Category Archives: Mediumwave

The Society of Broadcast Engineers urges FCC to Improve Mediumwave RFI

(Source: ARRL via Eric McFadden, WD8RIF)

The Society of Broadcast Engineers (SBE) has told the FCC that the regulatory agency needs to take another tack in its efforts to tackle AM revitalization. If the FCC takes the SBE’s advice, the result could be less noise in the MF and HF Amateur Radio bands. In comments the SBE filed in response to an FCC Further Notice of Proposed Rulemaking and Notice of Inquiry (MB 13-249) proposing ways to enhance the viability of the AM broadcast service, the SBE said the Commission must “commit to a regulatory plan which, over time, will reduce the levels of man-made noise in the MF bands, and more broadly in the bands below 30 MHz.” In comments it filed earlier in the proceeding, the SBE pointed out that “AM radio in particular is susceptible to interference from electronic devices of all types,” and that ambient noise on the AM band is only bound to get worse with further proliferation of noise-generating electronic devices, including certain lighting devices regulated under FCC Part 15 and Part 18 rules.[…]

Continue reading at the ARRL website…

Paul Litwinovich on “The Life, Decline and Possible Rebirth of AM”

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Many thanks to the SWLing Post reader who noted this latest post by Paul Litwinovich at WSHU (Paul is frequently referenced here on the Post).

A short excerpt:

“AM occurs elsewhere in nature. A lightning strike or manmade electrical discharge will produce a burst of electrical noise that varies in amplitude. Since AM radios are designed to detect variations in amplitude, this is why they are prone to interference from such things. AM held sway as the primary method of modulating a radio wave up to WWII, not only for broadcasting, but for all types of radio communications.

Every vintage consumer radio, be it standard broadcast or shortwave, up to WWII, received amplitude modulated signals. Nowadays, AM broadcast stations are associated with lower quality audio, but such was not always the case. Receiver design really came of age in the 1930s with the superheterodyne circuit and advancements in loudspeaker design. The grand floor consoles of the late 1930s leading up to WWII were capable of producing audio that was very good, even by today’s standards, the only exception being that they were monaural, as stereo technology was still a ways off.”[…]

Litwinovich’s article is a must-read as he gives a concise overview of amplitude modulation, AM vs. FM, and even covers current proposed uses of the broadcast band (something we’ve also recently mentioned).

Click here to read The Life, Decline and Possible Rebirth of AM.

Tuning the Scott Marine SLR-M at sea

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Many thanks to SWLing Post reader, Vendel Boeree (K2DSI), who writes:

Hi Tom, I just wanted to compliment you on your fine website. As a kid I would listen to Radio Netherlands which made me quite the hit with mom because she was homesick for our native Holland for quite some time. I was heart broken to find out that Radio Netherlands went dark not that long ago.

Back in 1967 my family moved to Australia and went there by freighter. Things didn’t work out as planned and we returned on an old American freighter, the “African Moon”.

I became friendly with the radio operator on that ship and he let me shortwave listen when he was off watch. The receiver was a “Scott” and appeared to be the same as yours. They also had a “Scott” receiver in the lounge that had a slide rule dial that was used for entertainment purposes. I was hooked. I wanted to be a radio operator.

Needless to say I didn’t follow through on that dream and I suppose that’s just as well seeing as how ROs are a thing of the past.

Take care and keep up the good work.

Vendel Boeree/ K2DSI

Thanks so much for sharing those memories, Vendel! I bet reception was nothing short of amazing while you were at sea. I’m guessing the slide rule model Scott you listened to in the lounge was the model SLR-F (click here for a photo).

Just the other day, my wife looked around my radio shack and asked what radio I would grab if the house were on fire. My answer was the Scott Marine SLR-M. It represents everything I love in WWII era receivers: built like a tank, great sensitivity, beautiful back-lit dial, built-in speaker, phono in, a magic eye and–since it was intended as a troop morale radio–beautiful room-filling audio.

Yep. Scottie’s a keeper!

Radio Caroline: A video diary of the weekend aboard the MV Ross Revenge

1 Reply

Many thanks to Mike Terry who shared the following note and video via Facebook:

The great old days when the signal was mellow and radio waves were not blocked by buildings and hills and propagated beyond the horizon especially at night, it all added to the excitement. We would never have heard many of the great records of the 60s and later without this station! So many international stars made their name on the offshore stations around our coast 50 years or so ago. UK radio was changed for ever.

[Note: This video may only be viewable via Facebook or the SWLing Post site.]

Mike’s low and high pass filter deals

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SWLing Post contributor, Mike Ladd, is an avid SDR enthusiast and an administrator of the SDRplay Facebook group. Mike contacted me about special pricing he has arranged for low and high pass filters through Rescue Electronics. Mike explains:

These filters retail for $70.00 each. I spoke to the builder. I told him who I was and what I do and got him to make a deal for anyone in the United States with these filters and a direct link to his site. I make zero dollars on this. I always try to give back to the hobby and the community any way possible.

You have 3 choices: a high pass filter, a low pass filter, or a combo package.

These are hand built one at a time by Paul W1VLF with your choice of SO-239 or BNC connections. Full details are below:

High pass filter $55 shipped anywhere in the USA

This filter will begin attacking the AM band at 1770 Khz and increase attenuation as frequency decreases.

You can see this in the screen capture of the swept filter below.

160 Meters and above is virtually left untouched, but below that is where the attenuation takes place.

The filter has attenuated 60 db by 960 KHz.

The AM band has some very large signals that can mix in the front end of your. A lot of these spurious frequencies can land in 160 meter band or above.

For instance, I have a big signal at 1080 Khz and another at 770 Khz, add these 2 together and you get a spur that falls at 1850 Khz

Picture this happening at multiple frequencies with multiple mixes and you have a raised noise floor in the 160 Meter band.

The filter is built into a 2″ x 4″ 1.25″ 1/8″ wall aluminum enclosure for excellent RF shielding

Low pass filter $55 shipped anywhere in the USA

The AM-2 filter has a cutoff at 520 KHz.

Then, and without a lot of fanfare it begins the attack on the MW band.

Purchase this filter if you are into NDB, DX’ing, Maritime Mobile, Navetex, FCC Part 5 600 Meter band.

Each filter is handmade and swept in my lab.

The AM -2 Low pass is equipped with BNC connectors.

The filter begins to roll off at 520 Khz and gives an ultimate rejection of around 80 Db.

The filter is built into a 2″ x 4″ 1.25″ 1/8″ wall aluminum enclosure for excellent RF shielding

Combo deal for both $100 shipped anywhere in the USA

Click here to view/purchase via Mike Ladd’s promotional page at Rescue Electronics.

Many thanks for sharing this Mike! During my presentation at the Winter SWL Fest last week, I spoke about the need for high/low pass filters for listeners who live in the presence of strong broadcasters and interference. Many of the inexpensive SDRs on the market do not have built-in filters and preselectors thus can overload under these conditions.

While filters can be homebrewed or built from kits, these filters seem to be a good deal for a quality shielded and tested product. Thanks for arranging this, Mike!

AM radio proposal has Class A broadcasters upset

42 Replies

(Source: Times Union)

When the sun goes down, AM radio signals travel much farther. You can listen to 50,000-watt stations such as WGY hundreds of miles away.

But that could soon change, if the Federal Communications Commission goes through with a plan to let more local stations broadcast through the evening hours and potentially makes changes in the daytime signal of WGY and other powerful stations.

The proposed change in protections to Class A stations such as WGY would ease restrictions on the smaller stations, which are now required to reduce power or change the direction they broadcast their signal so they don’t conflict with the more powerful Class A stations.

WGY has begun an online petition drive to oppose the changes.

Called “Save AM Radio,” the petition opposes reducing WGY’s so-called “protected service area.”

The changes, WGY says, “will make it very difficult for many of our listeners to receive our programming, especially at night and during morning and evening drive times.”

[…]The FCC, meanwhile, says the changes are being considered in an effort “to help revitalize the AM service.”

More local stations would give listeners a wider choice of programming, supporters of the change argue.

[…]WGY’s online petition is at http://www.wgy.com/features/save-am-radio-1919/
The FCC is accepting comments through March 21 and replies through April 18, at www.fcc/ecfs. Click on “submit a filing.” The proceeding number is 13-249.

Read the full article at the Times Union online…

I’m very curious what Post readers think about this proposal from the perspective of both access to regional information, as well as from MW DXing. Will this move crowd the AM broadcast band or give local stations a stronger voice?