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Friday, July 11, 2025
How many of you guys have changed the clutch on a Heathkit HW-101 (or similar rig)?
Sunday, June 15, 2025
A Nice Quick HW-101 Restoration Video
This video is almost enough to get me to work on my old HW-101.
Pete N6QW has been working on an HW-32A monobander. Some of the info in this video might be applicable.
Tuesday, November 2, 2021
Farhan's Amazing Knack Story: From a Boyhood SW Receiver to the Design of the sBITX SDR
-- Farhan talks about his practice of taking the pictures of new rigs with the new rig sitting atop the book that was most important in its design and construction. FB.
-- I was really blown away by Farhan's presentation of how the uBITX advertisement was inspired by and in many ways based on the Heathkit ad for an HW-101. Amazing.
-- I learned a lot from Farhan's discussion of SDR theory. I pledge to spend more time with this. I really like Farhan's hybrid HDR/SDR approach.
-- But I have a question: Farhan seems to say that we'd need a big expensive GOOGL computer to do the direct sampling HF SDR. But doesn't the little RTL-SDR do just that? Without a GOOGL?
-- Great to see Wes's AFTIA being used in the sBITX.
-- Really cool that Farhan has his mind on VHF transverters when designing the sBITX. I liked use of the TCXO module to free up one of the Si5351 clock outputs. FB. And great to include an idea from Hans in this rig.
Thanks very much to Farhan (who stayed up until 3 am to do this!) and to the RSGB for hosting.
Friday, October 1, 2021
Chuck Penson's Amazing New Book about Heathkit Amateur Products
Wednesday, March 3, 2021
The SolderSmoke Team Talks to the River City Amateur Radio Communication Society (Video)
Monday, November 9, 2020
Improving the Product Detector in the Lafayette HA-600A
Steve N8NM built the HA-600A product detector both in LTSpice and in the real world. It worked fine in both versions. Steve even put the product detector into his S-38 receiver -- he reported it worked well there.
I too built the thing in LTSpice. Then I went and rebuilt the circuit on a piece of PC board. I connected the new circuit to the HA-600A, using my external FeelTech sig generator as the BFO. IT STILL SOUNDED BAD ON SSB.
At this point I started Googling through the literature. I found a promising article by Robert Sherwood in December 1977 issue of Ham Radio magazine entitled "Present Day Receivers -- Problems and Cures." Sherwood wrote:
"Another area that could use additional work is the product detector. As the name implies, its output should be the product of the two input signals. If BFO injection is removed, output should go to zero. If this is not the case, as in the Heath HW series, envelope detection is also occurring, which causes audio distortion."
I checked my circuit. When I removed the BFO signal from the product detector, envelope detection continued. In fact, with the receiver in SSB mode, and with the BFO disconnected, I could listen to the music of WRMI shortwave. It seemed that Sherwood was explaining well the problem I was having: Simultaneous envelope and product detection was making SSB sound very bad in my receiver. What I was hearing just seemed to SOUND like what you'd get with a mixture of product and envelope detection: "scratchy" sounding SSB. This also seemed to explain why SSB would sound fine when using the diode detector with loosely coupled BFO energy -- in that case it would be envelope detection only, with no ugly mixture of both kinds of detection.
Finally, I needed to find a way to use the BFO in the HA-600A with the new product detector. Obviously I needed more BFO signal -- I needed about 7 dbm, enough to turn on the diodes. I converted the outboard product detector board into a simple amplifier and put it between the HA-600A BFO and the BFO input port of the new product detector. This works fine.
A few issues remain:
1) The output from the HA-600A BFO through the above BFO amp (and across the 50 ohm resistor) is NOT a pretty 455 kc sine wave. But the peaks of the distorted wave appear to be enough to turn on the diodes, and when I look at the voltages across each diode (on my two channel 'scope) I see mirror images -- one is on when the other is off. Is this good enough?
2) Moving the BFO input from L1 to the junction of the two 50 ohm resistors (that is actually a 100 ohm pot) has big implications for how this mixer works. With the BFO energy going through the toroid, BOTH diodes are being alternately turned on and turned off. But both are on, and then BOTH are off. With the BFO energy going in through the other side, one diode turns on when the other is off. I think the mixing result is the same, with AF coming out of the output port, but the way the mixer works in this configuration is very different. Does this sound right?
Tuesday, July 15, 2014
VK2SJA's Minima in a Realistic DX-100 Case
Steve, VK2SJA, is doing to a Realistic DX-100 what I have been thinking about doing to a Heathkit HW-101. With this kind of encouragement, who could blame me for making a Minima-101? I've been planning on keeping the 6146s and all the final (and perhaps driver) circuitry.
Here is Steve's very nice description of his project thus far:
http://www.hfsignals.org/index.php/UnRealistic_Minima
Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20
Monday, August 12, 2013
SolderSmoke Podcast #154
SolderSmoke Podcast 154 is available for download!
http://soldersmoke.com/soldersmoke154.mp3
August 11, 2013
-- Alligators! Real Alligators! (see picture below -- look closely)
-- Ten meter beacon project (with Arduino and Reverse Beacon Network)
-- Telescope repair: Chap Stick as lubricant, and the perils of macular pucker!
-- HW-101 saved from cannibalism!
-- The Wonders of WSPR and our need for instant feedback and gratification.
-- QST Review of SolderSmoke, The Book.
-- MAILBAG
Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20
Sunday, July 28, 2013
Soul in the Old Machine: HW-101 Saved From Workshop Cannabilism
More on this in SolderSmoke 154....
Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20
Friday, July 26, 2013
HB-101 ? BITX-101?
Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20