1ujr.com/written-word/gross-radio-company-circa-1931/ This device seem to be intended to hold in place a raw piece of quartz! Cool.
-- To the right of the books there is a serious-looking VFO. One dollar! Deal! It is a CB VFO, but the markings say it puts out 5.44 to 5.99 MHz. So it should be useful. The dual speed dial is very nice.
-- Above the VFO is a nice step attenuator from the "Arrow Antenna" company of Loveland Colorado.
-- Further to the right are some Electric Radio and Antique Wireless Association magazines that Armand WA1UQO gave me. Really nice. The AWA mags have a very thoughtful piece (warts and all) on Jean Shepherd. And the ER pile has an article by Scott WA9WFA that mentions my work on the Mate for the Mighty Midget receiver. Thanks again Armand!
-- I also got some ADE6+ surface mount mixers. The price was right!
Thanks to VWS for putting on this great hamfest!
In fact, what he was seeing was a red tapestry from Ecuador that was sent to me by Galo Constante HC1GC way back in 1993. I was in the Dominican Republic, running my first ever real homebrew transmitter. Here is an article about this project: https://www.gadgeteer.us/TXHB.HTM I think Galo was also QRP homebrew. My log shows that I worked him eight times from the DR.
Mitad del Mundo = Middle of the World (a reference to the equator).
Here is the QSL I got from Galo:
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