Tag Archives: Mr. Carlson’s Lab

Radio Waves: Crossband Test Postponed, VI3RA Event Videos, WWII Radio, and Look Inside a Panasonic RF-4900

Radio Waves: Stories Making Waves in the World of Radio

Because I keep my ear to the waves, as well as receive many tips from others who do the same, I find myself privy to radio-related stories that might interest SWLing Post readers. To that end: Welcome to the SWLing Post’s Radio Waves, a collection of links to interesting stories making waves in the world of radio. Enjoy!

Many thanks to SWLing Post contributors Harald Kuhl, Michael Bird, and Carel Kuijer for the following tips:

Annual Armed Forces Day Crossband Test Postponed (ARRL News)

Due to the ongoing COVID-19 response and mitigation actions, the 2020 Armed Forces Day (AFD) Crossband Test scheduled for Saturday, May 9, has been postponed. Because it’s uncertain just when stay-at-home orders will be lifted across the US, AFD planners chose to postpone this year’s event, because the government stations that typically support this event may not be available. Armed Forces Day Crossband Test planners are considering scheduling a November event in honor of Veteran’s Day, depending on COVID-19 mitigation actions. During the AFD Crossband Test, military stations in various locations transmit on selected military frequencies and announce the specific ham frequencies they are monitoring to work radio amateurs. — Thanks to US Army MARS Program Chief Paul English, WD8DBY

Radio Australia Event – Antenna Overview (Mount Evelyn DX Report)

Thanks to Lee VK3GK for this short video of the antennas used for the recent Radio Australia event using the call sign VI3RA. Take what will possibly be a final look at the feeders, switching boxes and antennas before they are pulled down and junked!

Also here is the final transmission of the event weekend with, of course, the famous Radio Australia music box interval signal.

Click here to view both videos at the Mt Evelyn DX Report.

World War II and Radio (All Things Radio)

I have added an article I wrote some years back on the code breaking efforts of the Allies during WWII. While certainly not exhaustive, I found many of the connections between countries and equipment rather fascinating, and new things continue to pop up regarding Bletchley Park’s role in training officers and decoding texts. While most famously known for breaking the Enigma code, also significant was the breaking of the Lorenz Cipher.

Click Here to download the article in PDF format.

73, Robert K4PKM

Look Inside This Radio Receiver! The Collectible Panasonic RF 4900 (Mr. Carlson’s Lab – YouTube)

Let’s look inside this Panasonic RF-4900 radio receiver, and see what we have to restore.

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Standing Inside a Broadcast Transmitter While it’s ON!

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I stumbled across a video from the fabulous Mr Carlson’s Lab YouTube channel. If you haven’t check out this channel before, and you are really eager to learn more about electronics, this is a wonderful YouTube site.

So, in the latest episode, Mr Carlson takes us on a tour of a very large Gates BC-250-GY broadcast transmitter from the 40’s era. Lots of big tubes, transformers and capacitors! This is an old mediumwave transmitter that he has restored. Although the technology has changed markedly since the 1940s, the basic principals of transmission are still present. And, interestingly, he points out that this particular unit was in regular service right up until as recently as 2003!

It’s an interesting show and even if you can’t grab onto all the technical information presented, I think you will enjoy looking at technology from a past era.

73 and good DX to you all,

Rob Wagner VK3BVW

Rob Wagner, VK3BVW, is the author of this post and a regular contributor to the SWLing Post. He also blogs at the Mount Evelyn DX Report.

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Mr. Carlson restores and repairs a Hammarlund HQ-140-X

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hammarlund-hq-140x Many thanks to SWLing Post contributor, Moshe, who writes:

Hi Thomas!
You must see this restoration job from Mr. Carlson’s lab:

Click here to view on YouTube.

Thank you for sharing this video, Moshe! I truly enjoy watching Paul’s videos–no doubt, any radio turned over to him is in expert hands. I love how he explains, in such detail, each action he takes to restore and repair these vintage radios.

Click here to view Mr. Carlson’s YouTube channel.

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Patrick comments on his newly-restored Sony CRF-320

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Many thanks to SWLing Post reader, Patrick Mason, who writes from Juneau, Alaska:

I am the owner of the radio that Paul Carlson restored in the video. The serial number is 31358.

I wanted to comment about a statement regarding the receiver’s sensitivity.

After Paul concluded his final tune-up of the radio I can confirm on the shortwave bands, particularly 80 and 40 meters, the sensitivity on AM was better than 0.2 uV/m. That’s outrageous! The VFO is rock solid with no detectable drift whatsoever.

Also, Paul replaced all nylon gears with custom metal gears… they will never fail again.

Anyone considering acquiring this radio, buyer beware! There are many on the WEB who will claim it to be in some ‘totally restored’ condition…when mine arrived from the seller it ‘seemed’ to be ok…..until the counter went fruit loops shortly after unpacking. When Paul got inside the radio it had been ‘tweaked and peeked’….all wrong.

I have a CONSIDERABLE sum invested in this SONY. If I could have known it’s ACTUAL condition BEFORE my purchase, I may have passed….however, I now own what I consider to be the quintessential example of SONY’s best engineering. All I can say, it’s an absolute joy to use

Patrick, you no doubt have a benchmark Sony in that CRF-320.

It’s funny: I was just attending a local hamfest here in North Carolina and a vintage radio vendor pointed out Carlson’s repair video for your CRF-320! He said (and I agree), that your CFR-320 was restored to a level that’s almost in a league of its own. I know you invested a lot in this radio, but you certainly have a fine example now–that is fully-functional–and will most likely outlast us all! Enjoy!

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Video: Yaesu FT-1000MP Repair

Video: Repairing, restoring and modifying a Sony CRF-320

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Many thanks to SWLing Post contributor, Ken McKenzie, for sharing the most comprehensive video you’ll ever find on restoring the Sony CRF-320 receiver: