Steven Walker Finds the Tecsun PL-660 Is Vastly Superior to the Sony SW7600GR

 

 

 

Addressing Craig's Tecsun PL-660 review, Steven writes:

As a life time experienced RF technician and later Engineer - I have often wondered why some of these reviews don't just quote the sinad sensitivity that the radios have been tested at that would give us all a clear answer to which one is the most sensitive -easy measure it. Thats what happens in real radio.

I work in a radio and this easy to do.
All this stuff about "I can get this station and that one" means nothing, as on air radio receiving conditions vary greatly and are hard to measure with any reliability.
Also when people quote which stations they get, they never say where they are in the world, there is a world out side the US of A.

Having said that I will say that I have a 7600GR and have always found it to be junk.
Try resolving SSB on, it you wont. There are mods on the net to fix this problem.
It is a most basic design problem, the designer should be totally ashamed.
Also if the sync lock is on and the station level is to low to lock onto, the stupid thing just screams in your ear, sounds like feed back.
The fake metal spray on case soon wears off and the sound is lousy.
As I have mentioned I have put up with it for five years. In Australia the standard retail price in 2004 was $550, yes, at the time about $US500.

I recently purchased a Tecsun PL-660 for $US150 and let me tell you despite what I have put above I will not be measuring the sinad sensitivity, no need to, the PL-660 is streets ahead of the ICF SW7600GR.

It suffers from none of the above problems and the sensitivity is clearly at least 15 db better, believe it or not.
No wonder I have heard that Sony have withdrawn from the short wave sector.

 

Comments

[Bob C]

Thank you Steven, for your comments. A few years ago, I fell for the hype and purchased an ICF SW7600GR and was terribly disappointed. The AM side is okay, the SW portion is okay, the LW is okay, the FM is dismal. It's junk - not very sensitive with horrid selectivity. Here in North America, FM can be as interesting to dx as the other bands, so that was a disappointment.

Yet I continue to read plaudits for the SW7600GR and I continue to see it cited as some sort of a benchmark. It is not. Yes, I kept mine as a keepsake. But I rarely use it. Frankly, my E5/G5, G3, PL-600, DE1103 and others outperform it. Sony could (and should) have done better with this one. Glad someone else has pointed out that the Emperor Has No Clothes!

[Henk]

I'm sorry, but these comments about the 7600GR are not serious. I won't comment on the PL-660, because I don not own one. So maybe the Tecsun IS better. But that is not my point.
The fact is, the Sony is REALLY good on SSB. May I quote PWBR 2002 (p. 104)?: "Single-sideband performance arguably the best of portable; analog clarifier, combined with LSB/USB switch, allow single-sideband signals [...] to be tuned with uncommon precision, and thus with superior carrier phasing and the resulting natural-sounding radio". On average the Sony gets a rating of 4.4 out of 5 (70 reviews) on eHam (and a lot of positive comments on its SSB-performance).
The comment about the spray paint is plainly untrue. Build quality is excellent.
Again, I am not claiming the GR is superior. But it is NO junk.
But I fear I'm feeding the troll.

Henk (Belgium)

[Bob C]

Sorry Hank, but I am as serious as a heart attack. I have numerous receivers and would rate the Sony in the lower echelon of that group. Yes, it's SSB is good - but I have other radios that do just as well. The digital tuning is also a drag - though that statement is more subjective. As an overall package, I find the Sony to be overpriced and overrated. And, I hate saying that because I've always considered Sony products to be of high quality.

I'll grant you this: the body of the radio is well-constructed and it's not 'spray paint' by any means. But my whip loosened up within a month and can't be tightened anymore. Thank you for quoting the very reviews that I was eluding to, which help to perpetuate the charade.

[Henk]

Dear Bob,

/start sarcasm
I guess I'd better confess: I AM a full member of the Big 7600GR Conspiracy. We have always been SO wrong. Sinad Sensitivity (measured selectively, of course) IS the only answer. I have burned my 7600GR (AND my beloved 7600G for good measure)!
/end sarcasm

Henk

[Bob C.]

OK Henk, you stick with your radio that's good at one thing (SSB) while I enjoy radios that manage to be competent on ALL bands. Personally, I think that a $150 radio should have better FM reception than your average clock radio - but that's just me.

[ke7cyt]

I've got a Sony ICF-7600G (not "GR") so it lacks the extra memories and variable attenuator of the GR but is otherwise very similar.

The sync detect really doesn't improve weak AM reception much; it's more of a "gee whiz the LED lit up so the reception MUST be better". Sony would've done better to forgo the sync detect and instead allow saving of mode (AM or USB/LSB) in the memory rather than requiring the user to switch-select mode.

The frequency slew buttons are a pain to use for band scanning. I suppose the radio was intended for users to set a few favorite frequencies and call it good. A tuning knob would've been much nicer.

The insightful - and sadly departed - Harry Helms wrote a great comparison piece on the ICF-7600GR and Eton/Grundig E5/G5. It really captures the essential differences between the two; and as the user of both rigs I can attest to it's accuracy. Here's a link to the piece:

http://harryhelmsblog.blogspot.com/2008/09/eton-e5-versus-sony-icf-7600gr.html

[Steven Walker]

Read carefully.
As I have already covered above, there is a design problem it is caused by the mixer being to directly coupled to the oscillator.
There was an article in Q.S.T. ( a mag for licensed radio operators, hams) on what causes this problem and how to fix it.
Check this link
http://stephan.win31.de/sony76-5.htm#7600d_dualgatemod
I am in good company with my observation on this SSB problem.

[John]

I have a 7600GR and on it, yes, with synch det. turned on, if the signal fades below a threshold, the radio will screech. And, Sony should have put a tuning knob on this radio and allowed a selection to leave the digital display light on. I also have a Sony SW1000t and it's synch detector is far better. I used to have the 2010 and it was the best in my opinion--that radio could hear SW stations on its whip that my Icom R71 with a dipole/long wire could not. These days, I don't have a favorite. I don't have the Tec 660 so I cannot comment on its value and performance. I think Sony kept the 7600GR on market to be able to offer a radio, and it's fine, but not excellent like the 2010 was. Sync Detection was only done right on the 2010 in my opinion---the designer of that radio really cared. I'd say the same for the designer of the Degen 1103---that radio has good design also.

[Rob]

I'm with Henk. The Sony ICF-SW7600G/GR is a great little portable and the selectable sideband synchronous detector is a fantastic feature (not as good as the Sony 2010 one though). This *is* the best compact portable for SSB reception *and* for resolving difficult to hear SW stations (due to the sync. detector); you must have had a (rare) lemon or not have taken the time to learn how to use it's many features properly. Build quality on the Sony is streets ahead of *any* of the Chinese radios (which includes the germanic sounding Grundig line), which are mostly all made in the same few factories anyway. Cheap, loose, rattly switches, scratchy pots, manual warbley/rumbley BFOs, rotary encoders that quit working and start skipping frequencies after a while, *very* variable performance from unit to unit due to poor QC, etc.

[Mark3785]

I've been reading the comments (and following the links) and I'm looking to getting my 660 tomorrow (er, later today) and doing a side by side comparison with my 7600gr. I'm very fond of the Sony and just earlier today tuning around was very impressed with the sync. It isn't perfect and I do a lot of ECSS with the radio but aside from the somewhat muddy audio, I've always thought highly of it and the older 7600g. (It doesn't compare to my old Drake R8, but not much does.) I'll spend a few weeks with both and post my impressions here.

Mark

[Mark3785]

Just a quick update, I've been running the 7600gr and the PLL-660 side by side for a few days (and nights) and everything I hear on one, I hear on the other. Intelligibility-wise, no appreciable difference. I have yet to do much with the memories on the 660, except to notice that while I was able to enter AM freqs in page 0, entering SSB freqs pops me into page 1 (Being able to save the SSB state in a memory is a definite plus). I need to experiment with this a bit, and I'd love to hear from users more familiar with this aspect of the radio.

So far, receiver-wise, I can't say one is better than the other. They're both great. Ergonomically… to soon to tell. I've been using the 7600gr since it first came out and the 7600g for many years before that, so I'm just really used to the way it works.

One thing, the detent on the 660's fine tuning was a very bad idea.

Mark

[Mark3785]

After a lot of listening to various SWBC stations, I've come to the conclusion that the Sony has a better synchronous detector, though not by any great amount. Both receivers will sync and and hold sync equally well (it really is amazing how equally both behave in this department). The Tecsun's sync seems to introduce some distortion into the audio when locked, as opposed to the 7600GR's sync which reduces distortion. An unlocked sync on either receiver just adds noise.

While on the subject of the synchronous detectors, both radios howl when tuning away from a locked signal, with the Tecsun howling like a cat in heat! Seriously, if the author of the above article thinks the 7600GR is worse in this department, then he must have a defective radio. When sync is not locked or lost, both receivers make noise and I find it far more productive to tune around in an ssb mode.

Now, mentioning that the Tecsun's sync adds some distortion isn't saying that SWLing with the 660 is unpleasant, far from it. The 660 has very good audio for a unit its size. It's wide filter is very wide and is only useful for powerful broadcasts without interfering signals on either side. I did all my testing with the 660's narrow filter. The Tecsun has the better audio section and that helps the intelligibility of badly buried signals. And to state the obvious, a good set of headphones does wonders for both receivers.

Ergonomically the Tecsun is better than the Sony. However there are a few caveats. First and foremost, my number one complaint is the detent in the fine tuning control. I like to do ECSS and that little detent makes it more difficult than it needs to be and also interferes with tuning ssb. It was a very bad design decision. The tuning knob is very handy but it could be wider. The attenuator switch is handy, but I prefer a variable control like the one present on the Sony. This is a very minor quibble. On the 7600GR it's easy to "trick" the sync into locking by switching to ssb and then turning on the sync. I was delighted to find that I could also do this on the 660! When it comes to the display the 660 has it all over the 7600GR. No comparison. Lots of info and a wonderful backlight and it displays the clock at all times! I don't care for the long rectangular numerical keys; the round buttons on the Sony are easier to hit, though I've been using this configuration since '94 with the SW7600G, and old habits are hard to break. I love that the ssb and sync controls are on the front and that the status of these controls are clearly shown on that wonderful display. It's nice that the 660 has two bandwidths, unfortunately the wide setting is nigh useless except for powerful signals in the clear, and I mean very powerful and very clear. The narrow filter is very good and comparable to the Sony's excellent single filter. It would have been very interesting if the 660 had multiple DSP based filters like the lesser 380/39x series.

I have yet to do more work with the memories, LW,MW,FM and AIR and will report on those soon (although I'll probably wind up ignoring the air band as I don't even concern myself with it on my scanners).

Incidentally, I'm running both receivers on Energizer L91 Lithium batteries. Speaking of batteries, the Tecsun came with 1000 mAh NiMH cells! What is this, the '90s? I've seen AAA NiMH that are spec'd at 900 mAh!

Mark

[Mark3785]

I promised some word on performance on bands other than SW. On MW the Sony wins by a hair, and that just may be due to the Tecsun's auto squelch. (I'm going to have to disable that). When it came to stations intelligible enough to make an ID, the station could be heard equally well on both receivers. Neither receiver comes close to my Grundig Satellit 750 as an MWDX box.

On FM the Tecsun is sadly a bit of a disappointment. Everywhere else it's been neck and neck with the Sony, but not on FM. Distant stations that come in with full quieting on the Sony are a staticky mess on the Tecsun. Even the addition of an external antenna only helps a little. Local stations are fine in mono, but an FMDX machine, this is not.

Air band and LW… I tuned quickly through the Air band and heard one intermittent station. Not enough to keep me interested. LW is pretty vacant here. The occasional strange noise but I haven't heard a beacon in years, though I haven't looked for anything down there in a long time and I guess looking down there during the aftermath of Sandy with the power outages in my area didn't help much, though it was a boon for MW, SW and FM.

All in all I think it all comes down to tuning aids, ergonomics, build quality and reliability.

The Sony has nice, clearly labeled buttons, hidden slide switches and pots, a dim display containing only the frequency or clock and synchronous detector state along with rudimentary memory and alarm information. The backlight is dim and only stays on for about 10 seconds. There is no meaningful signal strength indicator, the audio is optimized for voice and is distinctly LoFi.

The Tecsun has long rectangular buttons sitting in horizontal channels. Attractive, but it makes direct frequency entry unnecessarily difficult. The display is gorgeous! Bright and filled with all sorts of useful information. Unfortunately there is no way to keep the display from turning off, but it can be extended to 30 seconds and comes on when certain controls are used. One great feature is that on certain memory pages, mode is stored along with frequency. The audio is quite nice, but unlike the Sony, begins to distort when the synchronous detector is engaged. The Tecsun also has two bandwidth filters as compared to the Sony's one. The narrow filter compares favorably to the Sony's single filter, doing an excellent job mitigating adjacent channel interference. The wide filter, on the other hand, is virtually useless. It is so wide that a strong station can be mistuned by 5 kHz with virtually no degradation of signal! I'm guessing that the wide bandwidth is between 12 and 15 kHz. You could fly a 747 through that.

Even lacking a tuning knob, the Sony scans the bands as well as the Tecsun does. I doubted that this would happen, but as it turns out, Sony managed to do an excellent job designing this radio back in '94 when they came out with the "G" version. Even the AM/SYNC/SSB and LSB/USB sliders and fine tuning control are simple to access when holding the radio in the position used to tune the receiver with the right thumb. the forefinger sits naturally by all these controls, and with a bit of practice they become second nature to manipulate.

So which radio is better? Aside from the Tecsun's relatively poor performance on FM and its tendency to introduce distortion when using the synchronous detector, I'd say both are pretty evenly matched.
I love my trusty, battle worn Sony ICF-SW7600GR, but I'm so pleasantly surprised by the Tecsun PL-660, I can't declare a clear winner.

The Sony feels sturdier, but it's heavier so that may have something to do with it. Give me 5 - 10 years and I may have a definitive answer. As it stands, I really love both receivers.

Mark

Note, the design problem referred to (way) above, and the link provided refer to the first generation of digital 7600s the SW7600D / SW2002, introduced in 1983, and concludes with the statement: "Note that Sony fixed this problem in later (approx. 1985 onwards) samples, so these will not require this mod." The SW7600GR was released in 2001, 16 years after the reported fix.

[Gary]

Mark - I'm surprised the Tecsun 660 is so poor on FM and inferior to the Sony 7600GR, as my Sony 7600GR is worse than most of my other radios on FM.

Also, what is the point of a sync detector that adds distortion? One of the primary purposes of a sync detector is to reduce distortion.

[Mark3785]

Greg, I'm not much of an FM listener so I just compared the two receivers. I do recall though, the 7600gr doing a pretty decent job pulling in distant stations when I lived in Oregon.

The distortion I hear from the Tecsun is neither particularly severe nor immediately noticeable. I only noticed it the first time after listening to Radio Australia for an extended period of time and becoming fatigued and vaguely irritated. It was an interesting show so I switched over to the Sony and listened for a while longer without any problems.

Subsequently it became easier to detect the distortion. It really isn't all that severe and it still works well enough to eliminate adjacent channel interference and help with fading. Though the longer I listen to a particular station the more apparent it becomes.