by Norm Wilson N6JV – Visit the museum at N6JV.com
In their build up after WWI, the Royal Air Force developed a new triode transmitting tube that was capable of higher power than earlier types. The DET25 was a developmental tube similar to the “50-watters” being made in the US. In 1925, the RAF was still flying open cockpit biplanes so the DET25 had the L4 base, with its long voltage breakdown paths, for use in wet applications.
DET25
I have found two early RAF transmitters that used the DET25. The TR 4 is a single DET25 oscillator that has plug-ins to operate on the range 143 to 500 KHz or 3 to 15 MHz. It uses either CW or interrupted CW (ICW) where the keying lines are fed through a motor driven wheel like a spark transmitter. The TR 1091 was a MOPA design with the DET25 as the amplifier. It operated in 1.2 to 1.5 MHz and 2 to 3.4 MHz using plug-in capacitors and coils. It used the same CW/ICW keying system, but also had grid voice modulation. This was a larger unit and required a larger aircraft.
The DET25 has a published filament voltage of 7.5 volts but other sources give it as 6 or 8 volts. Filament current is somewhere in the 1-to-2-amp range. Plate voltage has a maximum of 1200 volts and a current given as 36 ma dissipation maximum. The user needed to know the average of the mode they were using. Fifteen WPM CW has an average of 45% depending on the fist. Hand written notes indicate that in practice about 80 ma was used for a 60-to-70-watt output.
The designation DET25 was changed to VT25 and then CV1025 (Common Valve) when the Inter-Service Technical Valve Committee in 1941 started their version of JAN numbers. The British Army also used the designation AT35 for the VT25.
We hams are famous for helping one another in many ways such as education, setting up equipment, or group operating events such as Field Day and emergency communications. Our team recently had a very successful experience helping a young CW op who was in need.
Twenty year old Jenna Hurley, N4JEH, is a blind student at the E.H. Gentry Facility, a component of the Alabama Institute for Deaf and Blind (AIDB). Adopted from an orphanage in China along with five siblings by her parents in Alabama, Jenna received excellent home schooling from her father, David. They even learned Braille together. David eventually discovered ham radio and started learning Morse code. That caught Jenna’s ear and together they used online resources to study and obtain their licenses when she was 17.
Jenna, N4JEH, showing off her new TS-590S and one of her favorite bugs. Photo credit: N4TMM.
They had a station set up at home, so Jenna was able to get on the air. CW was (and is) her passion and she quickly became highly skilled at it. So skilled and active in fact, that she was soon invited into both CWops and FOC, which is an honor for any telegrapher especially someone so new to the hobby. This led to numerous friendships worldwide.
After moving into the dorms at E.H. Gentry, Jenna was left without her own station to operate. With some difficulty due to poor blind accessibility, she was able to access some RemoteHams stations, and also did some POTA operating with her boyfriend, Gunner, KK7DEU. But every active ham really needs a proper station with a good radio and antenna. This is when those ham radio friendships really paid off.
There are many blind hams just like Jenna who may not be able to fully enjoy their hobby for various reasons, often financial. Gary, NA6O, started making friends with blind hams several years ago after realizing this need [Ref 1]. Specific radio models are of value to blind operators because they have a built-in voice guide and relatively easy-to-use controls. This is known as accessibility. The Kenwood TS-590S is perhaps the most accessible and popular. Gary started buying these radios on the second-hand market, outfitting them with the speech module, and then donating them to needy blind hams. One of his beneficiaries, Dave, W4CI (who is also an FOC member), mentioned that Jenna was a good candidate for a radio. That started the ball rolling.
Gary and Dave started working with Fred, KT5X (FOC of course!), who already knew Jenna, and in turn he recruited Jim, N4TMM, who turned out to be the key player in our success. Jim, who lives in Atlanta, would be in Sylacauga Alabama the first week of April to participate as a stone sculptor in the Alabama Marble Festival. Sylacauga is only a few miles down the road from Talladega, the location of E.H. Gentry and AIDB. So Jim was in perfect position to help set up Jenna’s station.
Jim approached the president of AIDB, Dr. Dennis Gilliam, and also Ms. Jessica Edmiston, who offered their full support. Meanwhile, Gary had sent Jim a power supply for the TS-590S that Dave was sending Jim. And Jim ordered a MyAntennas end fed halfwave wire antenna, a proven commercial design that will typically tune acceptably on several bands.
On Thursday, April 3rd, Jim met with EH Gentry maintenance people Joe Hutto, Don Llewellyn, and Tony Adams. Tony was there with his truck full of tools, ladders and other maintenance equipment, and Jim brought his radio toolbox and all the equipment for Jenna’s station that he had collected. After surveying the surroundings, Jim and Tony concluded that the best option was to lay the wire antenna, about 140 ft long, on the roof of the three-story dormitory where Jenna lives. So Tony got out his ladder and he and Jim installed the antenna on the roof and connected it to the radio in Jenna’s room. Thankfully they allowed a wall penetration for the coax, something that had been a concern for a long time.
At that point, Jim got on the phone with Gary, who was listening on his radio in California and also watching the Reverse Beacon network, gave feedback while Jim tuned and transmitted on various bands. The antenna and the station turned out to be excellent performers on 40 through 10 m, tuning fine and getting reports from NA as well as DX. The roof where the antenna is located is the highest point around, and the dorm is on a hill. The antenna lies generally in a Northeast to Southwest direction, and it propagates well in all directions. As a bonus, her noise floor is very low. We should all be so lucky in our modern age of rampant RFI.
In all of this, Jim was amazed and gratified at the support and assistance from AIDB and E.H. Gentry people in helping their student Jenna get on the air from her dorm and continue her excellent trajectory as a well-known CW operator. Jenna, in turn, takes great joy in operating from E.H. Gentry, thus adding to the fame and furthering the cause of this well known and highly regarded institute for the deaf and blind.
Jenna’s first contact with her new station was George, NE5A, who was also her advisor in the CWops CW Academy when she was starting out. A delightful coincidence! Since then, she’s been on the air every day, making contacts worldwide and is now a CWops advisor herself. And she is indeed a first-class operator, including QRQ, something that many hams only dream of achieving. Check out her YouTube channel, QRQ Maniacs [Ref 2.].
Jenna has a bright future ahead. She’s currently taking classes at Central Alabama Community College, focusing on computer science. She then plans to attend a university to obtain her BSCS degree, and has a particular interest in assistive technologies. Jenna wishes to thank some of her Elmers, particularly CWops advisors NE5A and AJ1DM, and her dad, David KO4WSU. We in the ham radio community are glad to have helped her along in some small way.
References
Gary Johnson, NA6O, “Summer’s Legacy.” Solid Copy, No… 177, October 2024. https://cwops.org/wp-content/uploads/2024/10/Solid-Copy_2024_October_FINAL.pdf
All the news from the “NCCC’s Kuiper Belt” – K6DGW
We had no meeting in April due to the International DX Convention, so no minutes to report, and the March minutes made it into the previous issue of The Nugget. Also no missives from the Pres. or VP this time. We’ll be back in sync next month! – Ed.
Gary N6AO is taking a break from the Antenna of the Month. Stay tuned.
And with the dissolution of the SCDXC, no more Deleted Country of the Month, unless someone would like to step up and continue them.
Another Editor’s Note – Club History
I am still hoping someone has some history about the first 5 or 6 years of the MLDXCC locked away someplace – please let me know if you do. If it is memories, I’m quite happy to interview you and take notes.
I’m also still hoping someone knows anything about John Fogg, K6AO. I have so far learned that he edited the NCDXC newsletter in 1965 (source: NCDXC SK list), he built a 2 meter “pip squeak” transmitter from a design in QST in 1972 (Palo Alto ARA news), he lived in Pine Grove as early as 1976 (ditto), and in 1949 he lived in Alhambra not far from where I grew up (Callbook). And, for a brief moment I was excited to see a Wikipedia article, but it’s likely that our John Fogg was not the mayor of Pensacola FL from 1994 to 2009 (Wikipedia). Hihi. – Jeff WK6I
Classifieds
I have three items for sale. All the items are on a make and offer basis. The items below are excess to my need, since I live in a HOA 55 plus community. I use a remote station location at W1RH’s QTH. Call or email me for more info. or offers. de Rick, W6SR ricksamoian@outlook.com or (530) 672-2885.
Ameritron 1306 power amplifier and matching power supply. 160M-6M 1300W SSB/CW/800W RTTY/FT-8. 40 watts drive = full output. I have original shipping boxes unit works 100%
Johnson KW matchbox very nice condition. This is an original unit that has NOT been modified.
Honeywell 4 cycle KW inverter sine wave generator. Used for portable operating. Quiet, and perfect for K3 and KPA 500.
ClubLog DXCC Standings
As of 15 April 2025. You can see complete MLDXCC standings on ClubLog here.
Overall
1
NK7I
215
2
W1SRD
206
3
W6DE
186
4
K6YK
168
5
NO5Z
162
CW
1
K6YK
139
2
NO5Z
116
3
NA6O
103
4
N6WM
103
5
W1SRD
98
Phone
1
NO5Z
114
2
W1SRD
113
3
K6YK
111
4
N6WM
111
5
K6TQ
90
Data
1
NK7I
204
2
W1SRD
172
3
W6DE
167
4
K7QDX
151
5
K6OK
129
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 Webmaster Jeff WK6I. Please do send me any corrections, omissions, or material for future issues of The Nugget. It is much appreciated!
You’ll notice that The Nugget is no longer published as an Adobe PDF file. It’s now being produced in a blog format. This is for a couple of reasons:
Nobody really knows what goes in the depths of search engines on the Internet, but it is generally believed that content posted as normal website content (using Hypertext Markup Language, aka HTML) show up higher in search results than PDF content. This helps us attract new members better.
PDF files are not easy to read on small devices like phones and small tablets. Modern web pages know how to adapt to the size of the device – they call this “responsive” – making it easier for our members to enjoy the content on any device.
Also, you’ll see that some of the major content and news is getting published right away – items like the Tube of the Month – rather than waiting for a monthly Nugget cycle. This is done to get the info to you in a more timely manner, and frankly it’s easier for your editor to spread the work out over the course of a month.
Since it’s now in a blog format, you can access The Nugget and related news and features using an “RSS Reader” application such as Feedly, which runs as a web app in your browser, as well as iOS and Android. Copy this link:
Do you have any other favorite radio blogs? Let us know in the comments!
If you are someone who prefers to print The Nugget, I’ve briefly tested it and things seem to print fairly reasonably. But if you have issues printing do let me know.
Here’s a few websites that I gleaned from DX Academy, Contest Academy, and Saturday presentations at the IDXC last weekend. Did I miss any? Add them in the comments! – Jeff WK6I
John NN6U presented “Contesting while activating POTA” (Parks On The Air). My takeaway is that, if you happen to be in a POTA park (like we often are during CQP for example), you can increase your visibility by operating as a POTA Activator. In particular, register your future activation on the POTA website, and when you go on the air you will get spotted there by POTA Hunters (and skimmers for CW/digital). This is not considered self-spotting. John said this presentation was basically the same as this one he made at the March 2024 NCCC meeting.
There were also presentations by Chris N6WM on Remote SO2R and 2BSIQ, and Hank W6SX on Having Fun Contesting.
A couple of websites from Bill K8TE’s “Tools for Propagation Prediction”. Here are some “Free DX Cluster Clients for Windows“. And Martti Laine’s book “Where Do We Go Next?” is available here to read for free.
Also two MLDXCC members placed first for call area 6 in their respective categories: Mike K7QDX in the Limited category, and Richard NC6RJ in the Formula 100W category.
by Norm Wilson N6JV – Visit the museum at N6JV.com
R3 – RECTOBULB
In the July, 1927 issue of QST magazine, an advertisement was published featuring the “6EX Rectifier” by a company named the National Radio Tube Company of San Francisco, CA. The call 6EX was held by a Garrett Lewis. Rectifiers like the 280 and the 281 had become available by 1927 for receivers and low power transmitters, but no rectifiers that would handle the voltage and current required to power the larger transmitting tubes hams were wishing to use. Arc rectifiers could be used but, they weren’t practical for most hams. It was unusual to see a tube named alter a ham. Hams would be assigned prefixes sometime in 1928.
The 6EX was later designated the R-3 and started life as a high vacuum type, but the final product was mercury vapor with an indirectly heated cathode. The maximum plate voltage was 7500 peak inverse volts at 250 ma. The filament ran on 10 volts at 1.7 amps. The tube had a standard UX base and a threaded stud out the top for the plate connection.
I don’t know how well the tubes were selling, but Lewis had a ham friend in Southern California who wanted to replace the ARC rectifier he had sold him and build a new power supply. The friend was Don Wallace, 6AM, and he wanted to go big. Lewis had also sold Wallace a re-built F328A which was a water cooled, 5 KW triode.
Don didn’t like QRP. Don bought six 3 KVA pole pigs that were 220 volts in and 6000 volts out from the power company and mounted them in a rack with six of the new R-3 rectifiers. The new power supply would be wired for six phase operation. The schematic and rack photo are copied from QST magazine of February, 1928, where Don and Robert Kruse of the QST staff, wrote a 9-page description of the final power supply. Six phase rectification results in an output ripple of six times the input ripple frequency. In 1928, 360 Hz was considered a good CW note and adding a filter condenser would be very expensive. The R-3 may have never been a commonly used tube as in a few years, the RCA 866 went into production and the R-3 became only a collectable. Before WWII, Lewis moved to Silicon Valley where Lewis Electronics was formed and participated in tube production for the war effort. In 1949 Lewis and Kaufman was organized and operated into 1956. In about 1962, I bought two 3 KVA pole pigs from PG&E for $3 per KVA.
Round Table Pizza, Jackson Meeting was called to order at 12:19 p.m. by Treasurer Sue Allred, K6SZQ. There were 12 attending in person, with 2 more attending via zoom. Of these there was one guest. Sue welcomed everyone. Each member and guest introduced themselves.
Old Business:
The January minutes were published in the February Newsletter. Rick Casey, W6RKC, moved to accept the report as published. Dave Sanders, K6TQ, seconded the motion, which passed unanimously.
The November and December treasurer’s reports were published in the February newsletter. Rich Hill, NU6T, moved to accept the reports as published. Stefan Nicov, AF6SA, seconded the motion, which passed unanimously.
New Business: None.
Member Achievements:
Rick Samoian, W6SR, worked VK9DX Norfolk Island on 6 meters.
Jeff Stai, WK6I, got the banquet organized for the Visalia International DX Convention
Announcements/Discussion:
The upcoming International DX Convention was discussed, along with the uncertainty with future events.
Bob Hess, W1RH, while managing the livestream, showed photos of Stefan Nicov’s Solid State HF amplifiers and discussed the possibility of him doing a presentation on them.
Bob Hess also passed around a list of equipment for sale from Tony Dowler, K6BV.
Next Meeting: Proposed date to be May 10, the location is Habanero Hots in Lodi.
Adjournment: Rick Samoian, W6SR, moved to adjourn the business meeting and move to the presentation. Jeff Stai, WK6I seconded the motion, which passed unanimously. Meeting was adjourned at 12:50 p.m.
Presentation: John Stanley, K4ERO, gave a fascinating presentation on Antipodal Focusing and its effect on ionospheric propagation near the opposite side of the earth from the transmitter. You can also get further information from his article in the March, 2025 QST.
Respectfully Submitted, G. “Skip” Chraft, N6NFB
Treasurer’s Report
Sue K6SZQ reported that, given the low level of activity, she’s going to switch to quarterly reporting. Look for the first quarter report in the next issue of The Nugget.
President’s Corner
Hi MLDXCC’ers,
Well, here I am as President of this club again. I swore it would never happen but Steve, NC6R, termed out. In an attempt to keep the club healthy, I made the suggestion that I’d take over as President and Steve will be VP… with one condition… Steve will keep running the meetings and I’ll continue to arrange the meetings and speakers. So, nothing has really changed other than a “loophole” in the Bylaws that allows us to continue as we have over the past three years.
I want to thank John Stanley, K4ERO, for a terrific presentation at last month’s meeting on the subject of Antipodal Focusing, meaning propagation from your QTH to the opposite side of the earth. We did record the meeting and, hopefully, Jeff will find a way to post the link on the all-new MLDXCC website.
I can’t thank Norm, N6JV, enough for what he has done for our website and newsletter. Without Norm’s constant “nagging” for content, we would not have had a newsletter and website with the great content we have had over the years. Alas, Norm has finally found someone to take over the website and Nugget. We all thank Jeff, WK6I, for taking on the challenge of filling Norm’s big shoes. Keep doing those great tube articles, Norm!
We have some really good speakers lined up for the upcoming months. Our May speaker will be Chuck, NA6XX, who will give a presentation on 6-meter DX’ing and propagation. Chuck, who lives in San Jose, will be driving to Habanero Hots, in Lodi, to give us his presentation in person. I also plan to stream this meeting. The date is May 10th.
A few others have agreed to do upcoming presentations. Stu, K6TU, will give a talk on his K6TU.net HF propagation site Craig, K9CT, will give us a presentation on his super contest station. Gary, NA6O, has also offered to give another one of his very entertaining talks. Other presentation for future months are in the works.
Both Steve and I have resisted streaming our meetings in the past for various reasons. We will be streaming more of our upcoming meetings. I do hope we can get more of our members from outside the core area to attend. Maybe even Will, from down south who often participates in our reflector conversation, will show us what he looks like!
In our February meeting, I did a contesting and DX’ing quiz, which seemed to get rave reviews, so we may do another one of those in the upcoming months. The February quiz, and the answers, are in this month’s nugget.
Last, and certainly not least, several of our members participated in the CQ WPX SSB contest last weekend at WC6H’s contest station. Besides Rich, the operators included Jeff (WK6I), Steve (NC6R), Gary (VA7RR), Tim (NU6S), and Barry (K6ST). The team did a whopping 14,097,405 claimed score to support NCCC’s effort.
For those headed to Visalia, travel safe and have a great time! – Bob W1RH
Tony K6BV has the following items for sale, please contact him at dxer@k6bv.net.
ClubLog DXCC Standings
As of 31 March 2025. You can see complete MLDXCC standings on ClubLog here.
Overall
1
NK7I
211
2
W1SRD
200
3
W6DE
181
4
K6YK
164
5
K6OK
154
CW
1
K6YK
136
2
NO5Z
113
3
N6WM
103
4
NA6O
102
5
W1SRD
95
Phone
1
W1SRD
112
2
N6WM
111
3
NO5Z
106
4
K6YK
101
5
K6TQ
81
Data
1
NK7I
200
2
W1SRD
168
3
W6DE
161
4
K7QDX
149
5
K6OK
128
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 Webmaster Jeff WK6I. Please do send me any corrections, omissions, or material for future issues of The Nugget. It is much appreciated!
At the February MLDXCC meeting Bob W1RH conducted a sort of trivia contest of various DXing and contesting questions. Here are the questions with the possible answers to choose from.
1 – The Following Contests Allow Self Spotting. Check all that apply:
ARRL SWEEPSTAKES CQWW IARU WORLD CHAMPIONSHIP NAQP
2 – K1LZ HAS A M/M REMOTE CONTEST STATION IN WHICH STATE?
Vermont Maine New Hampshire Rhode Island Massachusetts
3- In the North American QSO Party, the exchange is state/province and name. You do not need to use your own name. In the January NAQP, WO4O used W1N as a special event callsign. What name did he use?
Chiefs Bills Trump Eagles
4 – THE P49Y CONTEST STATION IS LOCATED IN WHICH ENTITY?
Aruba Bonaire Curacao Carriacou
5 – THE WINNERS OF THE 2024 SS CLUB COMPETITION ARE (Unlimited, Medium, Small):
At the February MLDXCC meeting Bob W1RH conducted a sort of trivia contest of various DXing and contesting questions. Here are the questions with the correct answers.
1 – The Following Contests Allow Self Spotting. Check all that apply
ARRL SWEEPSTAKES NAQP
SELF SPOTTING MEANS THAT YOU SPOT YOURSELF INSTEAD OF RELYING ON OTHERS
2 – K1LZ HAS A M/M REMOTE CONTEST STATION IN WHICH STATE?
Maine – Krazzy is from Bulgaria (LZ prefix).
3 – IN THE LAST NAQP, WO4O USED THE SPECIAL EVENT CALL, W1N. WHAT NAME DID HE USE?
TRUMP
4 – THE P49Y CONTEST STATION IS LOCATED IN WHICH ENTITY?
Aruba – Also P49L. Built by Carl, AI6V, as P49V. P49Y is Andy, AE6Y. P49L is John, W6LD
5 – THE WINNERS OF THE 2024 SS CLUB COMPETITION ARE (Unlimited, Medium, Small):
PVRC, MLDXCC, PL259 – (we hope)
6 – THE MLDXCC CLUB CALL IS
K6AO – Was John Fogg, Portola Valley, CA
7 – A FT8 CONTEST QSO CAN BE LOGGED WHEN YOU RECEIVE:
ALL OF THE ABOVE
8 – A STATION OPERATING 2BSIQ CAN USE WHICH MODES?
ALL OF THE ABOVE – TWO BAND SYNCHRONIZED INTERLEAVED QSO’S.
9 – 4U1WB COUNTS FOR WHICH DXCC ENTITY?
USA (WORLD BANK)
10 – HOW MANY CURRENT DXCC ENTITIES ARE THERE?
340
11 – THE PREFIX, FP, IS IN WHICH CQ ZONE?
5 – ST PIERRE AND MIQUELON
12 – THE VP8PJ DXPEDITION OPERATED FROM:
SOUTH ORKNEY ISLANDS
13 – THE PREFIX, VP9, IS IN WHICH CQ ZONE?
5
14 – WHAT WAS THE CALL OF THE FAILED BOUVET DXPEDITION?
3Y0Z – THE DXPEDITION FAILED BECAUSE THEY COULD NOT SAFELY LAND. THE BOAT GOT TO APPROXIMATELY ONE MILE FROM THE ISLAND
15 – ON A MULTI-ELEMENT YAGI, THE AZIMUTH AT WHICH MAX SIGNAL REJECTION OCCURS IS:
TO THE SIDE – A SHARP BROADSIDE NULL ABOVE THE ANTENNA
16 – THE BATTLE CREEK SPECIAL IS A:
MULTI-BAND VERTICAL (40/80/160) – WERE OFTEN USED ON DXPEDITIONS
17 – JAMES BROOKS HAS RECORDED MANY DXPEDITIONS. WHAT IS HIS CALL SIGN?
9V1YC – HE HAS FILMED MANY MAJOR DXPEDITIONS. HE OWNS A PRODUCTION COMPANY IN SINGAPORE
18 – THE VK0IR DXPEDITION WAS ON WHICH ISLAND?
HEARD ISLAND – 1997
19 – THE K5K DXPEDITION 2000 TO KINGMAN REEF COUNTS FOR DXCC
NO (Deleted March 19th, 2016 – was administered by US NAVY. Changed to US Fish and Wildlife, which also administers nearby Palmyra. Now counts as Palmyra/Jarvis.
20 – WHO COINED THE PHRASE, THE DESERVING?
HUGH CASSIDY, WA6AUD (first used in the West Coast DX Bulletin)
