I'll take an air-wound inductor over a toroidal inductor any day, space
available. The typical loss in an air-wound inductor is IR loss where a
toroidal has IR loss plus eddy current loss.
I know one thing, my Johnson Matchbox sure does a slick job of handling the
open wire, balanced antennas. My most recent tuner is home brew, being a
balanced L network much like the Palstar evaluated in March 2013 QST. It
will easily put the 40M dipole on 160M and handle legal limit power to boot.
Yes, Joel and company at ARRL did a magnificent job of testing and reporting
on these products.
73
Bob, K4TAX
DISCLOSURE:
This is to inform all persons, I am a Tentec Ambassador and I receive
compensation according to the Tentec Ambassador program. In addition, I
serve as a volunteer beta test person to Tentec for the Omni VII, Eagle
and Argonaut VI radios. I hold no employment relationship, no financial
interests nor do I conduct any commercial business, direct or indirect,
with Tentec.
----- Original Message -----
From: "Al Gulseth" <wb5jnc@centurytel.net>
To: <tentec@contesting.com>
Cc: "Rick - DJ0IP / NJ0IP" <Rick@dj0ip.de>
Sent: Saturday, February 16, 2013 9:58 AM
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
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
|