Category Archives: QRM

AirGig: a new BPL technology that promises less RFI

projectairgig

Many thanks to SWLing Post contributor, DanH, who writes:

I read this news item today. AT&T has a new approach to broadband over power lines called AirGig. Supposedly, this technology will avoid RFI issues encountered with previous BPL technologies. This shouldn’t be an issue in my neighborhood where power lines are underground. Underground utilities still have RFI issues. My next door neighbor’s AT&T high speed internet swamps out all nearly all shortwave signals below 4.7 MHz within radius of 30 feet from the connection box.

http://fortune.com/2016/09/20/att-internet-over-powerlines/

Many thanks, DanH! Here is a short promo video for AirGig:

South American shortwave catches, rarely heard in Europe

5 Replies

Hi there, I thought I would share some DX catches, all of which are rarely reported in Europe and yet I was fortunate enough to catch in Oxford UK, using a couple of different set-ups. The first is Radio Chaski Red Integridad from Urubamba Cusco, Peru, heard using an Elad FDM DUO and Wellbrook ALA1530 active loop antenna (indoors). The two subsequent receptions originate from Brazil; Radio 9 de Julho, Sao Paulo and Radio Transmundial,Santa-maria Camobi, both of which were caught using the venerable Sony ICF-2001D portable receiver and my 200 metre longwire antenna. In all three cases, persistence was necessary whilst optimum conditions of propagation aligned with my listening schedule at home and my less frequent, but regular DX’peditions.

I am soon to deploy a 200 metre Beverage with adjustable termination resistance for nulling ‘rearward’ signals and matching transformers suitable for 75 and 50 Ohm receiver antenna inputs. I hope this will further improve my reception capability on both the MW and SW bands. Another post specific to that project is in the pipeline, but in the meantime, thanks for reading/ watching and I wish you all very good DX.

Direct link to Oxford Shortwave Log for Radio Chaski Red Integridad reception video

Direct link to Oxford Shortwave Log for Radio 9 de Julho reception video

Direct link to Oxford Shortwave Log for Radio Transmundial reception video

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.

Phil demonstrates the BHI NEIM1031 Noise Eliminating In-Line Module

7 Replies

Many thanks to SWLing Post contributor, Phil Brennan, who writes:

[Recently] one of your contributors mentioned that he purchased a BHI DSP unit at a discounted price. I purchased one (a different model to the one in the previous post) some months ago before I headed away travelling.

The post reminded me that I had made a small video demonstrating the DSP unit on my FRG7. The video shows me tuning the DSP on a broadcast of Voice of the People on 3912 khz. While QRM at my place isn’t too bad, it’s still present and the DSP does aid in clearing up a signal.

Voice of the People is usually jammed by the DPRK and the DSP also assists in reducing the roar of the jammer. Of course one can go to far with DSP and the audio can suffer from that underwater sound.

Thank you, Phil! The FRG-7 is an ideal receiver for something like the BHI module since it precedes on-board DSP. The great thing about an in-line module, of course, is that it can be used with a variety of receivers.

Click here to view the BHI NEIM1031 MKII on BHI’s website.

Tropical Band DXing at home with Elad FDM DUO and Wellbrook ALA1530 active loop

5 Replies

Recently I have spent a little more time listening out for Tropical Band stations from my shack in Oxford UK, attempting to emulate some of the very nice signals I have previously recorded out on DX’peditions. The obvious problems with this (and they are numerous) include the relatively weak signal strength of many tropical band stations, the ubiquitous blanket of QRM, resulting in generally poor SNR, lack of space for a large antenna……need I go on?! Fortunately, the Elad FDM DUO has proven to be a very senstive and selective receiver, capable of, at times, incredible SNR, coupled with almost limitless signal conditioning options and SSB, SYNC, ECSS etc. Throw the Wellbrook ALA1530 active loop into the mix (not literally!) and you have a very powerful Tropical Band receive set-up. The Wellbrook is able to null most (although not all) QRM in my shack and that really can make the difference between simply observing a carrier and actually hearing audio. Clearly one cannot expect to hear DX at home under heavy QRM as well as you might outdoors, however, the following stations were logged in the past month or so, with respectable signals, with the ALA1530 indoors:

Video links also follow below, thanks for reading/ watching.

Direct link to Oxford Shortwave Log video; Radio Logos 4810 kHz, Peru

Direct link to Oxford Shortwave Log video; Radio Cultura Ondas Manaus 4845 kHz, Brazil

Direct link to Oxford Shortwave Log video; AIR Bhopal 4810 kHz, India

Direct link to Oxford Shortwave Log video; Rádio Educação Rural 4925.2 kHz, Tefé, Brazil

Direct link to Oxford Shortwave Log video; Radio Mosoj Chaski 3310 kHz, Bolivia

Myanmar Radio, Yangon, heard in Oxford UK on 49 and 41 metres

3 Replies

Hi there, I thought some of the readers of SWLing post might be interested in my reception of Mayanmar Radio, Yangon, during a late-night DX’pedition in Oxfordshire, UK. I managed to catch them on 5985 and 7200 kHz; the latter was a personal first and perhaps further confirmation that my 200 metre longwire is contributing in a positive way to my mobile listening post. Subscribers and regular visitors to Oxford Shortwave Log on YouTube will know that I am forever trying to push the performance of my vintage portables to the limit of what’s possible, in the hope that I might hear something very exotic. it’s happened once or twice and thus worth all the effort in the small hours. Thanks for watching/ listening.