new Tecsun PL-660, defective?

[nmerealfnky]

hi. i recently bought a pl660, but it seems to be defective.
because when the BFO knob for SSB is turned clockwise (+ side) about 3/4 in the radio goes completely silent. and the LW is off by about 5 kHz.
is this normal for the tecsuns?
another thing: i have read (in reviews) that the 2 screws inside the battery compartment
come sealed with stickers (for the warranty), but mine does not!
does somebody own one and did it come sealed like that?
could it have been manipulated somehow?

should i return it and get a refund?
i hope this is the right place to ask.
any help is appreciated! thanks

 

[ka3jjz]

It certainly sounds like its defective - I would do some homework on the PL660 Yahoo group and see whether your supplier is one that is reliable - to determine if and how returns can be processed. I'd also write the supplier to see what they say

Mike

 

[ka3jjz]

Here's the URL for the PL-660 Yahoo group

https://groups.yahoo.com/neo/groups/Tecsun_PL-660/info

Mike

 

[nanZor]

Mine was the same way, although I didn't test it on longwave.

The tip here is that you shouldn't actually have to go very far past center with the bfo in either direction. 3/4 is too far. Ideally the bfo should only need minor tweaking. Major changes are best done via the frequency tuning, and perhaps tweaking the bfo just a little here and there.

I suspect you may be trying to use the bfo too far before changing the frequency proper.

With my 660, it was also 1-2 khz off when listening to airband - not to mention no squelch made that no fun.

 

[WQPW689]

I just opened mine and there are no seals over the screws. There was never any indication that the unit was nothing but a new unused one.

My warranty marker is (I believe) a circular hologram sticker on the bottom just to the left of the reset button.

I tend to agree with hertzian on the BFO use. Doesn't take too much to get mine to tune LSB so I can understand it. Haven't heard much on USB, so I couldn't say there. I also seem to be off a couple of kHz when tuning optimally, so not sure what it is other than it sounds great.

 

[N6KB]

Infant mortality

First PL-660 I bought worked for a couple of days and then the display went blank. Returned for a full refund.

Second one I bought, from a different vendor at a higher price, about $125, worked for almost two months, Then I found it on one morning. Had turned itself on. Maybe the timer turned it on, though I had never set it to do so. It was stuck on FM and could not be changed to any other band, could not be turned off. Only way to turn off was remove batteries. Now it can only be turned on by simultaneously pushing power button and reset button. When it comes on it is on FM and will not go to any other band, cannot be turned off without either a reset or battery removal. Have attempted contact with vendor. No reply yet.

Wish I could get one that lasts, because when it is working I really like it.

 

[KT4HX]

I've had a PL-660 for two to three years and it has performed flawlessly. Granted its not used daily, but it has gone on several trips with me and I never once had any issues. Perhaps I should count myself fortunate. I agree that its a pretty good little radio for the price.

As for the OP, yeah, I would return it for either a refund or replacement. Good luck.

 

[BDM123]

Mine does exactly this with the BFO. I was told this is normal from the Tecsun Yahoo group. Cannot comment on the freq being off right now. But I was will say I've noticed it isn't exact. No biggie for me, I use it for listening on my trips it seems to perform fine in that capacity.

hi. i recently bought a pl660, but it seems to be defective.
because when the BFO knob for SSB is turned clockwise (+ side) about 3/4 in the radio goes completely silent. and the LW is off by about 5 kHz.
is this normal for the tecsuns?
another thing: i have read (in reviews) that the 2 screws inside the battery compartment
come sealed with stickers (for the warranty), but mine does not!
does somebody own one and did it come sealed like that?
could it have been manipulated somehow?

should i return it and get a refund?
i hope this is the right place to ask.
any help is appreciated! thanks

 

[N6KB]

I'm now starting on PL-660 number three. I really hope this one does not die, or at least if it does it happens soon enough to get a refund under warranty. I really like this radio (when it is working) and I really want one that does not fail. I'll update after a month or so.

 

[N6KB]

Local Oscillator no good above 28.0 MHz

I'm now on Tecsun PL-660 number three. It seemed to work fine, so I was using it to listen to the local oscillator on a receiver I am trying to restore, a Hammarlund SP-600. The SP-600 had some stability issues and I had replaced a bunch of silver mica capacitors in the VFO circuits to try to get it settled down. The new silver mica caps in the SP-600 seemed to do the trick, and I was using the PL-660 to listen to the SP-600 LO/VFO to get an indication of stability. I know the PL-660 is not a laboratory instrument, but you use what you have available.

When I got up to frequencies above 29 MHz it started getting very wobbly and by 29.5 MHz it was more of a wideband phase noise hash than a clean tone. Naturally since the SP-600 is about 50 years old and the PL-660 is brand new I assumed it was the SP-600 that had problems with it's LO and not the PL-660. The SP-600 is just a plain LC resonant circuit oscillator with no PLL system though, and I could not see how it could have that kind of fault. So I started to suspect the problem was really with the PL-660.

I brought the PL-660 into the lab at work and used a nearly new Agilent signal generator as a source to listen to on the PL-660. It turns out that above 28 MHz the PL-660 gets wobbly, and above 29 MHz it is almost completely useless. Sure a little portable like this can be expected to be a bit wobbly, but not to the point that when listening to a solid CW carrier all you hear is white noise hash. I'm convinced the PL-660 LO PLL is just not really locking above 29 MHz (or 29.455 assuming high side LO and 455 kHz IF)

I have not decided whether to just live with it or exchange it and go for PL-660 #4. With no BFO function on the AIR band, I cannot tell if there is a problem up there. FM broadcast and air traffic control AM signals sound alright, so I guess it's working okay up there. Throughout the rest of the shortwave, medium wave and long wave bands where the BFO does function it is stable enough to tune in a CW or SSB signal and listen. Just up above 28.5 MHz it falls apart.

 

[SCPD]

Get the PL-880... very nice radio and no friggin' BFO knob. Avoid anything with a BFO!

 

[N6KB]

BFO

A BFO is sort of essential for SSB and CW reception. All superhet receivers have a local oscillator, even if no BFO. The problem in my PL-660 is in the LO, not the BFO. The LO PLL is not generating a clean LO signal when tuned above about 28.5 MHz. I does not matter whether the BFO is turned on or not.

 

[majoco]

N6KB said:

A BFO is sort of essential for SSB and CW reception.

Real radios have two - a variable BFO for CW, a CIO (carrier re-insertion oscillator) for SSB.