Tag Archives: ferrite antennas

Giuseppe’s homebrew rotating ferrite antenna

Many thanks to SWLing Post contributor, Giuseppe Morlè (IZ0GZW), who writes:

Dear Thomas,

I’m Giuseppe Morlè (IZ0GZW) from Formia, on the Tyrrhenian Sea, in Italy .

I built this simple rotating directive ferrite antenna for medium waves and the 160 meters ham band.

Inside the tube there are 2 ferrites with 43 cable windings and 3 for the coupling link that goes to the receiver.

In this video the test as soon as I assembled everything …

In broad daylight, it was 12.00 local time, you could hear well over 2000 km.

The antenna is very directive and perfectly manages to separate several stations on a single frequency.

The pipes are in plastic for plumbing use (PVC), I bought only that one, 5 Euros, the rest is all recycled.

I wanted to share this simple and very functional project of mine with the SWLing Post community.

Thanks and I wish everyone a better year.

Greetings from Italy.
Giuseppe iz0gzw.

Thank you, Giuseppe! What a simple, effective antenna project. I like how you’ve invested so little and recycled parts from other projects. I also love your view there looking south over the Tyrrhenian Sea! What a great place for radio.

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The Professor reviews the RFA200 external ferrite antenna

Many thanks to SWLing Post contributor, The Professor, who shares the following review of the RFA200 external ferrite antenna:


The Tecsun R-9012 and RFA200 MW antenna (Photo credit: The Professor)

A Quick Review of the RFA200

The Professor

I’ve considered saying something here about RFA200, as I bought one of these not long after its existence was announced on this blog a few months ago, but I’ve been hesitating because I didn’t have much good to say about it. A couple of times I’ve placed it up snug up against the the top of the two Tecsun sets I have handy (the PL-310ET and the PL-880) and found that despite a lot of knob turning it had little or no effect on improving signal on medium wave stations. I was not impressed.

But I guess I’ve kind of changed my mind on that. And oh yeah, I bought another radio. It’s funny how you can talk yourself into things when you’re talking someone else into something. But after I had mentioned to a reader here the other day that the very inexpensive Tecsun R-9012 was a worthy analog DX portable, I decided to drop twenty and pick one up for myself. After all, it was about the same price as a fancy Brooklyn hamburger. It arrived a couple days ago.

So, I have been playing with it a bit over the last few days. It’s as good as the other ones I’ve had which are the same basic radio (I’d mentioned that the bandswitch slider broke in a couple of mine). It’s single conversion. The bandwidth is a little wide, but it’s a very sensitive and simple analog set.

Yesterday I was going through the AM band and remembered that ferrite from Greece, and I pulled it out recalling that in my experience some radios are more susceptible to reception improvements using passive loops than others. Maybe this ferrite bar might be similar. And sure enough, the antenna made a notable difference this time. By placing it up against the R-9012 and tuning the thing I could certainly increase signal a bit. And I could even see it in the slight brightening or steadiness of the tuning light.

So, not a total waste money after all. I would emphasize that the difference in reception doesn’t seem to be as dramatic or sustaining as you might hear with a tunable loop antenna next to your radio. But it’s not junk either. Then again, for fifty dollars shipped it is a little pricey. Twice as much as a Tecsun tunable loop antenna, and two and half times more expensive than the R-9012 itself.

I found the best way to use this antenna is to tune the radio separately first and when you find a weaker signal you want to improve physically go ahead and rotate the radio until the signal is strongest and THEN put the antenna along the top of the radio and adjust the tuning knob on the antenna. Focus in on strengthening the signal you actually hear, going back and forth until it gets strongest. If you seem to be pulling up other stations it’s because the antenna adjustment will bring in adjacent stronger stations if you move it too far either way.

I’m surely not able to pin down the science involved in exactly how these things work, but perhaps somebody can chime in on this. I’m wondering if analog radio tuning in particular is better suited to the use of these tunable passive antennas, as opposed to PLL and DSP radios?

If you buy one of these be prepared to wait. At least mine took weeks to get here from Greece. And don’t expect miracles. But it seems rather well constructed, and will probably work with some radios. The seller has a 100% rating on eBay and has all sorts of interesting antennas for sale. I’m glad to see people succeeding in that business.


Many thanks, Prof, for sharing your fine review of the RFA200! Thanks for also mentioning the Tecsun R9012–I purchased one a couple years ago with the intention of reviewing it, then gave it to teenager who expressed interest in shortwave. I don’t think I actually put it on the air myself. I do enjoy simple old school analog radio–especially when making band scans. 

Click here to view the RFA200 antenna on eBay.

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External Ferrite Antenna by playloudfm

Posted by SWLing Post contributor Troy Riedel:

I just noticed something on eBay.  Seller “playloudfm” based in Greece (100% feedback rating), the first to offer the high gain external ferrite antenna for the Tecsun PL-360/PL-365/County Comm GP5, has a new offering:

From the seller’s listing:

– Frequency: 530Khz – 1710Khz
– Tunable
– Passive, No external power or battery needed
– Wireless connection to AM Radios
– Plus a low impedance output 3.5mm mono plug for 50 ohm scanners
– Improves Sensitivity and Performance of your AM Radio Receiver for AM Band Dxing!
– Very small and lightweight, perfect for traveling antenna

This AM antenna can be used in two different ways
1) you can simply attach it near your AM radio internal ferrite antenna – wireless connection
2) use a 3.5mm cable to get a low impedance output for use with 50 ohm scanners

Use tuning knob to get the maximum signal

RFA200

 

Have any Post readers bought and used this?

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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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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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CountyComm: A note of caution about the high-gain ferrite bar antenna

Ferrite-Bar-PL-365After our post this morning regarding the high-gain ferrite bar antenna (available via eBay), I received a message from Nick at CountyComm.

Nick notes:

“[The high-gain antenna is] very cool however we wanted to let you know that we found out it [can] actually destroy the antenna input to the GP5/SSB or GP5/DSP because of its heavy weight. [W]e had at least five radios come back [after] customers had purchased the large ferrite antenna from an eBay seller.”

Many thanks, Nick, for the feedback. It is important to note that the high-gain bar antenna is not an OEM product, so CountyComm isn’t responsible if it harms the radio’s antenna jack.

While still relatively lightweight, the high-gain bar antenna is substantially heavier and longer than the GP5’s supplied MW antenna.

I’ve been concerned about dropping the GP5/SSB with the larger bar antenna inserted–fearing the jack could break off–so I’ve been very careful using it. I’ll probably continue using the larger ferrite bar, understanding that I’ll have to handle it with care.

If you’re concerned about damaging your radio, I would suggest using an inductively coupled AN200 loop antenna instead.

Again, Nick, thanks for the heads-up!

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Steven is impressed with the CountyComm GP5/SSB and high-gain bar antenna

GP5SSB-Front

Many thanks to SWLing Post contributor, Steven Crawford, who sent the following message to me (several weeks ago) and has kindly allowed me to share it here. Steven writes:

I hope this finds you and yours well. I just wanted to take a few moments and express my sincere thanks to you for your posts of 12/20/2014 and 1/6/2016, and for sharing Larry Thompson’s post of 2/28/2016, and Ron’s post of 1/16/2016. If you are in regular contact with the other individuals please feel free to pass along my thanks as each of you and the respective post convinced me to purchase a CountyComm GP5/SSB and Ebay seller playloudfm’s high-gain ferrite bar antenna. I am so glad I did, so a hearty Thank You to each of you.

The afternoon of March 19th local was the first chance I had to use my GP-5/SSB. After popping in three fresh AA’s on AM using the internal ferrite bar antenna Beaumont, Texas’ own powerhouse 5,000 watt KLVI 560 was there as was 1,000 watt Orange’s KOGT 1600, 23 miles away and my AM daytime benchmark 50 kW KTRH 740 Houston 70 or so miles away on the back side of their pattern. KTRH surprisingly can be a little difficult during the day due to noise. The surprise was 50 kW WWL New Orleans 240 miles away was intelligible above the background noise. Extending the whip a quickie SW test showed WWV Fort Collins time signal was present at 15 MHz.

On the AM side the real money lay after dark once the sun had set in Beaumont and San Antonio. Using only the internal ferrite bar antenna all of the aforementioned AM stations were present. Continuing the internal antenna’s test 50 kW WBAP 820 Dallas 244 miles away and 50kW WOAI 1200 San Antonio 266 miles away were present. I started grinning when 50 kW WLAC 1510 Nashville 598 miles away and 50kW KMOX 1120 St. Louis 632 miles away were just intelligible above the background noise. Keep in mind these stations were received using only the internal antenna.

GP5SSB-MW-Antenna-1

I popped the CountyComm included factory external ferrite bar on and used it 9 -10 PM Saturday local, 0200 – 0300 March 20 UTC. Using the external antenna rotated for best reception WLAC and KMOX improved to the point they were easily listenable. 50 kW WSB 750 Atlanta 625 miles away was listenable above the noise and most surprising 50kW WBBM 780 Chicago 892 miles away(!!!) was just intelligible above the background noise. Another quickie SW test was performed at 10 PM local, 0300 March 20 Sunday UTC by extending the built in whip and the WWV Fort Collins time signals were present at 5 and 10 MHz with 10MHz being particularly well received.

Ferrite-Bar-Antenna-PL-365-GP5SSB

Photo source: eBay

A real treat lay in store after receiving Ebay seller playloudfm’s aftermarket high-gain ferrite bar antenna, the subject of your 1/6/2016 and Ron’s 1/16/2016 post, yesterday. I am not experienced enough to judge what the space weather or propagation conditions were like from 0300 to 0400 March 27th UTC but I was extremely surprised and pleased with the reception results the new antenna afforded.

As I sat relaxing in my easy chair before bed I decided to try the combo out using the included earphones so as to not wake my wife. With the lights off and my iPad open to www.oldradio.com/archives/stations/ccs.htm to help identify clear channel stations I took the handheld combo for a spin. All of the stations found with the factory supplied external ferrite bar antenna were present. There was just so much more signal present using the aftermarket antenna each became easily listenable. For WOAI, WWL, WLAC and KMOX the effect was as if I was located within their local night coverage area. 50 kW WHAS Louisville Kentucky 740 miles away was newly found present. Chicago’s WBBM was there as before and I was surprised to find 50 kW WGN 720 Chicago as well. The reception quality was such that one could enjoy listening to a Cub’s game or breaking local news story should one be so inclined on WBBM or WGN. The listening experience was similar for newly found 50 kW XEROK 800 Ciudad Juarez 738 miles away.

The most surprising and gratifying, to me anyway, find of the night using playloudfm’s antenna was receiving 5,000 watt (nights!) KCMO 710 Kansas City Missouri 624 miles away. The ability to rotate the antenna to take advantage of it’s directional and nulling ability really aided in this reception. It really is a great benefit to be able to rotate the GP-5/SSB’s external AM antennas for peak signal strength while nulling interfering signals and noise. Indeed KCMO was missing in one antenna orientation but rotating the antenna 90 degrees and the station popped in. I really should have jotted signal strength to noise ratios down but I was just enjoying tuning through the spectrum too much. I have not fully tested SSB Exalted Carrier tuning on the GP5/SSB of difficult stations but have tried it 3 or 4 times and it does appear to work as does tuning 1 kHZ either side of the nominal frequency. The later technique did help clean up some signals by further reducing background noise without greatly affecting listenability.

As best I can tell I ordered and received either the last or next to last of playloudfm’s current batch of high-gain ferrite bar antennas as the Ebay add showed two available when I ordered and the ad was almost immediately replaced with an “accepting pre-orders” ad. Currently there are no ads by seller playloudfm.[Note: it appears more inventory has been added to eBay.] My transaction and shipping was quick and smooth. The bulk of the two week wait occurred after the package was received at the Athens airport where tracking stopped. It should be noted by buyers should more antennas become available the tracking number supplied does not work on the USPS tracking service but it will track the package to Athens through Greece’s Hellenic Post tracking service at http://www.elta.gr/en-us/personal/tracktrace.aspx

Note: all distances listed above are “as the crow flies”, straight line city center to city center and are not necessarily correct for the transmission tower location.

This little radio is fast becoming a hand holdable favorite with easy to learn button placement for use in the dark. I am all ready beginning to prefer it to my Sony SW7600GR / AN200 loop combo for MW broadcast AM reception but I really must do more work with SW before calling the CountyComm my favorite of the two.

Steven followed up a week or so later with this addendum to his review:

I finally got the opportunity to test the FM performance of the radio using only the extended whip on the afternoon of April 1st, April 1st 19:30 – 21:00 UTC. Using www.radio-locator.com and my zip code I found 51 FM stations listed as local, distant and possible fringe reception. I was very surprised and pleased when I was able to log all of the most distant fringe stations, KUHF, KKBQ, KTBZ, KKHH, KHMX, KBXX, KODA, KILT, KLOL, KMJQ, KRBE, KOVE, and KGLK, with ERP’s listed as 90 to 100 kW and distances in the given in the 80 to 90 mile range. In short I was able to log all 51 listed stations. The FM broadcast band is crowded indeed with this little rocket radio. It should be noted my little corner of Southeast Texas is dead flat with nothing between me and these stations broadcast towers but Houston skyscrapers, the typical urban / suburban sprawl, timber and marsh. Ground elevations range from 16 ft to 80 ft above sea level between me and many of the broadcast towers.

[…]My Sony SW7600GR / AN200 loop / Sony AN-LP1 loop combination sits in it’s go bag rapidly falling into disfavor, replaced by the easily used in the dark one handed CountyComm GP-5/SSB. Again thank you for your kind response and thanks again to all who motivated me to purchase this rig.

Steven, thank you so much for taking the time to share your experience with the GP5-SSB and the high-gain ferrite bar antenna.

I also have the high-gain ferrite bar antenna and have been meaning to post videos showing how it performs compared with the supplied GP5 antenna. I must say, it does do a pretty amazing job. I’ll get some videos posted in the coming weeks!

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