Mother Lode DX / Contest Club

Author: Jeff Stai

  • The Nugget – July 2025

    July 2025

    Volume 30 Number 7

    Next meeting: July 26th in Martel (Jackson). Find out more.

    In this issue: tubes, verticals, and… tuning forks? – new videos! – classifieds – DX – contests – State QSO parties! – funny stuff! – and more!

    From the Prez

    Hello DX’ers and Contesters,

    If you missed our last meeting, you missed a good one.  Craig, K9CT, gave us a presentation on his contest super-station in Illinois.  The good news is that Jeff WK6I will have the video of the presentation up on the website by the time you read this. Look for the Resources tab on the website, click on it and go to Videos (also linked below – J.)  

    I do have some videos available from our past meetings, but very few were actually recorded.  Little by little, I am editing these down and sending them off to Jeff, as YouTube videos, so he can add the links to the website.

    The California QSO Party will be here before you know it, so now is the time to start planning whether or not you’re going to operate from home or as a county expedition.  

    Last year, SCCC’s CQP score was 4,593,487.  MLDXCC was well under SCCC, with 3,817,733 points.  SCCC also won the Club Competition, in our category, in 2023.  MLDXCC beat SCCC in 2022.  Let’s go for the WIN in 2025!

    I have reserved our August meeting for a California QSO Party (CQP) strategy meeting. The Lincoln Swap is in September, so there will be no meeting that month.(As always, see the Meetings page for the latest!)

    County expeditions can be a lot of fun and can be a way to really rack up the points for the Club.  A group of us were in Alpine County last year and part of that group has also operated in Tehama County for several years.  We had a blast!   The more county expeditions MLDXCC members can do, the better, especially if they are in rare counties.

    Dean, N6DE, has done an exceptional job with CQP, and that includes compiling an annual list of rare counties.  I don’t see any 2025 updates on the website yet, but you can bet that they will be there soon.  You’re going to want to look at that rare county list and then claim it. (See below for the latest!)

    How many of you have wished you had the ultimate operating location during an HF contest, a VHF contest, or even when trying to work that all-time new one?  This could be on the top of a mountain, the side of a mountain, or on an ocean beach.  Chris, KI1P, lives in Northfield, Vermont, and with a location like that one would think that he has a pretty darn good QTH.  Not the case.  An HF beam, pointed at Europe, looks into a granite mountain that is nearly in his back yard.  To solve this problem, Chris bought a retired television live truck and turned it into a superb contest station, with top notch equipment.  It is essentially an HF and VHF rover.  There is a lot more to this story and you can hear all about it at our next meeting, which will be on July 26th, at Round Table Pizza, in Jackson (Martel).  I saw Chris’s presentation at the Contest Forum this year in Dayton.  Chris has a great sense of humor.  You will find it very entertaining and you may just want to find a retired television live truck and build one of these rover contest stations yourself.  Hope to see many of you there!

    From the Veep

    Hello MLDXCC! 

    Well, Field Day (2025) is now completed, how did you guys do? With a part time effort (due to challenges), there were 392 Q’s in the log. It always gives me pleasure to work the new (younger) operators. Their excitement is refreshing. Make sure you get your score and field day stories to Jeff WK6I so he can put them in the news letter. 

    Worked any good DX lately? As observed, HF conditions have been a little up and down. Stations in Europe on 20 are now workable in the evening providing some new Marathon contact.

    Six meters (50.313 FT8) however has been very active at times. The last several evenings the north (BC, WA & OR) and south (AZ & NM) path has been active.  Regarding my WAS search on 6 meters, I’m still waiting for a good east coast opening to Delaware & Rhode Island. 

    How’s your DX Marathon numbers looking? Remember even though you’ve worked a DXCC country before, they count as “brand new” again every year for the Marathon. WARC band & FT4/FT8 contacts all count for the Marathon as well.

    Also listen for the K6C Special Event Station starting July 11th. This is a special call for the California State Fair (Cal Expo). I will be on 20 SSB various evenings, so give me a shout.

    Well that’s all for now, time to go work outside before it gets to hot! Remember to stay hydrated!

    73 and Good DX, Steve / NC6R

    Treasurer’s Quarterly Report

    4/1/2025 Opening Balance = $2,787.07

    • Income = $140.00
      • 2025 Dues – Paypal = $20.00
      • 2025 Dues – Checking = $120.00
    • Expenses = $0.00
      • None

    6/30/2025 Ending Balance = $2,927.07

    Secretary’s Report

    Minutes of the June 21st Meeting (The Breakroom, Shingle Springs)

    Breaking News!

    (Imagine the sound of a chattering teletype…)

    The California QSO Party (CQP) is October 4th and that day will arrive faster than you think. The CQP web site has just been updated for 2025. You can now go there and register your planned activity, and you can track what others have planned.

    The Northern California Contest Club (NCCC) has announced a new special on-air event — the NCCC 55th Anniversary Fiesta, taking place Saturday, August 9, 2025, from 1900Z Saturday-0300Z Sunday (noon to 8pm Pacific Time). This is an “operating event” with no log checking, on CW, SSB, and RTTY. Find out more!

    The Southern California DX Club (SCDXC) notes in their July newsletter that due to waning interest, the August 2025 newsletter may be the last one. Readers are encouraged to respond if they desire to see more newsletters after that.

    One of your editor’s local clubs – Tuolumne County
    Amateur Radio & Electronics Society (TCARES)     – puts out a great quarterly newsletter, here’s the latest issue. (Tell us about your local club!)

    Articles

    Tube of the Month – July 2025 by Norm N6JV

    Multi-Band Verticals by Gary NA6O

    Study of a Telegraph Tuning Fork by Gary NA6O

    Newly Posted Videos!

    Subscribe to the MLDXCC YouTube channel! And Please “like” the videos, it will help people find them!

    More videos!

    Classifieds

    For Sale: New, never used,  EHU for BigIR  /  $250 or best offer – Thank you, Steve / NC6R k6sca@volcano.net

    For Sale: $995 takes all, HF Amp / Tuner / Swr-Power Meter / Dummy Load – see below.  Located in Northwest Reno, NV and can deliver to NCCC Truckee BBQ Sun July 27th if desired.  Barry K6ST k6st@arrl.net 

    HF Amplifier 160m – 10m Ameritron AL-811H. The Al-811 gives you 600 watts PEP output. 13.75 x 8.65 x 16 inches. Weight: 31 pounds. The Ameritron AL-811H is similar to the AL-811, but with four fully neutralized 811A transmitting tubes for 800 watts of power.

    LDG AT-600ProII is a general-purpose automatic tuner intended for use with midsize amplifiers with up to 600 watts output SSB, 500 watts CW, 300W Digital from 1.8 – 54 MHz. Easy to Read Bar Graph – Dual Antenna Switch – Switched-L tuning network.

    High Power SWR watt meter. HF, peak reading, 3kW

    MFJ-250X VersaLoad KW Wet Dummy Load with oil. Lets you tune up fast!

    For sale: Bob W1RH has a WaveNode WN2 Digital Watt Meter, with four HF sensors.  This unit sells new for $385, with a single sensor.  I have been using is in an SO2R configuration with a sensor on the input and output of each amplifier.

    That way, I can always see my input and output power.  Rick, W6SR, who uses my station remotely more than I do, has depended on the software display to know how much power he’s running. 

    There are several options for the look of the computer display.  And there are several other features such as rotator control and antenna switching but I have just used the wattmeter function.

    I’m selling this because I have purchased the Flex PGXL amplifier, which has built in and remotable watt meters.  It can be yours for $200. Contact Bob W1RH w1rh@yahoo.com.

    Bob W1RH also has the following items available:

    Alpha 91B amplifier.  $1200

    Brand new, in the box, Svetlana 4CX800A amplifier tube – $250

    Array Solutions 6-PAK 6 port SO2R antenna switch – $250

    Contact Bob W1RH w1rh@yahoo.com

    For sale: Eimac 8877 and 3CX800A7 tubes, all tested to factory spec (June 2025) by retired Eimac engineer, includes individual data sheet for each tube.  Price $700 each, $1200/pair. 

    Also for sale Jan 7203/4CX250B NOS in sealed can $100 each and Jan 7609/4CX150D NOS in sealed can $30 each.

    Contact Mike, K6LQ wn6yqs@aol.com

    DX…

    Upcoming DXpeditions via NG3K

    DX Calendar via 425 DX News

    Upcoming Contests

    Via contestcalendar.com:

    New! State QSO Parties (via statesqoparty.com):

    Humor!

    Steve NC6R found this on KL7J’s website, “How Cold Is It?“

    Send more funny stuff for the next issue! – Ed.

    ClubLog DXCC Standings

    As of 17 July 2025. You can see complete MLDXCC standings on ClubLog here.

    Overall

    1NK7I229
    2W1SRD227
    3W6DE205
    4K6OK187
    5K6YK183

    CW

    1K6YK163
    2NO5Z122
    3K6OK120
    4NA6O106
    5N6WM104

    Phone

    1W1SRD116
    2K6YK115
    3NO5Z115
    4N6WM111
    5K6TQ101

    Data

    1NK7I220
    2W1SRD200
    3W6DE180
    4K7QDX173
    5K6OK157

    Resources

    Check out the Resources menu up there at the top of every web page for useful DX and contest info.

    Prepared for the MLDXCC by Editor and Webwookie Jeff WK6I. Please do send me any corrections, omissions, or material for future issues of The Nugget. It is much appreciated!

  • Minutes of the June 21st Meeting (The Breakroom, Shingle Springs)

    Respectfully Submitted, G. “Skip” Chraft, N6NFB

    Meeting was called to order at 12:27 p.m. by Vice President Steve Allred, NC6R. There were 12  attending in person, with three more attending via zoom. Of these there were three guests.There was one guest: Randy Keen, K6TVT introduced by Steve Allred. Steve welcomed everyone. Each member introduced themselves.

    Old Business

    The May minutes were published in the Newsletter.

    The Treasurer’s reports are now being done on a quarterly basis, so there is no report  presented during this meeting.

    New Business

    None

    Member Achievements

    Norm Wilson, N6JV, worked his long sought E6 prefix via moonbounce.

    Jay Harmor, KE6GLA, activated 3 summits recently.

    Skip Chraft, N6NFB, made just under 200 Q’s in 9 hours in the ARRL Digital contest.

    Upcoming Contests

    Can be found at contestcalendar.com

     DX info is available at NG3K.com and DX425 News.

    Announcements/Discussion

    The IDXC 2026 convention is scheduled for Santa Maria on April 10 – 12, 2026.

    IDXC 2027 has been announced, it is a go. NCDXC will once again be hosting the event scheduled for March 12 -14 2027 in Visalia.

    Steve Allred recognized Norm Wilson, N6JV for his tireless effort as the former newsletter editor. He also thanks Jeff Stai, Wk6I, for stepping up, and making a great newsletter and website upgrades.

    Steve also encouraged us all to promote the club among our ham radio friends. 

    Next Meeting

    Is Scheduled for July 26, location TBD. 

    A joint meetings with NCCC is in the works, date and location.

    Adjournment: Moved and seconded, passed unanimously at 12:41 PM.

    Craig Thompson, K9CT, gave a fascinating virtual tour of his super station. His station defines what a super contesting station should be!

  • Tube of the Month – July 2025

    by Norm Wilson N6JV – Visit the museum at N6JV.com

    2C40 The Lighthouse

    Many of the tubes that were used to make the first experimental RADAR sets were standard types as the frequency was relatively low and would work without modification. Early large ground RADARs were in the 100 – 200 MHz range.  Developing higher RADAR frequencies quickly became a race to stay ahead of the competition and their ability to jam your system.  The limit that a tube could operate at is determined by its output capacity and the length of any internal inductances.  The grid to plate spacing in the 2C40 was only .3 mm. 

    2C40

    The 2C40 was developed to be a low power oscillator or amplifier at a maximum of 3370 MHz to be used in microwave receivers or signal generators.   That high frequency was achieved by using a tube with an output capacity of 1.3 pf and coaxial tank elements that were designed to mount directly on the tube.  The tunable cavity was designed to use concentric cylinders that were sized to slide over the 2C40 and make contact.  When the cavity was assembled, the tube could be plugged into the end and a socket fed with a cable supplied filament power.  The filament of the 2C40 was 6.3 volts at .75 amps.  In a conventional oscillator or amplifier, the plate voltage would be 450 maximum at 22 ma.  If used in a pulse application, 1400 volts could be used.

    The 2C40 had a low noise figure for this period so it was used in preamplifiers for RADAR receivers such as the AN/TPS -1D and the AN/FPS-37 and the BP shipboard IFF interrogator.

  • Multi-Band Verticals

    by Gary Johnson NA6O

    A holy grail for many hams is an antenna that’s usable on nearly all bands that takes up very little room. This time we’re talking multi-band verticals. While compromised in several ways, they at least get us on the air. For this survey, we’ll only consider the contraptions that are resonant on their supported bands (without adjustment) as opposed to the non-resonant ones that are heavily reliant on an antenna tuner, such as a 43-foot vertical.

    What About Radials?

    Every vertical antenna has an associated ground radial system, sometimes called a counterpoise. When dealing with multiple bands, an effective solution is ground-based radials which are non-resonant. The drawback is that you have to deploy quite a few long wires in your yard in order to achieve good efficiency (radials provide a low-loss return path instead of the lossy Earth). Another solution could be elevated radials which are resonant, but that would mean that you need separate wires for each band, and that’s quite a cobweb. Yet another solution is an off-center fed vertical dipole (OCFVD) where the radials are a single, fixed length, and need not be very long. We’ll review a couple of designs like that.

    Some Models That Use Ground Radials

    Reminder: All of these antennas require a robust ground radial system in order to maintain efficiency. See the ARRL Antenna Book for some design recommendations and tradeoffs for ground radials.

    DX Commander [Ref. 1] offers several models that use ground-based radials covering everything from 80 through 2m. For the vertical elements, they use an array of parallel 1/4-wavelength wires, making this the vertical equivalent of a fan dipole and nicely resonant on all bands. This is electrically very simple with no traps or elaborate mechanical contraptions though some elements fold back or have small loading inductors. Their kits include plastic guides that keep the wires parallel (Figure 1). Assuming you can put down an adequate radial field, this will be an efficient antenna with good bandwidth on each band. A drawback is that it’s going to be tall, e.g., 33 ft for 40m. They do have a loading kit for 80m to keep it from ending up in the stratosphere. Overall, I really like these antennas because of their straightforward design, efficiency, bandwidth, and power handling.

    Figure 1.  Detail of the wire guide/guy ring on a DX Commander vertical.

    Hustler is an old brand (now owned and sold by DX Engineering) of trapped verticals that require ground-based radials. For instance, the 6BTV covers 10, 15, 20, 30, 40, and 80m and is only 24 ft tall. There are five traps in series which add inductance thus shortening the antenna on the lower bands. They are rated for high power (1 kW CW) and have reasonable SWR bandwidth except on 80m where it’s roughly 80 kHz (2:1), which is typical of any shortened antenna. The only issue I have is loss in the traps and the possibility of trap failure with weather and time.

    Butternut is another older company now owned by DX Engineering offering a 6- and a 9-band version. The HF6V covers 10, 15, 20, 30, 40, and 80m and is 26 ft tall. They use several interesting tricks including loading coils, traps, and transmission line matching sections. Their traps are pretty serious, being made of large aluminum tubing and low-loss ceramic capacitors (Figure 2). This minimizes loss and fully supports high power. Once again its reduced height means bandwidth will be limited on 40m (150 kHz, 2:1) and 80m (<80 kHz). Like all complex multi-band verticals, plan on spending some time with an antenna analyzer and your toolkit to adjust the SWR on each band per the instructions. And if you choose the big brother with nine bands, tuning may be even more interesting. Overall, this is another solid though complex antenna design.

    Figure 2.  Closeup of a Butternut trap. This is very robust and low-loss design.

    The OCFVD Vertical

    Hy-Gain and Cushcraft made a number of popular models based on off-center fed vertical dipoles such as the R6000, R9 and AV640, but with the demise of MFJ, they are only available on the used market. Today there are a couple of other companies making antennas of this type that we’ll cover. But first, how do these antennas work?

    As an antenna hacker, my hat is off to the folks who designed these OCFVD contraptions using an arsenal of tricks. We begin with an off-center feed point. On the short end (nearer to the ground), add a set of radials of modest length, commonly about 6 ft long and made of stainless steel.

    Like an OCF dipole, you can experimentally find a place near one end that yields a similar impedance on all the desired bands. It’s similar on all bands, but not 50 ohms, so you add a matching transformer to yield a reasonable SWR.

    To improve the match on various bands, add some traps. These effectively cut off the far end of the antenna at their resonant frequency. They also act as an inductor at other frequencies, shortening the antenna. Traps can also be added to the radials.

    Next, add some capacitance hats near the top of the antenna. These are a low-loss method of lengthening the antenna. Length of the capacity hat wires is another tuning element. And by placing them between traps, you can tune particular bands. A Christmas tree is born.

    Finally, you can add one or more coupled resonator, or open-sleeve elements. These are typically 1/4 wavelength pieces of tubing that may or may not be directly connected to the rest of the antenna. Because they are resonant they literally “suck the power” away from the rest of the antenna structure on a specific band.

    Somehow the crafty designer combines some or all of these elements into a reproducible package. A drawback of this complexity is that it can be tricky to tune in the field because some of the elements interact.

    I should also mention that, being an off-center fed antenna, the outside of your coax must be isolated via a robust common-mode choke. Most of the commercial antennas include this in their matching box. The matching transformer is also under some stress and between that and the choke, quite often you will find power limitations due to overheating. Running high power, you may see the SWR start to rise. Keep going, and the whole matching unit will eventually melt!

    Figure 3. Left to right, antennas from DX Commander, Hustler, Butternut, and Chelegance.

    Some OCFVD Models

    Chelegance model KC4 [Ref. 2] covers 40, 20, 15, and 10m and is 26 ft long with 9 ft radials. They use three traps in the vertical plus capacitance hats. It has limited power handling, such as 500 W on CW, which indicates that the matching system is under stress and probably dissipates a bit of energy, typical of this kind of antenna. It’s pretty light (16 lbs) and doesn’t take up too much space. Mount it up on a pole as high as you can. This may be the only viable OCFVD antenna on the market at the moment.

    Diamond Antenna model CP6AR covers 75, 40, 20, 15, 10, and 6m. It uses three traps plus capacitance hats and, unusually, tuned radials with traps. It’s only 13 ft tall and radials are 6 ft long. Because it’s so short, SWR bandwidth and power handling a highly compromised. For instance on 75m, bandwidth is only about 20 kHz and on 40m about 30 kHz. Also, it’s only rated 70W CW. Clearly there’s an efficiency problem in the matching box, likely qualifying this antenna as an “outdoor dummy load.” The old Cushcraft antennas were taller but way better!

    Installation Tips

    Install guys: Many verticals require guys and they are most recommended in windy locations. Thankfully the wind loading isn’t too severe so the guy anchors can usually be something simple like a piece of pipe driven in the ground, or a heavy eye bolt attached to the house, fence, or tree. Dacron rope is recommended for long lifetime in the sun.

    Use an antenna analyzer: Don’t try tuning up one of theses complex multi-band antennas without an antenna analyzer or it will take forever. You will have to raise and lower the antenna several times.

    Elevate the base: If your chosen vertical does not use ground-based radials, it is very desirable to elevate the base of the antenna on some kind of mast or mount it on your roof. This will lower the takeoff angle and increase gain for better DX [Ref. 3]. Ideally the mast would be non-conductive but most of us just use some pipe.

    Advantages and Disadvantages

    As stated at the opening of this article, the reason for choosing an antenna like this is that you get multiple bands in a fairly compact installation, give or take some ground radials which at least you can hide. Efficiency is your main concern, followed by usable bandwidth, and some of the models we looked at are compromised in either or both aspects, so choose wisely. And like any vertical, we joke that they radiate “equally poorly in all directions,” but seriously, any antenna is better than no antenna.

    References

    1. DX Commander website https://dxcommander.com/
    2. Chelegance KC4 Antenna https://chelegance.com/products/cntou-kc4-shortwave-4-band-vertical-antenna/
    3. Jim Brown, K9YC, “If I Could Put My HF Vertical On My Roof, Should I?” http://www.audiosystemsgroup.com/VerticalHeight.pdf

  • Study of a Telegraph Tuning Fork

    by Gary Johnson, NA6O gwj@me.com

    Terrestrial telegraphy required countless inventions, and one of the more unusual devices from that industry is the subject of this report. I am calling it a Telegraph Tuning Fork (TTF) because I can find no better description at this time. It came to me via a friend who got it from a fellow who collected surplus equipment, in particular from the Navy’s Mare Island facility near Vallejo, CA. Considering the history of the facility beginning in 1854 and the Navy’s extensive use of all forms of communication, this could indeed be the provenance of this item.

    Figure 1. My mystery instrument.

    Who Made It and When?

    There is a partial label on the instrument, seen in Figure 2. It was made for The Western Union Telegraph Co., so indeed it has something to do with telegraphic communications. Its manufacturer turns out to be D. & H. Precision Tool Co. in Newark, NJ. This company was founded no later than 1918 by Mr. DeSaules and Mr. Hall, and still exists today as D & H Cutoff Co. So perhaps it was made in the early 20th century. Someone skilled at identifying early electrical components may have an opinion.

    Figure 2. This label gives us a starting point.

    Searching online, the closest match to my device was located at the Smithsonian (Figure 3). They identified it as a telegraph tuning fork, and the maker is Western Union Co. It does have some of the basic features and clearly we are on the right track for identification.

    Figure 3. Photo from the Smithsonian National Museum of American History, identified as a telegraph tuning fork [Ref. 1].

    Overview of the Instrument

    Figure 4 is an annotated top view that identifies the major components. The base is of cast bronze and the entire device weighs about 35 pounds. The main structure is literally a long, heavy tuning fork fabricated from steel and anchored at the left end. A series of weights adjust the resonant frequency. A large electromagnet (MAG-1) resides under the fork, with pole pieces just outside of the arms so that when energized the arms are pulled outward. Clearly this is the excitation method. Two sets of SPDT contacts are actuated by movement of the forks. At the far right end is a pair of coils (MAG-2A and B) that apparently are used to sense motion of the forks. Four terminal strips provide connection points.

    A clever gear-driven mechanism slides tuning weights along the forks, thus allowing the resonant frequency to be adjusted while the forks are in motion. I located a patent [Ref. 2] “Adjustable-Vibration Tuning Fork” assigned to Western Union Telegraph Co. in 1923 that describes this mechanism. Due to age and corrosion, the mechanism is frozen, and no attempt was made to restore it.

    Figure 4. Top view of the TTF, annotated.

    Looking at the bottom of the device in Figure 5, a number of electrical components are identified. Three identical capacitors, C1-C3, are all marked 1 uF and in fact tested good despite their age. A stack of three resistors, R1-3, measured 150 Ohms. A pushbutton module is connected in series with MAG-1, so that may be considered the on/off switch for excitation. I didn’t have a suitable instrument for measuring inductance but did measure the resistance of each coil.

    Figure 5. Bottom view of the TTF, annotated.

    Analysis and Operation

    After identifying components and doing some wire tracing, a schematic was produced (Figure 6). Operation is simple. Starting at rest with S2 closed, an applied voltage produces a current in MAG-1, forcing the forks to move outward, which opens S2. Current collapses, allowing the forks to move inward, then the cycle repeats. This is a kind of relaxation oscillator and will preferentially operate at the resonant frequency of the mechanical system. C1 and R1 form a snubber circuit which suppresses arcing when the contacts open.

    A second set of contacts, S1, also has snubber on each side and connections are simply routed to a terminal strip TS2. These could be used to synchronize an external device with the vibration of the forks.

    Coils MAG-2A and B are connected in series and brought out to TS3. They could be used for monitoring oscillation. TS4 is routed to a pair of wires that are disconnected on this instrument. There are some mounting holes in a black bracket above MAG-2A and B that may have held a now-missing device.

    Figure 6. Schematic diagram of the TTF. (Link to PDF)

    Even after a hundred years or so, this instrument is still functional! Some cleaning of contacts at S2 and terminals at TS2 was all it required. Connecting a DC power supply and beginning at 40V, I slowly adjusted the contact spacing and the forks sprang to life, with a current draw of just 10 mA. With further adjustment, I found that the TTF would start and run as low as 3 V. Amplitude was roughly proportional to excitation voltage. Sitting on the bench, it made a low purring sound with no vibration felt in the base due to careful dynamic balancing of the forks. 

    Connecting MAG-2A and B to an oscilloscope, I observed oscillation at exactly 30 Hz. Considering the mass of the tuning forks, this should be a very stable oscillator, drifting only slowly with ambient temperature changes. Assuming the forks are made of ordinary steel, I estimate that the temperature coefficient of frequency is about -24 ppm/degC.

    What is it For?

    Little information on “telegraph tuning forks” can be located with a web search, but a number of interesting uses are suggested in a patent search. One fundamental application is synchronous telegraphy where the two ends of the connection rely on stable, matched oscillators to encode and decode transmitted data. More importantly, such synchronization allows multiplex telegraphy where several independent data streams may be sent down a single wired connection. In one patent [Ref. 3], a TTF is shown at each end of the link with its auxiliary contacts causing a large rotary switch to advance with each pulse. In effect, the rotary switch dynamically chooses among several sender-receiver pairs in a kind of time-sharing arrangement.

    As time went on, manual sending and receiving of Morse code was sometimes replaced with faster automated transmission consisting of punched tape at the sending end and a variety of receiving devices. Synchronous timing is very important and once again the TTF appears. We would now call it a clock oscillator. By the way, these same mechanisms were also used for teletype data. Long terrestrial lines are problematic due to signal loss and distortion. What was needed is an amplifier of some sort, but that did not exist prior to the invention of the vacuum tube. So an electromechanical repeater was devised. The patent in Ref. 4 relies on synchronous telegraphy where the transmission occurs at a fixed frequency, and uses a TTF as a sampling device to pick out the best part of each signal pulse. The auxiliary contacts then produce a nice, clean output for retransmission.

    This turns out to be an important and useful invention in the telegraph industry. Being a telegrapher myself (radio, to be exact), these devices are fascinating. If anyone has additional information about the TFF, I’d love to hear about it (email gwj@me.com). Additional high-resolution photos are available.

    References

    1. National Museum of American History, “Telegraph tuning fork”, Cat. No. 331340. https://americanhistory.si.edu/collections/object/nmah_890715
    2. Walter A. Houghtaling, “Adjustable-Vibration Tuning Fork”, U.S. Patent No. 1,466,623, 1923.
    3. Poul La Cour, “Synchronous Telegraphy”, U.S. Patent No. 302,502, 1884.
    4. Herbert Angel, “Regenerative Telegraph Repeater”, U.S. Patent No. 1,673,726, 1928.

  • The Nugget – June 2025

    June 2025

    Volume 30 Number 6

    The next meeting of the MLDXCC will be on June 21st in Shingle Springs. Find out more.

    From the Prez

    Hello Nugget readers,

    I do believe all of you are aware by now, but MLDXCC has won the club competition for the 2024 ARRL Sweepstakes. This is our 10th first place win in a row. It was announced in the June QST. I really like competing in the Medium Club category. It’s always a good competition and a win every year is never for certain unlike the Unlimited Club competition where PVRC is just shooting fish in a barrel. Congratulations also go out to PL259 for winning the Small Club competition.

    I went to the Dayton Hamvention again this year and I actually spent some money. I came back with a Flex PGXL amplifier, the TGXL tuner, and the AGXL 8×2 antenna switch. All of this now makes for a complete SO2R remote station. To get to that point, I need to replace the Array Solutions 6×2 switch with the AGXL and W6SR and I need to do a bit more antenna work.

    I am really impressed with the PGXL amp so far. The protection circuits work as they should and this amplifier can put out a true 2 KW. The amp has three fan/blower modes: Standard, Contest and Broadcast. In the Broadcast mode, the fans absolutely scream and I like that in an amplifier. It never hurts to blow too much air on an amplifier. The down side of this is if the amplifier is located at the operating position, it can be incredibly annoying when running in Broadcast mode, which is recommended for RTTY, FT8 and SO2R operation. The good thing is that in an all-Flex station, the transceiver, amp, tuner and antenna switch are all on the network. No serial cables, USB cables, etc. are necessary. All control is over the network. This means that the transceiver, amp, tuner and of course the antenna switch can be located nowhere near the operating position. I am going to be rack mounting the 6700, tuner, amp, rotor controllers, bandpass filters, etc. all in an open-frame rack that will be located away from the operating position.

    We’ve got a great meeting planned for this month. Craig, K9CT, will be giving us a tour, via Zoom, of his contest super-station. Hope to see you at the meeting.

    From the Veep

    Hello MLDXCC! 

    As a reminder, Field Day (6/28) is just around the corner. Yesterday I received my ARRL 2025 Field Day T-shirt so I’m ready to go!  As of now, Sue K6SZQ and I will be working from our home station so keep an ear out for us. Remember to update your logging program for Field Day use too.

    Worked any good DX lately? I know HF DX lately has been a little sparse; however there has been some activity from Wake Island.  Six meters (50.313 FT8) however has been very active! Currently I’ve been able to log 46 states, only needing RI, DE, VA & WV at this time. As a suggestion from a club member I’ve started to pay attention to grids as well.

    How’s your DX Marathon numbers looking? Remember even though you’ve worked a DXCC country before, they count as “brand new” again every year for the Marathon. WARC band & FT4/FT8 contacts all count for the Marathon as well.

    Well that’s all for now, time for me to go check east coast six meter propagation.

    73 and Good DX, Steve NC6R

    Articles

    Another Bug Restoration

    Minutes of the May 10th Meeting (Habanero Hots, Lodi)

    Presentations and Slides from Dayton

    Photos from the 2025 IDXC in Visalia by N6TV

    Norm N6JV’s Tube of the Month

    SCDXC Newsletter Lives!

    The Southern California DX Club is gone, but a newsletter is still being published – and there’s a lot of great content there! Check out the June 2025 issue. (Thanks Rick W6SR for the tip!)

    Speaking of DX…

    Upcoming DXpeditions via NG3K

    DX Calendar via 425 DX News

    Upcoming Contests

    Via contestcalendar.com:

    Humor!

    Steve NC6R wanted everyone to see this 😅.

    “They say it’s probably safe to keep orbiting for a while, but if it stays on or starts flashing we might have to call someone.” (credit xkcd)

    Send more funny stuff for the next issue! – Ed.

    Classifieds

    I have a WaveNode WN2 Digital Watt Meter, with four HF sensors.  This unit sells new for $385, with a single sensor.  I have been using is in an SO2R configuration with a sensor on the input and output of each amplifier. 

    That way, I can always see my input and output power.  Rick, W6SR, who uses my station remotely more than I do, has depended on the software display to know how much power he’s running.

    There are several options for the look of the computer display.  And there are several other features such as rotator control and antenna switching but I have just used the wattmeter function.

    I’m selling this because I have purchased the Flex PGXL amplifier, which has built in and remotable watt meters.  It can be yours for $200. Contact Bob W1RH w1rh@yahoo.com

    Need a REAL dummy load, rated 500W continuous (2 kW peak)?  Here’s an old MIL TS-118A/AP, which is also a Bird 693. Flat to >1 GHz. Normally configured to use the included thermocouple sensors and a built-in meter, I’ve included a little shorting plug that turns it into a simple dummy load (disables the meter), but you can run it either way. The steel case weighs more than the instrument! Will sell for $140 because that’s what the special LC to N adapter cost me.   Manual:  https://birdrf.zendesk.com/hc/en-us/article_attachments/23027152223767
    Contact Gary NA6O gwj@me.com

    Jim K9YC passed along information about some free towers and antennas “for a lot of labor”. They are located west of Portland OR. More details here.

    Rick N6RNO has one of these shack warmers for sale, new in box. Contact Rick at rick@eversoles.com for details.

    ClubLog DXCC Standings

    As of 17 June 2025. You can see complete MLDXCC standings on ClubLog here.

    Overall

    1NK7I227
    2W1SRD224
    3W6DE201
    4K6OK184
    5K6YK182

    CW

    1K6YK162
    2NO5Z122
    3K6OK120
    4NA6O105
    5N6WM104

    Phone

    1W1SRD116
    2K6YK115
    3NO5Z114
    4N6WM111
    5K6TQ101

    Data

    1NK7I216
    2W1SRD195
    3W6DE177
    4K7QDX173
    5K6OK154

    Resources

    Check out the Resources menu up there at the top of every web page for useful DX and contest info.

    Prepared for the MLDXCC by Editor and Webwookie Jeff WK6I. Please do send me any corrections, omissions, or material for future issues of The Nugget. It is much appreciated!

  • Another Bug Restoration

    by Gary Johnson, NA6O gwj@me.com

    It seems that I spend too much time restoring old keys but somehow it’s more fun than trouble to me. I recently was given a beat-up and not very valuable Les Logan Speed-X model 510 bug.

    This represents the low-end of the market in the 1930s, with a cast zinc base and all-steel components. It’s also too light and almost demands bolting to the table. As received, it was dirty and rusty, missing the damper assembly, the dot spring was broken, and an adjustment screw had its head broken off. Also there was no return spring. I stripped and repainted the base, cleaned everything, and machined the required parts. So this sow’s ear is… Well, still not a silk purse but at least it functions and is non-toxic. If you need any Morse key of any type repaired, let me know.

  • Tube of the Month – June 2025

    by Norm Wilson N6JV – Visit the museum at N6JV.com

    8011 (The Micropup)

    In 1940, the British were just holding their own in the Battle of Britian.  The outcome was not certain as their cities were being flattened by the Luftwaffe and the German “U” boats were stopping much of their shipping.  Nations don’t like to share their top secrets with even their best allies, but if they lost, their allies could use their research and possibly stop the Axis. 

    8011

    A delegation under the leadership of Sir Henry Tizard, sailed to the United States with a collection of equipment they wished to share with the United States and Canada,  They met at the Massachusetts Institute of Technology (MIT) and shared their “Holy Grail”, the cavity magnetron, and some other equipment including a working RADAR system that would allow a plane to find surface ships and “U” boats in any weather.  The British were hoping to trade for the Norden bombsight. It was decided to form a new working group to conduct research.  This became the MIT ”Radiation Laboratory” or just the “Rad Lab”.

    The RADAR was the ASV (Air to Surface Vessel) Mark 11.  Its development started in 1937 and it had been successfully deployed against a “U” boat.  The transmitting pulsed oscillator used a pair of British VT90 valves that had an output of 7 kW at 175 MHz.  Copies of the VT90 were made by each country.  The 8011 was the RCA version.  The Canadians made the REL1 and Western Electric made the WE710A but all were interchangeable.  The sets were basically the same and the US sets were designated ASE/SCR-521.  The Canadians alone made 10,000 units.  A search aircraft could spot a destroyer or submarine at about 20 miles using the Mark II.  Larger vessels could be spotted up to 35 miles.

    The 8011 operated with 9 kV on the plate with a dissipation on 100 watts.  The filament operated at 8.25 volts at 7 amps.  The mu of the tube was 15 and the maximum frequency was 600 MHz.  Air for cooling was applied to the side of the plate through a notched tube.  I have never found the reason they called these tubes “micropups”.

    The British had been mounting their  Mark II sets in their PBY Catalina flying boats.  As new sets were available, starting in Dec. 1940, they were mounted in the U.S. Navy’s PBYs and were an instant success.  By the start of the U.S. involvement in WWII, the Mark IIs were widely deployed.   The Catalinas played an important role in spotting Japanese ships in the Battle of Midway and the Guadalcanal campaign.  The Mark II had a receiving antenna mounted near the end of each wing.  Other multi-engine aircraft were used including the B-17 bomber.  I have seen photos of B-17s flying long range security for a large convoy traveling to Europe.

  • Photos from the 2025 IDXC in Visalia

    Bob Wilson N6TV took a few nice snapshots at the International DX Convention. Visit the album here. Thanks Bob!

    N6TV

  • Presentations and Slides from Dayton

    Here are some useful links from the Dayton Hamvention this year. Please contact the Webwookie if there are any I missed listing here.