[Elecraft] high-power tuner

[WILLIS COOKE]

OK Guys, I have a Physics Degree too, but realistically, if the tuner uses real coils and air capacitors like the Matchbox it is really efficient.  If it uses link coupling like we did in olden days it is probably a scotch (technical term meaning a little bit) better than the more common T network.  If it uses toroids, small fixed capacitors and relay switching, it probably has even more loss.  So, maybe the answer is to buy a tuner that is the same size as your amplifier.  If you elect to run a KTA-500 you probably are not terribly concerned whether you get 475 watts to the antenna or 450 watts.  If you need an Alpha 9500 to be sure that you get through then you need the Alpha 4040 so it will look great near your 9500 and the 3 grand price will seem cheap after paying 8 grand for the amp.  You can always brag on your 75 meter net that of the 1499.9 watts out of the 9500 1499.8 watts get through the 4040 to melt the RG8X that feeds your Buddy Pole.
  But, if the KTA-500 is your thing then a tuner that costs more than your amp and is the biggest thing in your shack (unless you have a left over BC-610) will look pretty silly.

If you must measure your temperatures to figure your efficiency down to the milliwatt, be sure and use RTDs for measurement because thermocouples are not nearly accurate enough for precision measurements.
 
Willis 'Cookie' Cooke 
K5EWJ & Trustee N5BPS, USS Cavalla, USS Stewart


________________________________
 From: Tony Estep <esteptony at gmail.com>
To: Elecraft <elecraft at mailman.qth.net> 
Sent: Friday, March 9, 2012 7:01 PM
Subject: Re: [Elecraft] high-power tuner
 
On Fri, Mar 9, 2012 at 5:30 PM, Ian Kahn - Ham <km4ik.ian at gmail.com> wrote:
> This probably shows my gross lack of knowledge of the physics involved
> here, but what does the weight of the tuner have to do with its efficiency...
=============
Ian, the idea was to measure the power soaked up by the tuner by
measuring how fast it heats up. To turn degrees/second into a measure
of power, you gotta know how much mass was getting heated.

Tony KT0NY


-- 
http://www.isb.edu/faculty/facultydir.aspx?ddlFaculty=352
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft at mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html