Skip to main content

Posts

Tecsun PL-330 Arrives

   New toy for this summer. Order placed with Anon-Co on 21st April with expedited shipping (which included the battery), delivered on  28th April. Arrived with a UK Royal Mail postage label and a return address in Manchester, maybe it was shipped from stock already in the UK? I paid $71.44, inclusive of shipping and tax, which worked out at 53.44 of my British Pounds. Undocumented functions Press and hold 3 with power on: CH-S displayed selects whip antenna, CH-A displayed selects internal ferrite bar antenna. Press and hold 7 with the power on: Sets maximum volume for selected band using volume knob. Press and hold 9 with power off: Alternates between ON and OFF. Unknown. Press and hold 9 with power on: Number adjustable between 1 and 30 using tuning knob. Unknown. Press and hold VF/VM with power off: Segment test followed by firmware version. Mine is 3305.  I'll update the article when I figure out what they all do. Performance Early days but initial performance o...

Tecsun PL-310ET - MW/LW Antenna Coupler

After carrying out the external antenna connection modification to the PL-310ET, I built an external antenna coupler for MW and LW.  The coupler uses (obsolete) Toko 10mm inductors which are tuned on the primary side by the varicap diode on the SI Labs IC. The secondary side provides a low-impedance coupling to an external antenna. MW uses a Toko RWR331 230-300μH primary, 1.75μH secondary. LW uses a Toko 98299 2.9-4.0mH primary, 46μH secondary. Some excellent results have been achieve, particularly on Long Wave.

Sangean Equivalents

As I've collected a few Sangean-built sets over the years, I've put together a list of badge-engineered equivalents. In the US sets were sold under the Radio Shack brand. Here in Britain they were sold under the Roberts Radio brand. In Germany, sold under the Siemens brand. You can download the list in PDF format and it will get updated as I discover any new re-badging.  For example:   ATS808 was sold as the Roberts R808 and R809 (CE marked)

10 inch MW LW Ferrite Antenna

Large ferrite antenna for the PL-310ET all packaged up and ready for action!

Loop antennas for DSP Portables.

Over at the RADIO_TIMETRAVELLER blog there are some excellent articles about connecting loop antennas to Tecsun or similar portables. This ought to be my next step after tinkering with the larger ferrites. I need to study the SI labs data sheets for these radios again to see if it is possible to add a loop to the shortwave antenna connection, for use on the Tropical Bands . The SW input doesn't have a varicap tuner so it would probably require an additional variable capacitor to tune manually.

Tecsun PL-606 External Ferrite Loopstick Mods

As the PL-606 has the same antenna jack as the PL-310ET I though I'd take a look and see how easy it would be to carry out the modification. Actually more straightforward on this set. Unfortunately, when I removed the rear cover, I found the internal ferrite bar in two pieces. I've repaired this using superglue which has worked for me on other ferrite rods. The end results on LW are as impressive as the 310. On MW, despite trying two different coils (500µH and 200µH), results at the lower end of the band showed an improvement but at the top end the performance appeared worser than the internal ferrite bar. Conclusion? Definately needs the mod for LW but quite adequate for MW.

9700kHz 0519UTC - RNZ Pacific (weak audio, noisy reception)

RNZ Pacific moved their 04:59 transmission from 11725kHz to 9700kHz on 18th May. Always difficult to copy from home, here is today's attempt on a quiet 31 meter band. The transmission disappeared abruptly at 0624.

13760kHz 15245kHz Voice of Korea - Another Diversity Reception Demo.

For some strange reason, VoK always lends itself to my diversity reception experiments, this time with the XHDATA D-808 and RADIWOW R-108, recorded on 29 th June 2019. Enjoy!

Roberts Sensitive Sangeans

A couple of Roberts branded Sangean sets that are both faulty, but still manage to bring in the DX. I already have the R816 (ATS-909) so my curiosity got the better of me to see how the lesser models from that era perform. Roberts R617 is the Sangean ATS-606, early version with a DISPLAY button. The later models have a FINE tune in this position instead which allows 1kHz tuning steps. This one runs OK for a while and then the PLL circuit will lock up. At present, proving elusive to find the cause. Roberts R809 is the Sangean ATS-808. This one came to me faulty as it's obviously suffered display damage. Also had a 1kHz tone present on all the LW/MW/SW signals. Applying an unmodulated test signal, the tone got louder as I increased the RF level! After testing some suspicious capacitors around the PLL circuitry and finding them to be OK, I found contamination in various places on the microprocessor/keypad board which I've cleaned up and it now works. Another parts donor ...

YouTube :: Radiwow R108m2

So while I've been carring out a trivial mod to improve the PL-310ET, YouTube user 66vds has done a great job of improving the Radiwow R-108 by removing the internal ferrite and modifying the external antenna connecotor to work on all ferequencies. Here are links to the details: Internal photo: https://cloud.mail.ru/public/5z6s/35cewkshm Schematic: https://cloud.mail.ru/public/4oRK/DQjW2h9pK It is believed the R-108 was based on the design of the CCrane Skywave and the Digitech AR-1733. The stock radio is an amazing performer.

Tecsun PL-310ET Ferrite Rod - Part II

So I decided to try the mod originally documented by Laurie Mann to utilise the spare connections on the antenna jack to bypass the internal antenna when an external one is plugged in. I suspect this is how the Tecsun PL-360 works which has the option of internal or plug-in external ferrite antennas. The PL-606 also has the external antenna jack so maybe it is mod-able too. Rather than remove the rod and swap wires, I drilled a hole and mounted a 1.3mm pcb pin to use as a solder point for the wire from the ferrite rod. Run the first wire: Then the second wire to the new PCB anchor point: Showing the new wiring in position: Don't forget to cover the base of the whip antenna with some insulation tape to prevent it shorting across the new connections. So now I can connect my new external ferrite monster rod, with a selector switch for MW and LW sections of the coil. I found that it was necessary to change the coil switch before the Tecsun MW/LW band change othe...

Tecsun PL-310ET Ferrite Loopstick Improvements

Compared to other DSP radios of similar size (PL-380, R-108...) I find my PL-310ET to be extremely deaf on MW (AM broadcast band). The longwave band is even worse. So let's take it apart and see what can be done. The poor-quality ferrite bar is shaped like a banana. I borrowed the ferrite antenna from a rotating loop desing I buit a few years ago. After removing the connections to the internal loopstick, I found it worked quite well on the LW coil section. So I ordered a larger 10-inch monster rod which seems to work quite well on MW. Manx Radio on 1368kHz is a good daytime test signal, at the lower end of the band I can hear Carolone 648kHz and Spectrum 558kHz. The radio design has been around a few years so I'm sure someone else will have tried this. There are certainly some mods documented for the PL-380. Sure enough, I found an article on the Ultralights group showing how the spare contacts on the antenna socket can be utilised to switch out ...

9700kHz 0459UTC RNZI Sign-on and News Bulletin

When the bands are open, they're open!

The Shortwave Radio Audio Archive

Can't believe I only just discovered this site. A collection of amazing recordings that dates back to the 1960s. Slowly working my way through the podcasts and wondering if I have anything on cassette tape that I could contribute... THE SHORTWAVE RADIO AUDIO ARCHIVE

Real-World Amateur Radio: WSPR - Choose your magnetometers with care.

Interesting article on  MW1CFN amateur radio blog on the availability of magnetometer data for radio propagation studies. I was looking for this type of data as signals from North Korea and Japan to my location in the UK take the high latitudes somewhere over Finland. Real-World Amateur Radio: WSPR - Choose your magnetometers with care. : I'm currently running a longer-term WSPR campaign, with a focus on the auroral zone. I'e been scratching my head in trying to rela...

Blast from the Past - Sony ICF-7600DS

This was my first Sony portable. It was pushed into second place behind the ICF-2001D but it provided excellent service as my alarm clock prior to selling it in 2003. I do own the final model in the 7600 line, the ICF-7600GR which has the synchronous detector feature. Lots of information on the 7600 series can be found over at Stephan's excellent website http://stephan.win31.de/sony7600.htm . 

Blast from the Past - Sony ICF-2001D

This is my Late Sony ICF-2001D. The station is BBC Radio Scotland 810kHz and the location is Embo, Sutherland in NE Scotland. At the time I bought this (late 1990s) the ICF-SW77 and ICF-SW55 were current models but I chose to buy one of these. It served me well for many years (even as my daily alarm clock!) until it suffered terminal battery corrosion after being left in extended storage. The culprits were actually Duracell branded D cells, not exactly a cheap brand. I considered buying a replacement but with the price these now fetch on the second-hand market and the abundance of modern portables, I am reluctant to spend the money and risk being disappointed. The moral of the story - make sure your remove ALL batteries before placing in storage or if you're not going to operate for an extended period.

15820kHz UNID 1138z

Not sure what this could be, sounds like some kind of pager tone, maybe it's breakthough from another frequency. Or maybe it's really here?