Any experience using the T2FD antenna–?

The T2FD Antenna (Source: Wikimedia Commons)

Many thanks to SWLing Post contributor, Grayhat, who has recently been on a mission to create a low-cost SDR setup while sheltering at home due to Covid-19 restrictions. While exploring antennas he sent the following inquiry:

I recently found some information about the so-called Tilted Terminated Folded Dipole (T2FD) antenna which was apparently developed for military use as a wideband, general purpose one (which can mean if it isn’t efficient, simply throw some more KW at it). But for receiving, the antenna didn’t seem bad to me, at least based on the info I found.

In most (if not all) ham installations of the antenna, the T2FD is used in a “vertical” setup–that is, one wire above the other. When looking at military docs, the antenna is in “horizontal” setup, that is, wires parallel to ground. Looking at a 3D lobes simulation of the antenna, the pattern for a “vertical” one seems to be a “cloud warmer” with the most radiating lobe going down toward the feedline. If that’s true, this would mean that an “horizontal” T2FD should have its most pronounced lobe at the feedline side. Perhaps “vertical” installations of the T2FD could go from “works well” to “WOW” just flipping the wires–?

Do you think and SWLing Post readers may have info or experience with the T2FD antenna they could share?

If you have any experience using or building the T2FD antenna, please feel free to comment!

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Check out the Afedri LAN-IQ SDR: a new stand-alone touch screen SDR

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LAN-IQ SDR rev1.0 (Source: Alfredi SDR-Net)

Many thanks to SWLing Post contributor, Dan Robinson, who shares the following video from Fernando Duarte highlighting the new Alfredi LAN-IQ SDR:

I can’t wait to check out Fenu’s full review of the LAN-IQ when it is posted on his excellent website. The screen seems to be very responsive and layout well thought through.

The Afedri website notes the following features and specifications:

30 kHz to 1700.00MHz continuous frequency range
Direct sampling
DDC – Digital Down-Conversion
12- bit 76.8 MSPS A/D conversion
Stand Alone mode (AM, CW, SSB, NFM, WFM stereo, BPSK, QPSK demodulators)
Up to 2.2MHz recording and processing bandwidth
Waterfall display functions, when used with appropriate software
Recording and playback, when used with appropriate software
Sensitivity – MDS -136 dBm at 500Hz bandwidth (0.03MHz-35MHz)
Sensitivity – MDS -143.5 dBm at 500Hz bandwidth (50MHz-435Mhz)
USB 2.0 (Full Speed) interface
LAN interface for remote access
Compatible with: Linrad, Winrad, HDSDR, Studio1, SDR Console (SDR-radio), CuteSDR, SdrDX, Quisk, PowerSDR_mrx
Powered from USB or external power supply 7-10VDC
Dimensions 120mm deep x 78mm wide x 27mm high
Unit cost – $339

The LAN-IQ can be connected to a PC via USB or Ethernet (at a 2400 kHz sample rate).

The Afedri website also has a few videos of the LAN-IQ in operation:

As you might have noted, the encoder knob seen in Fenu’s video is not standard but can be added at an additional cost and extended lead time. If I were to order the LAN-IQ, I would want the encoder knob as well.

Also, note that due to Covid-19 affecting the supply chain, Afedri SDR informs me that LAN-IQ availability will be adversely affected. If you would like to order a LAN-IQ, contact Afedri SDR via their website.

Click here to check out the LAN-IQ and all specs at Afedri SDR-Net.

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Radio Waves: Crossband Test Postponed, VI3RA Event Videos, WWII Radio, and Look Inside a Panasonic RF-4900

Radio Waves: Stories Making Waves in the World of Radio

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 Harald Kuhl, Michael Bird, and Carel Kuijer for the following tips:

Annual Armed Forces Day Crossband Test Postponed (ARRL News)

Due to the ongoing COVID-19 response and mitigation actions, the 2020 Armed Forces Day (AFD) Crossband Test scheduled for Saturday, May 9, has been postponed. Because it’s uncertain just when stay-at-home orders will be lifted across the US, AFD planners chose to postpone this year’s event, because the government stations that typically support this event may not be available. Armed Forces Day Crossband Test planners are considering scheduling a November event in honor of Veteran’s Day, depending on COVID-19 mitigation actions. During the AFD Crossband Test, military stations in various locations transmit on selected military frequencies and announce the specific ham frequencies they are monitoring to work radio amateurs. — Thanks to US Army MARS Program Chief Paul English, WD8DBY

Radio Australia Event – Antenna Overview (Mount Evelyn DX Report)

Thanks to Lee VK3GK for this short video of the antennas used for the recent Radio Australia event using the call sign VI3RA. Take what will possibly be a final look at the feeders, switching boxes and antennas before they are pulled down and junked!

Also here is the final transmission of the event weekend with, of course, the famous Radio Australia music box interval signal.

Click here to view both videos at the Mt Evelyn DX Report.

World War II and Radio (All Things Radio)

I have added an article I wrote some years back on the code breaking efforts of the Allies during WWII. While certainly not exhaustive, I found many of the connections between countries and equipment rather fascinating, and new things continue to pop up regarding Bletchley Park’s role in training officers and decoding texts. While most famously known for breaking the Enigma code, also significant was the breaking of the Lorenz Cipher.

Click Here to download the article in PDF format.

73, Robert K4PKM

Look Inside This Radio Receiver! The Collectible Panasonic RF 4900 (Mr. Carlson’s Lab – YouTube)

Let’s look inside this Panasonic RF-4900 radio receiver, and see what we have to restore.

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Your support makes articles like this one possible. Thank you!

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Radio Purga: Russia turning to DRM shortwave to reach Chukotka region

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(Source: Radio World via Mike Terry)

Russia has resumed Digital Radio Mondiale broadcasts on shortwave. The country originally aired the Voice of Russia via DRM a few years ago. The new service is tentatively called Radio Purga (“Radio Blizzard”). The target area is the Chukotka region of the Russian Far East. Analog shortwave transmissions once served the area, but those ended in the early 2000s when the broadcaster left analog shortwave.

Chukotka is vast and the target audience only numbers a few thousand. Thus, shortwave is the only practical way to reach the population. The transmitter site, Komsomolsk Amur, used to broadcast Voice of Russia’s analog programming and is now being used for the DRM program.

The new service is a joint project between the government in Chukotka and the Far Eastern regional center of the Russian Television and Radio Broadcasting Network.

Using DRM for Radio Purga has several advantages over analog shortwave. Radio Purga over DRM, for example, offers a static-free and higher fidelity signal. Studies have shown that DRM is just as reliable as analog shortwave over this distance via single-hop transmission.

The broadcaster is considering transmitting two audio programs from a single DRM transmitter. This is something analog shortwave can’t do. It’s also planning on using DRM’s ability to transmit short text message or a type of RSS feed (Journaline). DRM transmissions also use only a quarter of the power that analog transmissions do.

“We have in these remote places 2,000 residents who need to be provided with communications services … the Northern Sea Route also requires attention,” said Roman Kopin, the governor of Chukotka, last spring when the project was initiated, according to a Russian press report. In addition to mariners on the Northern Sea Route, the audience includes geologists, miners, reindeer herders and hunters.[…]

Click here to read the full article at Radio World.

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Check out this amazing QSL and off-air audio from shortwave pirate “The Purple Nucleus of Creation”

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This morning, I uploaded a recording of 2001 shortwave pirate The Purple Nucleus of Creation to the Shortwave Radio Audio Archive (SRAA). The recording was submitted by Adam C. Smith, a regular over at the SRAA.

Adam’s six minute off-air recording was made on October 27, 2001 at 0009UTC on 6,928 kHz USB with Adam’s Grundig 800 and 100’ wire antenna. Check out the audio embedded below or via the SRAA.

But first? Check out this extraordinary QSL card:

This QSL is more intricate than a wedding invitation! I love it! Thanks for sharing, Adam!

Here’s Adam’s off-air recording:

Adam also included other correspondence from The Purple Nucleus of Creation:

Again, thanks so much, Adam, for submitting this recording and memorabilia with everyone via the SRAA. Now your recording will (literally) be shared with our thousands of podcast subscribers and also streamed to devices across the globe via TuneIn. It’ll also be permanently preserved on the SRAA website and the Internet Archive.

Note that you can subscribe to the Shortwave Radio Audio Archive as a podcast via iTunes or by using the following RSS feed: http://shortwavearchive.com/archive?format=rss You can also listen via TuneIn.

Of course, one of the best ways to listen to recordings and read all of the recording notes is by visiting the SRAA website.

Post readers: Did you log The Purple Nucleus of Creation back in the day? Who sent you your favorite pirate radio QSL card? Please comment!

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Solar Minimum: Deep, Deeper…and even Deeper?

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Solar Minimum is DEEP and appears to be continuing. Observer Franky Dubois from Belgium – who posts for the Solar Section of A.L.P.O. – Assoc. of Lunar & Planetary Observers (http://alpo-astronomy.org/) has fully observed three complete Solar Cycles over the past 38-years and he’s graphed the Sunsport R Number – defined as R = K (10g + s), where g is the number of sunspot groups and s is the total number of distinct spots.

This is what he posted yesterday on the A.L.P.O. Solar Message Group:

Minimum cycle 21: 11.4 April 19[8]6

Minimum cycle 22: 10.4 May 1996

Minimum cycle 23: 2.88 November 2008

Status of cycle 24 thus far: 1.6

Many experts in December (2019) speculated we had reached “Solar Minimum” (error factor of +/- 6-months). Well, it’s 5-months later and we’ve only seen a couple of next cycle [reversed polarized areas] sunspots/small groups – most of which died-out very quickly and did not sustain a full transit across the observable disc of the sun. We’ve seen no real evidence – yet – that we’re on the other side or up-side of Minimum. As an amateur/hobbyist astronomer & Solar Observer myself, I’ve seldom taken the time to set-up my gear & observe (even in wavelengths other than visible).

It’s been discussed here and elsewhere before, but looking at the last 53-years of data there has been a very, very sharp decline in Solar Maximums [and Minimums] sunspot numbers.

Guest Post by Troy Riedel

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