Here are some cards from earlier (in some cases MUCH earlier):
https://soldersmoke.blogspot.com/2023/11/some-short-wave-listener-qsl-cards.html
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Here are some cards from earlier (in some cases MUCH earlier):
https://soldersmoke.blogspot.com/2023/11/some-short-wave-listener-qsl-cards.html
Walter KA4KXX spotted an error in the schematic of my 2014 "Off the Shelf" regen receiver: The source resistor on the MPF-102 should be 2200 ohms, not 2.7 ohms. See:
https://soldersmoke.blogspot.com/2014/09/schematic-for-off-shelf-regen.htmlSuch a beautiful article. Ramakrishnan VU2JXN sent it to me. It reminded me of how puzzeled we were when we found "Schenectady" on old shortwave receiver dials, amidst truly exotic locations. Rangoon! Peking! Cape Town! Schenectady? Obviously this was due to General Electric's location in that New York State city. But reading this article, I am thinking that the presence of Charles Proteus Steinmetz had something to do with it. His informal title (The Wizard of Schenectady) confirmed that we have been right in awarding similar titles to impressive homebrewers.
Here is the Smithsonian article that Ramakrishnan sent.
And here is a link to a PBS video on Steinmetz:
https://www.pbs.org/video/wmht-specials-divine-discontent-charles-proteus-steinmetz/
Here is a SolderSmoke blog post about "Radio Schenectady":
https://soldersmoke.blogspot.com/2020/07/radio-schenectady.html
https://www.youtube.com/watch?v=LzPIOfpKkRM
As the owner and operator of what must be one of the few remaining HQ-100s, I feel obligated to defend the reputation of this fine piece of shortwave gear.
How many of you have HQ-100s?
This reminds me of a cool project I have not yet done: modifying the TinySA to allow the user to listen to the station: https://soldersmoke.blogspot.com/2021/10/how-to-listen-with-your-tinysa.html I notice that Dean KK4DAS (my colleague in DC receiver design) was the only commenter on the blog post describing the TinySA mod. TRGHS. We need to to do this.
Here are the reports showing when Vatican Radio and Radio Marti were on the air on November 18, 2022:
Here is another update on Direct Conversion receiver construction. In Northern Virginia we get very strong signals from the Radio Marti transmitter in Greenville NC. During the morning hours it is just above the 40 meter band at 7335 kHz. In the evening it is a bit higher in frequency at 7435 KHz. (in the video above I mistakenly give the morning frequency, when in fact they were on the higher evening frequency). In either case, Radio Marti has been a big source of unwanted AM breakthrough in our simple DC receivers. It now serves as something of a test of our bandpass filters and mixers.
In this video I try out the simple mixer described in detail here: https://soldersmoke.blogspot.com/2022...
The following morning, I tested the mixer with Radio Marti (in fact) on 7335 kHz. By adjusting the VFO signal input to the minimum value needed to turn on the diodes, I was able to bring Radio Marti AM breakthrough to minimal levels. But I could still hear it (weakly) in the background. Putting a very simple diplexer at the audio output of the mixer (just a .1uF capacitor in series with a 47 ohm resistor to ground) helped a lot.
I could also hear break through from Spanish-language broadcasts from Vatican Radio on 7305 kHz (using the 250 kW transmitter in Greenville NC) from 11:30-11:45. Perhaps most surprisingly, I was also getting AM breakthrough from 40 meter FT8!
Here is a short video showing the simple two-diode mixer in action during the morning hours:
I also tried out the more common two diode mixer with trifilar toroid. (In this one, the VFO turns both diodes on, then turns both of them off). The results were similar to what I got with the other two diode mixer.
We are trying to develop four circuits -- bandpass filter, mixer, variable frequency oscillator, and audio amplifier -- that will be simple enough for construction by high school students, but not so simple as to compromise performance. We want the receiver to work well.SolderSmoke Podcast #238 is available: http://soldersmoke.com/soldersmoke238.mp3
TRAVELOGUE:
Cathartic decluttering: Bill preparing for future winter travel to Dominican Republic. Will build SolderSmoke Shack South. Dividing everything up: Rigs, parts, tools, supplies, antennas, test gear. Everything.
PETE'S BENCH:
Rarely if ever will we come across a high quality NETFLIX series built around a shortwave broadcast transmitter. But that is what we have in Gloria. It is really good. We were especially interested in it because we lived in Portugal for three years. In addition to all the intrigue and drama you will catch glimpses of broadcast antennas, big transmitting tubes, and one out-of-focus shot of what appears to be a Hallicrafters receiver (SX-42?)
More info here:
Here's the NETFLIX link:
https://www.netflix.com/title/81073977
Thanks to Thomas K4SWL of SWLing Post for the heads up.