Many thanks to SWLing Post contributor, Gabry Rizzi (IV3MIR), who writes:
Hi, I’m an Italian radio amateur IV3MIR and I have a YouTube channel entirely dedicated to the radio “GabryMir Radio”. I’m sending you the link of one of my latest videos. If you like it I would be happy to see it on your blog.
I hope the automatic youtube translator does a good job.
Cordially 73 and Happy New Year!
Gabry Rizzi IV3MIR
The Tecsun PL-660 (left) next to the XHDATA D-808 (right)
Many thanks to SWLing Post contributor, Andy, who writes:
I wonder if any of your readers has noticed anything with later model PL-660s.
My old PL-660 met with an accident recently (purchased about 2015?).
I bought a new one and was disappointed by what appears to be
a difference with the narrow and wide filter.
My old version seemed to work well, with 3kHz and about 6kHz
widths as one would expect.
The new one is a disaster, you seem to get 3kHz and 18kHz widths roughly
resulting in poor performance, especially on local AM stations.
It’s like the same station appears twice.
Also the filter is not symmetrical.
It’s all on the HF side of the signal and it’s awful.
The older model centred the correct bandwidths properly.
I’ve tried to do a bit of research, not much really but the little info that I have found appears to show that others have the same problem.
It makes the use of the wide filter in any mode useless.
I’m gonna send mine back.
73 de Andy G0FTD
Thanks for sharing this, Andy. I haven’t purchased a PL-660 in ages–in fact, I gave mine to a friend interested in shortwave a few years ago. I still use my PL-680 regularly. I suppose it’s possible you might have received a lemon; this isn’t uncommon as quality control varies with production batches.
SWLing Post readers: If you have noticed these symptoms–especially an abnormally wide filter width–with your late model PL-660, please comment.
Many thanks to SWLing Post contributor, Andy (G0FTD), who writes:
Not sure if you’ve come across this, but earlier when I was cleaning my Tecsun PL660 and took the main tuning knob off the spindle, I discovered what looked like 4 holes of a hidden connector behind it !
I just did a quick search around and I came across a piccy of the PCB on a blog page here and yes there appears to be what looks like a small USB connector of some sort poking out the PCB where the VFO knob is. [Andy clarifies that he was trying to point out the area to look, but the pic appears to be from the opposite side, so you can’t see it.]
I can’t say that I’ve ever seen reference to it.
Maybe you or your readers might know ?
73 de Andy G0FTD
Thanks for sharing this, Andy. I am curious if that might be the port they use for firmware updates? Perhaps someone here can verify? I gave my PL-660 to a friend and no longer have it here for reference. Please comment if you have some info about this port.
This is a question that has circled around on the fringes of my consciousness for years now, but one that I’ve never quite found time to test. And it is a simple question: When using a random wire antenna with a portable shortwave receiver, is it better to string the wire vertically or horizontally, or does it even matter? Mostly this is a question when out camping, because arranging a 19′ wire vertically is usually a good bit more involved than just stringing it out along some nearby bushes.
Before going any farther, I want to point out that this is an exercise in ordinary backyard shortwave listening with relatively inexpensive equipment. There are many, many better-engineered and more costly solutions to the technical challenge of shortwave scanning, and this does not address any of those sophisticated approaches. This is for the person who opens up the box and wonders about the best way to hang the included long-wire auxiliary antenna.
Equipment: Tecsun PL-660 SW/AM/FM/Air Band receiver, with its included 19′ random-wire antenna. Internal battery power used.
Conditions & Time: Clear local weather. hamqsl.com’s nowcast of band conditions were fair from 3.5-14.35 MHz, and poor for higher frequencies, with SFI = 72, SN = 26, A = 5, K = 1. Time was 21:00-21:30 UTC, or 4-4:30 pm local CDT.
Procedure: Out in the backyard (typical residential neighborhood, well-spaced ~150′ between houses, above-ground power lines 125′ away), suspend random wire from ground to its full length. This was achieved using a length of paracord over a tree limb, with the tree trunk ~30′ from the radio’s location. With the PL-660’s antenna gain control set to “Normal” (i.e., the mid-setting of Local-Normal-DX) and the bandwidth set to narrow, use the receiver’s automatic scan function to see how many stations were received. Make notes of the number of transmissions detected, reception characteristics and quality, and any perceived noise levels. Re-orient the antenna to a low horizontal position, over two sawhorses approximately 3′ high (see picture), and repeat.
Sawhorses spaced ~17′ apart. Radio and notepad can be seen on ground in front of the near sawhorse.
Results: For the vertical antenna orientation, 32 stations were detected between 5959 – 15730 kHz. Nearly all were intelligible, with those at the lower end more steady and those a the higher end much more variable in strength. For the horizontal antenna orientation, 21 stations were detected between 9265 – 1570 kHz. Similar overall signal quality was heard for the received stations in either antenna orientation. More noise was noticeable at the lower frequencies between the stations for the vertical antenna orientation. However, this was significantly below the received signal levels, and not an issue in the overall listening quality.
Conclusions & Discussion:Suspending the wire antenna vertically worked better, especially at the lower frequencies. Getting a wire up 21’+ vertically is usually not as convenient as stringing it horizontally, but it may be worth the extra effort, depending on the location, campsite, nearby trees, etc. The overall conditions were typical for fall camping weather, with fair-to poor radio propagation conditions, so this result should be broadly applicable for how SW portables are often used. This result may change with propagation and radio noise conditions, both for atmospheric and local noise sources. Testing will continue as propagation conditions improve with solar cycle 25 getting underway.
Addendum, 10/12/20: While writing this up yesterday evening, it occurred to me that I hadn’t tested the PL-660’s built-in whip antenna. This comparison is important, because sometimes the wire antenna is too cumbersome to deploy. So, how does the whip antenna compare?
Conditions & Time: Overall, very similar to yesterday. hamqsl.com reports fair conditions from 3.5–14.35 MHz, and poor for higher frequencies. SFI = 72, SN = 26, A = 3, K = 1. Same time of day as yesterday’s testing.
Procedure: Repeat of yesterday, with the whip antenna added to the test. The whip was oriented vertically.
Results: For the vertical 19′ wire, 31 stations were found by the auto-scan function between 2380 – 15770 kHZ. Electrical noise was low but audible in the 3 MHz region, fading to none at higher frequencies, and not a significant source of interference with any stations. For the horizontal wire, 15 stations were found between 9265 – 13630 kHz. Electrical noise was barely audible. With the whip in use only 1 station was found. Switching the antenna gain to its DX (most sensitive) setting, 6 stations were found.
Revised Conclusions: Adding to yesterday’s conclusions, the whip antenna functioned but was vastly inferior to the wire antenna in either configuration, even with the gain set to DX. Today’s results with the wire antenna were, unsurprisingly, very similar to yesterday’s, given that the ionospheric and weather conditions were nearly identical. Noise was not a factor in receiving for any of these antennas or configurations, but did noticeably increase for the vertical wire antenna.
Thank you for sharing this, Rob! It’s experiments like this that help us determine, especially, what antenna setups work at our own particular locations since RFI characteristics can vary so much. I’m guessing had your horizontal wire been elevated to even 20′ off the ground it might have produced better results, but sometimes this can be difficult to achieve. I like how you used the auto search function to determine the number of stations you could receive with each setup and it was a great addition to include the built-in telescoping whip.
Many thanks to SWLing Post contributor, Marty Kraft, who asked that I share the following question with our community:
I’m still working on a receive-only passive hula loop magnetic antenna for my Tecsun PL-660.
After viewing thousands of YouTube videos (LOL), I built the PVC-pipe structure [you can see in the photo below].
But I need some tech help to finish…
The antenna is 90 inches tall; large loop diameter is 40 inches; and small loop diameter is 17 inches. The wiring is 14 gauge braided.
I plan to put the antenna outside on the porch. Then I’ll run coax from the small loop to the receiver inside and use a 365 pF air variable capacitor to tune the large loop.
My first question is, what’s the best coax to use for the 10-ft run from the small loop to the radio inside? Second, will that 365 pF cap tune the entire 3-30 MHz range?
It’s hot here in Louisiana, so I’d really like to tune the capacitor from inside my apartment, also using coax to connect the cap to the large loop. Will that work? Or does the cap have to connect directly to the large loop?
Any other tips or suggestions? Thanks for the help!
SWLing Post contributor, Klaus Boecker, sports a homebrew magnetic loop antenna on his balcony in Germany.
Many thanks to SWLing Post contributor, Marty, who writes:
I have a question about loop antennas; specifically which type is “better,” passive magnetic loops or active electric loops?
I know, “It depends.”–?
I live in a ground-floor apartment, with a small porch, lots of RFI and restrictions against visible antennas. Also there are no trees within 75 ft of my porch, which faces on a parking lot. My radio is a Tecsun PL-660, which works okay inside with my 10-ft bare wire antenna hidden on the porch.
With a loop antenna, I’d like to mount the antenna on the porch at night and have a remote tuner/control inside because it’s very hot n humid here in Louisiana even after dark.
No doubt there are a number of magnetic loop antennas that could serve you well in your situation, Marty.
To answer your first question, though, you should search for a wideband amplified loop antenna since you’re only concerned with receiving.
Passive loops are great antennas on the shortwave bands–and easy to build–but they best serve ham radio operators who wish to transmit. Passive loops typically have a very narrow bandwidth that requires the operator to constantly tune the antenna when they tune the radio a few kHz. Most amplified wideband loops need no separate tuning mechanism.
Last year, I posted an article about choosing the right loop antenna for situations like yours where one has limited installation options.
I do hesitate to encourage you to invest in an amplified loop antenna when your only receiver is a Tecsun PL-660. Some portables don’t handle amplified antennas well–they can easily overload and I imagine you can even damage the front end of the receiver.
I’m well aware, however, that there are a number of readers here who do couple their portable radio to an amplified loop. I have connected a number of portables to large wire antennas and found they could easily handle the extra gain, so I imagine an amplified loop would perform as well; the Sony ICF-SW7600GR, Tecsun S-8800, and Sangean ATS-909X come to mind.
But the PL-660 is a hot little receiver even with the built-in telescopic antenna–I’m not sure if amplification would help or hinder.
Please share your experience
This is where I hope the amazing SWLing Post community can pitch in and help us out here!
Does anyone here regularly connect their PL-660 to an amplified loop antenna? If so, what model of antenna are you using? Are there other portables out there that you regularly connect to amplified loops? Please share your notes, thoughts and experience in the comments section.
I spotted a £3 semi-rigid pencil case that looked like it might fit my new PL-680, and when I got it home, found that it was a great fit.
I cut out the internal flap that holds the pens with scissors, and the result speaks for itself.
Wow! That’s a brilliant case for for the PL-680, Mark! That exterior color will also ensure you never lose it in the wild. Thanks for sharing this tip. What a fabulous bargain at £3! Post readers in the UK, take note!
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