Nick B's SWL Blog

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.

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.

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!

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 ...

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.

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...

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 ...

See the full article at https://www.bbc.co.uk/mediacentre/latestnews/2019/world-service-steps-up-broadcasts-in-kashmir

When the bands are open, they're open!

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

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...

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 . 

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.

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?

Check out those TWIN ferrite rods! Not bad performance for a radio that is almost 60 years old!

I sent one of the RAD-108s over to Two Hands and a Radio for a YouTube review. Update - looks like 2H has taken his YouTube channel down so this is no longer available. Here is mine, a poor substitute.   It didn't do too well on the American AM broadcast band, probably due to tuning in 9kHz rather than 10kHz steps!

Tesco in the UK are selling a world-band portable for £8 incuding VAT (that's $12 USD at current exchange rate). I don't normally shop there but I might have to make a special trip to pick up one of these R-108 radios for evaluation. That'll be £12 then after adding the cost of the tram ride. It covers 12 bands: Long Wave Medium Wave FM Broadcast 88-108 SW1 60 meter SW2 49 meter SW3 41 meter SW4 31 meter SW5 25 meter SW6 22 meter SW7 19 meter SW8 16 meter SW9 13 meter Link to RAD-108 at Tesco.com

This radio is a one-chip wonder! The main active device appears to be a Sony CXA1691BM IC which was originally designed for radio-cassette recorders. Here it is with a strong signal from Pyongyang on 12015kHz. This particular one is a Kaito-branded model which I purchased from Universal Radio of Ohio whilst in the US And here is the schematic:

Although I've been itching to get my hands on the Tecsun R-9700DX, I wasn't really aware of it's smaller sibling, the R-9710 until I saw this review on the Two Hands and a Radio YouTube channel. Two Hands made the observation that the shortwave bands tune in the opposite direction to the AM and FM bands, which made me go and do a quick check other Tecsun analog radios. I found the R-9700DX also has this inverted tuning feature so some Googling later and I've located a teardown of the R-9710 plus other sets. The original article is in Chinese but you can view it through the magic of Google Translate . R-9710 teardown from http://www.leowood.net/sbdp209.htm Note it has eight crystals around the bandswitch for that fixed-crequency first local oscillator. Add the schematic found at http://www.fmdiy.com/ReadNews.asp?NewsID=305 More dead links to maintain unfortunately.

I've seen a lot of favourable comments on this analogue SW radio via various YouTube channels, along with it's sibling the R-9710. Sold in some (USA?) markets as the Grundig Yacht Boy 250. Exact specifications and schematics have evaded me so far, however I did find a teardown and comparison at RadioIntel.com from which I've borrowed this photo: Photo from http://www.radiointel.com/review-review-tecsunr9700dx.htm It appears to use dual-conversion on shortwave with a fixed crystal local oscillator (see the 10 crystals above the bandswitch). One feature is that the tuning on the short wave bands tune the opposite direction to the AM and FM bands. Here's my (incorrect) guess of how it works. AM band IF is 450kHz (from the orange block filter)  AM local oscillator tunes 975kHz - 2160kHz. The image of the AM band (1425kHz - 2610kHz) is used as a tuneable first IF for the shortwave bands. Each band is 600kHz wide so it probably uses 2000kHz - 2600kHz. The SW ba...