Author Archives: Thomas

A simple homebrew high pass filter

Many thanks to Jon Hudson, of SDRplay, who posted the image above along with the following note on Facebook:

David, WA7JHZ has designed and assembled this neat 2.6 MHz high-pass filter (HPF) for use with SDRs. He says that this simple input band-pass filter (BPF) might be of interest to anyone suffering from strong AM broadcast stations that are causing overloads…..David suffers from three nearby AM radio broadcast stations that overload the front ends of several of his receivers, including the SDRplay RSP and this is an ideal, low cost solution. He built this circuit from junk parts and commented that Amidon T44-2 iron powder cores would have made a better design, but that he decided to keep costs down with this design.

This design is simple enough for almost anyone to build and could help your receiver’s front end from overloading. Many thanks to David for the design/schematic and to Jon for sharing!

Video: This Is Radio Free Europe (1964)

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If you’re in the mood for a little Cold War era nostalgia, check out this video produced by Radio Free Europe in 1964. One of the things I found most fascinating was seeing the number of rack-mounted Hammarlund SP-600s (and other benchmark receivers) at the RFE monitoring station near Munich.

Part 1: SWLing Post shack photos

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The listening post and ham radio shack of Giuseppe Morlè (IZ0GZW) from Ponza Island, Italy.

Several months ago, we conducted a shack photo contest sponsored by Universal Radio. At the time, I promised to post all of your excellent photos soon–apologies to all for the extended delay!

The following is the first set of ten photos along with any notes that were included.I plan to post these photos in sets of 10 and tag your names in each post. These actually take time to format for the blog, but I hope to post new sets of shack photos in the coming days.

Click on images to enlarge and enjoy:

Stu McLeod

Notes:

1937 Philco 620 EZ 121
1936 Ultimate
1936 Philips P626 Superhet Radio Player
1937 World Radio
1936 Stewart Warner R-146X

Lower is my tweaked Icom IC-R71. Most fun is with the 1936 Philips P626 Radioplayer–for its age , its tuning sensitivity and selectivity is simply amazing.

Stephen Morshead

Notes: An Icom R71E and CommRadio CR-1a and a transmatch tuner running a sloping dipole longwire. My favourite rig at the momemnt is my Icom–maybe older but quite sensitive compared to the CommRadio–but the CommRadio is quite good on CW decoding. SWL callsign is MA3087swl.

John Magee (W4GLX)

Notes: My favorite gear to use is The Kenwood TS 2000. I also have an Kenwood R2000 for my short wave listening …

Robin Gist (K4VU)

Notes: Elecraft K3 transceiver, Alpha 78 amplifier, Vibroplex Iambic Deluxe paddle

Matt Champion (AC0TW)

Notes: My shack is simply a bedside table connected to a homebrew multiband dipole. I use the Radio Shack DX-394 for most of my DXing and the Grundig Aviator G6 Buzz Aldrin edition for local FM and shortwave during outdoor excursions.

Ken Carr (KE1RI)

Notes: My ham shack is my favorite listening post. Since all the children are now adults I am able to dedicate this second floor bedroom to radio.

From left to right: Ten-Tec Omni VI transceiver (with all Plus upgrades), Collins 302C-3 wattmeter, Yaesu FTDX-3000 transceiver,Ameriton AL-811H amplifier, Hammarlund HQ-OneSeventy receiver, Hallicrafters HT-37 transmitter, and, National HRO-Sixty receiver. To the far right can be seen part of a Grundig 8080 / USA.

Unseen are an additional 4 consoles, several Trans-Oceanics, and many others.

Vance Thompson (K7VNZ)

Notes: Attached is a photo of probably one of the smallest, most cluttered/disorganized (to the naked eye) listening station ever. Then again, maybe not… But seriously, I read your latest post, and just immediately took a picture. No cleaning up, staging, adding or removing things, or photoshop used. It is what it is and I like it.

My name is Vance Thompson and my callsign is K7VNZ, and this is where I listen.

Some highlights starting from top to bottom:

Top shelf: An old Griffen “Radio Shark” (1st gen) nestled in a homemade loop antenna made with an old Roi-Tan cigar box as the base, a lava lamp, a Colonial Viper, a Buddha box that looks like a weird radio.

Middle shelf: WWII blackout lantern, toy safe to hold all my secret spy number decoder books in :-), misc. vaseline glass and ‘glowy’ stuff, and a mask my daughter made. Dixie Cannonball crystal radio headset hanging on left, unnamed headset on right with cool radioactive stickers I put on it.

Monitor shelf: Viewing SWLing Post, of course. Raspberry Pi on left running ADS-B software when I turn it on, green laser pointer I used to tease my dog with, stack of misc. papers with a homemade crystal radio made on an expired plastic gift card on top.

Bottom shelf: Baofeng BF-F8+ with diamond antenna, recent hand-wound coil connected to breadboard prototype crystal radio I’m currently working on (tuning capacitor seen below next to the keyboard), digital audio recorder in there somewhere, Radio Shack DSP processor I found at a junk store for $4 with various alligator clip jumpers on top, round tin for small radio parts, moleskin logbook, Yaesu FT-60, my grandfather’s D-4 flight computer from WWII.

Arie van Bezooijen (PE1AJ)

Notes: I’m using a Kenwood 950s and an Icom IC7400 for HF. For 2m i’m using a Yeasu FT-7800 and other SW listening I can do with a Kenwood R2000.

Mitul Kansal (VU3MCN)

Notes: Recently, I visited RRI- Voice of Indonesia & Republic of Indonesia in September 2015 as a winner of International Quiz, “Wonderful Indonesia 2015.” I visited the RRI- Voice Of Indonesia Broadcasting Station .

There, I went on air, shared my views about RRI- Voice of Indonesia. It was an unforgettable moment for me. With other winners , I enjoyed listening on radio.

Jackie LaVaque (KC0ODY)

Notes: Here’s my humble listening post! Right now it consists of a Kaito KA1102, a Tecsun PL310, a Baofeng UV5R, and not seen because it’s not up and running yet, an RTL-SDR USB dongle which I plan to make into my winter project. My favorite rig is the Tecsun PL310 because not only is it a great performer on SW and MW, it also does pretty well with longwave using an added homemade cake form antenna.

Again, many thanks to all who sent in their listening post photos. I absolutely love the variety!

Follow the tag Shack Photos for more!

BBC to launch Korean news service via shortwave in fall 2016

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(Source: KBS World Radio via Andrea Borgnino)

The British Broadcasting Corporation (BBC) will launch a shortwave radio service to North Korea this fall.

A BBC insider said the British government has given final approval to the public broadcaster’s plan to broadcast news to North Korea and has even earmarked a budget.

The 30-minute daily broadcast in the Korean language will include news from the two Koreas, China and Japan. BBC will also run a website with a listen again section.

[…]The news program will be produced at the BBC headquarters in London and transmitted via shortwave from locations including Singapore. Many North Korean residents are known to own a shortwave receiver.

BBC has been discussing the launch of a North Korea service since last year, which has faced strong opposition from North Korea. A high-level North Korean diplomat visited the U.K. parliamentary in protest of the plan two months ago.

BBC is also considering broadcasting its Korean news service in South Korea as well.

Read the full article at KBS World Radio online…

Intergalactic DX: Detecting gravitational waves

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NASA illustration of LISA--spacecraft that will form an extremely large antenna system for detecting gravitational waves.

NASA illustration of LISA–spacecraft that will form an extremely large antenna array for detecting gravitational waves.

Many thanks to SWLing Post reader, Dan H, who writes:

The biggest news during the last week is not the Republican or Democratic national party debates, the surrender of the last Militia Man at Malheur National Wildlife Reserve in Oregon or falling stock prices for Tesla. The biggest story of the week involves some lasers enclosed in huge vacuum tubes.

The recent proof for gravity waves is something that should have a lot of appeal to readers of SWLing Post. This story involves very weak waves originating billions of years ago, measuring distances with lasers and old-style vacuum tube tech (albeit four 2.4 mile-long tubes located 1,900 miles apart). It sounds like DXing to me and DXing is interesting. But, this story describes changes in spacetime and that is really significant.

I get it, at least on a layman basis. I think that many SWLing Post readers would get it too.

This link to an older article is the best that I can provide to describe it all. The recent discoveries involved LIGO sites in Hanford, Washington and Livingston Parish, Louisiana.

http://www.nola.com/environment/index.ssf/2013/05/ligo_captures_gravitational_wa.html

I heard over 90 minutes of programming on this subject during the last seven hours from BBC. I heard it locally on SW in northern California at 7445 and 9740 kHz. The programs were featured on the Newsday and Science Day BBC programs. Yes, I was listening to two different BBC relays from different parts of the world on my apparently outdated and uncool Sangean ATS-909X.

You’re right, Dan! I had planned to post an item about this, but have been been a bit behind due to travels. I believe you can’t find any weaker DX than gravitational waves from distant colliding black holes! It’s a fascinating idea, too, to use a laser antenna to detect these waves across space/time.

I also enjoyed this article and video from the New York Times.

Oh, and regarding your Sangean ATS-909X? I think it’s one of the coolest looking portables on the market! Glad to hear it’s serving you well.

Thanks for sharing, Dan!