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[TowerTalk] Testing traps for heating

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Subject: [TowerTalk] Testing traps for heating
From: richard@karlquist.com (Richard Karlquist)
Date: Sat, 15 Sep 2001 09:43:07 -0700
Rather than the cumbersome test you suggested, simply
measure the Q of the trap with a Q-meter or other
impedance measuring equipment at low excitation levels.
Then you can calculate the loss for a given voltage.
If you want to know the temperature rise for this wattage,
simply excite the coil with DC of equivalent wattage
and see what the temperature goes up to.

You would need to use the impedance measurement of the
trap in EZNEC to determine the RF voltage
vs power on the trap.  It'll be 1000's of volts
at the legal limit typically, on the trapped band.

Rick N6RK


richard@karlquist.com
www.karlquist.com 

> -----Original Message-----
> From: owner-towertalk@contesting.com
> [mailto:owner-towertalk@contesting.com]On Behalf Of N0TT@ juno.com
> Sent: Friday, September 14, 2001 8:44 PM
> To: towertalk@contesting.com
> Subject: [TowerTalk] Testing traps for heating
> 
> 
> 
> Hi TTers,
> 
> I would like to test some homebrew parallel resonant
> traps for heating and breakdown without transmitting
> on the air with full legal power and without an elaborate
> setup.  
> 
> The two types of traps I want to test are high inductance
> self-resonant types and the "standard" inductor/coax
> capacitor type.  All are parallel resonant in the 20, 30,
> 40, 80 meter bands.  Of course the 30m trap need not be
> tested to 1.5 kw.
> 
> I'm thinking I could "feed" the trap-testing setup with
> a antenna tuner, with a trap connected in series with a
> dummy load in an off-resonant condition.  
> 
> For a parallel test I was thinking that I could hook the
> trap in parallel with another tuned circuit that would
> have taps for impedance matching for input/output.
> 
> Any suggestions or thoughts on this?
> 
> I looked on the web and TT archives and QST/QEX indices
> but no luck.
> 
> 73,
> Charlie, N0TT
> 
> 
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List Sponsored by AN Wireless:  AN Wireless handles Rohn tower systems,
Trylon Titan towers, coax, hardline and more. Also check out our self
supporting towers up to 100 feet for under $1500!!  http://www.anwireless.com

-----
FAQ on WWW:               http://www.contesting.com/FAQ/towertalk
Submissions:              towertalk@contesting.com
Administrative requests:  towertalk-REQUEST@contesting.com
Problems:                 owner-towertalk@contesting.com


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