[TenTec] OT: Openwire Balanced Antenna Tuners (QST Test)

[denton]

Another advantage of those old link coupled transmatches is their ability to 
reject out of band signals...they pretty much function as a band pass 
filter.

--------------------------------------------------
From: "Al Gulseth" <wb5jnc at centurytel.net>
Sent: Saturday, February 16, 2013 7:58 AM
To: <tentec at contesting.com>
Cc: "Rick - DJ0IP / NJ0IP" <Rick at dj0ip.de>
Subject: Re: [TenTec] OT:  Openwire Balanced Antenna Tuners (QST Test)

> Rick,
>
> TNX for the spreadsheet - it's an interesting read. What I gleaned in a 
> quick
> analysis is that while they aren't as convenient, the "old school"
> link-coupled tuners (in this case, the Johnson Matchboxes) seem to hold 
> their
> own pretty well against the newer technology, especially when it comes to
> efficiency. Maybe there's something to be said for the use of air-wound
> inductors and good quality variable caps (as opposed to toroidal inductors
> and fixed caps) when it comes to antenna tuners?
>
> 73, Al
>
> On Fri February 15 2013 9:48:57 am Rick - DJ0IP / NJ0IP wrote:
>> The March 2013 issue of QST has another Antenna Tuner test by Joel, W1ZR.
>>
>> This article is a good read because it also describes the ARRL's newest
>> test method for antenna tuners.
>>
>> ONE OF THE BIGGEST MISTAKES I find people make in their thinking is, they
>> believe that if their ATU can match the antenna, that's goodness.  NOT!
>> In addition to whatever losses the antenna itself may have, there may 
>> also
>> be SIGNIFICANT matchbox losses. as this article points out on one of the
>> boxes.
>>
>> The two Matchboxes tested here are the MFJ-976 and Palstar BT-1500A.
>>  <> What are their matching ranges?
>>  <> MORE IMPORTANT, how much power is lost in the matchbox when matching
>> the various impedances?
>>
>> BTW, I have added these results to my "MATCHBOX SHOOT-OUT Spreadsheet" on
>> my web site.
>> It compares these tuners to others which the ARRL has previously tested.
>> LINK:  http://www.dj0ip.de/antenna-matchboxes/matchbox-shoot-out/
>>
>> A HUGE THANK YOU TO JOEL and his colleagues for reporting on this
>> interesting topic.
>>
>> 73
>> Rick, DJ0IP
>>
>>
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