Category Archives: Antennas

Eric seeks advice: Building a directional mediumwave antenna for the RSP2 SDR

Many thanks to SWLing Post contributor, Eric McFadden (WD8RIF), who writes with the following question:

A request for assistance.

After comparing the reception of the RSP2 and 1/2 doublet to the reception of the County Comm GP-5 SSB and its little external ferrite-bar, I’ve decided I probably want to make some sort of directional antenna to use on AMBC with the RSP2. A wire loop, perhaps, or some sort of ferrite-bar thing, that connects to the RSP2’s Hi-Z input.

[Perhaps SWLing Post readers can suggest] options and then I can get the needed bits at the 2017 Hamvention.

Post readers: if you can offer Eric suggestions, or point him to antenna plans, please comment! I do believe he would rather build an antenna than simply buy one and he’s looking to permanently mount this antenna outdoors.

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Steven is pleased with the Tecsun PL-360 and Anon-Co


Many thanks to SWLing Post contributor, Steven Crawford, who shares the following:

I just wanted to take a moment and thank you for posting my inquiry on the Sony 7600GR. The post comments answered my question.

I also wanted to let you know your confidence in Ebay seller Anna and Anon-co continue to be well founded. Remembering your recommendation and wishing to pick up a Tecsun PL-360 as a spare to my CountyComm GP-5 SSB (Tecsun PL-365), I placed the order for it and a couple of other bits of Tecsun kit with Anon-co.

The order arrived in 6 working days to my Gulf coast Texas home, taking longer to travel from Chicago to my home than it took to move from Anon-co in Hong Kong to Chicago and clear customs.

I then had a question about the connecting cable included with the Tecsun badged, Tecsun / Kato / Grundig / Eaton, AN200 Loop Antenna. Posed through Ebay Anna promptly answered the question and added a photo of the cable to Anon-co’s Ebay listing for the AN200. It just doesn’t get better than that. You can continue to recommend Anon-co with full confidence from my perspective.

I picked up the PL-360 as a lower cost AM/FM/SW backup to the GP-5 SSB that would allow me to accept the risk of using the larger and heavier extended ferrite rod loop stick aftermarket antenna that garnered so much interest on your blog a year ago, before CountyComm warned of accelerated wear on the antenna jack. Happily the antenna works just as well on the PL-360 as it did on the GP-5 SSB.

Overall I am pleased with the PL-360.

The performance on AM and SW appears to match that of the GP-5 SSB (Tecsun PL-365) albeit with a slightly higher noise floor. Whether this is due to something akin to sample to sample variation or a direct result of inherent design differences between the PL-360’s Silicon Labs Si4734 DSP chipset versus the GP-5 SSB’s Silicon Labs Si4735 DSP chipset I can’t say. I can say the PL-360 with the included High Gain loop stick external tee antenna received my list of news gathering AM clear channel stations out to 900 miles during the night hours matching the GP-5 SSB. This list includes WGN, WBBM, WLS and KOA at the furtherest extreme. It also includes Mexico City’s XEEP 20kW at night at 800 or so miles. Switching to SW broadcast using the whip antenna and Tecsun’s / CountyCom EZTune system day or night the PL-360 and GP-5 SSB select and load the same stations within the PL-360’s slightly shorter SW tuning range.

Dittio on FM on the whip. Both radios snag my list of FM stations out to 60 miles.

For my purposes both are extremely close in performance to my Sony SW7600GR when using their supplied external loop stick. On AM if you combine one with the larger and heaver aftermarket loopsticks they will slightly outperform the 7600GR combined with a Tecsun / Kato / Grundig / Eaton, AN200 Loop Antenna. The Sony’s speaker gives it the edge in listening pleasure, but on earphones or plugs all three are close.

None of forgoing addresses the SSB performance as the PL-360’s chipset doesn’t offer that option.

I am pleased with the PL-360, Anna and Anon-co and I do thank you for posting my 7600GR inquiry.

I look forward to your blog.

Steve

Thank you, Steve! I’m happy to hear the 7600GR posting helped you–that’s what this community is all about…helping each other. Thanks to everyone who commented on that post.

And, yes, I think what surprises so many SWLs is the fact that Anna at Anon-Co actually knows Tecsun radios as well, if not better, than the manufacturer. I’ve only had good experiences working with Anon-Co and that’s why I recommend them so readily. Anna provides excellent customer service. (Click here to check out Anon-Co on eBay.)

I’m also happy to hear you’re enjoying the PL-360 and that you understand the risk of using the large ferrite bar on this radio series (PL-360, 365 and GP5 DSP and SSB). I use my antenna as well, though like you, very carefully.

I only use the large ferrite bar when I’m stationary and I’m careful not to put a strain on the antenna in any way; keeping it balanced and steady. In other words, you must handle it with kid gloves. If you take these precautions, I think your radio will enjoy expected longevity.

Thanks, again, Steven for sharing your review! I’m very pleased to hear you’re enjoying the SWLing Post!

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RNW: Video of Flevoland Shortwave station

Screenshot from Peter Veenendaal’s video of the RNW Flevo shortwave station

Many thanks to SWLing Post contributor, Peter Veenendaal, who shares the following video and notes:

I am a former employee of Radio Netherlands Worldwide, which stopped broadcasting exactly 5 years ago next May.

Three years ago I made this short video of the Flevoland Shortwave station RNW used until 2007. It’s still there, idle and hoping for better times.

Click here to watch on Vimeo–All rights Peter Veenendaal.

Many thanks, Peter–most impressive! The magnitude of those curtain antennas is simply amazing. Thank you for sharing.

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The new Cross Country Wireless HF Preselector

(Source: Southgate ARC)

Cross Country Wireless release HF Preselector

Cross Country Wireless have released a HF Preselector.

It is a passive high Q design that does not use an amplifier or external power.

It tunes from 0.5 to 52 MHz.

It is ideal for use with simple SDR receivers like the RTF-SDR dongle with upconverter or SDRPlay. It can also be used with the new receiver socket modification on the IC-7300.

The web page has more details including network analyser plots showing the selectivity of the Preselector.

The web page is:
http://www.crosscountrywireless.net/preselector.htm

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The Panasonic RF-B65: the legendary portable with a cult following amongst DXers

Hi there, back in 1990 I was given a Panasonic RF-B40 for my birthday (I think it was my birthday…1990 was a long time ago!). I found that radio to be very sensitive on shortwave, more so perhaps than my Sangean ATS-803A, but ultimately it didn’t really add much value to any serious DXing because it would only tune on shortwave in 5 kHz steps. This rather course tuning arrangement was very limiting in terms of tuning out adjacent noise and copying tropical band – and other signals that weren’t quite on-frequency etc. Frustrated, I  lent my RF-B40 to my brother a few years ago and serves me right; following a house move, he managed to lose it! Quite a shame really because almost three decades later, I would have been very interested to put the RF-B40 through it’s paces on a DXpedition or two. You really don’t see them in action very often at all these days.

 Above: the Panasonic RF-B40 (not mine – unfortunately) and the RF-B60, mid-DXpedition!

At that time, which was around the beginning of the 1990s, I read a review somewhere and it became clear that the better receiver was quite obviously the RF-B65. Upon it’s introduction into the market, the RF-B65 was immediately recognised as an excellent receiver, however, in the intervening years it’s reputation has continued to grow to the point today where it enjoys legendary status amongst DXers and bit of a cult following. There’s a lot of information on the RF-B65 to be found on the internet, so I won’t go into huge detail, but the obvious question is: what makes thsi receiver so special? Well, it’s a quite compact PPL double conversion receiver, covering 153 kHz to 29,999 kHz AM and 87.5 to 108 MHz, FM. It has a keypad for direct frequency input, although you have to press either the ‘FREQ’ or ‘METER’ buttons prior to punching in the numbers to define whether you wish to access a particular frequency, or band. I actually find that slightly annoying, but you easily learn to live with such trivial matters when using a radio of this quality and performance.

Furthermore, there’s an electronic signal strength meter, a DX/local attenuation switch, external antenna jack, SSB reception mode, 1 kHz tuning steps on shortwave (unlike it’s little brother the RF-B40) and fine tuning. The single bandwidth filter is 6 kHz wide and thus limits selectivity a little, although the SSB option and fine tune helps offset that somewhat.  It would have been nice to have a couple more filtering options, particularly narrower for serious DXing in crowded bands, to combat adjacent channel QRM. Build quality is generally excellent as you would have expected from a high-end Panasonic portable and with a very compact form-factor – roughly the size of a paperback book and weighing in at just 1.4 Ibs, it is eminently more portable than a Sony ICF-SW77 or the iconic ICF-2001D/2010.

 

Ultimately, the RF-B65 continues to enjoy an excellent reputation today, nearly 30 years after it was introduced because it is a wonderfully sensitive receiver and arguably the best-ever performing shortwave portable in the paperback book size category – often touted as ‘travel portables’. I managed to acquire an example in as-new condition from eBay, although mind you, I paid through the nose for it lol – that cult following ensures prices remain very robust! I have tested my example against the equally legendary Sony ICF-2001D, still considered by many to be the benchmark for shortwave portables, and in my experience the Panasonic is right up there with it. There’s virtually no difference whatsoever in sensitivity. Where the Panasonic comes a little unstuck is the lack of bandwidth filtering and SYNC, leading to lower selectivity. However, clever use of SSB and fine tuning does provide quite good compensation for these shortcomings. Overall though, given it’s size, sensitivity, build quality and audio, as a complete package, in my opinion, the RF-B65 is equal to the ICF-2001D, and this is why today, it remains so highly sought after.

Below are embedded reception videos and text links to the Oxford Shortwave Log YouTube channel, with various DX catches on the RF-B65. Some of these are considered quite rare in Europe, for example EXPPM Radio Educación’s 1 kW signal from Mexico City, the now defunct ABC Northern Territories on 120 metres and Radio Bandeirantes from Sao Paolo, Brazil, amongst others. Please note; right at the bottom of this post is a link to some very recent comparisons with the brilliant Eton Satellit – one of the very best portables currently on the market today. The vintage Panasonic holds its own, despite 30 years of supposed technical innovation in electronics. Thanks for reading/watching/listening and I wish you all great DX.


Click here to view on Oxford Shortwave Log

Click here to view on Oxford Shortwave Log

Click here to view on Oxford Shortwave Log

Click here to view on Oxford Shortwave Log

Click here to view on Oxford Shortwave Log

Click here to view on Oxford Shortwave Log

Click here to view on Oxford Shortwave Log

Click here to view some comparison videos of the RF-B65 and Eton Satellit

 

Clint Gouveia is the author of this post and a regular contributor to the SWLing Post. Clint actively publishes videos of his shortwave radio excursions on his YouTube channel: Oxford Shortwave Log. Clint is based in Oxfordshire, England.

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Advice on cancelling locally generated noise

An SWLing Post reader recently contacted me with the following question:

“What devices work well to cancel out local RFI? I’ve been told that both the Timewave ANC-4 and a number of BHI products are all worth considering.”

Unfortunately (or fortunately, for me) I’ve no experience with outboard DSP or noise cancelling devices because I live in such an RFI-free area.

I know this reader already has a Wellbrook Loop, but he’s looking for a way to even increase noise mitigation further at his home listening post.

Post Readers: Can you help guide him?  Please comment with your experience. Is a product like the Timewave or BHI the next logical step? If not, what is?

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Using the Sony ICF-SW7600GR with external antennas

Many thanks to SWLing Post contributor, Steven Crawford, who writes:

As the 7600GR supplies 6v DC to the external antenna jack to power their active loop antennas there seems to be a great deal of confusion on the web about whether one can or cannot use an external antenna such as a random length of wire attached to the center tip of a barrel connector.

I have been unable to locate the blog entry but I seem to remember you discussing this in one of your posts. In it you mentioned you had built a widget that killed the voltage and allowed you to use the external antenna of your choice. I would appreciate your thoughts on a random wire to center tip antenna and details of the widget you built when you have time.

Thank you for your question, Steven.  I hope a reader can help point to the post you’ve mentioned.  I believe I recall reading this in a guest post–I know I’ve never used a device to kill the 6V phantom load in the antenna out jack.

 

I suppose I’ve (incorrectly?) assumed the Sony would only push voltage out if connected to the Sony AN-LP1 (see right).

I know I’ve used a number of antennas with the ICF-SW7600GR: long wires, the PK Loop, The EF-SWL, the NASA PA 30, and even a rather large multi-band dipole when I recorded the final broadcast of RNW. I’ve never experienced a problem, nor damaged the antenna/receiver as of yet.

Can anyone shed some light on this? Please comment!

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