Category Archives: Radios

AM Dxing with the Sangean PR-D15

Guest Post by Troy Riedel

Since the demise of my Sony ICF-SW100, I’ve decided to do some AM Dx’ing. A few years ago I purchased a Sangean PR-D15 as my dedicated “AM Dx Radio”. Despite owning it for a few years, I hadn’t yet really put it through its paces.

Note: My 1994 Gründig Yacht Boy 400, with its 150mm (5.9″) ferrite rod antenna, performs splendidly on AM and until this purchase, the YB400 was the radio I grabbed for AM Dx.

At the time of my purchase – if my memory is correct – the other models I had considered were the CC Radio 2 (now discontinued), the CC Radio 2E (it was a relatively new release at the time), and the Original CC Radio EP (now discontinued & replaced by the CC Radio EP Pro).

Admittedly, part of my decision was based on cost. At the time, the CC Radio 2 & 2E were priced over 2x the cost of the PR-D15 and the CC Radio EP was $15-$20 more when shipping was added. Besides the cost, I chose the PR-D15 based on a few things I had read online. But the aspect that really appealed to me is the 200mm (7.9”) Ferrite Rod Antenna and that compared favorably with the C. Crane offerings (yes – ferrite size isn’t everything, but it is an important consideration). So after having read online comments (reviews, discussion boards, etc.) about the PR-D15, I felt very comfortable with my decision and it wasn’t based on cost alone.

Frankly, I don’t really care how well my AM radio performs during the day (I hope this isn’t sacrilege). Why? During the day whether I’m in the car, working in the garage – whatever – I’ll typically stream my favorite station (NYC) via on my iPhone so I can pause, rewind, or pick-up where I left off. Until my Sangean PR-D15 can do that, I prefer to daytime stream. My “hobby” of AM Dxing is in the evening – to relax and have fun (and isn’t that what a hobby is supposed to be?). Keep that in mind as I reveal my results.

I intended to do my AM Dx Nighttime Test in one night, but I was getting so may stations that I had to extend it over two nights. I started each session around 8PM and they lasted until 11:30PM – 12AM (over 7.5-hours of testing on consecutive nights late this week). I had my PR-D15 on a lazy susan turntable and I had two nearby laptops – one to aid as an AM Station locator and the other I used to stream. Stream? Yes – to count as a recorded station I had to get a positive station ID. However, many radio programs are syndicated. Syndicated radio (and ESPN radio) can go on seemingly forever between station IDs. If I didn’t get a station ID within 15-minutes, I used the second laptop to go to the web site of the station I believed it to be to “listen live” to see if the radio and the stream matched-up (luckily live web streams are slightly behind live terrestrial radio so the IDs were easy). Often by the time I had given-up and gone to my 2nd laptop, I’d finally get an on-air station ID. I just didn’t want to waste too much time on one station and miss other stations.

Since my test extended for 2 nights, on night two I quickly dialed-through nearly all of the stations I confirmed on night one to make a quick re-confirmation they were still audible on the 2nd night.

Since I captured so many stations, I was overwhelmed trying to finish and thus I feel this test is still incomplete. My wife typically ends all of my radio playtime (my man cave is a “sitting room” off the side of the master bedroom & there is no wall – no door – so it’s completely open). But my wife and my step-daughter have a weekend out of town in mid to late March. And that means I can stay up all night and do one non-stop test session. Is it bad to say that I cannot wait to be alone?

My QTH is ~ 35-miles east of RIC (Richmond, VA) Airport. The tables below (broken into three files) are my results. Some frequencies have multiple station IDs – since when turning the radio and nulling signals, sometimes one station disappeared and another jumped onto the dial. If/when I post an update of my all-nighter, I’ll add another column to the spreadsheet to include the transmitter strength for better context. It should also be noted that I recorded straight-line distances & not driving distances (via an online straight-line/GPS calculator).

I was impressed that I successfully captured three Iowa stations. And though I find it almost unfathomable, I truly believe I was on the verge of successfully logging a station in Sandy, UT which is over 2000-miles away (there are only six stations assigned to the 1640 frequency, and given the content I [barely] heard, all indications are that it was KBJA)!

I also believe I captured at least one Super-Clear Channel station from Mexico, but unfortunately I just couldn’t successfully verify the station ID. I hope to have a future opportunity to add it to my list.

My ultimate goal is to: (1) compile & maintain a spreadsheet of every AM station that I am able to successfully ID; and (2) maintain a record of the most AM stations I was able to ID in a single one-night, non-stop session.

Despite being somewhat incomplete, I’m impressed by my results. I’m interested to see what you think so please post your comments below!

I should note that my results are strictly off the internal ferrite antenna – no external antenna, no passive loop antenna was used to enhance any signal.

To save column space, please click on each table below. A larger & easier to read image will open in a separate window or tab (depending upon your browser setting).

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Chuck’s re-capped GE Superadio II might set a new AM BCL benchmark

I recently took delivery of a better-than-new classic solid-state portable broadcast receiver: the venerable GE Superadio II.

This Superadio II was generously given to me by SWLing Post contributor, Chuck Rippel (K8HU), who has–in his spare time–been re-capping and restoring all three of the GE Superadio series models and bringing them back to life. Chuck wanted to send me one of the units he’d recently finished, knowing that it might help me when doing AM reception evaluations. He insisted “no strings attached.”

Besides thank you, all I can say is…


Note angels singing in the background.

When I received the Superadio II a week or so ago, I removed it from the box and it looked brand new; even sporting the original “Headset Capable” grill sticker.

This is a case, however, of a refurbished radio likely out-performing the original.  Here’s a list of the main modifications:

  • All of the original dry capacitors replaced with Nichicon Audio Grade components
  • FM AFC and AM and FM IF and RF sections have been aligned
  • Rebuilt the volume control

I’m sure there are other modifications Chuck didn’t mention.

Chuck told me each radio takes a full day to restore. Some of the alignment, rebuilding, and re-capping is surprisingly tricky and varies with each of the three models. Why is he doing this?

Chuck told me, “My enjoyment comes from giving these radios a new lease on life.”

A new lease on life, indeed!

Last weekend, we had a break in the weather–and I had a short break in my schedule–so I took the GE Superadio II, GE 7-2990A, C.Crane CCRadio3, and Panasonic RF-2200 outdoors for some fresh air.

It was late afternoon and, frankly, I didn’t have the time to do a full comparative session, but having spent the better part of an hour tuning around and comparing the characteristics of each radio, I decided to make a short video to share.

The video features the GE Superadio II, but I speak to some of the pros and cons of each model. Keep in mind, this is very much a casual/informal comparison:

Click here to view on YouTube.

The SR-II not only has the best audio fidelity in this bunch, but it’s also extremely stable and has no noise floor to speak of. No doubt, this is the result of those Nichicon Audio Grade components and a skilled technician.

Side note: Chuck is well-known in the radio world because he used to restore the Collins R390A which must be one of the most mechanically-complicated receivers ever made.

I haven’t even properly tested the SR-II on FM yet because I couldn’t pull myself away from the mediumwave dial that afternoon!

I asked Chuck if he would consider refurbishing GE Superadios for other people and I think he would.  If interested, contact me and I’ll put you in touch. Else, Chuck might leave details in the comments section of this post.

He does currently have a restored GE Superadio II on eBay. I just checked and in his listing, you’ll see a full description of the modifications made.

Click here to view on eBay.

Chuck, thank you once again for sending me this SR-II. It’ll become a permanent addition here at SWLing Post HQ. Again, I’m simply amazed at the audio fidelity of this 1980s era receiver. Honestly, I don’t think there’s anything made today that can even compare.

And thanks for doing your bit to refurbish these classic portables!

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A preliminary look at the Tecsun TU-80 FM Tuner

Many thanks to SWLing Post contributor, Mei Tao, who writes:

Hi Thomas:

I saw one reader had asked about Tecsun TU-80 FM Tuner several days ago, Fortunately, I have had this machine for only a couple of weeks.

Tecsun’s Chairman, Mr Liang Wei has told us that TU-80 was not designed for the pure Bclers not for the pure audiophiles either, but for the person who is both Bcler and audiophile. We have to use it with high quality external speakers. That’s it.

Let me show you some pictures I took yesterday:

Additionally, one reader misunderstood me as a seller, absolutely no, I am just a radio enthusiast and a college teacher, I major in western philosophy, especially American Pragamatism.

Yours sincerely.

Mei Tao

Thank you, Mei Tao. We truly appreciate your early access to these various models of portable radios. The TU-80 appears to be a truly unique model and I’m sure FM DXers are following it carefully. Thanks again!

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The new HanRongDa HRD-747: Mei Tao shares preliminary info and photos

Many thanks to SWLing Post contributor, Mei Tao, who shares the following:

Hi Thomas:

Before the Chinese New Year, I received a prototype of the HRD-747 radio and was asked for suggestions on how to improve it. As far as I know, this little gem will hit the Chinese market in April.

Here are its major features and some photos:

  1. More like a handheld wideband receiver: covers UHF?300—520MHz), VHF?30—300MHz), AIR, FM (64—108MHz), SW, MW, USB, LSB, WFM, NFM, and AM.
  2. Based on a DSP chip?sensitivity and selectivity are excellent.
  3. SSB?selectable USB/LSB?reception with 10Hz step tuning.
  4. Multiple tuning methods: ATS, presets, manual tuning, auto tuning, etc.
  5. Equipped with tuning knob.
  6. Bandwidth is selectable.
  7. Squelch level can be adjusted.
  8. ATT control, external antenna jack.
  9. 1000 memory presets.
  10. Powered by BL-5C cellphone battery (removable).


Mei Tao


Thank you, Mei Toa! The HRD-747 certainly offers a wider frequency range that we’re used to seeing in small portable radios. I’m very curious how sensitive and selective it is in those higher VHF/UHF bands and if imaging or poor selectivity are issues.

Thank you so much for the preliminary info!

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Autopsy Report: Sony ICF-SW100s

WARNING: due to the graphic nature of these photos, those radio enthusiasts who love the Sony ICF-SW100 may want to look away. Parental Discretion is advised.

Guest Post by Troy Riedel

Some of you may remember my recent lamenting regarding the unexpected loss of my beloved Sony ICF-SW100 posted on this blog. The Medical Examiner opened the radio’s chassis last week. The manner of death is rather obvious, but what caused it?  Before I reveal my research, allow me to quicky remind you of the context to the situation.

Due to a medical emergency, I “deployed” for two months to tend a remote farm (one of the few benefits was being able to drive a tractor – a kid from my generation grew-up dreaming of piloting heavy construction equipment and farm implements). I traveled there with two shortwave portables: the Sony ICF-SW100s and the XHDATA D-808. After a long day of work, shortwave radio was my only mode of relaxation during my extended period of solitude.

I had always used Eneloop nickel metal hydride (NiMH or Ni-MH) rechargeable batteries in my SW100. I’m not a physics nor a chemistry major (the closest knowledge I have is enough atmospheric physics to have once been a moderately successful synoptic weather forecaster & aviation weather briefer in the military). As such, my education doesn’t directly correlate so I offer an advance apology for my overly simplistic and layperson synopsis of the specific cause & manner of death of my SW100.

I think we all know that a battery is “energy stored inside of a small container”. And energy is heat – measured by random motion (random motion is directly proportional to heat meaning as motion increases or decreases, the heat generated by the motion will do the same).

NiMH & Lithium battery cells have an alkaline electrolyte, usually potassium hydroxide (potash). The electrolyte serves as the catalyst to make a battery conductive by promoting the movement of ions from the cathode to the anode on charge and in reverse on discharge. The electrolyte is sensitive as it has to be to promote charging & to generate power. And the heat that’s produced by the battery can be dangerous because as we previously discussed, a battery is a “closed” container that stores energy … and if we think about it, so is a bomb, right?

Well, the term closed is slightly misleading and not 100% correct. A rechargeable household battery has a vent which acts as an exhaust. This vent allows excess heat to escape. If you Google image search “NiMH battery anatomy”, there are two ways to vent heat. On Panasonic Eneloops and most commercial household batteries, the vent is the rubber puck (disk) under the positive button tab. This disk seals the internals (thus the term “closed”) while also permitting excess heat to [generally] safely vent. Some manufacturers actually have multiple exhaust openings (holes) around the button top that act as vents. Regardless of how it’s done, these batteries do have an exhaust or venting system.

To summarize thus far, rechargeable batteries vent excess heat (whether generated during use or during charging) from the top of the battery. Venting heat during charging is critical because as well all know, one does not want to overheat batteries during (re)charging. This is why everyone should use a smart charger.  A smart charger is one that monitors the energy level of the battery and shuts-off when it reaches capacity (I learned that capacity is defined differently by different manufacturers but all seem to shut-off somewhere at 90% or greater). I remember the portables that were released maybe 10-15 years ago that introduced charging inside the radio. The very early models were not smart, the user had to either program how many hours you wished to charge the battery/batteries or the radio itself was programmed to charge for x-amount of hours regardless of whether the batteries needed to be charged for that long (you could very easily continue charging for hours after the battery attained 100% capacity – a very dangerous situation for your valuable radio!). Thankfully most newer radios, except the inexpensive “no-frills” radios, have smart changing technology. Regardless, I have never been a fan of using my radio to charge batteries as I’ve always felt this is too dangerous because the process produces heat and I do not want [excess] heat generated (or vented) inside of my radio!

There are typically more shipping restrictions, more transportation restrictions with Lithium batteries than there are for NiMH batteries (I’m sure most people have noticed shipping restrictions when buying electronics regarding the shipment of Lithium batteries – and if shipment is allowed, it’ll cost more to ship because Lithium batteries cannot be shipped via all modes). Lithium (3.7v) & NiMH (1.2v) batteries are essentially the same technology, except Lithium generates more “power” aka “more heat” (3x the voltage) and are thus much more sensitive to heat (including environmental heat) .

In doing my research, I found a slight conflict regarding the stability of NiMH batteries in storage. Some manufacturers warn that NiMH batteries should not be stored in temperatures over 30C (86F) while others list 40C (104F) as the threshold. What happens above this threshold? The electrolyte catalyst is activated, and the battery will generate its own heat (heat that must be vented).

At this point, I’m sure you can see where this is going. I had two NiMH batteries inside of my SW100. The two stacked batteries increased the inherent risk (in a worst-case situation, two batteries would create & release/vent more heat than a single battery). I was in a hot environment, I lacked air conditioning for most of the time, and I had a long drive of nearly 300-miles to/from my location at the start & the end of the two months I was there. My SW100 was apparently put into peril when it encountered environmental [ambient] temperatures that exceeded the Eneloops threshold (30C? 40C?). And this caused the NiMH Eneloops to heat-up beyond normal, vent the excess heat, and thus “melt” part of the PCB and the back case of the SW100.

This did not happen during normal storage of my radio in my temperature-controlled house, but rather it happened in the adverse environment I temporarily subjected the radio to.


Yes, I know … think what you want (but please don’t say it). User error.  I should have known better.  It was my fault. It was dumb. Yes, yes, yes & yes answer those four statements. I know, I know …

There are three positives to this:

(1) I learned a painful albeit valuable lesson;

(2) Maybe others can learn from my folly; and

(3) Parts to maintain these classics must be salvaged. I donated my radio (including the AC adapter) – it’s not a total loss and it still has value as a “parts radio”. My SW100 is now in the hands of a skilled, master technician who might be able to save the life of another (or multiple) SW100 radio(s).

My loss just might be someone else’s gain? I take comfort that my radio may live on (as an organ donor) to potentially provide years of enjoyment for someone else.

Postscript re: my initial post:

I have picked-up a few of my other shortwave radios since my initial post (PL-390, PL-880, XHDATA D-808, Satellit 750) & I have started listening again.

And I did have surgery a couple of weeks ago for the physical injury I sustained while tending the farm (my ICF-SW100 wasn’t the only casualty during this period of time). After a frustrating 2+ weeks, I’m starting to make progress with my physical healing. And now that I have a definitive answer on the manner & cause of death of my SW100, I’m psychologically healing from that as well.

UPDATE after my initial post:

I neglected to make the following statement: one can debate whether the excessive heat being vented caused the PCB & case to melt, or if the vent(s) in one or both batteries failed, or if the battery heated-up too quickly & too much for it to safely vent?  The only thing I do know: the batteries exhibit no physical damage or defect so the exact mechanism of the the excessive heat will remain unknown.

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New RX-888 MK II SDR Receiver on the Way

Jinze (Justin) Peng, developer of the high performing, high value RX-888 SDR, has just announced an improved “MK II” version.

I’ve been very pleased with my original RX-888 in all performance aspects, and it’s wideband demodulation and IQ WAV recording have opened up new DXing possibilities (small capacity hard drives need not apply :^)

The new receiver is now appearing on eBay and AliExpress.


We are pleased to announce the second-gen of RX888. RX888 mkII is the new generation of RX888 with the following improvements and enhancements:

1. Add a tunable (variable) attenuator in the HF path, which can tune from 0 to -31.5dB.

2. Change the fixed LNA of RX888 to a VGA, which gives the -10dB to +33dB range. VGA applies to both HF and VHF.

3. Use the newer generation of tuner chip R828D instead of R820T2.

4. Use an enhanced version of 64M LPF to improve image rejection further.

5. A jumper can select the internal reference clock or an external 27Mhz reference clock.

The primary motivation is giving users smaller granularity control on the RF front-end and a big dynamic range to fit the demands of both strong and weak signals receiving. The tunable range is -41.5dB to +33dB for HF and 0db to 55dB for VHF, which covers most use cases.

During the mkII development, we are working very closely with the original author of BBRF103, IK1XPV, on his new universal driver. The new driver supports RX888 and RX888 mkII now. The new driver can download here: And we expect the power of open source will significantly improve the software support and the lifetime of RX888.

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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Radio life after death

A guest post by Troy Riedel:

This is a sad story.  Well, it’s sad for me.  But hopefully my sad story will yield “radio life” for somebody else and that life will bring them joy.

I’ve been an SWL’er since the early-90s.  Due to the decline of international broadcasters, “collecting” has become just as – if not more – important to me than listening.  I’ve always been fond of the Sony ICF-SW100 pocket radio.  I often read here on this blog about Thomas’ affection for it.  To make my dream a reality, on 19 November 2017 I found the perfect SW100 (with the leather case) and I purchased it.  It did not disappoint!  That radio has to be the most sensitive radio for its size out there.  No, correction – that little baby has held its own against any other portable shortwave radio (of any size) that I own (I have 17 or 18, incl. this SW100).  That’s quite amazing for a true pocket radio.

But please allow me go back to the beginning of my story.  Once I acquired the ICF-SW100, I assembled a “kit” … piece-by-piece (remember, I’m a collector).

I surmised that the SW100 would fit into the Sony ICF-SW1 case – and I was correct (sans the SW100’s leather case).  The SW1 case was one of my first purchases for my SW100 as I wanted something rugged to protect it.

The Sony AN-1 antenna works great with the SW100, and that was part of my kit.  Of course, I also wanted the OEM Sony Compact Reel Antenna.  “Check” – found one on eBay!  The OEM AC adapter? Yes, “check” that one off the list.  A photocopy of the OEM manual would not do – I found an original on eBay and “check”, that was added to the kit.

I already owned a Sony AN-LP1 (active) antenna.  That would not fit into the case, so I added a TG34 active antenna that I already owned (that’s a Degen 31MS clone).  Why?  I gotta have a ready passive antenna in my kit.

Wait, who wants a 30+ year old OEM set of earbuds?  Exactly, neither do I.  This is the only thing I did not want to be OEM!  I bought a new pair of Sony earbuds (off Amazon) to throw into the kit.  Other than the TG34, everything in the kit had to be Sony.  In the end, this handy little case was my Eutopia – it had everything I needed in its own “shortwave bugout kit”.

Of all of the radios in my shortwave arsenal, this was by far my favorite.  Hobbies should bring us joy.  So even if there weren’t many broadcasters to listen to, this little pocket radio never failed to bring me joy.

The last time I really used this radio was June-August 2020.  My newborn grandson was in the NICU far from my son’s home.  I “deployed” (with my SW100 bugout kit & 5th wheel camper) to my son’s very rural & very remote farm (275-miles from my home).  I was there to tend the farm, solo, for that period of time while my son and his family could be with my grandson at a specialty hospital some 350-miles away.  During this stressful & physically demanding time – tending to more farm animals than I care to mention and rustling bulls that escaped from the pasture – my SW100 was the only friend that I had.  It provided many, many hours of enjoyment.  Literally, other than a neighbor about ¾ of a mile up the road my ICF-SW100 and I were alone (not including the 50+ animals I tended to) from June through August.

Fast-forward to the present: last weekend I reached for my kit and I removed the my SW100.  I turned it on and there was no power.  Not surprising but actually very unusual as my NiMH Eneloop batteries typically last for a year or more inside my radios in “storage”.  I reached for the battery compartment, I felt an anomaly on the backside of the case and imagine my horror seeing this as I turned it over!

Surprisingly, there is zero damage to the Eneloop batteries (they did not leak).  I can no longer power the radio via ANY batteries, but amazingly the radio seems to operate at full capacity via AC Adapter.  Whatever happened inside the radio, it still seems to operate (though admittedly I haven’t taken it through all of its usual paces).

Unfortunately, a pocket radio that only operates via AC power does not suit me.  There is a better option: my loss may be someone else’s gain?  I am sending the radio and the necessary components to Thomas’s friend Vlado for a full autopsy (Vlado emailed that he has worked on these radios for years and has “never” seen this issue before).  After the autopsy, my radio will become an organ donor.  The remaining healthy components of this radio – and there are many – will be used for repairing other SW100s (singular or plural).

Strangely, I cannot detect any other “trauma” to the radio other than that one melted corner.  The battery compartment *seems* undamaged though I refuse to open the case as I do not want to accidentally damage the radio’s healthy components (I’ll let the professional “coroner” do that).  I am looking forward to the coroner’s report because I need to know what the heck happened to my baby?!

In closing, though we’ve only had a 3-year plus relationship I can honestly say this amazing little pocket radio had become a great friend.  I’m sure it’s grief, but I am considering liquidating the remainder of my radio & antenna collection – my heart just isn’t “in” to SWL at the moment.  And the timing of this is just awful for me: I’m having surgery Tuesday for an injury I incurred eight months ago while tending my son’s farm.  I had big plans that my SW100 and I would pass the time while I convalesce.  But alas, my buddy will be headed to radio heaven as an organ donor.  May others benefit from my loss.

Guest Post by Troy Riedel

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