Move over Michigan Mighty Mite and Mate for the Mighty Midget. There's a new M^3 in town. And it is SMALL.
Hack-A-Day had an article on this today, and while it seems only tenuously connected to ham radio, I found it intriguing.
Serving the worldwide community of radio-electronic homebrewers. Providing blog support to the SolderSmoke podcast: http://soldersmoke.com
Solar X-rays: Geomagnetic Field: |
Hack-A-Day had an article on this today, and while it seems only tenuously connected to ham radio, I found it intriguing.
Selenium rectifiers. The name kind of sounds like Dilithium crystals, possibly related to flux capacitors.
Anyway, there were two of them in the Globe Electronics V-10 VFO Deluxe that I recently bought. Obviously they had to go, so I took them out yesterday, replacing them with a 1N5408 silicon rectifier.
The new diode had a significantly lower voltage drop than the selenium rectifiers -- this pushed the output voltage from the power supply up to around 200V. It is supposed to be around 185 V. So I put a 470 ohm, 5 watt resistor (found in the junkbox) in series. This brought the output voltage to 167 V. Close enough. VFO seems to be working fine.
I'm glad I did the extraction before these aging components released their nasty toxic smoke.
W3HWJ has a good article on replacing these nasty old parts, with some interesting info on their history: http://www.w3hwj.com/index_files/RBSelenium2.pdf
Backgound on the element Selenium: https://en.wikipedia.org/wiki/Selenium
Rod's son David Newkirk is radio wizard himself and has produced many great articles for QST and other publications. His dad is a Silent Key and David has taken his call.
This morning I was looking at an article on David's web site in which he looks at some of his dad's old QSL cards. Most of the affiliations on the cards (ARRL etc.) are easily recognizable, but there was one that was unclear: WFSRA.
David figured out what it was:
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A W9BRD Affiliation Mystery Solved
My father's pre-World-War-Two QSL cards include the usual list of affiliations: ORS (Official Relay Station), RCC (Rag Chewer's Club), WAC (Worked All Continents), A-1 Op (A-1 Operator's Club). One affiliation, WFSRA, remained mysterious. A clue in the correspondence column in March 1938 QST pointed me to an "I. A. R. U. News" item on page 74 of July 1935 QST, and I had my answer:
W.F.S.R.A.:
The World Friendship Society of Radio Amateurs has requested publication of the following pledge, which is the sole obligation for membership in the Society:
"I hereby promise that I will, to the best of my ability, make such use of my amateur radio station as will be conducive to international friendships; that I will never voluntarily permit by station to be used as the tool of selfish nationalistic interests; and that I will do what I can, as a radio amateur and as an individual, to promote world peace and understanding. (To be followed by the signature, address and station call.)"
Membership in the Society is open to all amateurs in all countries. All that is necessary to become a member is to copy and sign the pledge, and send it to the secretary, Duane Magill, W9DQD, 730 N. 6th St, Grand Junction, Colorado, U.S.A. Copies are preferably to be made in English or French, but may be made in the language of the member."
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The WFSRA was apparently one of the many, many peace organizations that were born in the interwar period in response to the carnage of WWI. In addition to the QST correspondence mentioned by David, Google shows WFSRA in many articles in UK ham and SWL publications, and there is one mention of it in the May 1954 edition of Boy's Life magazine.
Much as the CBLA seems to have been presaged by the FMLA, the IBEW seems to have much in common with the WFSRA.
RECEIVER: https://qsl.net/ve7sl/neophyte.html
TRANSMITTER: https://qsl.net/ve7sl/neotx.html?fbclid=IwAR3cM6tSRjyTsNouHWVz_buuzz4C9O-IwQbdZM5dekkle69ZW7-JBQcHTVI
Three cheers for Steve VE7SL! I've been linking to his blog for several years, but somehow I missed this magnificent red rig.
Steve's online notebook: https://www.qsl.net/ve7sl/
Steve's blog: http://ve7sl.blogspot.com/
https://www.qrp-ja.net/jf1ozl/index.html
There is a LOT of tribal knowledge and lot of great ideas on his site. Kazuhiro-san has apparently quit wireless, but is climbing mountains near his home. We hope is doing well and that he will someday return to radio (perhaps for the peak of cycle 25).
We last posted about him back in 2011. In the comments to that post you can see the sad news about the demise of his web site (which is now back on the web):
http://soldersmoke.blogspot.com/2011/12/homebrew-hero-kazuhiro-sunamura-jf1ozl.html
JF1OZL's bio:
My name is Kazuhiro Sunamura. I am a 50 year old mechanical engineer, born in 1956. I am not an engineer in electronics. I have been interested in electricity and radio from the age of ten. For the last ten years, I have been active on my ham radio station JF10ZL. I have also written articles about my some of my radio projects in Japanese for the Japanese CQ Magazine. Now I have decided to get onto the internet and will take the opportunity of showing you my equipment and ideas. Please have a look at my schematics. I will be very happy if this material helps you with your own radio projects. I am a member of the J.A.R.L. affiliated Tsuchiura Club, the local ham club in my home town.
-- FT-8 does give you the chance to work DX that would have been difficult on other modes.
-- Chinese hams showing up on FT-8 -- more than other modes.
-- I think FT-8 is good for hams who just want to have a lot of "contacts." It is definitely not for the rag-chewer.
-- I find it it kind of cold and antisocial. More like a computer game than ham radio. A bit like sending short text messages on a cell phone.
-- I think FT-8 contacts are in some ways more meaningless than a "59!" contest exchange -- unless you look, you don't even know the report you got, nor do you know the report you sent.
-- For me it is more impersonal than CW. But at least we let the technology decode the characters instead of having to memorize dot and dash sounds. In a phone contact you can hear the other person's laugh. In a CW QSO, you hear him key "HI HI." FT-8? No laughter at all.
-- With PSK Reporter, FT-8 gives you a good feel for how propagation changes during the day. But it is kind of like 2-way WSPR. As with WSPR, it is -- at first -- fascinating, but then it loses its charm. Yes, everyday you are heard in Belgium.
-- It seems to be getting kind of crowded. The passband for FT-8 contacts is often full, and it is hard to find an open space.
-- There is little opportunity for the homebrewer. I hooked it up to my homebrew transceivers and had a small bit of fun using a 2N3904 as a switch triggered by the RTS signal for T/R. But that's about it.
-- I get the sense that the ham himself is not really needed in FT-8. This mode seems like it could easily be automated or run by an AI. Just tell it to go out there, make a lot of contacts and log them. Maybe prioritize the DX you "need." Has this already been done?
-- After a session with FT-8, I had a really nice 17 meter ragchew SSB QSO. That SSB contact left me happy. The FT-8 session was a bit like spending time on social media or a video game. It left me edgy. FT-8 made me appreciate phone even more.
But hey, to each his own. A lot of people really like FT-8. I hope they have fun.
Here is the link to the Orr book:
Thanks to Tony K3DY for sending us the link that led us to this book. There are many other great books there: http://www.rsp-italy.it/Electronics/Books/indexhtm
I've been hanging out on 17 meters with my homebrew VXO-controlled BITX transceiver. The antenna is my 75 meter doublet fed with window line through a homebrew tuner made from dead ( I swear) DX-40s and DX-60s. I can tune it up just fine on 17 meters, but I realize I probably have lots of nulls and lobes in the radiation pattern. Apparently one of the lobes is over my old stomping grounds in Panama. Almost everyday I talk to either HP9SAM or HP3SS.
Robby, HP3SS, is using SDR gear now, but he was a real homebrewer back in the day. Years ago he built an HBR-13C receiver. That's quite an achievement.
Robby -- formerly VY2SS -- told me that he sold his HBR-13C to none other than Joe Walsh, the rockstar from The Eagles. FB.
As I was talking to Robby yesterday, I came across this wonderful web page about the receiver:
https://sparcradio.ca/wp-content/uploads/2015/12/Restoring-a-HBR-13-Amateur-Receiver.pdf
Robby told me that his receiver looked almost exactly like the one on the SPARC site, but he didn't recognize the small box with what looked like a speaker on the chassis. I told him that my guess was that this was a crystal calibrator in an oven.
I also told Robby that I feel an affinity with the HBR project, not just because I like homebrew superhets, but also because my call in the UK was M0HBR.
There are some great quotes in the SPARC pdf:
The SPARC page led me to the amazing website of Kees K5BCQ:
https://www.qsl.net/k5bcq/HBR/hbr.html
Here is Kees's QRZ page:
-- Bottom line: I still don't know why ham radio adopted as a convention LSB below 10 MHz and USB above 10 MHz. There are several theories. but so far there is no convincing explanation in favor of any one of them. And almost all of the people involved are probably Silent Keys by now; this makes it more difficult to gather first-hand information.
-- I'm not even sure when the convention began to be observed in ham radio. Many of the early SSB books and articles make no mention of it. We don't see it in early ARRL Handbooks. The first mention of it that I found was in the 1965 issue of the ARRL's "Single Sideband for the Radio Amateur" page 8. This article claims that adding a provision for selectable sidebands would "add appreciably to the cost of the equipment. " It went on to say that, "For this and other reasons there has been a species of standardization on the particular sideband used in the various amateur bands. Nearly all operations in the 3.5 and 7 Mc. phone sub-allocation is on lower sideband, while the upper sideband is used on 14, 21, and 28 Mc."
-- We know that the informal convention was being followed as early as 1958. Jim N2EY reports that in 1958, the manual for the Central Electronics 20A shows that LSB was the "sideband most commonly used" on 75, with USB preferred on 20:
-- There is a widely held belief that this practice originated in the design of a rig that had a 5.2 MHz VFO and a 9 MHz filter. According to this theory such a rig -- due to sideband inversion -- would produce LSB on 75 meters and USB on 20. But, as we have demonstrated, this doesn't work, so this theory has to be discounted.
-- Early SSB activity seems to have been concentrated on 75 meters, and there was a competition for space with AM stations. SSB operators appear to have used the very upper band edge as their gathering spot. Using LSB allowed them to operate very close to the upper band edge -- a lot closer than AM stations could go. This may explain why LSB became the preferred SSB mode on 75. But how do we explain USB on 20 and above? That remains a mystery.
-- It is important to remember that in the early days of SSB, for most hams there were only two important phone bands: 75 meters and 20 meters. 40 meters was CW only until 1952, and even after that was crowded with shortwave broadcast stations. So a design that allowed for both 75 and 20 was twice as good as a monoband design.
-- Early on there were designs and parts for phasing rigs. You could take that ARC-5 VFO at 5 MHz, build a phasing generator around it, and then mix it with a 9 MHz to get on either band. But with just a simple switch, this kind of rig could operate on USB or LSB on either band. So the early popularity of this kid of rig does not explain the convention.
-- There were a lot of surplus 5 MHz ARC-5 VFOs available. There were also FT-243 and FT-241 surplus crystals at both 5 MHz and 9 MHz that could be made into filters. Later in the 1950s, 9 MHz commercial crystal filters became available. If you used a 9 MHz filter with a 5 MHz VFO, there would be no sideband inversion in your rig. If the SSB generator was putting out LSB on 9 MHz, you'd be on LSB on both bands. So if there was a desire to have LSB on 75, why not just also have LSB on 20?
-- But if you built a 5.2 MHz filter and a 9 MHz VFO, you could have LSB on 75 and USB on 20 without having to shift the carrier oscillator frequency. This would save you the trouble and expense of moving the carrier oscillator/BFO to the other side of the passband. This desire to economize and simplify may explain why we ended up with LSB on 75 and USB on 20. But this still begs the question: Why the desire for USB on 20?
-- Both the manufacturers and the hams wanted there to be sideband standardization. With monoband rigs, the manufacturers would be able to cut costs by building for only one sideband. Hams also wanted to cut costs, and they did not want to have to figure out which sideband a station was on when trying to tune him in.
-- By 1962-1963 Swan and Heathkit were selling mono-band SSB transceivers that used the "conventional" sidebands: The rigs for 75 and 40 meters were on LSB while the 20 meter rigs were on USB. There were no provisions for switching to the other sideband. This seems to have reinforced the practice of observing the convention. (Heath later added sideband switching to the HW monobanders -- in view of the growing observation of the convention, they may have been better off sticking with their original design. Does anyone know why they did this?) But again, why USB on 20 and above?
-- In 1963, Swan, by then in Oceanside California, came out with the Swan 240. Swan used a filter centered at 5174.5 kc. The VFO ran from 8953 kc to 9193 kc on 75 and 20. The VFO ran from 12222 to 12493 on 40. This gave the buyer 75 and 40 on LSB, and 20 USB with only one carrier oscillator frequency. (Swan offered a mod that allowed hams to install an additional, switchable carrier oscillator frequency. I luckily acquired one such modified rig.) But again, there is an explanation for LSB on 75, but why USB on 20 and above?
This is an important part of ham radio history. There should be a clear answer. We need to find it. If anyone has any good info on this, please let me know.
https://kk4das.blogspot.com/2021/09/simplessb-three-way-qso.html
Here's Dean's presentation to the club describing the project and Pete's rig:
As Pete says, "The radio does not build itself..." Indeed it doesn't! The VWS builders made these rigs. FB!
We were in Boston and the Cape Cod area this week. We stopped off at the Marconi Wireless site at Wellfleet, Mass.
This is from the National Park Service web site:
Spanning the Ocean
https://www.nps.gov/caco/learn/historyculture/marconi.htm