Steve G0FUW talks Homebrew and Kits with Charlie NJ7V

Our homebrew direct-conversion receiver challenge (see below) has led to a discussion of the differences between homebrew and kits.  Our intent in designing this rig was to come up with something that was simple enough to actually homebrew (that is the challenge:  homebrew it!) .  Building it from a kit would be something different.  I like the way Charlie and Steve talk about the differences between homebrew and kits in this video.  Around 33:49 Charlie mentions that after a while you just get good at building kits.   Steve points out that building kits is a bit like "painting by numbers" (a great metaphor).  Steve then goes on to talk about the formation in G-QRP of the "scratch-built group." Steve tells us that he has built some 84 radios.  Steve talks about "the joy of building it yourself" (43:49)

Steve gives a very kind shout out to SolderSmoke at around 23:58.    The references to Tony G4WIF and Ian G3ROO were also very nice. And there are many great mentions of Pete Juliano N6QW. 

And remember:  If you are not a member of G-QRP you are just wrong!  Join here:  https://www.gqrp.com/join.htm 

Thanks Charlie and thanks Steve! 

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November 13, 2024

Bill's appearance on the Ham Radio Workbench.  (Bill made some overly harsh comments about radio rejuvenation, and was trying to make amends.)  But now we throw down the gauntlet.  WE CHALLENGE the HRWB guys to build -- to homebrew - our TJ DC RX.  They will experience JOO, JVO and the elite status that comes with having built their own ham radio receiver.  And if they go on to build a 10 minute transmitter, they can use it for CW contacts.  Like on POTA (Thomas!)

December 13, 2024: 

Bill was on Ham Radio Workbench: https://soldersmoke.blogspot.com/2024/11/bill-n2cqr-appears-as-guest-on-ham.html  Our challenge to HRWB.  Gauntlet thrown down... OUR CHALLENGE HAS BEEN GRACIOUSLY ACCEPTED!     We now extend the challenge to the entire SolderSmoke community: Build one of these:  https://hackaday.io/project/190327-high-schoolers-build-a-radio-receiver

Homebrewing is not for the faint of heart!  Accept the challenge!  Build stuff! 

A Tale of Woe -- Troubleshooting my 15-10 Rig in the Dominican Republic

-- Problem first showed up as a low level oscillation in the background.  Annoying. 

-- I suspected the simple AF amp from the TJ DC RX project was oscillating.  Wasted a lot of time. 

-- Isolated the problems by cutting off all of the RF input to the SBL-1 mixer. 

-- While watching the carrier osc signal, noticed that the hum appeared as the waveform got fuzzy. 

-- I had used the osc/product detector circuit from the BITX 20. 

-- I had added an amplifier stage to get the signal to higher level. But it was poorly designed. 

-- After some struggle, I decided to rebuild the osc/mixer board. 

-- Redesigned amplifier stage using LTSpice. 

-- Changed from an SBL-1 mixer to a singly balanced mixer like in the BITX 20. 

-- This worked well.  Hum disappeared. 

-- But I had neglected to put the .001 uF cap to ground from the AF port! Thus the cartoon! 

-- This is a very important cap.  Circuit was a lot more balanced with this cap in place. 

-- Noiticed that output on 10 was only about 25 watts PEP, while on 15 it was around 100. 

-- Checked input to final amps.  Input on 10 was a lot lower.  

-- Tweaked the 10 meter bandpass filter and got the output on 10 up to about 80 watts. 

Scott KQ4AOP's PTO Coil Forms for the High-School Direct-Conversion Receiver (Video)

Scott KQ4AOP listened to amateur radio signals for the first time using a homebrew receiver.  That is really something.  See:  https://soldersmoke.blogspot.com/search?q=KQ4AOP

Scott then very kindly offered to 3D print the coil form for the PTO that is one of the four stages of our High School receiver project.  The above video shows the coil forms being 3D printed on Scott's machine, and explains where some of them are going. 

Dean KK4DAS will soon launch a video and e-mail-based build of the receiver.  Stay tuned. Dean's series should clear up any remaining questions about how to build this receiver.  As Scott so rightly said: 

"This was my first receiver build and, it was great fun. When you finish the build and prove you are able to tune through the band, you are welcomed into the secret society! The build is the initiation. I am happy to print and ship the PTO if needed."  

Donnie WA9TGT's Direct Conversion Receivers

Donnie WA9TGT writes: 

I recently built my first basic 40 meter (DC receiver) from http://www.qrpkits.com/  that uses the common SA602 & LM386 chip combo with Varactor diode tuning. I didn’t want to scratch build a DC Rx simply because I first wanted to build up this simple kit with its included PCB and at least play with it a little just to see if it was something I mite wanted to further pursue. I’ve since decided yes I want to, even with all a DC receivers short comings. It’s was nearly as rewarding hearing my call being sent back to me for the very first time coming through this little DC Rx after calling CQ as it was back in 1966 during my very first Novice contact. 

Donnie's inspirational QRZ.com page:  https://www.qrz.com/db/WA9TGT

Happy New Year from the Dominican Republic! SKN from HI7/N2CQR

As you guys know, here at SolderSmoke we are all about tradition.  Things like homebrewing, thermatrons,  crystal radios,  April 1, and even (at least once a year), MORSE CODE.   This morning was the morning for morse.  Straight Key Night my friends.  I got on the air with a QMX transceiver that my friend Bob had given me, and with a Sankar VU3XVR key that Farhan gave me a few years ago.  It all worked great.  First contact was with DF0W, then in quick succession WA3KCP, K3CQR, and K4DY.  All 5W 20 meter CW with a 1/4 wave vertical.  TRGHS. FB. HNY!

2 days of RBN spots, QMX barefoot to vertical at HI7/N2CQR

December 31, 2024 -- January 1, 2025