Shortwave listening and everything radio including reviews, broadcasting, ham radio, field operation, DXing, maker kits, travel, emergency gear, events, and more
Many thanks to SWLing Post contributor, Jim (W4OXB), who writes:
I have been involved in SWLing and ham radio since the middle 1960s. Mostly listening before I got my ham ticket in 1969. My current call is W4OXB.
I used to record dx catches on mediumwave and shortwave that I put in my logbook. About 20 years ago, I transferred my recordings from reel-to-reel to digital format.
My goal is to share the old recordings with other radio enthusiasts and the easiest way I’ve found to do that is YouTube. So, I have been working on this for a few weeks.
Excellent, Jim! You’ve got some great recordings in your list already. Thanks for sharing and, Post readers, note that Jim also plans to share some of his recordings with the Shortwave Radio Audio Archive. We really appreciate the support, Jim!
The highly anticipated AirSpy HF+ Discovery SDR has been in the hands of early adopters for about two weeks–and I’ve seen nothing but positive comments!
After a long run (2007-2013) with a Microtelecom Perseus, my SDR of choice became the Elad FDM-S2, and more recently an Elad FDM-DUOr “hybrid” SDR receiver. The two Elads have the same core processing components and identical performance when the DUOr is connected via SDR software.
This week I’ve compared the HF+ Discovery ($169) against the FDM-DUOr ($899) using Studio 1 software and identical modes & settings. The following video features the radios’ performance on a crowded daytime medium wave band from suburban Seattle-Tacoma USA.
Mode, filter bandwidth, AGC, etc. are the same for each radio
768 kHz sampling bandwidth used for both receivers
Stations tuned are:
1320 KXRO Aberdeen WA, 74 miles @ 5 kW (in-line with antenna)
1110 Oak Harbor WA, 78 miles @ 500 watts (in antenna’s null)
1040 CKST Vancouver BC, 147 miles @ 50 kW (in antenna’s null)
1430 KBRC Mt. Vernon WA, 85 miles @ 5 kW (in antenna’s null)
750 KXTG Portland OR, 118 miles @ 50 kW (in antenna’s null)
I purposely sought out signals difficult to hear in the presence of powerhouse stations. Only 1320 kXRO (in-line with my antenna) and 750 KXTG are what you might consider average or fair quality signals. Headphones are recommended for most of these, particularly 1040 kHz.
You’ll note that the pass band has been “pulled” over the edge of the carrier frequency by a few hundred Hertz. This is an excellent trick that can often reduce noise and/or improve intelligibility. It’s a feature unique to Perseus, Studio 1, and SDRuno software; it works in sideband modes and in selectable sideband Sync AM (SAM) mode.
After listening to the signal comparisons, what are your thoughts on the HF+ Discovery? Please leave your comments below.
Guy Atkins is a Sr. Graphic Designer for T-Mobile and lives near Seattle, Washington. He’s a regular contributor to the SWLing Post.
Many thanks to SWLing Post contributor, Ron, who shares the following review of the PK Loop Mini (A-LOOP-MTAM):
Standard PK Loose-Coupled Loops (the “A” series) are 14 inches in diameter…they are
for use with a receiver having a built-in ferrite bar antenna.
Don’t think they’re not capable of serious DX…a few years ago a friend in Texas
snagged and recorded France Inter (162 kHz) on a 14 inch standard PK LW
loop using a Sony 7600GR.
But this is about the PK Mini 10 inch loop for Medium Wave (there are none for
other ranges).
The build quality is superb as with all PK loops. The band has two ranges: 525 to
710 and 710 to about 1720 kHz. Paul Karlstrand uses a unique design consisting
of flat computer cable and a custom made circuit board to connect the turns
end-to-end.
The low end simply switches in a fixed capacitor across the variable to lower the
frequency.
The Mini has 25% less sensitivity than the standard 14 inch loop according to the website.
Currently it can be had for $66 USD delivered to your door from Melbourne…this one
was ordered on a Monday and showed up a week later,which is outstanding considering
it had to clear customs in NYC.
Performance is virtually identical with the Tecsun or Terk loops, which are 9 inch loops.
So why buy a PK?
You get what you pay for, or not…the PK is fairly robust compared to the Tecsun or Terk.
It’s made to last and it’s a PK Loop.
Thank you, Ron, for sharing your experience with the PK Loop Mini. It certainly sounds like an excellent option for travelers and, like you, I agree that the construction quality is superb!
Many thanks to SWLing Post contributor and producer, Peter Atkinson, who shares the following review of the new Sangean PR-D17 AM/FM radio:
Sangean PR-D17 review
by Peter Atkinson
I’ve been visually impaired all my life and a radio enthusiast for over 40 years. I was intrigued when I learned that Sangean was offering a radio for the visually impaired. I purchased one, and wanted to share my thoughts about the Sangean PR-D17 from the perspective of a visually impaired listener.
For those readers who are mainly interested in the performance of this radio, please stay tuned, while I talk a moment about the features geared to the visually impaired.
First of all: the manual, [see photo above] while it is comprehensive (as most from Sangean are), it is odd that it’s printed in the smallest type I’ve seen from this manufacturer.
The yellow controls on a black radio are easily seen. I like that the preset buttons on the bottom row of the front panel, are in Braille. The raised symbols, however, on the upper row, may be too complicated to be easily discerned by touch alone. The yellow-on-black motif, is reminiscent of my Sangean HDR-16.
When the 6 C batteries are first inserted, or AC power is connected, the radio announces that it has entered the setup menu. The voice prompt menus (whose volume can be adjusted independently of the radios’ main volume but cannot be disabled) make setting up this radio somewhat straightforward. The setup might have been easier, if the clock setting function was available as part of the menu system. The voice prompts are surprisingly comprehensive. The voice not only speaks the frequency, time & menu options, but will also tell you when something is connected to (or disconnected from) the AC input, headphone or AUX-IN jacks.
When the radio is turned on, it announces that the radio is on, the battery level & the frequency to which it is tuned.
When tuning, the voice gives the frequency at each change. It’s especially helpful when using the seek function, knowing where the next station was found.
The same information is given when recalling a preset. One quirk of the voice prompt, is that when announcing the time, it speaks full numbers (e.g. “twelve thirty-seven’), but when giving the frequency, each digit is spoken (e.g. “one two three zero” or “nine six point one”).
This radio is the same cabinet as the HDR-16. Aside from the voice prompts, it operates similar to the PR-D5. Therefore, I’m comparing its performance to that model. Like the PR-D5, the AM tuning steps can be set for 9 or 10KHz, but the FM tuning steps are fixed at 100KHz (0.1MHz).
There are 5 presets per band. The display also shows RDS information for any FM station that transmits RDS. The clock can be set from the RDS signal, as well. I’ve found several stations, in my area, that are sending the wrong time.
Audio
The sound from the twin 2-1/2” speakers is very balanced. The bass is substantial, but not overpowering. The highs are good for definition, without being too brassy. There are no provisions for customization, though.
There is a 3.5mm AUX-IN jack for connecting an external sound source, such as an MP3 player or smartphone.
AM
While the AM sound is a bit muffled for my taste (the bandwidth cannot be changed) it makes for excellent selectivity. There was no hint of my nearby 50KW 620, on 610 or 630. Like many Sangean radios, the noise floor is very quiet. The long 200mm internal ferrite bar antenna does a superb job at snagging those weak stations. I was able to get a noisy, but readable signal on a 50KW station on 700, at 350 miles, during the day. That one is my benchmark for a great DX machine. The top end of the band is no slouch, either. Another benchmark station (10KW 1690 at 75 miles) came in loud and clear. The long ferrite antenna also helps to better null unwanted signals. This is a greater benefit for nighttime DXing.
FM
The PR-D17’s performance on FM is stellar. It has shown to be very sensitive, pulling in stations as well as my PR-D5 & PR-D9W. I easily hear FMs at 60 miles. The selectivity is also amazing. I can listen to stations on 95.9 & 96.3, with a 6KW station on 96.1 less than 10 blocks from my window. Even though the PR-D17 pulls in those weak stations with ease, it requires a stronger signal to receive stereo.
The RDS is quick to display station information. It starts off by showing the 8-character PS information of the RDS signal, then switches to the scrolling display of the RT segment.
Summary
Overall, I am very happy with the Sangean PR-D17. It is a superior radio, now with the added benefit of voice prompts. Hopefully, this will alleviate some of the annoyances visually impaired listeners may have with operating a digitally-tuned radio.
Thank you so much for sharing your review, Peter and thank you for being an SWLing Post producer!
It looks like the Sangean PR-D17 is an excellent choice for those radio listeners who would appreciate voice prompts, high contrast controls and tactile keys. I’m also happy to hear you rate AM selectivity as excellent. When radios only have one chosen bandwidth, I’d rather give priority to selectivity than audio fidelity for the purposes of nighttime AM DXing.
Many thanks to SWLing Post contributor, Marty, who shares the following article by John Schneider in Radio World:
In the early years of AM radio broadcasting, all stations utilized non-directional antennas. Most all of these were wire antennas suspended between towers or buildings. Interference, especially at night, was severe. An interfering signal of 5% or less in signal strength was enough to disrupt reception of the desired station, and if the frequencies of the two stations were slightly separated, there would be a heterodyne beat note. As a result, only a few widely-spaced stations could operate on each of the AM broadcast channels in the entire country at night. This limited the number of stations that could coexist to about 500 nationwide, with many of them sharing time on a single frequency.
As antenna technologies were developed and improved in the early 1930s, a few progressive stations began experimenting with multi-element directional arrays. This approach offered two attractive benefits: 1) It could reduce radiation towards other stations on the same or adjacent frequencies, permitting more stations to share a frequency; and 2) a broadcaster could direct more signal towards the desired coverage area, and away from wasted areas such as open water in the case of coastal stations.
WFLA-WSUN
The first known use of a directional antenna was by a pair of stations in Tampa/St. Petersburg, Fla. In 1927, the Clearwater Chamber of Commerce acquired station WGHB and changed the call sign to WFLA. A companion station, WSUN, was operated by the St. Petersburg Chamber of Commerce. The two stations shared the frequency of 900 kHz, broadcasting on alternate evenings to promote tourism and business opportunities in their respective communities. In reality, they operated with two station licenses, but there was only one transmitter and one antenna.[…]
