Re: Guy Atkin's Independent Testing of PL-380 7.5" Loopstick

Tony Germanotta

Here's a website that has a photo of the radio in question. The Loewe 3NF tube was considered the world's first integrated circuit because they put resisters and capacitors inside the glass. The wooden framed one in front is the one he brought in. His coils were a pretty pale blue and seemed less dense. Maybe this one in the photo is for LW reception. It isn't very big. Almost would qualify for UL status. Later models were even battery powered, with a special version of the tube known as 3NFBs. What we won't do to avoid a little tax payments. You know that tube had to make that radio a lot more expensive than one that simply used three discrete stages. And one thing goes wrong and the entire set is done. The company did repair its tubes for you. 

I'd love to see how they wove that coil though.

I guess this is pretty far afield from UL, so I'll cease and desist. But coils and loops are so much of the fun with UL reception, even if it does move everything into the unlimited class.

On Feb 11, 2010, at 2:51 PM, Tony Germanotta wrote:


Yea, mine was built for speed not beauty, but I used it for years to listen to the Phillies games in daylight here some 300 miles south of the transmitter. That's a much tougher task than just DXing, because you need a consistent signal and the ability to null out those pesky SAs when twilight falls or you miss Harry Kalas calling a historic home run. Harry's gone now, died of a heart attack in the booth last spring. And the 4-foot loop is still over at Chuck Ripple's compound waiting for me to find a large enough vehicle to transport it home or a warming trend so I can drop the top on my Miata and drape it around my shoulders once again.

 I have a nice work of art loop here that I bought at a silent auction years back at the old SWL Winterfest. It's an altazimuth model complete with preamp and works like a charm as the MW antenna for my Drake R8A. Coupled to a longwire and an MFJ phasing unit and I can do a lot with it. But it sure doesn't qualify for Ultra Light status.

Yesterday at a meeting of our local antique radio club, one member brought in a single tube radio made in Germany that has a single tube that does the work of three. It was designed for the local market there to cheat on broadcast taxes that were based on how many tubes your radio had. Anyway, the thing used small, plug in air core loops wound in a combination of spiral and box format. They were only a couple inches large but amazingly beautiful. They looked like something out of string theory.

On Feb 11, 2010, at 2:39 PM, jim_kr1s wrote:


--- In, Tony Germanotta ...> wrote:
> Or watching those lights climb on a 2010's signal meter. It still seems like magic when everything lines up. Even grizzled old hams have a hard time believing in inductive coupling of a loop until you sit a Select-A-Tenna next to a radio and show them how it works. (A whole lot more convenient than that 4-foot box.)

True, but IMO there are few things prettier than a well-made box loop. You look at one of those things and you just know it will suck in the signals! (Even if its purpose is to null 'em.)


Jim, KR1S 

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