Category Archives: Portable Radio

Dan reviews the Tecsun PL-368: “Large Receiver Features In Smaller Vertical Handheld”

Many thanks to SWLing Post contributor, Dan Robinson, for the following guest post and review:

Tecsun PL-368: Large Receiver Features In Smaller Vertical Handheld

by Dan Robinson

It was back in 2020 that the first photos surfaced online of the PL-368 – posted on Facebook by someone attending the electronics fair in Shanghai, China.

Photos showed the successor to the PL-360/365 receivers – and also the PL-990, successor to the PL-880, as well as the new king of the hill for Tecsun, the larger dual speaker H-501.

Things looked promising, and it was pretty exciting. Tecsun designers upgraded the PL-365 which had become a favorite of preppers and SWLs, but which was hobbled by the lack of a keypad, to the re-named PL-368.

The PL-365 and PL-360 before it were plagued by the problem of being overly sensitive to the touch – when holding the radio, reception was fine, but remove your hand and signal levels plummeted. Usually, a full hand grip was necessary to obtain full sensitivity and any variation in grip reduced sensitivity – this was noticed mostly in shortwave mode.

Previous 360/365 models were known for the included small rotatable ferrite

AM amplified antenna which performed miracles in nulling mediumwave stations – for those who still like to listen to the AM band. The 368 also comes with this additional ferrite antenna.

And the 365/360 (which were and still are sold by CountyComm as the GP-5) used AA batteries, making it very easy to find replacements anywhere the radio is being used in the field. Tecsun changed that on the 368.

After the photos appeared, I contacted Benny Zhao, who had posted them on one of the Facebook groups and asked if he could send me a sample of the PL-368. He obliged and a 368 was sent on its way.

The radio was sent without the BL-5C flat lithium battery which was prohibited in postal shipments. It took a long, long time (3 months, apparently the package was sent by snail mail) but it finally arrived here and I have been putting it through some tests.

The PL-368 that I received has the notation “2020.12 VER 1” so it’s clearly a first version from 2020 production.

Like the models before it is a great, handy, portable to grab if you’re going on a trip. It is lighter than the older 360/365s. The change from three AA batteries to the flat BL-5C explains some of that. There is a heft to the older models that the 368 doesn’t have. I am not sure about differences in thickness of the 368 cabinet. Perhaps we will find out more from Tecsun (see notes below regarding issue of tapping the front of the 368 cabinet).

The 368 retains the two multi function adjustment wheels on the right side, one for Volume, the other for Tuning. These are also used for time and bandwidth control.

Tecsun PL-368 (left) and PL-365 (right)

On the 360/365 radios, I never found the tuning wheel approach to be particularly efficient since it was limited to a certain number of kHz per turn, either 5 or 1 kHz depending how fast you turned.

On the 368 it appears you can obtain up to 40 kHz from a single turn of the wheel, while on the 360/365 that was limited to 15 to 20 kHz depending on the speed you were turning.

Tecsun PL-368 (left) and PL-365 (right)

The antenna on the 368 is thinner, but 8 inches longer than the 360/365 models, and in the box you will find the included and very effective rotatable ferrite antenna for mediumwave that inserts in a jack on the top.

On the 368 the volume wheel has detents, whereas on the 360/365 the wheel had smooth turning.

We have gone from 14 buttons on the old PL-360/365 models to 28 buttons on the PL-368, including addition of the keypad.

UPGRADES

Tecsun has upgraded the 368 in line with improvements seen in the PL-990x and H-501 receivers. There are now adjustable bandwidths – a particularly useful tool. These bandwidths also operate in SSB, something that the new Sangean ATS-909×2 doesn’t offer. Bandwidths are: LW/MW 2.5, 3.5, 9.0 SW: 2.5, 3.5, and 5.0 SSB: 0.5, 1.2, 2.2, 3.0 and 4.0 kHz

Also in the 368 is now synchronous detection, a feature left off Sangean’s 909×2. And you get the same intelligent tuning features seen in the 909x/501x models as well as the previous PL-880.

Tecsun added a control that enables activation of the light – this is located on the same button as the Step control which adjusts the tuning steps.

The 368 display now has the ability to tune in 10 Hz increments, an overdue upgrade from the 360/365 models.

Charging of the BL-5C battery can be carried out by connecting a DC 5V/0.5A adapter to the micro-USB port on the side of the radio. The English manual notes that when charging, the charging time is displayed at the top right corner of the display while the “Charge” indicator flashes.

Adjustments for 9/10 kHz mediumwave, Longwave, and FM frequency range can be found on the 1, 2 and 3 keys.

The manual notes that in addition to the internal ferrite bar antenna, the external supplied MW/LW ferrite antenna can be connected to the antenna socket on top and rotated to obtain optimum reception.

Addition of the keypad makes the PL-368 far more useful than its predecessors for instantaneous frequency access. This was the major drawback of the 360 and 365 receivers. This can’t be emphasized enough.

This is a day versus night difference and vastly improves the attractiveness of the 368 over previous models.

There are 850 memory presets, 100 for FM/LW, 150 for MW, 300 for SW, and 100 each for SSB and SYNC.

ATS tuning, like the 990x and 501 receivers enables ATS within all meter bands by holding the [<] or within a selected meter band by holding the [>]. The manual also notes the ability to auto scan all stored stations within a frequency band or mode (SYNC/SSB) staying on each station for about 5 seconds before resuming.

The 368 has what Tecsun now calls Enhanced Tuning Mode (ETM+) – as explained in the manual, this allows auto tune and storing of FM, LW, MW and SW stations into ETM memory. Unlike ATS, scanned stations will not be stored into regular memory (VM) – in this way, when in a different city or country, ETM+ can be used to auto search new stations without overwriting any previously stored stations.

FM De-emphasis Time Constant – as explained in the manual, while receiving FM broadcasts, long pressing [4] will adjust the de-emphasis setting for Europe, Australia, Japan (and most other locations), or for Americas and South Korea.

Add Seconds to the Clock – with the device powered off, press and hold [8] to add seconds to the clock.

Sleep Timer – as with its predecessors, the 368 has a Sleep Timer, with an indicator on the LCD display.

Alarm – and like earlier models, there is also an Alarm function, which allows the radio to turn on at a preset time. It’s possible to select a specific frequency to be used with the Alarm.

RE-CALIBRATION – I have not been able to determine yet if the 368 has a re-calibration function as can be found on the PL-330, 909x, and H-501.

PROBLEMS

Let’s get one headline out to start: The 368, as with the 909x and H-501 all have the useful Synchronous Detection mode. However, SYNC continues to be hobbled, showing distortion and loss of lock.

As I have mentioned in reviews of the 330, 990x, and 501x any successful use of SYNC requires a delicate dance involving careful selection of various bandwidths while in SYNC mode and fine tuning.

The 368 manual contains 3 pages of explanation of SYNC noting that it can “eliminate distortion generated in the IF filter due to local fading, slight offset, modulation overshoot, as well as inter-channel interference and cross-talk modulation, and can also reduce noise interference.”

The problem with all of the Tecsun DSP chip receivers after the PL-880, which had a hidden SYNC feature that was the worst of the bunch, is the extent to which SYNC still suffers from distortion and loss of lock that renders the feature far less useful than it could be.

Ideally, one would want SYNC to match the capability achieved in such older receivers as SONY’s ICF-2010, SW-100S, SW-07, 7600GR. You’re not going to get that with Tecsun receivers.

Like its predecessors, the 368 is still sensitive to touch. I noticed this immediately on the old 360/365 receivers, especially when using the radios

at the beach. If I was recording a station on shortwave, and left for a few minutes, I would return to find that sensitivity had dropped because the radio was not still being held in the hand, which rendered the recording useless.

I am continuing testing of the 368 to try to determine if this issue has been reduced to any extent and will update this review with any further findings. This sensitivity issue is not specific to the 368 – it can be seen on other older and newer receivers.

Many older portables (the SONY ICF-SW55 comes to mind) were constructed with robust cabinets that were less sensitive to touch. Touching the whip antennas on some older receivers improved reception, while on others touching the whip antenna actually reduced sensitivity.

URGENT ATTENTION FOR TECSUN: My initial testing of this particular China market unit of the PL-368 – again, it is marked as December 2020 Version 1 production – identified an additional issue.

When in SSB modes or SYNC, tapping on any area of the keypad and LCD display produces a warbling/distortion effect in the audio. One can only surmise that this is attributable to insufficiently robust construction of the PCB board underneath.

(Video shows problem created when physically tapping front of PL-368 cabinet.)

This is NOT a problem seen with my PL-365 when it is in SSB mode.

I hope that Tecsun gives this the attention it needs and corrects the problem in future production runs.

SUMMARY

Were it not for the major problems detailed above, the PL-368 would be an automatic must-buy receiver in my book.

Addition of the keypad is a night and day improvement and when combined with additional features such as multi-bandwidth options and the still-to-be-perfected synchronous detection, the 368 would be a killer portable.

But as with the PL-330, 909x and 501x the problem with SYNC mode is still a major drawback on a feature that is supposed to lift Tecsun receivers out of the pack of portables that are on the market in 2021.

One can live with the issue of cabinet sensitivity – but the additional issue I identified where there is instability introduced when tapping on the front panel/keypad/LCD is a QC problem that simply must be addressed by Tecsun.

But as I have said in reviews of other Tecsun receivers, let’s back up a bit. Imagine if we had had portable receivers with the capabilities that these have, back in the 1960’s or 1970’s.

It’s one of the great ironies of the radio listening hobby, that in 2021 any company is willing to continue producing receivers of this caliber as use of shortwave by major broadcasters continues to decline.

The obvious other killer feature to include in portables such as this would be to somehow integrate DRM into them. However, I have a feeling that will never happen

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Dan reviews the Tecsun PL-330 portable shortwave radio

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Many thanks to SWLing Post contributor, Dan Robinson, who shares the following guest post:

Tecsun PL-330: The Powerful Mini With One Serious Design Issue

by Dan Robinson

As SWLing Post readers know, I have a huge radio collection – including premium receivers and portables, now nearly 100 in all.

So, these days I am hesitant to add too many, but I continue to take interest in what companies such as Tecsun and Sangean are doing in the way of stuffing the latest chip technology and capabilities into portables radios.

The last receivers I reviewed included the Tecsun PL-990x, which has developed quite an enthusiastic following since its consumer version was released in 2020, and the Tecsun S-8800.

Out for some time now is the Tecsun PL-330. By now there are many reviews of it on You Tube and elsewhere.

It’s become a familiar observation for many of us – if this were still the 1960’s and 1970’s – even into the 1980’s, which could be considered the golden days of shortwave and we had receiver technology like this, well what a joy that would have been.

When I traveled around the world both before and after college, and professionally for Voice of America in the 1980s and 1990s, wow what a good time I could have had with today’s portables!

Some world band portables radios back then were superb performers. The Grundig Satellit series 500/700/600/650 come to mind – but these were not exactly what I would call small portables.

Paging through Passport to Worldband Radio from 1990 (wow, that’s 30 years ago!) you see others such as the SONY SW-1, Panasonic RF-B65, and of course, the SONY ICF-2001D/2010 which introduced killer synchronous tuning technology in the 1980s and remains popular today decades after it first appeared.

Also available were the SONY ICF-SW55 and later in competition with the 2010, the SONY ICF-SW77. Today, I have four SW-55s and two SW-77s and still use them regularly.

Tabletop receivers back in the good ol’ days offered multiple selectivity positions. One of those was the Lowe HF-225 (and later Europa version) along with the HF-250, Kenwood R-5000 and R-2000, ICOM IC-R71A, and Yaesu FRG-8800 among many others.

But as far as smaller portables go, features such as synchronous detection and multiple selectivity were still pretty limited, and a number of receivers didn’t offer selectable synchronous as was eventually offered on the Drake R8B and later production of the SW-8.

The RF-B65 by Panasonic – which today remains sought after for its amazing sensitivity – was hobbled by having a single selectivity position. Same with SONY’s SW-1 and SW-100, and 7600GR, though SONY’s PRO-80 had two bandwidths.

Indeed, it wasn’t until Eton brought out the E-1, with its three bandwidths combined with Passband Tuning (though no notch filter) that a portable finally reflected capabilities of some of the better tabletop radios (though lacking a notch filter).

The Grundig Satellit 800 was close in competition with the E-1 (though the earlier Sat 600/650 series also had multiple bandwidths) but was bulky.

Fast forward to 2021 – credit due to Tecsun and more recently to Sangean with its 909X2, for some years now we have enjoyed Asia-originated portables with multiple selectivity and synchronous mode, though sync implementation on some has left much to be desired.

Which is where the PL-330 comes in. When I look at the 330, I am reminded of one of the now ancient SONY portables, the ICF-4920 which was a super small slide-rule receiver that nevertheless was quite sensitive.

Like the 4920, which you could easily slip in a pocket, the PL-330 is a perfect travel portable. Only the Belka-DX SDR and still wonderful SONY SW-100 compete in terms of performance and size.

The 330 is basically a PL-990x in miniature: smaller speaker obviously, shorter antenna, no bluetooth capability or card slot. But as many people who frequent the Facebook groups have observed, pretty much anything the 990x can do, so can the 330.

This radio has ETM/ATS tuning, synchronous detection, multiple bandwidths in AM, SSB and MW, FM mono-stereo speaker control, alarm/timer functions, external antenna jack, display light, and other features.

Tecsun decided to go with a BL-5C battery here – the same with the new PL-368. I think this is unfortunate, since it requires one to obtain a number of those flat batteries if you want to travel and not have to re-charge. On the other hand, this is not a crippling design decision.

What is an unfortunate design problem, in my view, involves the simple question of tuning the receiver.

The main and fine tuning knobs on the right side of the PL-330 are embedded into the cabinet just far enough as to make easy rapid finger tuning of the radio nearly impossible.

In fact, in my testing it’s impossible to thumb tune the radio more than 10 kHz at a time. The same applies to using the lower knob which controls volume. When in FM mode, this issue make tuning just as frustrating almost forcing one to use rapid scan mode.

Another puzzler: Tecsun limited bandwidths in AM SW to three, while in SSB you have 5 bandwidth options. In AM mode, you have a 9 kHz bandwidth, another puzzling choice. Longwave too is limited to 3 bandwidths.

But overall, none of these problems really knock the PL-330 down very far. This is one mini powerhouse of a radio, one that makes you think “wow, if I had just had this back in 1967 or 1973 or 1982.

Some additional thoughts. My particular PL-330 was supplied by Anon-co but is a pre-production version and so does not have the latest firmware. Thankfully, I have not experienced the issue of SSB tuning running in reverse as others have.

NOTE: As most users know by now, but some newer users may not, you cannot charge one of these radios – whether Tecsun or Sangean – using the mini-USB port and use them at the same time. . . there is just too much noise introduced from the charging process.

This little mentioned feature: just as the Tecsun 909x has a re-calibration function, so does the PL-330. Tecsun itself initially declined to acknowledge this, but finally confirmed through Anon-co.

The procedure: Switch to LSB/USB. If the station is not zero beat, hit STEP button once and then quickly again to move the flashing display down arrow so it’s above the far right digit. Then fine tune the station for zero beat. Hold LSB or USB in for a couple of seconds. The LCD blinks. You then have zero beat – but be sure to repeat the process for LSB and USB.

I should mention that just like on the 990x, the re-calibration process doesn’t mean the receiver is then zeroed up and down the shortwave bands. You will likely have to repeat the process from, say 25 meters, to 19 meters, to 49 meters, etc.

I have come to enjoy using the PL-330 here in my house, though like other portables in my collection I need to position it in one particular corner of my home away from incoming cable TV lines.

The PL-330 and the Belka DX are currently king of the pile when it comes to my smaller travel portables.

I fully expect there will be no further receiver development by Tecsun after the PL-330/990x/H-510 radios – but that company will certainly have left us with some great receivers as the days of shortwave approach an end.

Video

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Shortwave portables, external antennas, overloading, and electrostatic discharge

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Many thanks to SWLing Post contributor, Jack Dully, who writes:

I am just wondering what portable receivers are more susceptible to overloading with long dipoles, say 60-70 ft.

I regularly use such and I have never noticed anything unusual happening with a Sony ICF-7600GR, Grundig G3, or PL-880 to name a few. I just ordered a Tecsun 680. Perhaps many of the newer radios have better AGC thresholds or more robust front ends but I really don’t know for sure.

[Also] how exactly do you know if your receiver (portable OR not) is being overloaded by too big of an antenna (ie. dipole, inverted V and the like) and will it damage your receiver? Is there still a way of using a large antenna to capture more distant stations safely, especially with good quality portables?

Thank you for sharing this question, Jack, and my hope is that SWLing Post readers can chime in with details and advice in the comments section of this post.

These are deep topics, but I’ll try to answer a few of your questions…

First of all, you definitely can harm a portable radio by hooking it up to a large antenna. Many portables have no means of protecting themselves from ESD (Electrostatic Discharge). By hooking a portable up to a long wire antenna, you can expose it to ESD which will essentially deafen your radio until you’re able to repair it. Indeed, this reminds me of an article from our archives regarding a Tecsun PL-600 ESD repair. Some radios do have built-in ESD protection (like the PL-680), but I’m not entirely sure it would offer protection from a particularly strong ESD pulse.

Symptoms of overloading can vary. Sometimes overloading can sound like background splatter and even popping. Sometimes you’ll hear “images” of broadcasters across the bands; muffled audio of a blowtorch station. Another sign of overload is when your signal meter jumps at the same time your receiver goes deaf. It’s as if your radio is simply overwhelmed by strong signals and it can manifest itself in odd ways especially since the AGC usually falls apart.

Like you, I’ve found that my Sony ICF-7600GR seems to be able to handle large wire antennas with no discernible overload. Also, the Tecsun S-8800 (above) is well-equipped to handle larger external antennas and even sports a proper antenna port on the back. I know Sangean ATS-909X owners who only use their radio with an external wire antenna and have excellent results.

Some portable radios are very sensitive with the built-in whip antenna, but fall apart if attached to a long wire antenna.

In general, the cheaper the radio, the less likely it has a front end and filtering that can cope with overloading.

Overloading advice?

Please comment with your experience regarding overloading. Have you found some radio models better than others at coping with blowtorch stations, for example? What do you do to protect your receivers from electrostatic discharge when hooked up to large antennas? Please comment!

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Michael pairs the Tecsun PL-990 and the AOR LA400

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Many thanks to SWLing Post contributor, Michael Ye (BD4AAQ), for the following guest post:

In the Loop: PL-990 and LA400, a Perfect Match

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.

Overall performance of the PL-990

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.

Working with loop antennas

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!

Antenna Switch on the PL-990

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.

“Ext” antenna input for all bands

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.

Tecsun AN-200 loop antenna

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.

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AM Dxing with the Sangean PR-D15

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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 2^nd 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

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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…

Wow–!

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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Autopsy Report: Sony ICF-SW100s

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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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