Category Archives: Antennas

Oxford Shortwave Log: transatlantic MW DX catches with 200 metre Beverage – part 1

worspectrum

Hi there, a few weeks ago I posted a couple of medium wave DX catches with the Elad FDM DUO and newly constructed 200 metre Beverage antenna. Since then (and following my trip to Brazil) I have uploaded several more catches, some of which I would like to share with you. It has become evident that the Beverage’s low-gain but high SNR properties resulted in a huge increase in the sensitivity of my entire set-up and as a result. I have achieved numerous personal firsts on the medium wave band, coupled with many other signals that I can only describe ‘best-ever reception’. If nothing else, this endevour has underlined the importance of utillising the best antenna possible for your particular circumstances. We’ve all read at some point, how, in many respects, the antenna is more important than the receiver – and these catches demonstrate how absolutely true that statement is. All of the reception videos were captured using the Elad FDM DUO running on a home-brew battery-pack and connected to the Beverage via a 50 Ohm input transformer.

Below is the first set of reception videos, most of which are signals from East Coast of the United States. However, there is also an absolutely booming signal from WGIT Puerto Rico into my QTH in Oxford UK. Part 2 will follow almost immediately, but in the mean time thanks for watching/listening and I wish you all great DX!


elad

 

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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A preliminary review of the PK Loop C-LOOP-HDSW6-18

eecraft-kx3-pk-loop

The Elecraft KX3 and the PK Loop C-LOOP-HDSW6-18

Over the past year, a number of SWLing Post readers have asked me to review the PK Loop portable magnetic loop antenna produced by Paul Karlstrand in Australia.

I finally caved in and purchased one.

I ordered the shortwave version of the loop, the  C-LOOP-HDSW6-18 in early November and received it about one week later.

sony-sw100-pk-loop

The Sony SW100 tuned to WBCQ.

I was first introduced to this antenna by SWLing Post contributor, Mark Fahey, who brought it to the SWL Fest and our 2015 PARI DXpedition.

Mark has taken his PK Loops (both the shortwave and mediumwave models) on his numerous travels around the world. He finds that they’re relatively effective portable antennas in RFI-dense environments like hotels and guest houses. They’re better at mitigating RFI than, say, portable wire antennas or telescopic whips.

Mark hooks up his portable SDR to the PK Loop and makes spectrum recordings (wideband recordings)–from, say, his hotel room in Kuala Lumpur–then takes the recording back home to listen and tune at his leisure via his laptop or tablet PC.  While I’ve certainly made spectrum recordings while travelling in the past, the appeal of such a portable loop antenna is what finally caused me to pull the trigger.

Overview

pk-loop

The PK Loop is a small loop antenna–measuring about 12″ in diameter. It’s encased in UV-stabilized PVC conduit and the matching box also seems to be made of PVC. It feels very durable and can, no doubt, even survive the wildest of luggage handling.

The PK Loop has an attached battery 9V battery holder, but can actually be powered by any 9-18 volt DC supply. Current consumption is less than 15 mA. On the matching box, you’ll find a tuning knob, a BNC connector, DC power in port and a HI/LOW gain switch. My loop shipped with a 2 meter BNC-BNC Cable, 3.5mm adapter, and DC Power lead to open ends.

Operation

Operating the loop is very simple:

  1. Power the antenna with a 9V battery or other DC source
  2. Chose either the high or low gain setting
  3. Place it on a stable surface (height from the ground is not a critical issue, but you should avoid placing it next to noisy electronics or mobile phones)
  4. Connect the PK Loop to your receiver’s antenna jack with the supplied cable
  5. Turn on your receiver to the desired meter band, then adjust the loop’s tuning knob until you hear the signal level peak
  6. Start listening, keeping in mind that as you tune around the band you may need to adjust the loop’s tuning knob for maximum gain

Loop antennas, in general, are fairly narrow-band and–unlike a Wellbrook or Pixel Loop–manual adjustments need to be made with the tuning knob to match the PK Loop as you scan across bands.

Still, I see why Mark favors the PK Loop for spectrum recordings: the bandwidth is wide enough that if I tune the loop to the middle of the 31 meter band, for example, it does a fine job covering the entire band.

On the air

pk-loop-kx2-sw100

My free time has been very limited since receiving the PK Loop earlier this month, but over Thanksgiving holiday, I took it to my family’s home that has relatively high RFI levels.

The following are a couple of videos I made with my Moto X smartphone. I’ll be the first to admit that these are not the best videos–I had no tripod and the Moto’s microphone leaves much to be desired–but I think you’ll still get the idea of how well the PK Loop works.

With the Sony SW100

Click here to watch on YouTube.

With the Elecraft KX2

Click here to watch on YouTube.

So far, I’m very pleased with the PK Loop. It does seem to mitigate noise better than other portable antennas I’ve used in the past and certainly improves my SW100’s reception. It makes SWLing with the Elecraft KX2 or KX3 easy and convenient.

One word of caution: if you use the PK Loop with a transceiver like the KX2, please turn off the ATU, and set the power level to 0W before using. The PK Loop is receive-only and will not handle any RF power.

Note that with the SW100, I have only used the PK Loop’s low gain setting. I’m a little nervous about overloading the SW100, so do not plan to use the high gain setting. The Elecraft KX2 seems happy to handle either gain setting: I imagine this will be the case with most general coverage transceivers and tabletop receivers.

More to come!

In a couple of weeks, I’ll be staying in a hotel room (likely with inoperable windows and heavy RFI) so I will attempt to put the loop through its paces and compare it with my radio’s built-in antenna.  Stay tuned!

UPDATE: Click here to read my follow-up review.

Post readers: have you used the PK Loop or other similar portable/travel antennas? Please comment!

Click here to view PK’s Loop antennas on Paul Karlstrand’s website.

Paul also sells his antennas and ships internationally on eBay–click here to view the selection.

pks-loops

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Radios With Rotatable AM Antennas?

The Panasonic RF-2200 sports a rotatable AM/MW antenna

The Panasonic RF-2200 sports a rotatable AM/MW antenna

Many thanks to SWLing Post contributor, Mario Filippi (N2HUN), who writes:

With your broad knowledge of radios, wondering if you can add anything to this list of portable radios, past and present, that have 360 degree rotatable directional AM ferrite antennas. Reason is I am looking for an AM portable for the nightstand for nulling out unwanted AM stations while also doing a little DXing.

The list I have from data mining the ‘Net is:

New models with rotatable AM antennas:

  • CountyCom GP5/SSB,
  • Tecsun PL-360,
  • Grundig Satellite 750,

Older (vintage) models:

  • Panasonic RF-2200,
  • Panasonic RF-1150,
  • Panasonic RF-877,
  • Panasonic RF-1180
  • most RDF (Radio Direction Finder) radios that were used on boats

“Boom Box” variety:

  • Radio Shack 12- 795,
  • Emerson MBR-1,
  • Rhapsody RY-610.

[RDF radios] are kind of big, however Raytheon, Ray Jefferson, and Nova-Tech did have smaller model RDFs that could be considered table-tops).

The alternative is to build or buy a passive indoor antenna.

Maybe readers know of other models?

Thank you for your inquiry, Mario! I will do a little research of my own because you listed every model (and more) I could think of off the top of my head.

Post readers: Please comment with any models we could add to this list.

I will take all of the suggestions and make a master list to post here on the SWLing Post so it’ll be easier for others to research in the future. I’m pretty sure this question has come up before.

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The brilliant little Tecsun PL-310ET: serious DXing on a budget – part 1

tecsun-pl-310etHi there, a good friend of mine Mr Thomas Brogan mentioned to me recently that his little Tecsun PL-310ET was proving to be an excellent receiver and that it would suit my DXpedition activities. Now, as someone who likes to push the envelope of performance with sophisticated portables, usually coupled to very large antennas, a cheap little Tecsun might not have been an abvious choice for my next purchase. However, Mr Brogan (who has an excellent Youtube channel by the same name – check out his wonderful collection of vintage and modern receivers) previously suggested I buy, for similar reasons, the Sony ICF-SW100. That little masterpiece of electronics turned out to be one of the best receivers I’ve ever owned. I felt compelled to take notice because Tom never gets this stuff wrong! A few days later I found myself in Maplins – again – and there it was on the shelf at just under £40, so I bought one.

I got back into shortwave listening about 18 months ago, after many years of inactivity whilst my poor Sangean ATS-803A rotted away in the garden shed and Sony ICF-7600G long-gone via eBay. To start all over again, I bought a Tecsun PL-360.  What a great little portable that turned out to be – there are over 100 reception videos on my YouTube channel demonstrating how it continually performed above and beyond the very modest price tag. I even managed to hear ABC Northern Territories 4835 kHz on it once –  simply amazing for a receiver under £30. Given my extensive experience with the PL-360 and having learned the PL-310ET shared the same DSP chip, I was expecting the same, or at least very similar performance and the only real benefit to upgrading to the PL-310ET was the direct frequency access.  However, I was wrong about that!

pl-360

The brilliant Tecsun PL-360 got me back into shortwave radio for less than £30

About a week after buying the PL-310ET,  I managed to get out on a DXpedition and with 30 metres of wire attached to it via the external antenna socket, I started tuning around the SW bands. Quite simply, I was amazed at the sensitivity and selectivity of this diminutive little portable. With the proven DSP receiver chip and a number of audio bandwidth filter options  from 1 to 6 kHz, coupled with direct frequency access via the keypad, it was a joy to use and listen to. In just over an hour I had  copied signals from North Korea, including their internal service KCBS Pyongyang, Zanzibar BC, ABC Northern Territories (at the first attempt!), Zambia NBC Radio 1, Radio Oromiya and Radio Amhara from Ethiopia, amongst others. Brilliant stuff and clearly demonstrating that the overall hardware/software package with the PL-310ET is a step up in performance over the PL-360 and capable of proper DX for a very modest outlay. Interestingly, in a conversation with Thomas Witherspoon regarding the PL-310ET, he reminded me that it was one of his go-to radios for travelling and confirmed it’s excellent performance.  I would definitely recommend this radio to novices and experts alike.

Reception videos follow below, with more to come in part 2; I hope you enjoy them. Thanks for watching/listening and I wish you all excellent DX!

 

 

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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Review of the DoxyTronics 8020CA magnetic loop antenna

8020ca-assembled-1

(Image source: DoxyTronics)

Many thanks to SWLing Post contributor, Troy Riedel, who shares the following guest post:


Review: DoxyTronics Portable HF Magnetic Loop 8020CA

-by Troy Riedel

Before I purchased the DoxyTronics 8020CA antenna, I emailed the owner/manufacturer and asked if he felt this antenna would be a good choice with the radios that I own. He promptly and courteously answered my question and I purchased the antenna on September 30th. I received the antenna approximately 6-days after I ordered it.

The DoxyTronics 8020CA magnetic loop antenna

The DoxyTronics 8020CA magnetic loop antenna

I have been evaluating the antenna for 5-6 weeks mostly on my Grundig Satellit 750 and my Grundig G3. I have used other portables but the two aforementioned Grundigs were the radios I used most.

The antenna control box has a ¼-20 hole on the bottom so it can be mounted to a video camera tripod. The assembled antenna weighs 3 lbs. I tried using a light duty DSLR tripod that I own, however that was nowhere near sturdy enough. I had to use a heavier duty tripod (Ravelli AVT) that I use for astronomical purposes. This Ravelli has a weight capacity of 16 lbs and it easily supported the antenna. I’m confident a much smaller and lighter duty tripod than the Ravelli could be used, I simply don’t own anything in-between as my astronomical binoculars and binocular telescopes weigh 5 – 14 lbs.

The 8020CA Antenna consists of a large tuning knob and control box. The control box has switch settings of 3-5 Mhz and 5-15 Mhz. In testing, I found that I could “tune” up to 17.840 MHz.   No batteries are needed to operate.

The antenna worked equally well with all of the “portable” radios that I tested (I am a SWL’er, not a ham).

I can summarize the antenna’s performance as this: it is not a magic elixir that will allow you to capture signals too faint to recognize without the antenna attached, but it definitely enhances the signal and “stabilizes” it to the point where the level of the signal remains relatively constant (less peaks & troughs in signal strength).

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Hopefully you can hear what I have summarized and concluded. I have included a two and one-half minute recording of the following:

Radio: Grundig Satellit 750
Recorder: RadioShack 140-214
Freq: 7.310 MHz
BW: Wide
Broadcaster: Radio Romania International
Date of Recording: 15NOV2016
Time: 2309 – 2313 UTC

Click here to download as an MP3.

00:00 – 00:30: 8020CA Antenna Attached
00:30 – 01:00: Radio’s Whip Antenna
01:00 – 01:30: 8020CA Antenna Attached
01:30 – 02:00: Radio’s Whip Antenna
02:00 – 02:30: This last 30-second segment is with the 8020CA attached, however I am panning the Ravelli tripod 360-degrees in the horizontal. You will hopefully notice that there is a “sweet spot” where the signal and reception is the best of the entire 2:30 recording. I had set-up the antenna and I completed a quick, test recording of Radio Romania. But conditions changed slightly and the best signal during the recoding was approximately 50-60-degrees away from where the best reception was earlier. This is a positive for the antenna: you can pan the tripod head where the antenna sits to null and/or find the best signal.

Note: this is my first shortwave and radio-related review I have ever done. I have done many astronomical reviews – where I have much more experience – so please be kind towards this first attempt.


No worries, Troy! We’re kind and appreciative here–especially since guest posts are all about sharing our experiences and experimentation!

I must say, the DoxyTronics loop is doing a fine job mitigating the local QRM/interference that is easily heard when only the telescopic whip is being used. I’m also impressed that a passive loop this modest in size has so much gain without amplification. 

Thanks, again, Troy for sharing your review! 

Click here to view and/or purchase the DoxyTronics 8020CA magnetic loop antenna.

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Which is the best? Sony ICF-2001D/2010 or ICF-SW77? The halfway score

Hi there, here is a summary of the first half of tests comparing the Sony ICF-2001D against it’s replacement the ICF-SW77. Both receivers are widely acknowledged as being amongst the best shortwave portables ever made, but how close are they in performance? Is there a clear winner after the first 8 reception tests? I hope you enjoy the summary video. Links to the first half of reception tests follow again, below, whilst the second half will follow in a separate post. Thanks and good DX to all.


 

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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Oxford Shortwave Log: DXing in the tropical rainforest of Pará, Brazil – part 2

img_9956pl-680

Hi there, here is part 2 of my reception videos taken in the tropical rainforest of Pará, Northern Brazil. As I mentioned in my previous post, I took a Tecsun PL-680 with me on the trip because I didn’t want to risk losing or trashing one of my precious vintage portables but also because of the following:

  • It can handle a longwire very well without overloading (I actually only used a 5 metre wire)
  • An excellent synchronous detection circuit and audio bandwidth filtering options
  • Excellent sensitivity, as demonstrated by the many DX reception videos on YouTube
  • If it got lost or damaged it would be a pain, but not difficult to replace

So, what can you hear in the jungle? Part 2 of my group of reception videos follow below – I hope you enjoy them.


Tropical rainforest DX in Pará, Brazil: RMI Overcomer Ministry 11530 kHz

 

Tropical rainforest DX in Pará, Brazil: Radio Tamazuj 11650 kHz, Madagascar

 

Tropical rainforest SW in Pará, Brazil: Radio Nacional Brasilia 11780 khz

 

Tropical rainforest DX in Pará, Brazil: R Aparecida 11855 khz (TX distance 2430 km)

 

Tropical rainforest SW in Pará, Brazil: R Brasil Central 11815 kHz, Goiania

 

Tropical rainforest DX in Pará, Brazil: Voice of Turkey 11980 kHz

 

Tropical rainforest DX in Pará, Brazil: Radio Dabanga 13800 kHz, Madagascar

 

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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