I’m very pleased this morning to see that SWLing Post contributor, Paul Walker, appeared in an interview on ABC News Breakfast:
A brilliant interview, Paul! Thanks for representing your radio DXing community so very well.
And…WOW! Hobart from McGrath, AK! What a catch indeed!
I’ve received a number of inquiries from SWLing Post readers lately regarding an inexpensive Si4732-based mini stand-alone receiver being sold on Amazon and eBay for around $56-66 US shipped.
The radio is based on the Silicon Labs Si4732 DSP chip which provides the following frequency coverage:
It appears the bandwidth selections are 0.5, 1.0, 1.2, 2.2, 3, and 4 kHz.
If 4 kHz is the widest AM bandwidth, that is a bit unfortunate. The radio does have a BFO for tuning SSB and CW signals.
If I’m being honest, even though the price is a no-brainer, I’ve been hesitant to buy it simply because, due to my limited free time, I really do seek enthusiast-grade receivers for review these days. I’m less interested in radios that are cheaply made and lack the sensitivity, selectivity, noise floor, and features an SWL would desire. In other words, I’m a bit skeptical this receiver will be a proper performer.
The frequency range is certainly adequate and Silicon Labs chips are a quality product, but as we know the Si4732 is only as good as its implementation (click here to read the PDF data sheet).
I’m curious if any SWLing Post readers can comment with their experience using one of these Si4732-based receivers. Did it live up to your expectations? How does it compare with, say, an XHDATA D-808 or Tecsun PL-330? Is it sensitive with the supplied whip antenna? Does it have many birdies or other internally-generated noises? Please comment and let me know if this radio is worth checking out!
Click here to search eBay for this radio.
Click here to check it out on Amazon.com. (SWLing Post affiliate link)
Many thanks to SWLing Post contributor, Mad Radio DXer, who writes:
Hi,
I want to let you & your readers know of a Tecsun PL-330 trick that I saw mentioned in the comments section of your blog some time ago which does not seem to have a lot of awareness. This is for using the telescopic antenna for the LW & MW bands, & it works for the 3305 version of the PL-330 which I understand is the export version. The original comment I saw said this also works for the Chinese version of the PL-330, before firmware 3305.
It is very easy to do & instructions are the following…1. Turn on the radio.
2. Select either the MW or LW band.
3. Press the number 3 key down for a few seconds, until the display shows “CH-S”.
This means the MW & LW bands can now be received with the telescopic antenna.
4. To use the ferrite bar again, press the number 3 key until “CH-A” appears on screen.I also did a YouTube video showing this trick in action…
This reminds me of the trick used for the Degen DE1103 PLL version which allows reception of the telescopic antenna for the MW band. However, in my opinion this is much easier to use on the PL-330 than the DE1103 PLL which could be very fiddly. Also this trick is most effective on the LW band, as I find Chinese portables are usually very weak on this part of the band which is good news for LW DXers. I hope you & everyone reading find this trick very useful & that it works.
Thank you so much for the excellent tip!
Many thanks to SWLing Post contributor, Michael Ye (BD4AAQ), for the following guest post:
by Michael Ye (BD4AAQ)
PL-990 and LA400
I have been a happy owner of Tecsun’s PL-880 world band receivers for years. In fact I have two PL-880 radios, one sitting at home and the other staying in my car. So, after Tecsun introduced the new model PL-990 in late 2020, it didn’t take me long to decide to purchase one. In this article I will discuss the Tecsun PL-990 receiver working with loop antennas, while referencing some relevant features of the PL-880.
Merely by its model number, it is easy to regard the PL-990 as an upgraded version of the already highly reputable PL-880. As expected, the PL-990 can very much be regarded as a combination of all the existing fine radio features of the PL-880 AND the music and bluetooth additions, with a number of improvements for instance in shortwave and medium wave performance. The ergonomic design of the PL-990 looks and feels different from that of the PL-880 in a number of ways. Although I may prefer the the more slim and elegant appearance of the PL-880, the PL-990 gives a more rugged and durable feeling, among other improvements over the older PL-880.
The PL-990 and the PL-880 side by side
Living on the twelfth floor of a condominium in the crowded Shanghai, I have often been fascinated with loop antennas. As a licensed amateur operator, I have used the MFJ-1786X and have been impressed with its performance. On reception, I also find loop antennas appealing, as they are able to pull in weak signals while noticeably reducing electro-magnetic interference rampant in the urban environment. I have an unbranded shortwave loop antenna which I believe is based on and performs similarly with the AOR LA320. Despite its excellent performance, it is only good for the 5MHz – 15MHz shortwave range. So a few years ago when AOR launched the new LA400 wideband loop antenna, I bought one, which I often pair up with the PL-880 and other radios for shortwave listening, and get satisfactory results!
Now, back to the PL-990. When I first tried the PL-990 with the LA400, the results were generally good but not as good as as compared with using the same LA400 on my PL-880. This puzzled me for a day or so until I realised that the PL-990 actually has an antenna switch which the PL-880 does not have. The switch is used to toggle between an internal antenna (i.e. the built-in ferrite bar/telescopic antenna) and an external one (e.g. the AOR LA400). So a new PL-990 user who has often operated the PL-880 when first using the PL-990 could easily ignore the switch which should be pushed to “Ext” when plugging in an external antenna. This explains why the PL-990 may suddenly appear less sensitive than expected.
Contrary to the PL-880 whose external antenna socket is only good for shortwave signal input, the PL-990’s external antenna socket works with all bands, from long wave to FM. I found this to be an important and very useful change, and a pleasant surprise for my LA400, which covers a wide range of frequencies from long wave to medium wave to FM and up to 500MHz.
Once the LA400 is connected, the correct band selected, and last but not least the antenna switch turned to “Ext”, the PL-990 and the LA400 work like a charm in the indoor setting, remarkably better than the built-in telescopic antenna. With the loop connected, while there is not much to expect on the long wave band because of very few long wave stations remaining in the world, reception improves considerably on all other bands including on the medium wave and FM bands, as is also reflected on the upper right hand display of the signal strength and S/N ratio readings. Needless to say, performance on shortwave is as good as on the PL-880, if not better (again, remember to push the antenna switch to “Ext” when using it on the PL-990). Using the AOR loop on the PL-990 for FM reception is somewhat different as there does not seem to be a noticeable tuning point. Simply select the “Others” band, which appears to be broad enough for fair FM reception.
It is worth mentioning that I have a Tecsun AN-200 tunable medium wave antenna, which I have not used often. As its name suggests, it is for medium wave reception only. I tried it on the PL-990. Works great.
The AN-200 and the PL-990
It is hard to tell which one, the PL-LA400 or the AN-200, fares better, as the signal strength and S/M readings are quite close. They both perform better than the radio’s internal ferrite bar antenna to varying degrees, by improving the signal strength or the S/N ratio or both. The Tecsun loop is a passive antenna, meaning no power is required, making it easy to be used “wirelessly”, by simply placing the loop close to the radio, without having to be connected to the radio via a cable.
Chocolate, our house cat, tries to enhance reception with her tail
It should be noted that in the “wireless” mode of the AN-200 the antenna switch on the PL-990 should remain at “Int” so as for its built-in ferrite bar and the loop to couple with each other.
Many thanks to SWLing Post contributor, Matt Blaze, for the following guest post:
by Matt Blaze
Here’s a very simple construction project that’s really improved my travel shortwave and mediumwave listening experience.
When I go somewhere interesting (whether a day trip on my bike or a longer excursion to an exotic locale), the two things I’m sure to want with me are my camera gear and at least one good receiver. Fortunately, there are plenty of good quality shortwave receivers to choose from these days; the hard part is packing a suitably portable antenna that can do justice to the signals wherever it is I’m going.
I’ve long had a Wellbrook antenna on my roof at home. These wide-band amplified loops famously enjoy a reputation for excellent intermod and noise rejection, as well as an almost magical ability to pull in signals comparable to much larger traditional HF and MF receive antennas. A portable Wellbrook – something I could pack in my luggage that performs as well as the one on my roof, would be just ideal.
Fortunately, Wellbrook sells a “flex” version of their antenna intended for just this application, the model FLX1530LN. It’s essentially just the amplifier of their fixed-mount antennas, equipped with a pair of BNC connectors for you to attach a user-supplied ring of coaxial cable that serves as the antenna loop. This way, you don’t need to travel with the awkwardly large 1 meter diameter ring of aluminum tubing that makes up the normal Wellbrook. You can just bring a compact spool of coaxial cable and configure a loop out of it when you arrive at your destination.
The tricky part is how to actually form a stable loop out of coaxial cable without needing lot of unwieldy supporting hardware. In particularly, I wanted something that could be set up on a camera tripod to be freestanding and easily rotated wherever I happened to find myself wanting to play radio. The key would be finding or making some kind of mostly non-metalic support for the coaxial loop that could be folded down or collapsed to fit in my baggage or backpack for travel.
And then I found it: a humble 3-section telescoping broom handle sold on Amazon for about $15 that’s exactly the right size: the “O-Cedar Easywring Spin Mop Telescopic Replacement Handle“. It collapses to 22 inches (just short enough to fit in my suitcase), and extends to 48 inches (comfortably long enough for a one meter diameter loop).
Normally, a wire loop would need both vertical and horizontal supports in a cross configuration, but by using a reasonably stiff coaxial cable, I figured I could get away with just using the broom handle vertically. I found that LMR400 (the basic kind, not the “Ultraflex” version) holds its shape quite well in a one meter loop supported this way.
At this point, it was just a matter of the details of attaching and mounting everything together into a portable package.
A one meter diameter loop, which is the ideal size for the Wellbrook amp, can be made from 3.14 meters of cable (ask your middle-school math teacher). That’s about 10 feet for Americans like me. High precision is not required here, so I just cut 10 feet of LMR400.
The next step is to attach the middle of the cable to the top of the broom handle. The O-Cedar handle has a loop at the end for hanging it on a hook in your broom closet. It happens to be just the right diameter for LMR400, but not with BNC connectors attached. So you’ll have to thread the cable through before you crimp or solder on the with connectors. (See photo above). I used the Times Microwave crimp-on BNC connectors, which I had some extras of lying around. I also put some shrink wrap on the cable at either side of the broom loop, just to keep it from slipping out and becoming unbalanced, but that was probably unnecessary.
Now I needed a way to to attach the Wellbrook amplifier to the other end of the handle, as well as some way of mounting the whole thing to a camera tripod. My first thought involved a lot of duct tape. But I wanted something more permanent and reusable.
The key is something called an “L-Plate”, which is a piece of hardware intended to allow you to mount a camera to a tripod in either “landscape” or “portrait” mode. It’s basically two tripod dovetail mounts attached at a 90 degree angle. I used one that was in my junk box, but you can buy them new or used on eBay. I also needed a clamp to attach the L-plate to the broom handle. I used the Novoflex MiniClamp 26, which I got from B&H Photo. The clamp attaches to the inside of the L-plate with a captive screw. (See photos)
Next, I attached the amplifier to the other side of the L-plate using an ordinary screw-on hose clamp. Easy enough, and surprisingly sturdy.
And that’s it. To assemble the antenna, just extend the broom handle to about one meter, allowing for a roughly one meter diameter loop that’s as round as you can make it with the amplifier at the bottom. Then clamp the L-plate to the bottom of the handle so that the handle is just above the base of the plate, and attach to the tripod. (See the photos).
The Wellbrook is powered over the feedline with a 12VDC bias-T injector. So you need a clean source of 12 volts. I use a cheap Talent Cell battery pack (available on Amazon in various capacities). These actually deliver 11.1 VDC (3x 3.7V), rather than the 12V the Wellbrook calls for, but it works fine in practice. I can also use the same pack to power the radio and digital audio recorder.
In the photos, you can see the finished antenna setup on my roof, with my permanent base Wellbrook on the rotor in the background. The performance of the two antennas is quite comparable.
(Note that there’s an eBay seller that makes a somewhat similar travel loop. The performance is quite good under normal conditions, but it is a bit more subject to MW overload when near a transmitter site. So I prefer the Wellbrook, which is much less susceptible to overload, I’ve found.)
My usual complete travel setup is either a Reuter RDR Pocket C2 radio or a Sangean ATX-909X (recently upgraded to the X2 model). Both these radios work well with the Wellbrook. I use a Sound Devices Mixpre 3 to record airchecks in the field. In the photos, I’m on a rooftop DXpedition listening to Toronto traffic and weather from CFRX on 6070 kHz on a warm later winter afternoon.
The whole setup breaks down for travel pretty easily, and fits easily in my suitcase, backpack, or bike bag (see photos). I usually bring a larger tripod than this if I’m also taking my camera.
The Wellbrook setup has really made bringing a receiver into the field a lot easier and less uncertain. There’s no worry about finding trees or other supports for wires, and packing and unpacking is quick and easy. Have fun!
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 radio.com 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).
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:
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.”
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.
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!