Відео

Patrick, the SR-286 can receive AM-DX on either the stock whip antenna or the internal loopstick, unlike almost every other portable. AM-DX reception on the whip antenna is typically more sensitive than on the internal loopstick, as long as no RFI noise is picked up by the whip. The sensitive whip antenna reception on AM is probably related to the DSP chip, which was designed for car radios using whip antennas.

Yes, turning off the display does turn off the noise as well, in confirmation that this is digital display noise. But of course, it is inconvenient to chase DX without a display.

@@DXerGary Yeah, true, lol. What bit of hash I hear does not seem to get better if I turn off the display. Must be from the CPU itself or something.

@BH3RQW, thanks for your comment!

I found something similar on every radio, turned out my phone's NFC works somewhere around 11 mhz and that was sending out periodic signals to detect nearby devices which was caught on my radio.

@@anulearntech interesting, this however is specific to the qodosen. I'm going to try turning off the display.

@@DLH65 maybe it's detecting something others aren't. Do you get it everywhere? In High rfi area and other places?

All times and locations, MW band only.

Yup, turning the display off makes the popping go away!

Hi Steverolfeca, a longer ferrite (like the Amidon 12 inch long Type 61 rod) would provide a slight increase in sensitivity over the 7.5 inch rod, but generally not worth the $95 cost and decreased portability. It would also require a new coil design, if used with the SR-286. For the XHDATA D-808, CC Skywave and other Silicon Labs 473x DSP chip models (PL-380, PL-330 etc,), these 12 inch long ferrite rods also provide a slight sensitivity boost over the 7.5 inch rods, but at very high ($95) cost and decreased portability. It's much better to get a sensitivity boost from an inductively coupled FSL antenna, if more sensitivity is desired.

@@DXerGary thank you for your advice. I grew up around tube and solid-state audio equipment, but RF is a whole new world for me.

Yeah. And if you wanted to listen to PR1 in UK or somewhere farther than 1000-1500km from the transmission site, building that antenna would be great idea.

Hello DoctorWu03, Congratulations on your successful modification of the Tecsun PL-380! The project to hard wire a small FSL into the PL-380 (in place of the loopstick) works well, but it's a challenge to find the lightweight 100mm x 20mm x 3mm ferrite bars in some countries. I'm sorry that I don't have a file to make the orange antenna frame with a 3D printer-- I usually just cut these on a miter power saw. Best of DX to you! 73, Gary

Hi Jkratoville, the tricky thing about cabinet disassembly on the SR-286 is the rubber "feet" on the bottom of the cabinet. After you have removed the six screws, you must also pry half of each rubber foot off of the cabinet base before you can separate the front and back sections. Then, gently pry the two sections apart with a rocking motion. There is a snap connector on the side where the tuning and volume controls are located, and this is usually the final hangup before complete separation. Also, be careful of the wires from the battery connectors-- they break off very easily.

Thanks KA5DWI, that "table" is really just a piece of plywood tossed over an old PVC base for a 9 foot box loop 🙂My wife hates it, but it does hold up the radios and antennas! Good luck with your future SR-286-- Gary (N7EKX)

No, because when the buttons 1+3 are pressed to turn off the display, the noise disappears as well (to confirm that it is display noise). You may have been lucky enough to get a model without this quirk.

@@DXerGary let’s hope the new official version the DX 286 has no such issues. Much cheaper also !

@RSears, a design photo of the 2.8 inch Micro FSL is posted at dreamcrafts.box.com/s/whfqm8av3j6335uddei4b0c0sjuht8nz Although the performance of the Micro FSL is superb, each of the 28 Amidon 4" x 1/4" ferrite rods costs $US8, so it's kind of a special project (with a total cost of around US$300). Despite this, the performance is so special that the high cost is worth it if a DXer desires a lightweight FSL for air travel, or other portable situations. I've used it for air travel to Hawaii, where it really ran wild.

@@DXerGary Thanks. I'll cost it out. I really like the package and want to try one of your FSL designs. I got 560 KMON Great Falls, Montana 5kW at 1 pm MDT today. And from Lacombe AB that's 560 km / 348 mi. I was using a SR-286 and a 25' long wire (up a 7m vertically mounted goture and 8' counterpoise). That seemed big to me; how does it compare with your experience?

Hi! When display is disconnected, noise disappears. But this is not a good solution as the units would not radiate any hash or they had to be well screened, at least!

Yes Alexey, like Jorge (IberiaDX) says, the SR-286 display noise does go away when you press the 1 and 3 buttons simultaneously. But of course the lack of a display isn't very convenient for DXing, especially when you are trying to change frequencies and investigate multiple DX stations. Turning off the display (and the display noise) would be OK for an audio recording of one DX station, however.

Hello Johann, actually I first discovered this display hash noise on some SR-286 models when neither the camera nor a YT recording was involved. I agree with you that the hash noise in the video is pretty mild, but since these loopstick transplant modifications are designed to encourage very weak signal AM-DXing, anything that interferes with that goal should be investigated before the radio is modified. Overall, though, I do agree with you that the SR-286 is a very fun radio to use, and that the TEF-6686 chip provides a real technical breakthrough! 73, Gary

@baayers2, a good battery for the SR-286 would be these button-top 18650 batteries with high capacity www.amazon.com/CBJJ-Rechargeable-Battery-Flashlight-Doorbells/dp/B0CJ2MH36J/ref=sr_1_28?dib=eyJ2IjoiMSJ9.Q0kSSDF1Edn9aM0fQ2DVZZwCuYvm3Jf1GBmwmgVzt_rg7hxDi4mf_JG3fx2qNAQTgCvhpZZuT5VM-DvVG9AvhTzkw6bWy9Riz7zrw9PDx7SlUiy_zloVWszQVd5ylt_ZlQyXl7xPfaAunpohNtorpZTNOQC0jOcMunr0CECsMtt2pVGcF6p2ZrZCrBakOmgN69-jYYoiXS5CGXN8rCsNSTniwKR0PAq9u3h2AnoSGU6ALQterO_HJnMAP7VeryNvns25sDSlo5IpsAa1k5aPyo9TAPd8pbzubG7KdRC93p4.3g47t0JeLMuOCO7b9QFY_KpagSp-xsCRydUWok24o1o&dib_tag=se&keywords=18650%2Bbattery%2Bbutton%2Btop&qid=1709893498&sr=8-28&th=1

@tiqueky, Thanks for your comment! In developing this modification I simply duplicated the connections of the stock loopstick, which are shown in the photo at the following link (with the connections labeled in yellow lettering). Qodosen does not give out a schematic diagram of the SR-286 model, so that is the only way to connect an improved loopstick dreamcrafts.box.com/s/ajrv2do0x45jc0ep8spqxxguye0s8lu1

Dear Klausputh, thank you very much for your comment. Best of DX to you, my friend! 73, Gary

AM-DXing is like that, Ronald. It is pushing your luck to receive weak and unstable stations far away from your location.

@user-fo2ud9kq4k, congratulations on your purchase of this exciting radio! As for the upgrade loopstick modification, unfortunately nobody is currently offering to do it for a price, although I will provide technical details to anyone who is interested. Best of DX, Gary

Compared to the new Qodosen SR-286 model, I would agree with you.

Tarchonglitch9545, yes, it is true. I have personally disassembled the SR-286 and verified this. "F8605" is one of the designated markings of the TEF-6686 chip from NXP, as shown in the disassembly photo posted at dreamcrafts.box.com/s/xsrk0d2psfgbm2pafut28a1d3qlpaqf5

@n1kkri, yes, both 1520-KXXA and 1520-KMPG (the Spanish co-channel) are on north-south bearings from my location, the same way that the radios are set up for best reception. Here on the west coast most major stations are located along the coast.

The SOS button shaped like all other buttons is a pet peeve of mine. D-109wb same too. I use the radio in bed in the dark and don’t want to wake everyone in the house.

Can that feature be disabled? I'm about to buy between this and the D109WB ​@@AD2DU

Yes Alexey, you can watch the stock Qodosen SR-286's performance with a 5 inch FSL antenna in the following video (from 3:30 until the end of the video) ua-cam.com/video/ZCmP6Po7CWU/v-deo.html Also, I plan to make more videos showing the stock SR-286 with an FSL antenna. Good DX to you!

@gabrymir-radio, Thank you for your comment. Best of DX to you!

Thanks, Lee! Good DX to you.

@GlobalUnboxingTV, Thanks for watching! Best of DX to you.

@petegallaguer8978, I agree with all your comments. The TEF-6686 chip from NXP provides a whole new league of AM and FM-DXing performance compared to the Silicon Labs' Si473x series chips. Hopefully the radio manufacturers will upgrade their models with NXP chips as soon as possible!

I can see how it seems the TEF is a much newer chip, but the data sheet copyright is 2005, not much later than the SiLabs chips. It's not a new chip, it's just new to portable radios. WHY it took 20 years to be "discovered" I haven't heard a good answer to. NXP wouldn't sell it to anyone not a major mfg? I don't buy that, not for that long a time period. The power consumption does make it kind of an 18650 only sort of chip. 150mA or so just to power on. Also, I'm enjoying my new radio, but not finding it to be more than a tiny bit better than any of the competition. I think you have to be in a VERY low RFI area to hear a difference.

Digitalmediafan, actually the internal ferrite stick performs very well for the radio's tiny size-- it's just that the whip antenna performs better for MW reception. The SR-286's whip antenna will beat out all of the compact portables in MW reception.

@@DXerGary OK hmm a bit strange. If I get one I was hoping it would work with my wellbrook loop for MW tbh

The ferrite still provides better reception on most common reception locations, that is, inside your house or outside in urban areas, where you're still around sources of noise. Once you go to a low/very low noise location - this is my theory - the internal receiver noise is captured by the ferrite rod as it's only a few centimeters of the microprocessor, display drivers and switched regulators. This is when the telescopic antenna gives outstanding results. I've tested three receivers - SR286, PL-330 and Belka DX - and had excellent results at the beach during noon time with their telescopic antennas. When I switched the SR286 and PL330 to the ferrite rod antenna, SNR decreased by 6-10db. However, as soon as I got to the Airbnb apartment we rented, reception on the balcony was way better with ferrite antenna; the telescopic antenna was flooded with electric QRM from LED bulbs, LCD TV sets and switched power supplies.

I get more stations with even just the built-in whip, but a TON more RFI. I had no idea that the streets of my suburb were THAT full of electrical buzz. You don't hear it (or only faintly) on the loopstick. Even through the buzz, though, I can find more stations. I just would never want to try to actually listen to them with the buzz. The 10 and 50 foot wires out my back window work just fine, though. I'm not sure why they aren't full of noise.

Sorry Christopher, I'm not currently making or selling these. With the Ukraine war, the supply of Russian surplus ferrite rods from Ukraine has practically vanished on eBay.

Sorry Dadwire1483, I've never owned a Sangean ATS-803 or Realistic DX-440, so I can't really answer your question. This Qodosen SR-286 in stock form is the most sensitive AM-DXing Ultralight-sized radio I have ever tested, though (when the whip antenna is used).

..thanks for your reply..@@DXerGary