Category Archives: Radios

Digging in the Noise: Weak Signal Audio Recovery with the AirSpy HF+ and Elad FDM-S2

I’m currently spending the better part of a week at Cape Lookout State Park on the Oregon coast, with a great view of the ocean through tall evergreen trees. This is one of my favorite parks in the Pacific Northwest, especially when DXing during the blustery winters from one of the nice cabins at Cape Lookout.

The view from the beach near my cabin; the turbulent waves were a precursor to the gale force winds at the park during the night of the 23rd!

https://youtu.be/EYUSU_gzgu4

Although I’m at the park for trans-Pacific medium wave DXing, I’m also comparing receivers, both SDRs and portables. This morning I sought out a few weak shortwave signals, pitting the Elad FDM-S2 SDR ($529 USD) against the AirSpy HF+ ($199 USD). I have a pair of the HF+ receivers to cover all of medium wave (as the FDM-S2 easily does). Many SWLing Post readers already know that the upstart HF+ trades bandwidth to gain high performance in order to keep the price reasonable.

My antenna used for the following recordings was a small “Flag” antenna using a Wellbrook Communications FLG100LN module and a 2K ohm variable potentiometer for termination. The design uses crossed tent poles in an “X” formation to support the wire loop. This design travels easily in a compact package; I have Dave Aichelman of Grants Pass, Oregon to thank for this very useful “tent pole loop” implementation of the Wellbrook FLG100LN.

The Wellbrook-based antenna functions superbly, and its low-noise design helps hold down QRM from the nearby cabins (which unfortunately have been “upgraded” recently with noisy cold fluorescent [CFL] light bulbs). The area around the Cape Lookout cabins used to be superbly low noise and suitable for radio listening, but now it is more of a challenge than before. The Wellbrook FLG100LN is perfect for the situation though; Wellbrook ALA1530LN Pro and ALA1530S+ 1-meter loop antennas work commendably at the park too.

The Wellbrook FLG100LN module with a home brew RFI choke in-line

A 2K ohm variable potentiometer is protected from the elements in a small plastic bag. The “pot” is adjusted for the best nulling of medium wave stations off the back side of the antenna’s reception pattern.

The “tent pole loop” antenna is strapped to a fence railing with ultra-strong Gorilla Tape to keep the 7-ft. square loop vertical.

On with the recordings…

For the FDM-S2 and HF+ comparisons I used the SDR-Console V3 software. Every parameter was identical for the receivers–sampling bandwidth, filter bandwidth, AGC, mode and so on.

Take a critical listen to the weak signals recorded with the SDR receivers, identified as only “Radio A” and “Radio B”. A link to a poll is at the end of this article; please indicate which recording of each pair has the most intelligible audio in your opinion, and submit your choices when you’ve made up your mind on each audio clip. After a week or so I’ll post the results of the voting, and identify the receivers.

9.615 MHz, LSB, Radio A

9.615 MHz, LSB, Radio B (note: the same male announcer heard in clip “A” begins at 00:14 in this “B” clip)

9.730 MHz, USB, Radio A

9.730 MHz, USB, Radio B

7.230 MHz, S-AM, Radio A

7.230 MHz, S-AM, Radio B

9.860 MHz, S-AM, Radio A

9.860 MHz, S-AM, Radio B

Note on 7.230 MHz recording: this was an interesting frequency, as the signal was tightly surrounded by a very strong local 40m ham radio LSB station as well as a strong China Radio International signal. There were other strong amateur and broadcast stations within 30-50 kHz of 7.230 MHz, also. This A-B test more than the others may indicate receiver performance in a strong RF environment on a crowded band.

Ready for the poll? Register your votes at the Google Docs form below:

https://tinyurl.com/ya38wj69

In a week to 10 days I’ll post the results in another article. NOTE: I haven’t provided a “both sound the same” choice in the poll to encourage you to ‘dig deep’ into the audio and listen critically–to find something that stands out in one clip versus the other.

Guy Atkins is a Sr. Graphic Designer for T-Mobile and lives near Seattle, Washington. He’s a regular contributor to the SWLing Post.

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Doctor Vlado repairs the Panasonic RF-2200 (Part 1)

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Last year, at Hamvention, I picked up a Panasonic RF-2200 for $70. It came with the original box, manual and was in superb cosmetic condition.

The seller told me that over the years he exclusively used the radio to listen to a local FM station.

At that price, I didn’t hesitate to make the purchase even if this would have simply been a non-functioning parts radio for my other RF-2200.

After I brought the radio home, I unpacked it and gave it a quick test.

FM worked brilliantly. Mediumwave and shortwave, however, were essentially deaf. I made the assumption that the ‘2200’s switches and pots likely needed cleaning with DeoxIT. The next day, I was leaving for a two month trip to Canada though, so I packed the RF-2200 back into its box and set it to the side of my shack table.

Fast-forward to yesterday…

While digging around my shack, I re-discovered the boxed RF-2200. Since I was planning to visit my buddy Vlado (the best radio repair guy in the world) yesterday evening, I thought I’d take the RF-2200 and do a proper contact cleaning. Several of the RF-2200’s switches and pots cannot be easily cleaned without removing the chassis.

(Click photos to enlarge.)

Vlado is familiar with the RF-2200 and since it’s not the easiest radio to work on, I asked for his expert hands on the job. Within seconds of handing him the radio, he plugged it in, tested the switches and pots, then removed the back cover (disconnecting the battery compartment leads) and then the front cover (disconnecting the speaker leads).

The magic behind the RF-2200’s classic analog dial:
Vlado offered a word of caution to anyone operating on their RF-2200: as you can see in the photo below, the dial string snakes around the front of the radio and is very close to some key components. You must exercise caution when having a soldering iron tip near the string, or using lubricants nearby.I didn’t realize this, but by the time Vlado started taking apart the RF-2200, he had already determined that even though the contacts needed cleaning, this wasn’t the source of the audio problem for the MW and SW bands.Vlado expertly pulled out the pot for the FM/AM/SW selection–not an easy task–began cleaning it, testing it and re-soldering contacts.

Vlado determined the pot was actually in good shape, thus started testing the rest of the circuit.

After a few minutes of performing tests and getting intermittent performance, he determined that at least one, if not more, of the RF-2200’s caps need to be replaced. Of course, neither one of us was terribly surprised. At this point though, it was getting late and I had an early wake up time in the morning, so I left my RF-2200 with Vlado.

Am I worried about this prognosis? No, not in the slightest…

Doctor Vlado is on the job!

Vlado will have the RF-2200 back on the air in no time, working as well as it did when it was new. He’s actually performed a similar RF-2200 repair for an SWLing Post reader and I’m willing to bet this repair job is relatively simple compared to most he encounters (including the Icom IC-7200 he recently repaired after it was hit by lightening!).

I’ll try to post a “Part 2” update with photos of the RF-2200 repair. Follow the tag: Panasonic RF-2200 Repair

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Looking under the hood: Comparing the XHDATA D-808 and Digitech AR-1780

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Last week, I posted a few photos of the new XHDATA D-808 and Digitech AR-1780–two of the hottest portable shortwave radios to hit the market in recent months.

Several readers have requested “under the hood” photos of each radio, to compare internal designs. This morning, I had a few minutes to crack open each radio and take a few shots. Note that I didn’t pull off the circuit boards from the chassis or try to take a look behind shielding. I have yet to do proper performance comparison tests with these radios and didn’t want to accidentally compromise one (especially since the XHDATA D-808 is getting complicated to purchase here in the US).

Inside the XHDATA D-808

Opening the D-808 requires pulling off the encoder knob and removing a total of six small screws. Note that one of the screws is located in the battery compartment. Click photos to enlarge:

Inside the Digitech AR-1780

Opening the AR-1780 requires pulling off the encoder knob (not an easy task on my unit) and removing a total of seven small screws. Note that two of the screws are located in the battery compartment. Click photos to enlarge:

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Radio Deal: C. Crane CCRadio 2 at NPR Shop

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Many thanks to SWLing Post contributor, Kevin Turinsky, who notes that NPR is having a “final” clearance sale on the excellent C. Crane CCRadio-2. The price is $110.11 US plus shipping.

Click here to view the CCRadio 2 on the NPR Shop.

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A review of the Sangean HDR-16 AM/FM HD Radio

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It’s funny that, while I’ve written dozens and dozens of radio reviews over the years, I’ve never written even a single review that included an HD radio.

Well, the time to begin is now: HD radio, here we come.

Those readers living outside North America may be scratching their heads, asking, “What exactly is ‘HD radio?’” To answer in clear terms, I’ll turn the question over to Wikipedia:

HD Radio is a trademarked term for iBiquity’s in-band on-channel (IBOC) digital radio technology used by AM and FM radio stations to transmit audio and data by using a digital signal embedded “on-frequency” immediately above and below a station’s standard analog signal, providing the means to listen to the same program in either HD (digital radio with less noise) or as a standard broadcast (analog radio with standard sound quality). The HD format also provides the means for a single radio station to simultaneously broadcast one or more different programs in addition to the program being transmitted on the radio station’s analog channel.

Got that? In brief, HD radio is digital radio broadcasts that occupy the same FM/AM spectrum currently allocated for analog broadcasts. Wikipedia adds:

[HD radio] was selected by the U.S. Federal Communications Commission (FCC) in 2002 as a digital audio broadcasting method for the United States, and is the only digital system approved by the FCC for digital AM/FM broadcasts in the United States.

For my own part I had mostly ignored HD radio, assuming there would be few stations to listen to from my rural home location. That is, until recently, when I purchased a car that has built-in HD radio reception. I was impressed by the number of commercial stations I found that I can receive via HD radio. In truth, only a handful of the mainstream HD station offerings had any appeal for me, but I really took notice when I received a commercial-free jazz station via the HD2 channel of my favorite NPR member station, WFAE. Having been a jazz fan since I studied music in college, I was intrigued: could a portable HD radio receive this distant HD station reliably? I had my doubts; moreover, I really didn’t want to purchase a radio, then be obligated to send it back if it didn’t receive anything.

Instead, I contacted Sangean. The company was more than happy to send me a loaner radio for review. I requested the HDR-16––at the time it was Sangean’s most affordable HD portable, one about which a number of SWLing Post readers had expressed their curiosity.

Overview

The Sangean HDR-16 is a simple radio with a modern design. The chassis is a glossy black hard plastic and feels substantial. It has a useful fold-out carry handle and substantial telescoping whip antenna. The front face features a 16-character two-line backlit display, five function buttons, five dedicated preset buttons, and a dedicated power button. On the right side of the radio you’ll find a dedicated (two function) tuning knob and smaller volume/tone knob. The left side of the radio features an “aux-in” port, a “rec-out” port, an earphone jack, and a 7.5 volt “DC-in” port.

Features

HD Radio digital and analog AM / FM-Stereo reception
10 Memory Presets (5 FM, 5 AM)
PAD (Program-Associated Data) Service
Support for Emergency Alerts Function
Automatic Multicast Re-Configuration
Automatic Simulcast Re-Configuration
Auto Ensemble Seek
Real Time Clock and Date with Alarm and Sleep Function
2 Alarm Timer by Radio, Buzzer
HWS (Humane Wake System) Buzzer and Radio
Snooze Function
Tone & Bass Control
Information Display for Channel Frequency, Call Sign, Radio Text, Audio Mode, Service Mode, Signal Quality and Clock Time
Easy to Read LCD Display with Backlight
“Battery Low” LED Indication
Auxiliary Input for Additional Audio Sources
Record Output for Connecting to Hi-Fi System or Recording from Audio Program
I/O Jacks: DC In, Line-Out (Rec-Out), Aux-In, Headphone and HD / FM Rod Antenna

Audio

The HDR-16 sports two 2.5” front-facing speakers that deliver crisp audio that can be customized with simple treble/bass EQ settings. I found increasing the treble just a bit and the bass quite a lot produced the best audio for music broadcasts. Even the default audio settings are pretty good, however. The HDR-16 doesn’t have the rich fidelity of the Eton Field BT or the Tecsun S-8800, but it does offer stereo sound that is room filling and pleasant. Sangean obviously took audio fidelity seriously when designing the HDR-16.

The left side features AUX in, Record Out, Earphone and a DC power port.

Note that the the HDR-16 sounds especially good in spoken word/news broadcasts.

Operation and Ergonomics

The Sangean HDR-16 is a very simple and intuitive radio to operate. I sorted out all of its functions simply by following button and knob labels, but even the most tech-challenged person in your family could give the owner’s manual a single read-through and operate the HDR-16 with ease.

But let’s get one gripe out of the way…perhaps a case of simplicity gone too far: the HDR-16 only has five station preset buttons. Five! Actually, it offers a total of 10 memory allocations: five for AM, five for FM. Still…even in my rural market, I can easily program ten station memories on an FM radio, especially since HD Radio channels offer that many more new options. But the HDR-16 forces me to curate my presets down to a mere five stations per band. In my view, this strict limitation is an unfortunate design oversight.

Performance

The HDR-16 is an AM/FM radio that receives both legacy analog broadcasts and HD/digital broadcasts on both bands. I’ll break down performance by mode and band below.

HD performance

Digital FM

Of course, what I was most eager to explore was FM HD reception from my home. After unpacking the HDR-16, I placed the radio on my kitchen countertop and initiated an HD Seek scan via the dedicated button on the front panel. Couldn’t have been easier.

The HDR-16’s scan/seek functionality is impressively quick.

I quickly found there were a number of commercial radio stations––about four, to be exact––that I could instantly receive with little to no effort. Mind you, I live in a relatively rural market in a mountainous area. No doubt, if I initiated an HD radio search in LA or New York City, the dial would be chock-full of terrific stations.

All of the HD radio stations I received were either local, or powerhouses from neighboring markets. I was disappointed to find that I could not receive my most desired station, WFAE HD2.

I then moved the HDR-16 to a south-facing window and tuned to WFAE’s FM frequency of 90.7. I found I could easily receive the analog station and its RDS information, but still had no option to listen to HD2. After tinkering with antenna position and placement in our kitchen window, a sweet spot for reception was found, and voila! WFAE HD2 came in fully decoded, without any drops.

Recalling the days when I used to tinker with the rabbit ears on a TV, once I found that sweet spot, I carefully left the HDR-16 alone and didn’t move it further. As a result, over the course of the afternoon, I had nearly 100% copy from WFAE HD2.

I knew WFAE was a fringe station and checked their propagation map for HD radio. My location was actually outside of the fringe reception area. I looked up GPS coordinates of the WFAE 90.7 MHz transmitting site and found it is exactly 101 miles/162 km from my home.

Obviously, the HDR-16 is a sensitive HD radio on FM!

Via the 1/8″ stereo AUX in jack, you can use the HDR-16 as amplified stereo speakers for your favorite portable music device.

Turns out, FM HD reception is pretty flaky when dealing with fringe stations, though.

Over the course of the next weeks, I tried the HDR-16 in different positions and locations. There was only one spot in my house where the HDR-16 could get reliable reception of WFAE HD2. When I started the evaluation, it was August; our trees were still had a canopy full of green leaves. Sangean kindly allowed me to hang onto the HDR-16 to see if reception improved in late fall when all of the leaves were off the trees. As I write this review, we’re in winter, and the tree branches are bare. But curiously, reception of WFAE’s fringe signal is about the same as before. Nor have I noticed any difference in the reception of other commercial stations.

The HDR-16 accepts four C cells.

My conclusion is that the HDR-16 is a true performer on the FM band in HD mode. I have no other HD radios with which to compare it, but based on what I know about HD radio, this rig certainly exceeded my expectations.

Digital AM

The HDR-16 can also receive AM HD signals. There are far fewer AM HD broadcasters on the air, however. In fact, one of the first in our region dropped their HD coverage last year due to a lack of listeners.

With that said, I’ve read that a number of HDR-16 owners who live in the vicinity of AM HD broadcasters love the fact they get a digital audio quality signal on the AM band. One SWLing Post reader recently told me he even gets the occasional night-time AM HD DX signal with an HDR-16.

There are no local AM HD stations near me, and despite my best efforts, I never decoded an AM HD broadcaster in the evening. Perhaps if I did a little research and planning, then inductively coupled the HDR-16 to a MW mag-loop antenna, it would increase my chances.

Analog performance

I’ve done almost as much analog FM listening on the HDR-16 as I have HD listening.

The HDR-16 can hold its own with most of my portable radios, in that it can receive all of my benchmark FM stations, and even some fringe analog stations.

RDS decoding also seems to be quite effective, even with fringe stations.

AM (mediumwave) performance is surprisingly good. Perhaps my expectations were low, but I expected analog AM reception to be an afterthought. Or perhaps to have acceptable AM HD reception, Sangean had to put some extra effort into overall AM performance. Honestly, I don’t know, but what I do know is I’ve been pleased with the HDR-16 on the AM band. The AGC is pretty stable, noise relatively low, and sensitivity better than on other similar digital radios.

Many of my shortwave portables, like the PL-660, PL-310ET, and PL-880, could outperform the HDR-16 on the AM band, but frankly performance is on a level that it’s going to please most radio listeners. I’ve even had luck getting solid copy from one of my favorite AM DX stations, CFZM (740 kHz) with the HDR-16.

Should you purchase the HDR-16 for AM/MW DXing? No; there are better radios for this exclusive function. But for what I would consider a “bonus” band on a digital radio, I’m very pleased.

Summary

Every radio has its pros and cons. When I begin a review of a radio, I take notes from the very beginning so that I don’t forget some of my initial impressions. Here’s the list I’ve developed over the time I’ve spent evaluating the HDR-16.

Pros:

Excellent FM HD radio reception
Excellent FM analog reception
Very good AM broadcast band reception for a modern digital portable
Good audio from internal stereo speakers
Nice carry handle that tucks away
Both auxiliary-in and -out jacks for audio
Dedicated earphone jack
Design is compact, sleek, yet sturdy
One of the more affordable HD radio options currently on the market
Easy access to bass/treble tone controls through volume multi-function
HD seek functions work on all but the most fringe stations

Cons:

No ability to internally recharge C batteries
No external antenna jack to improve FM HD reception with directional antenna
Limited to just 10 memory presets (five for AM, five for FM)
~~Fringe HD stations may continuously flip between digital and analog, annoying when HD station content and analog broadcast content are quite different~~ Update: I recently tried to have the receiver replicate this behavior but it did not, so I’m striking it from the cons list!

Conclusion

Can I recommend the HDR-16? Absolutely.

If you’re looking for an AM/FM HD radio that’s well-rounded, simple to operate, and provides quality audio, I don’t believe you could go wrong with the HDR-16. The HDR-16 has proven to me that it’s a worthy FM HD receiver as it’s sensitive enough to snag fringe HD stations with some reliability. I’m certain I could design a small FM antenna and get 100% copy from my favorite HD station 101 miles from my home.

I think the HDR-16 would be a safe purchase for anyone, as it’s easy to operate, relatively compact, and makes the process of seeking HD stations a breeze.

I’m especially pleased with the HDR-16’s AM analog reception. It pleasantly surpassed my expectations and makes it easy to recommend the HDR-16. The HDR-16 is one of the few HD portables that also includes AM HD reception.

If you’re looking for a well-rounded HD and analog portable, grab the HDR-16. If you’re looking for a mediumwave DX machine, go for a benchmark mediumwave radio instead, like a GE Super Radio, C.Crane CC Radio 2E, CC Radio EP Pro or even a “Holy Grail” vintage Panasonic RF-2200.

I like Sangean’s high gloss finish (though it does show fingerprints rather well!).

I’m very tempted to purchase the HDR-16; I’ve found it difficult to justify, though. Living in a rural location, I have fewer HD stations to choose from––all but one are commercial, chock-full of advertising, and lack any real variety and diversity. I am very pleased with WFAE’s jazz station on HD2, but it’s hard to justify a $100 purchase just to receive one station over the air. Especially since I can easily stream WFAE HD2 from my Sangean WFR-28, Como Audio Solo, or Amazon Echo.

But if I lived in an urban area, with the accompanying diverse radio market, I wouldn’t hesitate to buy the HDR-16.

Here are some retail options for the HDR-16––at the time of this writing, almost all retailers price it at $100–Amazon, New Egg and some eBay vendors offer free shipping:

In closing…I should add that there’s another tempting Sangean HD radio coming just around the corner: the HDR-14. It’ll be priced lower than the HDR-16, and is even more compact, suggesting that it might make an excellent portable for the traveler. I will certainly review the HDR-14 when it’s available, as I’ll be very curious if its equally effective at snagging fringe HD FM stations. Note that the HDR-14, unlike the HDR-16, has only one speaker, so I doubt audio fidelity will match that of the HDR-16, which should be a better choice for home and local use.

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Mark recommends the Otterbox 3000 as a robust case for the XHDATA D-808

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Many thanks to SWLing Post contributor, Mark Hirst, who writes:

Thomas,

I’m something of an obsessive when it comes to hardcore protective cases for radios, phones and other gadgets.

I was very pleased then to discover that my new XHDATA D-80, which arrived today from Amazon UK, fits inside my Otterbox 3000 dry box with room to fit small accessories.

Click to enlarge

Although they are discontinued now, I’ve picked up Otterbox dry boxes (such as the 2000 box) from eBay new or lightly used.

My early impressions of the radio are all positive, and I’m looking forward to exploring it further in the next few days.

Click here to search eBay.

As you well know, Mark, I’m a certified pack and case geek. Seeing how well it fits your D-808, I know the Digitech AR-1780 should fit too.

How enabling of you, Mark! I think I’ll have to grab one of these. I have a couple of Otterboxes, but all larger (deeper) than this one. Purchasing a used case would be safe as Otterbox products are incredibly durable and nearly indestructible. Thanks for the tip, Mark!

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A photo tour of the 2018 Greenwood, SC hamfest

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Last week, my buddy Vlado (N3CZ) informed me about a small hamfest in Greenwood, SC–I had never attended, but had heard positive comments about it.

I believe Vlado was somewhat on the fence about going, but once I expressed a strong interest in selling some gear, he did too so it quickly became a plan!

Greenwood, South Carolina, is about a 2.5 hour one-way drive from my home. Vendors were encouraged to arrive around 7:00 to set up (general public admission was at 9:00), so Vlado and I hit the road by 4:30 AM!

Notice the lack of traffic on the interstate at 4:30 AM!

We arrived as the doors opened and purchased a total of three tables to sell our gear. My goods took up most of one table and Vlado packed the other two with his gear!

By general admission time, less than half of the vendor tables were occupied, which did worry me. However, overall foot traffic wasn’t bad at all! This vendor was certainly pleased.

I sold at least 80% of the items I brought with me, no doubt due to my generous and agressive pricing scheme (i.e. nearly giving things away–!). Vlado sold some large items, too.

In the end, I didn’t purchase a single item at the hamfest. I was in selling mode, not buying mode, at this hamfest as I’ve been making an effort to downsize some of my collection and use the money to offset the costs of travel this year. With that said, I would have snagged a classic portable had one appeared.

This BC-317 is just asking to be taken home!

Mind you, I was very tempted by two BC-317 receivers being sold together for an asking price of $60, but I resisted as the whole idea of “thinning the herd” is to make room in my small radio shack.

I find that small hamfests like Greenwood actually have better vintage radio pricing than the larger ‘fests.

Greenwood Photo Gallery

Though the hamfest was modest in size, there were quite a few quality offerings among the vendors. I was very impressed with the number of transceivers–indeed, a new ham would have had a selection of affordable benchmark 90s era rigs to choose from!

Click on the thumbnails below to enlarge or comment on the photos. Most of the photos were taken prior to the doors opening but I did my best to capture price tag information if available: