Category Archives: Nostalgia

Tubes and Valves: Dan’s research uncovers three vintage films

Hammarlund-SP-600

Many thanks to SWLing Post contributor, DanH, who writes:

I have been working on my Hammarlund SP600-JX-21 for the last two weeks. Results of the filter cap replacement were encouraging. I’m going after an AVC issue that is probably capacitor-related as well before doing a re-alignment with the signal generator.

All of this activity has turned my attention toward vacuum tubes. I found three vintage industrial films online that caught my interest…

The Mullard Radio Valve Company produced The Blackburn Story in 1962. The film was shot at what must have been close the peak of vacuum tube mass production. This presentation is unique in its finely detailed documentation of miniature tube construction. The hand labor required to build some of these tubes is incredible, considering it is a mass production operation. A surprising degree of automation is present for manufacture of some of the more popular tube types. The video resolution is not the best but I found myself ignoring this limitation after the film got underway. I have a few Mullard tubes in my tube boxes.

Click here to view on YouTube.

Western Electric presents A Modern Aladdin’s Lamp (1940). This look at the electron tube is hosted by none other than Lowell Thomas. From the age of four pin and octal base tubes animation shows how tubes work.

Click here to view on YouTube.

Electronics at Work (1943) is a WWII offering by Westinghouse. The description of vacuum tube technology is a little more detailed and again animation is employed for visual impact. A variety of vacuum tube applications in industry and the military are shown from curing plywood to producing X-rays. The excellent animation was contributed by Famous Studios (when they weren’t doing the wartime Popeye cartoons).

Click here to view on YouTube.

Wow–thanks for sharing these excellent videos, Dan!

From the BBC Archives: The first 21 years of the World Service

BBC-AT-WAR

Many thanks to SWLing Post contributor, Andrea Borgnino, who shares a link to the excellent archived radio documentary, The first 21 years of the World Service, via the BBC World Service‘s online audio archives.

The recording/broadcast dates from December, 18 1953. Here’s the description of the recording:

The first 21 years of the World Service: how it began in 1938, its important role in WW2 and its aftermath, including historic moments as they were first broadcast by Churchill, de Gaulle, Eisenhower.

Click here to listen to the documentary via the BBC World Service.

VOG Interval Signal

I learned an interesting fact in this documentary: I had no idea that the BBC used the Greek radio interval signal for their Greek language service while Greece was occupied in WWII. After liberation, the BBC Director General “solemnly” handed the famous interval signal–“the sound of shepherds’ pipes mingling with the bells of their flocks”–back to Greece. Amazing.

The Greek radio interval signal is one of my all-time favorites. Indeed, my mobile phone’s ringtone is the VOG interval signal:

If you would like to add this ringtone to your mobile phone, check out this post from 2013.

eBay Sighting: Kurzwellen Empfänger Siemens

Siemens-Receiver

Once again, the intrepid Dan Robinson has discovered an eBay gem. Dan notes:

From eBay Germany comes this rarely seen and apparently in beautiful condition relic:

Siemens-Boat-Anchor-eBay

Wow–Dan–what a beautiful receiver! It has a dial blind like my BC-348-Q, but a dial design like my Hammarlund SP-600. The best of both worlds, in my opinion.

Siemens-Dial

And the green indicator lamps? Classy!

Siemens-Receiver-Indicator-Lamps

Siemens-Receiver-Panel

Siemens-Receiver-Right-Panel

Siemens-Receiver-Side

Siemens-Receiver

I assume, by the design, that this is a Cold War era receiver? I’m afraid I’m not at all familiar with Siemens receivers of the era.

Post readers: If you can shed light on this particular Siemens receiver, please comment!

Click here to view on eBay Germany.

Bob’s 1961 Radio Havana Cuba QSL Card and full text from DXers Unlimited on 55th anniversary

RHC QSL

Many thanks to SWLing Post reader, Bob La Rose, who shares a QSL he received (see above and below) from Radio Havana Cuba after they had only been on the air a few days back in 1961.

RHC Letter 16May61

Amazing, Bob!  Thanks for taking the time to scan and share this report!

Also, many thanks to Arnie Coro, Host of Dxers Unlimited at Radio Havana Cuba, for sharing the full text/script from his May 1st 2016 anniversary edition of DXers Unlimited:

Radio Havana Cuba
Dxers Unlimited
Dxers Unlimited’s weekend edition for 1 May 2016
By Arnie Coro
Radio amateur CO2KK

Hi amigos radioaficionados, welcome to the weekend edition of Dxers  Unlimited,  today l am happy to celebrate with you all the 55th Anniversary of Radio Havana Cuba… Yes amigos, it was on the first day of May of 1961, during the May Day celebrations when Cuba had just won the battle against the mercenary invasion that we went on the air using our present name Radio Havana Cuba… Two announcers, Orlando Castellanos and Fernando Alcorta announced to the world that Radio Havana Cuba, was on the air… Previously we had used the name Cuban Experimental Short Wave, but from May one of 1961, we are known worldwide as Radio Havana Cuba…

So today is a very special day… remembering those who have passed away after many years of valuable services to our station, like Pedro Costa the General Administration Manager, Carlos Estrada our Chief Engineer, and former Director Generals Marcos Behamaras. Orlando Fundora, Jose Antonio Caiñas and Alfredo Viñas. I also keep very nice memories of Angel Hernandez our bilingual announcer with the most effective voice for short wave radio that I can recall, and also I remember Manolo Ortega, reading our Spanish language editorials so that they could be heard clearly through his powerful voice…

Si amigos, I was there at the station 55 years ago as a young radio technician in charge of supervising the operations of our studios and transmitters that at that time included four Brown Boveri Swiss made short wave transmitters connected to a still under construction antennas farm, and the two studios borrowed from Radio Progreso until we could finish building our first studios .

The history of Radio Havana Cuba is full of very relevant moments, like the day that our Experimental Station announced to the world that the mercenary invasion that entered the Bay of Pigs had been defeated after sixty six hours of fierce combats .

With a lot of enthusiast and the impacting presence of a new generation of announcers, journalists , technicians, engineers and support personnel we are moving ahead to provide the best possible programming keeping our short wave transmitting facilities because we do believe on the use of international short wave broadcasting, while not disregarding the feeding of streaming audio to the Internet-

I am Arnie Coro, your host here at this special 55th Anniversary edition of Dxers Unlimited, that will continue in just a few seconds after a station ID..

Musical short cut

Yes amigos this is Radio Havana Cuba, using short wave frequencies at different times of the day on the 16, 19, 22, 25 ,31, 49 and 60 meters bands… and now our next radio hobby related item, a very popular section of this show under the name   Antenna Topics , that is dedicated today , at the request of several listeners to a very effective Dxing antenna, low take off angle radiator, known as the HENTENNA, A great number of listeners  from all around the world  have written to me recently, asking to learn more about  this Japanese  antenna design , known as the HENTENNA, that seems to continue to be making headlines in radio publications around the  world once again… But before telling you more about the mysterious HENTENNA…. A solar activity update… believe it or not, we are seen the solar flux moving up to very near 100 units for the first time in many weeks… following the typical ups and downs of the tail end of solar cycle 24… so  propagation conditions have improved on the short wave bands …. Now back to the HENTENNA…

By the way, the first original report about the HENTENNA that went on the air  here at Dxers Unlimited, dates back to  1999,more precisely, it went on the air the 12th of October of 1999, and  according to my records, it  then generated a lot of interest from our listeners, who were at that time, 1999, getting ready to enjoy the peak  years of solar dream solar cycle 23 !!! >Never as powerful as super cycle 19, but nevertheless much better than the present very poor cycle 24.

So amigos here is  at the request of Dxers Unlimited’s fans , a special Dxers Unlimited’s report on the HENTENNA, the Japanese elongated  rectangular loop antenna with an easy  match to coaxial cable feedlines of any impedance, be it 50, 60 ,75 or  93 ohms…or even 150 ohms !!! Of course that you can feed it with parallel transmission line of 300 to 450 ohms too, it is just a matter of minutes to find the perfect match for the feedline in use.

Let me start by saying that  I recently built yet another HENTENNA for the FM broadcast band, and it  is working nicely, having already picked up some Sporadic E skip DX stations from Mexico, the US and Puerto Rico during first few days of this year’s spring and summer  E skip season.

Now you will have to learn something very unusual about the HENTENNA…  the HENTENNA produces or receives VERTICALLY  polarized waves when the antenna is placed horizontally; that is, with  the long sides of the rectangular loop parallel to the ground. AND, if you want horizontal polarization, just flip the HENTENNA so that the long sides  of the loop are vertical, and the short sides are parallel to the  ground, something that is puzzling, but that’s the way it is amigos…

By the way, one of the world’s foremost antenna experts, Dr. L. B.  Cebik, amateur radio operator W4RNL, did during his fruitful life an extensive analysis of  elongated loops, and his findings are really fascinating. Dr. Cebik , now sorrily a silent key specialized in computer modeling of complex antenna systems, and his work with the HENTENNA and other similar elongated loops shows that the  HENTENNA is a very good performer indeed.

In a few seconds, be ready to write down, the formulas for calculating HENTENNAS  in the frequency range from 14 megaHertz all the way up to 220 megaHertz.

And now, as promised  more about the japanese wonder antenna… the  HENTENNA. Dr. Cebik’s computer modeling shows that the elongated loop HENTENNA has an edge over a regular square one  wavelength loop and the regular elongated loop.

HENTENNAS for receiving FM broadcast signals are very easy to build,  using a wooden or PVC pipe frame and copper wire. I built the one just
mentioned cut for 100 megaHertz, using PVC insulated no. 12 wire, the  one that is typically used for home wiring.

The loop was closed by soldering with a butane torch, and using regular  solder with rosin core… The reason for using the butane torch is that no soldering iron at hand here could handle the heavy wire PLUS the high  speed heat transfer of the copper wire.

The loop for the 100 megaHertz antenna is 1.5 meters on the long sides of the rectangle and 50 centimeters on the short sides. The feed point  for the 50 ohm cable is was found to be  located about 55 centimeters from one of the  short sides of the loop.

The antenna is installed with the long sides in a vertical position; for receiving horizontally polarized FM broadcasts. I tried both 50 ohms and  75 ohms coaxial cables, and could not detect any difference on the  weakest station that I am picking up here regularly with the FM band HENTENNA.

Again, now please pay extra attention …if you want to make of these elongated loops for receiving, here  are the measurements to use: for the long sides of the rectangle 1/2 of  a wavelength at the operating frequency, for the short side, the length  is 1/6 of a wavelength… and the connection point for the coaxial cable  of 50 ohms impedance is a little more than 1/6 of wavelength from one of the short sides of the rectangle, and it must be found experimentally by locating the point that provides the minimum standing wave ratio.

HENTENNAS can be built for any frequency between 10 megaHertz and 300
megaHertz by using heavy WIRE, and for the frequency range from about 50  megaHertz to 500 megaHertz you may try building HENTENNAS with copper or  aluminum tubing.

Hope to have you all listening to my middle of the week edition of Dxers Unlimited amigos and do enjoy the improved short wave propagation conditions now in progress, especially after your local sunset. 

Remembering the 5th anniversary of Radio Havana Cuba

HalliDial

Many thanks to SWLing Post reader, Jake, who writes:

Just passing along this scan of an Associated Press story about the 5th anniversary of Radio Havana Cuba. It ran in The Virginian-Pilot on May 8, 1966.

Fun read considering so many of us have listened to the station over the years.

Keep up your good work!

RHC Virginian-Pilot 5_8_1966

Wow–as of May 2016, RHC has been on the air for 55 years. Thanks, Jake, for sharing this bit of radio history!