Category Archives: AM

Battery Endurance Contest Results: Sangean DT-160CL vs Sony SRF-39FP

On August 4, 2016, the same day I received my new Sangean DT-160CL, I popped a fresh set of CVS Max Alkaline batteries into the DT-160CL as well as into my trusted Sony SRF-39FP. The mission? To see which radio could perform longest on a set of batteries.

I set my stopwatch as I turned on both radios, tuned to the same frequency, set the volume to the same levels…and waited.

And waited. And waited. And as I waited, I posted updates.

But at last, the waiting is at an end: here are the contest’s final results.

Sangean DT-160CL: Impressive Performance

On August 9, I reported that the Sangean DT-160CL finally threw in the towel, logging an impressive 116 hours 30 minutes of operating time–!

Without a doubt, this is one of the longest run times I’ve ever experienced from an AM/FM radio with digital display.

Interestingly, the day after the DT-160CL shut down, I turned it back on, and it operated for an additional 45 minutes or so, obviously absorbing a little more voltage from rested cells. During that 45 minutes period of time, the audio and overall performance was respectable. No doubt the DT-160 shuts down before audio is terribly compromised.

Sony SRF-39FP: The Endurance King!

Amazingly, the Sony SRF-39FP kept running well beyond 116 hours. Well beyond…

By Wednesday morning–one full week from the time I began the endurance contest–the Sony SRF-39FP finally began showing signs of low-voltage: the audio had a small amount of splatter and sensitivity began to be compromised.

Unlike the Sangean DT-160CL, which clearly has a cut-off voltage, the SRF-39FP kept milking the battery for its last vestiges of power.

I decided that I would call a “time of death” for this AA battery when the Sony struggled to receive local AM stations, as well as transmission from my in-house SStran AM transmitter.

This happened approximately 163 hours and 54 minutes into its marathon run.

This stopwatch app tracked the full endurance test. I pressed “stop” when the Sony SRF-39FP finally gave up.

Wow, wow, wow. I simply had no idea any portable could operate almost one full week on one AA cell–!

In truth, I’m sort of relieved the ’39FP finally gave up the ghost. I was beginning to think the thing was powered by some supernatural force…

When I started this test, I thought the Sony SRF-39FP was rated for about 40-80 hours of run time on a single battery. I couldn’t remember where I got that number until I recently re-read this article from The New Yorker, which highlighted the 39FP’s role in correctional facilities:

“The SRF-39FP is the gold standard among prison radios in part because it runs on a single AA battery, and offers forty hours of listening time…”

Wait, just forty hours? Perhaps from the cheapest AA battery made…

With an advanced chemistry cell like the Duracell Quantum or Energizer Advanced Lithium series, you’ll clearly get three to four times that performance.

DX mode

And here’s the thing: I’m convinced I could’ve gotten much more time out of the SRF-39FP.

Like similar Sony portables, the SRF-39FP has a “DX/Local” switch. When set to DX, the receiver is made to deliver maximum performance.

If you’re listening to a local station, however, “Local” mode is a better choice. You’ll still be able to receive your target station, yet draw much less from the battery.

I left the Sony SRF-39FP in “DX” mode for the entire battery endurance test. Had it been in “Local” mode, I believe I’d be reporting an even longer run time. How much longer, I don’t know, but you can bet that my curiosity will soon get the best of me…I plan to do a separate endurance test to find out.

Clear choices for battery longevity

Sangean-DT160CL and Sony SRF-39FP No doubt, our little test has proven that radios marketed to the prison system do offer excellent battery performance.

Now I’m very curious whether the standard Sangean DT-160 will offer the same battery performance as its clear-cased counterpart, the DT-160CL. The only difference in the two appears to be that one offers a clock, while the other doesn’t. I wonder if that would have any significant difference on battery life.

Additionally, the Sony SRF-39FP has shown us that analog receivers can be much more efficient than their digital counterparts. We’ve known this a long time at Ears To Our World, and which is why almost all of the radios we supply to schools in remote, rural locations are analog.

Sadly, analog radios are getting much more difficult to find these days as DSP-based receivers have become more affordable to produce.

The Sangean DT-160 is available at Amazon.com and Universal Radio. The Sangean DT-160CL (the version tested) is available through Amazon.

Click here to search eBay for the Sony SRF-39FP.

Readers: Know of any other battery-miser radios? Please comment!

200m longwire update: rarely heard Radio Tawantinsuyo 6173.9 kHz, Peru, recorded in Oxford, UK

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Hi there, I thought I would share my first reception of Radio Tawantinsuyo, from Cusco, Peru, recorded during the inaugural test of my 200 metre longwire antenna. Of course this particular reception could be coincidence, but a very welcome catch in any case. Once again, the Sony ICF-2001D performs very well with this large antenna, but as on previous occasions, the rule is always to ‘choose your battles well’ targeting weak DX signals in uncrowded areas of the Tropical Band and elsewhere on shortwave. More details on the longwire antenna to follow in another post. Recorded at the ‘DX woods’ in Oxfordshire, UK on 31/07/16 at 00:27 hrs UTC. Thanks for watching.

Direct link to Oxford Shortwave Log reception video of Radio Tawantinsuyo

Clint Gouveia is the author of this post and a regular contributor to the SWLing Post. Clint actively publishes videos of his shortwave radio excursions on his YouTube channel: Oxford Shortwave Log. Clint is based in Oxfordshire, England.

The Sony ICF-5500W: My morning companion

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I spent this morning doing a lot of work around our property. When it was time for a break, I turned on my trust Sony ICF-5500W and tuned to WTZQ: one of my favorite regional AM braodcasters. Though WTZQ is over 30 miles from my home, any good AM radio, like the ICF-5500W, can receive their 1,000 watt signal with ease.

As luck would have it, when I turned on my 5500W, WTZQ started playing Love Me Do by The Beatles. It sounded absolutely amazing via the 5500W’s internal speaker: full-on, rich AM audio fidelity! Absolutely brilliant!

I cranked up the volume so our local black bears could enjoy.

I relaxed a good half hour, and caught up on reading the latest two issues of RadCom with my ICF-5500W playing WTZQ in the background.

Sometimes it’s the simple stuff that starts one’s morning off the right way.

That and plenty of good coffee.

Warsan Radio 7750 kHz Baydhabo Somalia; on the Sony ICF-2001D telescopic antenna

1 Reply

Hi there, great to hear this new station broadcasting from Somalia, during an early evening DX’pedition at my usual spot – a local Oxfordshire wood! Even better to hear it with just the telescopic antenna!

The ICF-2001D is renown for being extremely well ‘tuned’ to it’s own telescopic and this has been demonstrated many times over the past year or so that I’ve been using it. This signal from Somalia was recorded on 08/08/16 at 19:15 hrs UTC using just the ‘whip’. Please click on the image below to access the reception video.

Alternatively click here to watch the reception video on Oxford Shortwave Log

I have another video of the same signal which I will upload soon, demonstrating reception with a 50 metre longwre and the ICF2001D. Until then, I wish you all excellent DX!

Update 4: Sangean DT-160CL v Sony SRF-39FP

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If you’ve been following the Sangean DT-160CL versus Sony SRF-39FP battery endurance test, I have some news to report: one of our competitors has finally thrown in the towel…!

Yesterday, while I was on the road for about 1.5 hours, the Sangean DT-160CL at last gave up the contest.

Since I was traveling at the time, I can’t say with absolute certainty what o’clock the DT-160 cried uncle––but roughly, we’re looking at 116 hours, 30 minutes of run time, give or take 30 minutes.

Sangean claims the DT-160 series will operate for 100 hours with two AA batteries. That claim is obviously pretty conservative.

Though I used CVS Max Alkaline batteries (a generic version of Duracell’s Quantum batteries)–an improvement on the standard alkaline battery–I set the volume higher than I believe Sangean or Sony would have set it for testing purposes. This should have drained the batteries faster. The radios were also tuned to a variety of stations: weak AM, strong AM, weak FM and strong FM.

In short: I’m very impressed with the DT-160.

A 116 hour play time from two AA cells on a digitally-tuned receiver is, well, pretty incredible.

Now that the endurance test is over for the DT-160CL, I’ll replace the batteries with a fresh set of CVS Max Alkaline cells and start testing the AM/FM receiver performance.

…And how about the Sony SRF-39FP?

My iPhone’s stopwatch has been tracking progress since last Wednesday.

Even more amazingly, the Sony SRF-39FP is still going strong––!

I actually fell asleep last night listening to the SRF-39FP and woke up this morning with music still in my ears. What a champ!

So, how long has the Sony SRF-39FP now been operating on one AA battery?

At time of posting, this little Sony’s clocked one hundred thirty nine hours.

Though I’ve always known that the SRF-39FP was a true battery miser–one of the reasons it’s been a choice radio in the prison system–I had no idea it could operate this long on one battery.

Of course, I’ll continue tracking the Sony SRF-39FP.

How much longer will the SRF-39FP last? Stay tuned to find out!

Follow this review thread by bookmarking the following tag: Sangean DT-160CL v Sony SRF-39FP.

Update 3: Sangean DT-160CL v Sony SRF-39FP

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My iPhone’s stopwatch has been tracking the endurance test.

It’s been one hundred nine hours since I started the Sangean DT-160CL versus Sony SRF-39FP battery endurance test and both radio are still hanging in there!

Not knowing which radio will check out first, I’ve been taking them with me everywhere and have been careful to keep their settings identical the whole time.

Last night, I even prepared my Zoom H2N digital recorder to monitor both radios simultaneously. Having passed 100 hours of operating on the same set of batteries, I was certain one would call it quits last night.

Not so.

There was one noticeable change this morning: the Sangean DT-160CL’s battery indicator now shows a depleted cell.

It’s still operating, though–no noticeable difference in volume and reception.

The end must certainly be near! Indeed, it’s hard to believe I started this endurance test last Wednesday!

I’m very interested to see which pocket radio will go first.

Field time

Yesterday, I spent the better part of the afternoon at Mt. Mitchell State Park. Of course, I brought the DT-160CL and SRF-39FP along.

Mt. Mitchell is the highest point east of the Mississippi river. It’s a great place to play radio.

At one point, I tuned both radios to WAIZ 630 kHz: a 1,000 watt AM station about 95 miles east of the park. It’s one of my benchmark daytime stations from Mt. Mitchell.

Though most DT-160 reviewers have given the receiver low marks for AM performance, I found that the DT-160CL did a better job locking onto WAIZ than the venerable SRF-39FP.

Perhaps this is due to the fact that both radios, at that point, were operating on low voltage? Or perhaps the CL version of the DT-160 series has better AGC characteristics and sensitivity?

I doubt the latter assumption, but once the endurance test is complete, I’ll put the 160CL through the paces.

Follow this review thread by bookmarking the following tag: Sangean DT-160CL v Sony SRF-39FP.

Tom Servo reviews the Sangean DT-160

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Many thanks to SWLing Post contributor, Tom Servo, for sharing the following review of the Sangean DT-160. His review was originally posted on the radio discussions forum:

Got my Sangean DT-160 today. Thanks, Santa Claus!

Initial impressions are positive, both in the build quality and performance.

It’s a lot bigger than I thought it’d be, though.

I was picturing in my mind something closer to the SRF-M37 but it’s bigger than a pack of cigarettes — taller and wider.

Some of the performance issues others have noted, I’ve noticed as well. The FM reception is superb and outperforms the Insignia HD portable that’s my benchmark FM radio. It can hold its own with the Grundig G8 in that regard.

The sound quality is weird, though. It sounds “crunchy” or watery. Like everything is being played via a low bit rate mp3. Granted, most my local stations ARE playing low bit rate mp3s and sound terrible (which is why I don’t listen to local radio much anymore) but the few stations that aren’t still sound “weird”. Crispy. It could be the DSP or just some odd EQ’ing on Sangean’s part. It’s not a deal-breaker by any stretch but when side-by-side with a different radio the audio differences were stark. The Insignia sounds truly “flat” while the Sangean sounds treble boosted. And crispy. Did I mention that?

[At first] the wide-narrow setting [seemed to make little] difference on FM. The only station that narrow mode improved was while listening to WTGF out of Milton, FL. It’s a mono station and I’m on the fringe, and the narrow cleared up a bit of static. It makes a much more noticeable different on AM, though. Not as much as a well calibrated “wide/narrow” filter might but enough to help some talk radio stand out from the noise.

[I did eventually] figured out where the wide-narrow setting makes the most difference on FM. It’s when you have two signals on adjacent channels, the narrow really does help cut out adjacent channel splatter. Not that there’s much of a problem to begin with, but it is a little extra added oomph.

With the narrow activated, I was able to pull in 93.1 WGDQ and 94.3 WKZW from the Hattiesburg, MS market. Two stations I haven’t heard in probably a year or better, and both are first-adjacent to local 100 kW sticks that are less than 15 miles from me.

Selectivity even in wide mode is fine. Definitely better than the Insignia and on par with the Grundig. We have a crowded dial here on the Gulf coast and sometimes you need a selective radio to pull out all the stations side by side. Here’s an example of what is possible to hear on a decent night:

98.1 – WHWY – Fort Walton Beach
98.3 – WLVM – Mobile
98.5 – WYLD – New Orleans
98.7 – WYCT – Pensacola

I was surprised to hear WYLD coming in this afternoon. In fact, at first I thought it was an image of local 99.9 WMXC, because it was the same song/DJ. But the IDs were different. That’s a good pull and something neither the Grundig nor Insignia could pull off.

The dynamic bass boost is a horrible sounding gimmick, though. It makes everything sound muddy on my “real” headphones. I didn’t try the ones that came with it. I hate it that it lacks RDS, since so many Sangean radios have that and it makes DXing more interesting. The AM has a weird squelch like damping when it’s on an empty channel. If there’s a weak signal there (like my semi-local but hard to hear WABF out of Fairhope) it just sits there, perfectly quiet. It’s not until I used the Tecsun loop with it that reasonably clear audio came out of nowhere. I strongly suspect it’s “muting” weak signals on purpose on AM.

WWL is a moderate but noisy target here; the signal strength is usually good enough for even basic radios to pick it up… Not this Sangean. It took careful alignment before I heard anything. The slightest bit of movement and it went almost completely deaf again. Very odd.

It’s a shame that conditions for FM DX have been so poor on the coast this year, I think this would be a killer DX machine on FM. My friend in Florence has heard Mexico and Wyoming this year. I’ve barely made anything further west than New Orleans, which is pitiful.

Another plus is it drives my large Sennheiser headphones louder than any other “pocket” radio in my collection.

Thanks for sharing your review, Tom!

I sounds like the DT-160’s AGC or soft mute on the AM broadcast band is causing otherwise intelligible signals to drop out.

At time of posting, I’m still running the battery endurance test of the Sangean DT-160CL vs. Sony SRF-39FP, so I haven’t really given the DT-160CL (the correctional version of the DT-160) a proper receiver performance test. I will soon enough, though!