Category Archives: AM

Bill tweaks his AM loop antenna for optimal mediumwave performance

Many thanks to SWLing Post contributor, Bill Hemphill (WD9EQD), who writes with the following update to his previous post:

As you may remember, back in May, I picked up a beautiful home-made loop antenna. It was 25 inches on a side with 23 turns of wire. My initial testing showed that it would tune from 280 kHz to 880 kHz. While I was familiar with loop antennas, I had never tried using one.

My initial tests were disappointing. So I spent some time on the internet reviewing AM loop antenna designs. I came across a reference to an AM Loop Antenna Calculator by Bruce Carter:

http://www.earmark.net/gesr/loop/umr_emc_calc.htm

I first measured the tuning capacitor and found that it tuned from 25 to 400 pF. Entering the data into the calculator:

This matches closely to what I was experiencing.

I then proceeded to calculate various Number of Turns to see the effect on tuning range. My goal was to tune the entire AM broadcast band.

I settled on ten turns which gives the following from the calculator:

Perfect. I removed 13 turns (which left ten turns) and then added a two turn secondary loop which would be connected to the radio. The results were fantastic.

I have created three short videos showing the difference between using the Tecsun S-8800 without the loop on a weak station and then using it with the loop.

[Note: If you’re viewing this post via our email newsletter you might need to view this post via a web browser to see the following embedded videos.]

Without the loop

With Loop

As you can hear, a very noticeable difference.

[After making these videos] I tested the of reception of 1510 kHz on the Panasonic RF-2200:

The results are amazing.

I have logged three stations on one frequency. Just peak the one station, then tune the loop and peak the second, then turn the loop some more and peak a third station.

I’m having a lot of fun with the loop. When it gets a little cooler, I plan to take it to the park where there is zero noise and really put it through its paces.

Excellent job, Bill! You’ve proven that doing a little research and making small adjustments to an antenna design can yield impressive results! Thank you for sharing!

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Jason gives a favorable review of the Sangean DT-120

Sangean DT-120

In reply to Olivier’s post about the Sony SRF-M95, SWling Post contributor, Jason, notes:

Another amazing AM ultra light performer, the Sangean DT-120 or DT-180

I have the DT-120 in my pocket and it has got many hours of use. Travelling in outback Australia in April/May I was very impressed with it’s performance on AM.

Camped at the Devils Marbels 412km north of Alice Springs, I could receive it’s 783 kHz AM signal OK, weak obviously but definitely listenable. Of course the signal from Radio National at Tennant Creek on 684 AM was stronger, since it’s only 100km to the north of Devils Marbles.

Very happy with the little Sangean. It’s by far and away the pocket radio with the best DX reception I’ve ever owned, but the Tecsun R-209 and the Sangean SR-35 are probably the two best AM DX pocket radios with a speaker.

One day I will pick up a Sangean DT-250, but it’s probably not much better than the Sangean DT-210 I already have, which is another good choice with a speaker.

Thanks for sharing your comments, Jason! And, wow, I’d love to make that camping pilgrimage to the Devil’s Marbles–sounds remote and fantastic!

If you like ultralight radios like the Sangean DT-120, check out our endurance test of the Sangean DT-160CL and Sony SRF-39FP.

Links:

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Gary shares some catches from the first day of the Rockwork 5 DXpedition

FSL Antennas poised to grab DX! (Photo: Gary DeBock)

Many thanks to SWLing Post contributor, Gary DeBock, who shares an update from the latest Rockwork (Utralight) DXpedition. Gary notes (in bold):

First day FSL antenna setup at the Rockwork 5 ocean cliff near Manzanita, Oregon (Craig Barnes in the photo)– outstanding conditions for 558-Fiji and 1017-Tonga!

558 Radio Fiji One Suva, Fiji Awesome signal with island music and medley song ID on the half hour at 1230 (including “Radio Fiji One, Na Domoiviti” at 1:36) :

Click here to download audio.

765 Radio Kahungunu Napier-Hastings, NZ The usual S9 signal from this 2.5 kW overachiever with distinctive Maori music at 1218:

Click here to download audio.

1017 A3Z Nuku’alofa, Tonga Monster signal with island music at the start of the session at 1221:

Click here to download audio.

Monster signal with island music near the close of the session at 1314 (in other words, all session long):

Click here to download audio.

Wow! Impressive catches, Gary! Someday I would love to join your team as you snag signals from the edge of the Rockwork cliff.

Thanks for sharing, Gary and good DX!

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Guest Post: A DSP Hi-Fi “Stupid Radio Trick”

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


Stupid Radio Trick – DSP “Hi-Fi”

by TomL

If you can remember the 1960’s, there was an audiophile rage going on called Hi-Fi.  The base unit consisted of a ponderous piece of furniture consisting of a rectangular cabinet and equally large mellow sounding speaker of fairly smooth frequency response, say in the range of around 40 – 15000 Hz.  They would have a built-in radio (using vacuum tubes) with large analog scale. Most would also have a “record player” embedded on the top to spin some vinyl discs (78 or 33 rpm).

For pedestrian consumers, it became a decision of how to keep up with the Joneses, so-to-speak.  And that meant a trip to Sears to look at the latest offerings. When the decision finally came to purchase, of course no one could buy it outright.  So, to add to the suspense, one had to put money down on “Lay-A-Way” plan that did not allow you to take possession of your prized choice until the last monthly payment!  One had to visit or mail in a check every month.

So where am I going with all this?  Well, as you can see from the photo [above], I have purchased three portable radios for three very different purposes.   All three were painstakingly studied and reviewed and weighed against all other possible choices. All are highly rated by the usual reviewers like RadioJayallen, SWLing Blog readers and other internet personalities.  The Sangean is for home use and listening to baseball games when I did not want to fire up the stereo hooked up to the Grundig Satellit 800. The small Sony ICF-19 is a phenomenal knock around radio for the car and listening while out to lunch or a walk in the park.  The large Tecsun S-8800 is a possible replacement for my ailing 20+ year old Sony ICF-2010 for shortwave use.

Well, I was tired of listening to any one of them in terms of sound quality.  The Sangean has too much upper bass/lower mid range, the small Sony is very carefully maximized for total speech clarity, and the Tecsun seems to lack a little in the mid range frequencies (compared to highs and lows).  Staring at them, I thought to self, “What if I turn on the Sangean and Sony together???” What ensued was a revelatory sonic experience (it sounded pretty good)! One seemed to fill in the other in certain ways. But it was not perfect.

Duh, I had the new Tecsun in a carry case while trying to decide if I send it back for a tuning quirk and dug it out and plopped it on top.  Turning it on, I heard more lows and highs, just like a Field Radio should have but with the mid range filled in! After very careful volume adjustment, I now have something that could rightly be called DSP Hi-Fi.  At least, that is what I am calling it for now. ?

Violin and piano pop-out of an orchestra but not too harsh sounding.  Rock & Roll sounds loud and punchy without that boombox effect. Bass lows are there (could be better, now all I need is a small subwoofer connected to the Tecsun line-out ???).  Highs are there too but well controlled. Mid range voice clarity is stunning, as if someone is in the room with me but not sounding too forward! It is not room-filling but acts more like a near-field monitor.  I like that I can line-up the speakers over each other.

The really fortunate thing is that all three radios have complete DSP for FM and receive my favorite over-the-horizon station with very similar reception quality.  Also, they process DSP with a similar delay before output to its respective speaker. The sound is fairly coherent and even though it is still mono output, the full range of musical fidelity can be appreciated better.  It is not audiophile quality but it is very satisfying and I can actually hear more details in the music than with any one of the radios by themselves. Just goes to show you that you CAN teach a new Radio dog old Tricks (LOL)!

Happy Listening,

TomL


I love it, Tom!  Thanks for pointing out that sometimes it takes a “stupid radio trick” to really produce some amazing audio fidelity! This reminds me that in the early 90s, I used to have a Zenith Transoceanic and RadioShack DX-440 on my radio table in my room.  If I recall correctly, the Zenith was on my left and the DX-440 on the right. I used to tune to shortwave, MW and FM stations and produce a makeshift “stereo” effect by playing both at the same time. Sometimes, on shortwave, it actually helped me discern voices in weak signal work!

Thanks again, Tom!

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Guest Post: The Days of AM Pop Music in New York City

Dan Ingram (September 7, 1934 – June 24, 2018)

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


Dear Thomas,

Thank you for all good articles on the SWLing Post.

After the passing of Top 40 radio disc jockey Dan Ingram of WABC 770 AM and later WCBS 101.1 FM, the golden days of Top 40 radio in New York City, the biggest radio market in the United States has been observed in TV and articles. Since 1988, no major AM station in the New York market plays pop music.

Video: Big Dan Ingram Tribute of YouTube

Click here to view on YouTube.

In 1960 WABC 770 AM changed format top Top 40 with upbeat disc jockeys, taking advantage of its 50,000 Watts clear-channel undirectional transmitter with the possibility to reach distant suburbs even 100 miles away during daytime and large portions of eastern United States and Canada after sunset. Its competitors at time were Top 40 stations 1010 WINS, 570 WMCA and 1050 WMGM but with directional transmitters.

Link: News12: A look inside the WMCA Meadowlands radio tower

http://www.news12.com/story/38678814/a-look-inside-the-wmca-meadowlands-radio-tower

Link: WMCA Transmitter Building in LEGO

http://robbender.blogspot.com/2011/02/wmca-transmitter-building-in-lego.html

Link: Photos of the WMCA Transmitter on Flickr

https://www.flickr.com/photos/docsearls/albums/72157686311013535

In the mid-1960s and on to the 1970s WABC had a long line of radio personalities like Dan Ingram, Harry Harrison, Ron Lundy, “Cousin Bruce” Bruce Morrow, and Chuck Leonard to name a few. Teenagers would enjoy listening to WABC with their transistor radios being popular. In the 1970s WABC was often No 1 or 2 in the New York radio ratings.

However, the Top 40 format was to become less popular in AM with FM stations starting to play hits. WMCA dropped its Top 40 format in the fall of 1970. Despite rivals from FM stations like WXLO 99X, soul station WBLS, album-oriented rock stations like WPLJ and WNEW-FM, WABC stayed on top until 1978 with the only notable AM competitor being 660 WNBC with an adult-leaning Top 40.

But when FM-station Mellow WKTU 92 changed format to disco and became Disco 92, an FM became the No 1 station in New York City putting down WABC to No 2 in December 1978. WABC started to play more disco but the audience became confused. With new management WABC started to aim for an older audience playing more adult contemporary songs. By 1981 WABC played more oldies and started to promote talk shows. In May 1982 it was announced that WABC would become a talk radio station. On May 10, the music ended on WABC and it was in radio called the day music died.

Video: Dan Ingram air check from 1980 on WABC in AM Stereo (Youtube)

Click here to view on YouTube.

Link: AM Stereo – the Kahn system (WNYC)

https://www.wnyc.org/story/am-stereo-the-kahn-system/

Video: The end of music on WABC (Youtube)

Click here to view on YouTube.

Video: Aircheck from WKTU Disco 92 in 1979 (Youtube)

Click here to view on YouTube.

1010 WINS dropped rock and roll music in 1965 and became an all-news station. 1050 WMGM (WHN from 1962) had various music formats until 1987 when it became all-sports.

660 WNBC was the last of the major Top 40-stations to drop music. It had various pop music formats until 1988 when it became all-sports 660 WFAN since WHN/WFAN changed to that frequency. 660 WNBC introduced shock jock Don Imus and afternoon jock Howard Stern.

Videos: WNBC sign-off

(WCBS-TV)

Click here to view on YouTube.

(WNBC-TV)

Click here to view on YouTube.

Many of the disc jockeys, including Dan Ingram, would join 101.1 WCBS-FM, playing oldies with the Top 40 disc jockey upbeat. The classic Top 40 era with double-digit ratings and the nighttime signal reaching hundreds of miles away was gone.

The website Musicradio 77 has a lot of resources and memorial about WABC but also WMCA: https://musicradio77.com

Patrick


Thank you, Patrick, for the stroll down Memory Lane–and thanks for sharing the informative links and videos!

I truly appreciate honoring Dan Ingram as well–no doubt, there are many SWLing Post readers who remember him from WABC. He was and will always be a radio legend.

Post readers: Do you have any memories of AM Pop Music in New York City? Please comment!

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Olivier is pleased with the Sony SRF-M95, shares internal photo

Many thanks to SWLing Post contributor, Olivier Tkaczuk (F4BXV), who writes:

Hello, my name is Olivier TKACZUK 36 years F4BXV and I live in the north of France.

Just to present my last Sony SRF-M95 AM/MW bought on eBay for 13 euros.

[I regularly receive] Absolute Radio in England…and also Radio Nacional de España.

[H]ere is an internal photo:

Thank you for your website it gives me taste on the radio.73’s Olivier F4BXV

Many thanks, Olivier! I’ve always loved this über-compact AM/FM radios. They remind me of the small radios I used to sneak into school when I was a kid! Sounds like the SRF-M95 is a capable little receiver as well–thanks for sharing the photos.

Glad you’re enjoying the SWLing Post!

Click here to search eBay for the Sony SRF-M95.

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Bill tunes to WWFD in AM HD

Many thanks to SWLing Post contributor, Bill Mead, who writes:

Thomas, I’m sending you a short clip from WWFD 820 kHz in Frederick, MD. It’s America’s only all-digital station, apparently. They are HD only with a relatively eclectic music format. I’m hearing them at my QTH in Harrisburg, PA, about 80 miles or so north of their transmitter which is 4.3 Kw daytime. I sort of doubt they’ll come in at night when they drop down to 430 watts, but who knows.

My experience with HD on MW is that it can be heard at pretty decent distances under ideal conditions but the slightest bit of interference, a lightning strike or someone switching on the lights for example, and it’ll lose the HD lock.

My HD receiver is a Sony XDR-F1HD. It’s well-known as an excellent FM DX machine. What’s not as well-publicized is that it’s a very decent MW receiver as well. All it needs is a good MW loop antenna directly connected to the AM ANT terminals on the back of the radio.

Click here to view on YouTube.

Excellent!  Thanks for sharing, Bill. I’m passing by Frederick, MD in a couple of weeks and plan to tune to WWFD in both my car and with the Sangean HDR-14.

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