Just go to http://soldersmoke.com. On that archive page, just click on the blue hyperlinks and your audio player should play that episode.
http://soldersmoke.com
Allison KB1GMX alerted us to this rig. Pete and I had been discussing with her various designs for SSB transceivers. I recently completed an NE602 rig. I really like the KN-Q7 (click on the picture above for a closer look). The T/R switching is much simpler than my use of three DPDT relays. It even seems simpler than the Epiphyte's switching of the BFO and VFO frequencies. I also like the analog VFO and BFOs inside the 602s, but I think Pete would use an Si5351. The AF amp muting circuit is kind of neat. I questioned the need for the extra IF amp for the receiver. My rig just uses the two NE602s and an AF amp circuit from the BITX40 module (2N3904 and an LM386), and with this I can hear the band noise floor on 40. But Allison points out that different bandpass and crystal filter have different losses, so with these components some additional gain may have been necessary. YMMV.
It is interesting that Peter notes a need for additional mic gain. Some of the NE602 rig designs run an electret mic right into the NE602 balanced modulator with no mic amp. For a few days I had my amplified D-104 mic running into the NE602 in this way. I too found that I was having to "loud talk" into the mic. I put an LM741 mic amp in there and it fixed the problem. I wonder if later versions of the KN-Q7 included a mic amp. I will check on this later.
Ernesto Marquez alerted me to the offerings of CRKITS -- Chinese Radio Kits:
http://crkits.com/ Their Si5351-Arduino Pro Mini "sandwich" is quite interesting. Here is a video on the device:
I must say, that nice little sandwich seems to be crying out for an organic slice of OLED.... How about it Adam?
While there is, of course, an enormous amount of electronics coming out of China, I haven't seen much that comes from actual Chinese radio amateurs. But CRKITS is the work of a real Chinese ham. Adam Rong (Rong Xinhua) BD6CR seems like a very interesting fellow. From qsl.net:
About BD6CR/4
Adam Rong (Chinese name: Rong Xinhua), BD6CR/4 was first licensed in 1996 while in university in Hefei, Anhui province and now holds Class 2 Chinese amateur radio license (FCC Amateur General license equivalent). After graduation from university, he moved to Shanghai and call sign changed to BD6CR/4 in July 2003. Adam is now living in Pudong new district with his XYL and their son. Adam holds a Master of Engineering degree in computer architecture and is an Engineering Program Manager in computer hardware industry. In spare time, Adam has written a lot about ham radio for magazines and papers, mainly about QRP, homebrew projects, APRS (Automatic Packet / Position Reporting System) and ham radio software applications. Adam has also translated two ARRL's books into Chinese for Post and Telecom Press in China, including part of the ARRL Handbook and ARRL's Low Power Communication: The Art and Science of QRP by Rich Arland, K7SZ. You can contact Adam by email, or track Adam's real time position on Google map by clicking this link.
More amazing low-cost test gear from China. Elisa gave me this device on the occasion of my completing another solar orbit. Amazing capability for less than $90. The video above gives you a good sense of what this thing can do. I have already had success with the freq generator function. The frequency counter also works great. The sweep function looks very useful for filter checking. And the ability to generate square waves at different phase relationships will be very useful in phasing receiver and transmitter projects. This little box should help me eliminate a lot of clutter on the work bench.And it looks good next to the Rigol 'scope.
They come with a variety of different brand names: I ordered a Jinwen but got a FeelTech. They are obviously the same device. Be sure to begin your Amazon shopping on the Amazon search link on the SolderSmoke blog (upper right).
On September 22, 2015 at around 1120 UTC I was able to hear the CW beacons from the fleet of new amateur radio satellites put into orbit by China. Here is a recording:
I have pulled my 2 meter down converter out of storage and have connected it to the Drake 2B. These satellites are due to be over my location at 0720 local tomorrow. I will be listening.
-- Some enhanced audio testing (Mellow, with Presence!) -- Pete's trip to Fake-shu-out, China -- My visit to the National Academy of Sciences --Bench Reports: Pete's JBOM Re-born Bill's plans for a new SSB Transceiver -- Arduino Woes BASTA!!!!!!!!!!! -- Si5351 VFO/BFO development -- Chuck Adams, Tribal Knowledge, and Muppet boards -- KX3 QRO? -- What antenna for Pete? MAILBAG
As I mentioned in the last podcast, we've been in some pretty serious negotiations with a new sponsor that I think is going to bring some MAJOR changes to the podcast.
"Homebrew 4 U" å®¶é‡€çš„ä½ is an innovative new company based in Fakeszuhow, China. Up until now they specialized in custom circuit board manufacturing, but they recently contacted us with an expansion idea that we found very interesting. They have been listening to the podcast, reading the ham radio magazines, and monitoring the U.S. amateur frequencies (especially 75 and 40). They noticed some things:
Most hams DO NOT build their own gear.... but many seem to feel vaguely guilty about this. They seem to react with unease when they encounter a ham using a homebrew rig. They grow defensive and scornful. The jealousy is quite palpable. Obviously there is an exploitable niche in those sentiments!
Many hams express a DESIRE to build gear but then follow-up and say they "have no time" (what with all the contesting, video games, NASCAR, and golf!)
Other hams say that they really want to build their own gear, but don't know anything about electronics (even though they are Extra Class -- how did that happen?) and they don't really want to learn.
Some hams say they would really like to build their own gear but find parts of the process quite distasteful. Like winding toroidal coils. Or reading schematics. And then there's all that soldering! But they insist that in spite of all this distaste for actual building, they really DO want to join the ranks of the homebrewers.
So.... Homebrew 4 U is developing a FANTASTIC product line that meets the needs of these guilty, busy, knowledge-free, toroid hating, solder-averse homebrew wannabes!
On April 1, 2016, Homebrew 4 U will roll out a line of GENUINE homebrew radios. To bolster their genuiness, they will henceforth be referred to not as radios but as "RIGS" (nice touch, don't you think?)
Unless the buyers select the optional "really build" option (see below), each "rig" will be complete and ready to operate. And here is the beautiful part: it will be a genuine homebrew rig, BECAUSE the company is doing all their work in an actual HOME in Fakezuhow! Pretty great huh? So you WILL be able to proudly announce on 40 meters that you are running a homebrew rig (Remember: rig, not radio!)
Each of the H4U rigs will share some common features, all designed to provide the proud buyer (I mean homebrewer) with opportunities to remind people that he is running a genuine homebrew rig:
-- They will drift a bit. Not too much, but enough to provide you with the chance to mention that your "rig" is "homebrew." Prepare to be envied my friends! -- The frequency readout will be set up to put you automatically on "wrong" frequencies. Like 7.162.025 instead of the "correct" 7.162.000000000000000000000000000000000000. Again, another opportunity to gloat. Pretty neat, huh? -- The audio quality on SSB will be SUPERB. EXCELLENT. This will provide some wonderful opportunities to compare signals with the Enhanced SSB gang. Yours will sound as good or better than theirs, and you can follow-up by telling them that you are using a Radio Shack electret mic element, a one transistor mic amp, and NO EQUALIZER. They'll love it!
REALLY BUILD OPTION: For those wanting to enhance the truthiness of their on-the-air homebrew experience, for just a few dollars extra, H4U will leave one part UNCONNECTED. You will then be able to make that critical final connection (don't worry, it won't be a toroid, and the connection will be via alligator clips -- if you've gone this far we know you don't own a soldering iron!). You will thus be able to tell your envious interlocutors about the happy day when you "finished" your radio. I mean rig. You know what I mean.
Pete is heading out to China this week to supervise the manufacturing (I mean the homebrewing). Thanks Pete! Skype in OM!
So remember, the roll-out is set for April 1, 2016. Watch out Yaesu!
These little frequency counters from China have a lot of potential. And they add a dash of digital color to an otherwise bland analog hamshack. I got mine on e-bay. My BITX17 has now been "accessorized" with 1) A rotatable Moxon antenna (big improvment!) 2) A 120 watt Communications Concepts Linear amplifier (another big improvement) and 3) This digital frequency readout. What next?
For the past month or so I have been wondering about a strange echo that I've been hearing on the 31 meter transmissions of Radio China International. I first noticed it on my "Kings Speech" regen receiver. Then I heard it again on my "Off the Shelf" regen. For a while I thought that what I was hearing was a propagation effect: Perhaps the very strong RCI relay station in Quivican,Cuba was sending north a signal so strong that it was travelling around the earth along the grey line and coming back to me about .133 seconds after the original reception. This sounded plausible (and it does happen sometimes). But there were reasons for skepticism: Why wasn't anyone else hearing this? Why wasn't the effect showing up on signals from Radio Havana Cuba? Pete Juliano had suggested that perhaps I was getting signals from TWO different RCI transmitters. I had quickly checked the RCI schedule and didn't see them transmitting on the same frequency at the same time from multiple transmitters, so I kind of put that idea aside. Hey, the round-the-world idea was just more appealing! But then I remembered something strange about the echo: It seemed to disappear when I tuned close to the center frequency of the RCI signal, but then appeared when I tuned off to one side. Hmm.... That was an important clue. I've long been wary of regen receivers and for a while suspected that I was dealing with some weird regen effect. Regen and Echo seem to go together, right? Well, as it turns out, no. But I was right about this being an effect of the nature of my receiver... Last night I was listening to RCI English service at around 0030 UTC on 9570 kHz. Nice clear signal. No echo. At 0100 UTC the program changed, and the echo started. A very strong echo. I went to the RCI schedule. Here I found the answer: At 0030 they were transmitting from their relay station in Cerrik, Albania on 9570 kHz. At 0010 they switched programs, frequencies and transmitters. At 0100 Cerrik shut down, but the Quivican, Cuba relay came on on 9580 kHz. At the same time the RCI transmitter in Kasi Sabagh in far-off exotic Western China, in Xinjiang, fired up on 9535 kHz. Both transmitters were carrying the RCI English service. You see, my little regens are not very selective, and the RCI transmissions are quite strong. So if I have my receiver tuned to around 9560 kHz, I'll be hearing BOTH the signal from Cuba AND the signal from Xinjiang. That would explain the echo. To try to confirm this, last night I fired up my old Hammarlund HQ-100 receiver to see if I could discern the two different signals. I could. And the echo appeared when I tuned BETWEEN the two. You can hear this in the video above. There is one remaining question here: Is the echo caused by the RADIO path difference between the two transmitters? Or are we just seeing the effect of the programming being transmitted at slightly different times, perhaps with this delay caused by INTERNET latency? Anyone know how RCI gets its signals from its Beijing studio to its distant transmitters? I calculate that the path difference is about 10,000 km. With c at 300,000 km/second, that would yield an echo of only about .03 seconds. The echo we are hearing sounds longer than that, so I suspect we are hearing a difference in studio-transmitter transmission time. What say the SWL RF gurus? BTW: I think the same phenomenon may explain the echo on Brother Stair's "Overcomer" signal. I see that starting at 2200 UTC he is on BOTH 7570 kHz and 7730 kHz from RMI transmitters in Florida. Perhaps they are not synched up. I think this is all very cool. Think about it: Here I am, sitting in Virginia in 2014, listening to the Albanian, Cuban, and Xinjiang relay stations of Radio China International on a receiver first built by some guy in England during the 1930s. And I'm trying to figure out if the echo I hear is caused by the limits imposed by the speed of light and the size of the earth, or by the time it takes packets to move through sub-oceanic fiber optic cables.
Several people have e-mailed me suggesting that the weird echo I have been hearing on shortwave broadcast stations is in fact one of the fabled "Long Delayed Echoes" that radio amateurs have been hearing intermittently since about 1927. I was skeptical at first, but -- at least in the case of the Radio China signal -- I think LDE caused by the signal going around the globe several times does explain what I've heard. Each trip would add a delay of about .133 seconds, and that seems to match what we hear in my recording: http://soldersmoke.blogspot.com/2014/08/strange-echo-on-china-radio.html Compare that with what K9FIK recorded on 10 meter SSB (thanks Stephen!): http://swling.com/blog/2013/10/hearing-the-speed-of-light-dx-double-echo/ (you can listen to the audio on this one). It sounds very similar. If this is in fact LDE, I'm lucky -- this is pretty rare. And it is a eerie that I first heard it on on Regen receiver from the 1920s! Above is a picture of the regen used to study the FIRST LDEs. See: http://folk.uio.no/sverre/LDE/
A few weeks ago I noticed a strange echo on Radio China International's signal. If you scroll down a bit you can see my YouTube recording of the problem. On one of the SWL lists, there was speculation that this problem was the result of a flaw in the RCI digital studio gear. But then a few days ago I heard it again on RCI -- surely the tech-savvy Chinese would not have let this kind of problem persist for weeks. Today I heard the same effect on a very different SW station -- this one an the 24/7 fire and brimstone broadcast that appears at many points on the dial. The effect is very similar to what I heard on RCI. So OK all your shortwave gurus: What is going on here?
Last night I was doing some shortwave listening on my new (OLD!) regen. As always, China Radio International was booming in on multiple frequencies. But as I tuned them in, I noted something strange: a very distinct echo on the signal (you can hear it in the video above). Very strange. Kind of like the Long Delayed Echos we've all heard about. I started thinking of explanations. Might this be some weird regen reverb effect? (You see -- I'm still wary of these regens!) But no, I checked -- the echo was there when I listened with my superhet HQ-100. Could it be that this was some strange multipath effect, perhaps involving multiple powerful transmitters in different locations? I was listening to the 0100-0200 UTC (20 Aug 2014) CRI English language service. (The echo continued when they switched to Chinese at 0200) I think the frequency was 9580 kHz. An SWL website says the transmitter was a relay station in Quivican, Cuba. What do you guys think? These fellows might have an explanation: http://swling.com/blog/2014/07/china-radio-international-warbling-on-daves-home-brew-receiver/ I really like shortwave listening with this old homebrew 1930s radio. There are still a lot of interesting signals out there. Recently heard: Voice of Vietnam, Radio Turkey, Radio Romania, WWV, WWVH, CHU, W1AW, transatlantic aircraft, Radio Australia, Radio New Zealand... and the mysterious numbers.
Today I bought a copy of "Feynman's Tips on Physics." I wasn't sure about buying it, but this story in Ralph Leighton's foreword convinced me:
"At a lonely border post high on the Himalayan frontier, Ramaswamy Balasubramanian peered through his binoculars at the People's Liberation Army soldiers stationed in Tibet ― who were peering through their scopes back at him. Tensions between India and China had been high for several years since 1962, when the two countries traded shots across their disputed border. The PLA soldiers, knowing they were being watched, taunted Balasubramanian and his fellow Indian soldiers by shaking, defiantly, high in the air their pocket-sized, bright-red copies of Quotations from Chairman Mao ― better known in the West as "Mao's Little Red Book."
Balasubramanian, then a conscript studying physics in his spare time, soon grew tired of these taunts. So one day, he came to his observation post prepared with a suitable rejoinder. As soon as the PLA soldiers started waving Mao's Little Red Book in the air again, he and two fellow Indian soldiers picked up and held aloft the three, big, bright-red volumes of The Feynman Lectures on Physics.
One day I received a letter from Mr. Balasubramanian. His was among the hundreds I have received through the years describing the lasting impact Richard Feynman has had on people's lives. After describing the "red-books" incident on the Sino-Indian Frontier, he wrote, 'Now, twenty years later, whose red books are still being read?' "
Pretty impressive for a guy whose previous project was a crystal controlled DSB transceiver, don't you think? They say that variety is the spice of life, and the Arduino board has been adding quite a bit of spice to my tech life lately. That tiny board up above the proto board is the six dollar DDS-9850 board -- it arrived in an envelope from Shenzhen, China last week. I hope to connect it to the Arduino and the LCD to make a sig generator or VFO.
I've been wondering about amateur radio in mainland China. Given the very large population, and the high levels of technical and engineering activity, you'd expect to see evidence of more ham radio activity from that country. Sure, there are plenty of commercial rigs manufactured there, but I've never seen an article about a Chinese homebrew rig, or a reprint from a Chinese ham radio magazine. I did some Googling, and unfortunately found out that my suspicions are correct: There are very few Chinese radio amateurs.
What a pity! Imagine the great rigs and circuits that would come out of that country.
The total number of individual amateur radio stations in the mainland of China is about 19,000, while the number of active club stations is 124， as counted in March 2009. In fact there are over 10,000 new comers get amateur radio station licenses each year, the total number of certified amateur operators during the past 10 years is accumulated as over 70,000. However, as the license is valid for 2 years and about the same number of previous licensees did not renew their license in time in each year, the net population of valid transmitting amateur radio station appears almost flat.
"SolderSmoke -- Global Adventures in Wireless Electronics" is now available as an e-book for Amazon's Kindle.
Here's the site:
http://www.amazon.com/dp/B004V9FIVW
NEAR-Fest Reports!
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Greetings!
Had a great time at NEAR-Fest. Please post your experiences and what you
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By DX EXPLORER
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