California Historical Radio Society

California Historical Radio Society The California Historical Radio Society (CHRS) promotes the restoration and preservation of early radio and broadcasting.

Capping the Jars -- Part 10 of Reconstructing the Kilbourne &Clark No. 6 Spark KitBy Bart Lee, K6VK, for CHRS, 16 V ’1...

Capping the Jars -- Part 10 of Reconstructing the Kilbourne &Clark No. 6 Spark Kit

By Bart Lee, K6VK, for CHRS, 16 V ’19

. The Jars o’ Capacitance are now complete. Each of the glass jars – Leyden jars – now has an aluminum foil layer inside and another outside. The outside is grounded, or will be system-grounded. The jar tops, dropping lamp-chains to the inner foil, are connected to the clip on the left. The tops of the jars, when charged by the induction coil, will offer high voltage to the spark gap. As already noted, high voltage even in this primitive configuration, is dangerous; as Hugo Gernsbach warned for the customers of his Electro-Importing Company:

. “AIl our jars can be charged with even our 1/2-inch coil and the discharging crash of even our 1 — pint jar can be heard for blocks. It is powerful enough to kill a cat with a single discharge.” (emphasis added)

. Five new safety features seem warranted. A plastic cover insulates each jar top. The (red) wires from the tops are now high-voltage insulated wire. The joint positive terminal on the left is double insulated. A high voltage cable comes off this terminal. And, a warning sign is affixed:

. John Staples, W6BM measured one similar but smaller “jar” last year:

. I performed a simple experiment to measure the capacitance of a simple Leyden jar

. Using a peanut butter jar, I put aluminum foil inside and outside and measured the capacitance at 135 pF with the inside foil as close to the glass as reasonable, but not exactly.

. Filling the jar with salt water increased the capacitance to 470 pF, with a dissipation factor of 0.025. This means that the ESR measured at 1 kHz is about 8.5K, not a very good capacitor.

. The array of jars – dry – measures about 913 pF (picofarads – see photo).

. This is about 0.001 microfarad. Adding salt water (heavily salted back in that day) should multiply the capacitance by at least a factor of three.

. The term “Jar” as a measure comes from Marconi’s early gear. His Lizard Peninsula (Cornwall, UK) station circa 1910 is preserved (David Barlow, G3PLE, Curator), including its jars:
See: Transmitter Capacitance (“jars”) at Lizard Wireless Station (Lee photo).

. The Internet asks (and answers): “How many microfarad in 1 jar? The answer is 0.00111265.” So the new array, dry, is about one jar of capacitance. (The Royal Navy used the “jar” as a unit of capacitance until after World War One).

. A next step will be charging the jars. (de K6VK) ##

The 2019 Sherwood Awards
The 2019 Sherwood Awards

The 2019 Sherwood Awards

It's time to vote for your favorite Bay Area radio personalities in the 2019 Sherwood Awards! Named for

De Forest Audion Discovered -- found by Kent Leech in the Radio Central Tube Vault .          Kent Leech “knows his tu...

De Forest Audion Discovered -- found by Kent Leech in the Radio Central Tube Vault

. Kent Leech “knows his tubes,” and those of CHRS just as well. Asked to find an early vacuum tube for a recent video shoot, he came up with just such an early tube. We called it an “Audiotron” because that’s what Elmer Cunningham called his 1915 bootleg San Francisco tubular triodes before World War One. But Lee de Forest knew how to compete:

. Nearby is a De Forest Radio Telephone and Telegraph Company ad from QST about October 1916. The tube appears with an open cylindrical plate. And for those with equipment with a screw-base filament connection, they could buy an adapter for 40 cents.

5 DeForest Screw Base for Audion, Audion ad QST 1916

. The nearby photos show the tube Kent unearthed

1 Tubular de Forest Audion, CHRS on screw base & homebrew 4-pin base K6VK photo

2 Tubular de Forest Audion, CHRS on screw base & homebrew 4-pin base W6BM photo

4 Tubular de Forest Audion, CHRS on screw base & homebrew 4-pin base K6VK photo

. So, we have two clues here: 1) the cylindrical plate is open, and 3) the width of the tube is 13/16ths of an inch. How does this compare to the San Francisco bootleg Cunningham tube?

. In the nearby photo of a Cunningham Audiotron measured by calipers, note that the width is 14/16ths inch (14.2?). Note the San Francisco tube shows a fully closed cylinder.

6 San Francisco "Audiotron" pre-WW I = 14+ /16ths wide (author’s collection)

. It is fair to say, a century later, that the CHRS tube is indeed a De Forest Radio Telephone and Telegraph Company Tubular Audion Type-T as advertised.

. It would appear that an adept amateur affixed the tube’s filament leads to the added screw base. Then he made a wood base with four pins for use in a standard 4-pin socket. This may well have happened after 1916.

. CHRS has not yet tested this tube, which would be a pretty delicate operation. provides a couple more 1916 de Forest ads for the Type-T. But the ads show that the Type-T could go directly into the DeForest company Ultraudion Detector. This featured the de Forest style standard lamp socket for an Audion at the top.

. This regenerative circuit, introduced August, 1916 could handle “undamped waves”, i.e., CW by arc or vacuum tube oscillators, and AM also (’though there wasn’t much AM on the air in 1916). See: .

Dueling Radio Towers,-- From the CHRS Radioana Archives(by Bart Lee, K6VK, Archivist) .        .           Radio station...

Dueling Radio Towers,

-- From the CHRS Radioana Archives

(by Bart Lee, K6VK, Archivist)


. Radio stations seem to have arranged for promotional postcards back in the day – the AM broadcast, pre-television day, that is. It also seems that size matters, no doubt for reasons having to do with propagation and whatnot. Two postcards from that era each proclaim the depicted tower to be “America’s Tallest Radio Tower.” They can’t both be true – so, caveat lector. WSM says:

. “America's Tallest Radio Tower” -- So, Nashville, TN makes a claim. But then, so does Yankton, SD – WNAX: “America’s tallest radio tower” (and the cards are undated).

. The cards’ texts clear up the puzzle. They also tell a story about the importance of AM radio in the Midwest at the time, with millions of regular listeners to each station, and considerable listener involvement. Before TV, radio knit the country together while providing regional perspectives. “I heard it on the Radio” passed on the words of the new and modern oracle, broadcasting.

. The cards’ texts say:

. “WSM America's Tallest Radio Tower, 878 Feet, Nashville, Tennessee. 323 Feet Higher Than the Washington Monument.' on back of card: Known as the Shield Station, WSM is the broadcasting station of the National Life and Accident Insurance Company, Inc., whose Home Offices are located in Nashville. WSM is found at 650 on the radio dial, and broadcasts 18 hours daily with a power of 50,000 watts. Its 225 radio artists receive well over 50,000 letters a week.”

. “WNAX, YANKTON, S. D. America’s tallest radio tower is 927 feet high the equivalent of a 90 story building. It is the tallest radio tower on the Western Hemisphere. WNAX services more them 4 million listeners in Iowa, Nebraska, Minnesota, North Dakota and South Dakota.”

. By the numbers, WNAX wins. In Poland there once was a 2,000-foot tall broadcasting tower, but it fell down.
Mike Adams notes: "The WSM tower is the famous Blaw-Knox design, only a few still in operation. When I was doing the Columbus radio book the CBS station WBNS has just repainted its Blaw-Knox, still broadcasting, details and photos in my book in the CHRS Library. "

Jonathan Winchell notes that not only do the postcards tell a story but this is also good for collectors like myself to put into my ephemera album. ... thank you for emailing these postcards. It takes you back in time to what individual homes did to be entertained.

Arden Allan notes: " ' "I heard it on the Radio"
passed on the words of the new and modern oracle, broadcasting....” From fireside chats to firebrands.

(de K6VK) ##

CHRS post scripts to Martime Historical Radio postingIt turns out that the MRHS lady is Tina Shinn, our Paul Shinn's wif...

CHRS post scripts to Martime Historical Radio posting

It turns out that the MRHS lady is Tina Shinn, our Paul Shinn's wife. Paul has operated W6CF and regularly volunteers at KPH.
Second photo is Chief Radio Operator Richard Dillman at a KPH operating console.
and finally Earl Hammers shows off his The History of Radio by Earl Hammers again available on Amazon

CHRS comes to the Historical Aid of the Maritime Historical Radio Society: .          The Maritime Historical Radio Soci...
Maritime Radio Historical Society

CHRS comes to the Historical Aid of the Maritime Historical Radio Society:

. The Maritime Historical Radio Society devotes itself to the history of maritime radio principally by operating the fully restored marine radio system in Bolinas and Pt. Reyes in Marin County. It now operates under the historic callsign KPH, as supervised by Chief Radio Operator Richard Dillman for the National Park Service. Tours of the facility may be arranged, and taking such a tour is likely to turn one into what MRHS calls a “True Believer.” Its weekly newsletter can be had from They have been doing wonderful work and CHRS has named four of its principals as Fellows in Preservation.

. The MRHS newsletter recently noted, about a photo of an old operator Bill Meloney whose “sine” was “WM”:

. “Bill Meloney/WM at the MF/HF operating position at KPH. WM had an interesting background from his Pennsylvanian origins to his interest in amateur radio (if memory serves he was (W8GOM) (ed. We attempted to validate that information and, as of now, have not been able to ensure that that was WM’s amateur radio station callsign. We would appreciate any help in this area from True Believers!)”

. CHRS Assistant Librarian Dave Harris took on the research:

. “Here is the information I found about William M. Meloney.

. “First, I looked him up in the Amateur Radio Call Directory Name Index, 1982-83 edition, and there he was listed with Station W6HTG-CA. In the following year edition he was listed as born in 1917, having a Class E license, and the same listing in the 1985-6 edition.

. “Then I looked in the Call Books, and the first listing I found for W6HTG was in Volume 35, #4, Winter 1957-58, for William M. Meloney at Star Route, Inverness. Same listing through Volume 66, #1, for 1988. Then in Volume 67 #1, for 1989, listed at PO Box 474, Inverness, through Volume 71, #1, for 1993. Then, in Volume 72, #1, for 1994, the station is listed as a Silent Key. “

. Nearby are a couple of MRHS images. One is a “True Believer” modeling a MRHS shirt. (The website has a “store” page). The other is Chief Radio Operator Richard Dillman at a KPH operating console. “RD” has now put together two worldwide radio communications networks. See “Greenpeace Radio…” Popular Communications, Jan. 1984 p. 24 (de K6VK) ##

In cooperation with the Point Reyes National Seashore, part of the National Park Service, the Maritime Radio Historical Society (MRHS) has taken on the job of preserving the historic ex-RCA coast station KPH and returning it to the air.

Earl Hammers, CHRS library assistant, has published a radio history.  Earl's take on radio is interesting and reflective...
A Twiddle of the Knobs

Earl Hammers, CHRS library assistant, has published a radio history. Earl's take on radio is interesting and reflective of the present state of US manufacturing and what that has meant for the country. The compendium of radio advertising tells several fascinating stories by itself. What follows is HIS forward to it; the book is titled The Twiddle of the Knobs. (de K6VK)

The History of Radio by Earl Hammers

The purpose of this forward Is three fold; first this is a brief history of the Radio art as I learned about It. The entire era covered from the late 19th century to the present. The best part of this history is what I call “the Golden Age of Radio.” This was the time that the radio was the Dominant form of entertainment. This period was from the 1920’s to the early 1950’s.

I am not trying to duplicate Morgan McMahon's Book, I will give a brief history of the major events in this development. The second half of the book will be ads of Radio, Television, and ads for schools plus a military section. The military section is patriotic ads. There will also be a parts section. The wonderful thing about the industry was, we not only made the Radios and TVs; but, we made the parts that went IN the RADIO or TV! At Philco for example they even made the screws and hardware that went in the units

The second reason is to show that we once made RADIOS and TELEVISION in this country. It provided a lot of jobs for people with average education. You usually were trained on the Job — except for the technicians that repaired the Radios and TVs, their training was usually obtained In a Radio School. The thing I like about it was, you could support a family, buy a car, a radio or TV. You didn't make a fortune but you could maintain a middle class life style.

The third is my own philosophy about this whole art form. In the early days of radio in the Golden Age WE MADE THINGS; I don't believe people care about that, The radio was considered an ART at that time. I present with out further a due my history of radio…. [as written by Earl Hammers, CHRS library assistant; a photo by Mike Adams of Earl in the library is nearby].

Product details:The Twiddle of the Knobs; $7
Paperback: 202 pages
Publisher: CreateSpace Independent Publishing Platform (August 3, 2018)
Language: English
ISBN-10: 1724789996
ISBN-13: 978-1724789990
Product Dimensions: 8.5 x 0.5 x 11 inches
Shipping Weight: 1.3 pounds


Join other radio enthusiasts at 2152 Central Avenue in Alameda for big old time radio fun this Saturday, May the 4th.The...

Join other radio enthusiasts at 2152 Central Avenue in Alameda for big old time radio fun this Saturday, May the 4th.

The vintage radio swap meet has been a CHRS tradition for 45 years. Yikes! Where has the time gone. It's a tradition to get together and share stories and swap and sell our extra gear. And for buyers it's a chance to find that special radio or part you have been looking for. We look forward to offering these opportunities to our members and friends.

As part of the swap, where members sell their own goods, CHRS will also be selling ham gear, vintage broadcast sets, vintage audio, parts and tubes. Lots of stuff for lots of interests. We have been accepting donations of gear to keep it from the landfill and now must pass it along to lucky radio collectors. Many unique items are available. So spread the word... We need buyers. Tell your friends to come by and buy :-)

The event will start at 9:00 sharp (no early selling) in the parking lot adjacent to CHRS Radio Central. There is free parking in the lot and on the street. We have bathrooms and coffee inside. You can also take a tour of our nascent museum after the event. Nearby restaurants and coffee shops are walking distance from CHRS so bring a friend or spouse and enjoy a lunch afterwards.

EARLY IN THE MORNING PLEASE RESPECT OUR NEIGHBORS AND BE AS QUIET AS POSSIBLE. We do not want to make a bad impression as everyone in Alameda has been very nice to CHRS.

1. There is NO sellers fee… but donations are gladly accepted.
2. Set up no earlier than 8am.
3. Cover your items until 9am.
4. Any pre 9am sales means buyer and seller will be asked to leave.
5. Recurring Sellers: Your Membership must be current.
6. One time only sellers need not be Members.

See you Saturday for Big Fun!

Enjoying Radio with the Help of the California Historical Radio Society .        By Jonathan Winchell, CHRS.         Len...

Enjoying Radio with the Help of the California Historical Radio Society

. By Jonathan Winchell, CHRS

. Len Shapiro introduced me to the California Historical Radio Society some years ago. I have always been interested and now I feel connected as a volunteer (among other things, I convert tapes to MP3s) and as a radio listener.

. I first got interested in listening to radio years ago by hearing Dr. Don Rose on KFRC with his one-liners and sound effects. I also heard John Mack Flanagan on KFRC. (Then in 2017 I met him at the CHRS Bay Area Radio Hall of Fame in Alameda. I also recently met Stan Bunger from KCBS at Radio Central).

. I listened to Bill King on KNBR 680 from 1974-75 announcing the Golden State Warriors winning the Championship. I listened in my bedroom while my family was watching TV.

. My interest in radio continued, as I became a radio caller about sports and politics. I called Rush Limbaugh and Sean Hannity in the mid-late 1980s. In 1991-92 I was a fan on KNBR 680 radio talking sports with Ken Dito, discussing Magic Johnson. I also called KNBR in the mid-90s talking to Gary Radnich, Rick Barry, Tom Tolbert, Ralph Barbieri, Bob Fitzgerald and Rod Brooks. I listened regularly and called often.

. This sparked my interest in the radio industry, and distant AM stations. I started enjoying DX-ing in August of 2016. I used my Sony S01 CD Radio Cassette-Corder. I then noted on my monitoring logbook the stations I listened to. Then I followed it up by writing many reception reports, sending my monitor-QSL card.

. In return I received QSL cards from many of the stations.

. For cross-country reception on November 14, 2016 I received the best QSL card of all from KDKA, 1020 AM, in Pennsylvania (reception between 1:15 am and 1:30 am). KDKA’s (multiple) card shows KDKA historically as the first licensed U.S. broadcast station.

. Then after awhile ephemera such as record surveys, radio station personalities photos, and recordings of Bay Area Stations caught my interest.

. For shortwave radio listening I now use multi-band radio equipment such as the Eton-Grundig Satellit 750 (on my card). For DX-ing at home, two antennas provide good signals. I get stations from Los Angeles on the AM broadcast band, and on shortwave, Cuba, China, Brazil, and other stations that I enjoy listening to. Now I am also beginning to use a VHF scanner and a discone antenna. I also collect some vintage radios such as Philco and Zenith sets.
. Lastly, I want to dedicate my interest in radio broadcasting to my Mom because she listened to the radio when the Kansas City Athletics broadcast in 1955. In honor of my Dad – he also had interest in radio because he had listened to The Shadow in the 40s and 50s. I also want to thank Len Shapiro for his perspective and Bart Lee for helping me with shortwave radio. – Jon Winchell.


2152 Central Ave
Alameda, CA

Opening Hours

Saturday 10:00 - 15:00


(510) 522-1974


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