Many thanks to SWLing Post contributor, Charlie (W4MEC), who shares a PDF of the 1940 Sears Roebuck Co. catalog section featuring a wide array of radio gear and test equipment.
This file is hosted on the Pro Audio Design forum and can be downloaded as a PDF (15.8 MB) by clicking here.
It’s a real nostalgia trip reading through the fine Hallicrafters, Hammarlund and National HRO descriptions. Thanks so much for sharing this, Charlie!
Many thanks to SWLing Post contributor, DanH, who shares the following comment in response to this news article from the Citizen Times featured in Radio Waves yesterday:
Here are my thanks to members of the Amateur Radio community and The News-Record & Sentinel for remembering the legacy of Hammarlund Manufacturing Company Incorporated. It is good to know that this part of our radio history is valued and preserved. I loved the newspaper article!
I have a few vintage Hammarlund radios including two Super-Pro models. The SP-600-JX-21 is one of my daily drivers. This relatively late production SP-600 is in stock condition with the exception of a half dozen electrolytic capacitors that I replaced mostly in the power supply. By the time this SP-600 was built in 1957 Hammarlund had replaced the short-lived black beauty electrolytes with ceramic disc capacitors. Like military and industrial users I upgraded the original nickel plated tube shields with IERC heat dissipating tube shields where possible. I also installed vintage GE No. 1847 long-life incandescent bulbs as direct replacements for the brighter (too bright, for me) No. 47 dial lamps.
Here are my two most recent reception videos of the SP-600. The first features reception of Radio National da Amazonia and the second is a brief operating demo of the SP-600. The loudspeaker used in both videos is a full-range vintage Jensen 10? with matching transformer from the 1950’s instead of a communications range speaker typically used with these radios. This makes a big difference when listening to broadcasts.
This old Hammarlund is still working pretty well.
Wow! Thank you for sharing this, Dan!
I used to own an SP-600 myself and I do miss it. The only reason I sold it is I was struggling to find a spot in my very compact shack where I could keep it on the air as a daily driver, yet still have enough room to bring new radios and accessories into the shack for evaluation. Moving it around all of the time (especially higher on my radio shelves) was incredibly difficult as she’s a hefty girl indeed! I ended up selling the ‘600 to a good friend for a song. That’s okay because like you, I know he’ll keep her in prime operating condition and I can even pop by to visit when I wish! I do miss having the ‘600 in the shack, though. It was truly a champion MW receiver as well!
Because I keep my ear to the waves, as well as receive many tips from others who do the same, I find myself privy to radio-related stories that might interest SWLing Post readers. To that end: Welcome to the SWLing Post’s Radio Waves, a collection of links to interesting stories making waves in the world of radio. Enjoy!
Many thanks to SWLing Post contributors Trevor, Dan Robinson, and the Southgate ARC for the following tips:
During the 1950’s and ’60’s, when the Hammarlund Manufacturing Company had a factory just west of Mars Hill College, the town could have been considered a world center of advanced electronic technology. With a company motto of “Quality Without Compromise,” almost 90% of American WWII wartime military electronic equipment employed Hammarlund capacitors. They also built U.S. Navy search radar installed on aircraft carriers, battleships and cruisers.
Hammarlund was one of the three leading brands of radio communications equipment at the time, along with Hallicrafters and Collins Radio. These three companies dominated in providing state of the art electronics equipment to the U.S. military, large and small corporations, and to private individuals who had the means and taste to own the very best.
Hammarlund Radio initially operated out of New York City starting in 1910, in the early days of radio. They began consolidating all of their operations in Mars Hill in 1951, in a newly constructed facility that spread out to over 100,000 square foot on Hammarlund Drive — now named Hickory Drive. The site employed hundreds from around the area and their work lives on today. […]
Building radio receivers from scratch is still a popular project since it can be done largely with off-the-shelf discrete components and a wire long enough for the bands that the radio will receive. That’s good enough for AM radio, anyway, but you’ll need to try this DIY FM receiver if you want to listen to something more culturally relevant.
Receiving frequency-modulated radio waves is typically more difficult than their amplitude-modulated cousins because the circuitry necessary to demodulate an FM signal needs a frequency-to-voltage conversion that isn’t necessary with AM. For this build, [hesam.moshiri] uses a TEA5767 FM chip because of its ability to communicate over I2C. He also integrated a 3W amplifier into this build, and everything is controlled by an Arduino including a small LCD screen which displays the current tuned frequency. With the addition of a small 5V power supply, it’s a tidy and compact build as well.[…]
by Dan Robinson
Trump USAGM CEO Michael Pack Was Attacked For Attempts to Focus on Problem
It was May of 2016 and Amanda Bennett was only a few weeks into what would become a nearly four year stint as director of the Voice of America, among the “plum” jobs in Washington, D.C.
Bennett was just getting her feet wet, and at the time was dependent on a group of longtime embedded VOA managers that she would at one point describe as a “fantastic leadership team.”
She had received fair warning, from former VOA employees and extensive reporting by the independent watchdog website BBG and USAGM Watch, of disturbing issues at VOA, located in what has long been one of the most dysfunctional of federal agencies.
Some VOA journalists were using their taxpayer-funded positions to engage in self-promotion and campaign for political causes, a fact little known to most Americans. VOA’s website and digital operations were plagued by failures in breaking news coverage, and inaccuracies in content.
Both VOA and what was then called the Broadcasting Board of Governors (BBG) were increasingly seen by U.S. lawmakers as moribund. A Republican-led and eventually bipartisan effort in Congress proposed major restructuring – there was little patience left on Capitol Hill where the agency was increasingly considered to be “broken,” “rudderless,” and “worthless.” President Obama signed the reform legislation in December 2016 to create a powerful agency CEO position and to make the BBG Board purely advisory.[…]
An ARISS Slow Scan TV (SSTV) event is scheduled from the International Space Station (ISS) for late December. This will be a special SSTV event to celebrate the 20th anniversary of ARISS.
The event is scheduled to begin on December 24 and continue through December 31.
Dates are subject to change due to ISS operational adjustments.
Dave, AA4KN
ARISS PR
The Geminids are a prolific meteor shower caused by the object 3200 Phaethon, which is thought to be a Palladian asteroid with a “rock comet” orbit. This would make the Geminids, together with the Quadrantids, the only major meteor showers not originating from a comet.
They are the biggest meteor shower of the year, and normally occur between 4 December – 17 December.
The peak is expected on 14 December.
Expect FM “pings” and hopefully interesting dx opportunities.
Mike
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Many thanks to SWLing Post contributor, David Korchin, who writes:
Stumbled on this rig at an estate sale and laid out a cool $5.00 for her. She was mostly in pieces in a big plastic bag covered in a LOT of dust, and the battery compartment had seen better days. But I thought I could get it going.
Once I got to the chassis I noticed someone with a Golden Screwdriver had been rooting around in there (the PS module was missing screws to the frame and there was some solder bits dancing around inside).
Threw in 4 C cells: pots were noisy, but there was sound, and after liberal application of De-Oxit and some scrubbing the thing snapped to life! Quite good MW reception: I snagged KMOX 1130 St. Louis at 06:30 GMT this morning, a good hop of 960 miles.
Hammarlund only made this Weather/Marine band receiver in 1969-70, so it’s a rare bird, though probably not collectable, per se. Still, it was fun to get the thing operational.
Oh wow! Thanks so much for sharing your flea market find with us, David! I’m so glad you were able to not only give this HR-10 a proper clean-up, but also bring her back to life–and even snag some DX!
And your photos, as always, are simply gorgeous.
I’m curious if anyone else in the SWLing Post community owns or has owned the Hammarlund HR-10. Please comment!
Many thanks to SWLing Post contributor, Colin Snow (KM6NTW), who notes that the following 1944 film “Maintaining Workers’ Interest” from the US Office of Education, features the Hammarlund Super Pro.
The video starts at the point in the film where the Super Pro is featured. To view the film from the beginning, click here.
https://vimeo.com/399908150
Many thanks to SWLing Post contributor, Dan Robinson, who discovered a very rareHammarlund SP-600 JX21A on eBay. Dan writes:
Collectors of classic boatanchor gear know what has been probably the rarest of tube sets year after year, decade after decade. That set is the Hammarlund SP-600 JX21A.
While there have been numerous JX21s on eBay, there has not been, to my memory, a single JX21A appearing. This particular model was a version of the SP-600 that was produced in small quantities in the 1960’s, and according to one writeup was the only one with a product detector and switchable sidebands. According to Radiomuseum it was the last model in the SP-600 series, and was recognizable for its knobs which were different because the silkscreen information was printed directly on the front panel rather than on the edge of the knob skirts.
According to Les Locklear’s excellent history of SP-600 models, the JX21A was produced between 1969 and 1972.
Now, an ultra-rare SP-600 JX21A has appeared on eBay. Like other models in the series, this would likely require replacement of numerous capacitors and a thorough refurbishment. The seller in this case has started bidding at a very low level, but if history is any guide, a rare model like this one may indeed go for thousands of dollars when all is said and done at the end of the auction.
Click here to view the Hammarlund SP-600 JX21A on eBay.
Amazing! Thank you for sharing, Dan! What a gorgeous set. Though the seller states it’s in need of restoration, I’m pretty sure this one will get snagged up at end of auction. I’m very curious where the final price will land.
Are there any SWLing Post readers who own an SP-600 model–or the JX21A? Please comment!
Many thanks to SWLing Post contributor, Daniel Hawkins, who leaves the following comment in reply to our previous post about the Northern Radio SP-600 and discussion about diversity operation. Dan writes:
Diversity operation: two or more receivers and antennas used to copy CW or RTTY from one or more transmitters.
Most of the Hammarlund SP-600s were models built for diversity use including the well-known JX-17, the most common SP-600. Diversity models can be used as single receivers. In this eBay example Northern Radio has modified a SP-600 J-11 for diversity use.
SP-600 nomenclature: J means joint army/navy (JAN) mil-spec components. L means low frequency. X means crystal frequency control in addition to VFO. My SP-600 is a JX-21, which is not a diversity model. Higher model numbers do not necessarily mean later production dates. All SP-600s use the same serial number sequence regardless of model. Somewhere between serial numbers 15,000 and 17,000 (mid 1950’s) Hammarlund stopped using molded black beauty capacitors and switched to installing ceramic capacitors.
The two-digit model numbers indicate model types. JX-1, 7, 10 and 21 were similar non-diversity receivers. SP-600s built for military contracts will have an additional tag showing the military model number(s).
Here is a great page showing Northern Radio modified SP-600s in action with accompanying Northern Radio RTTY gear.
Thanks for the primer, Dan! I believe I have one of the X models with crystal control, but I’ll need to verify once back home. Any other SP-600 owners out there in the Post readership?