[Lowfer] [EXTERNAL]Re: 29.499 again tonight-OP2H

[Howell, Laurence J]

Its when things start melting or turning Purple with a fizz you know your running a little hot :-)   I do think my investment of an Ir laser thermometer has been well used - especially in the early days when 77 would run for its life if it saw me...

Laurence - snowing again...

 

Sent from my iPhone

> On Mar 14, 2014, at 5:20 PM, "jrusgrove at comcast.net" <jrusgrove at comcast.net> wrote:
> 
> Dex
> 
> 77 material is fine at 29.5 kHz .... you may just need more turns. A three stack of FT240-77 needs 
> 12 turns minimum on the 50 ohm side. I wouldn't get too excited about 25 degrees temperature rise 
> ... but I would put on some extra turns.
> 
> Jay
> 
> 
> ----- Original Message ----- 
> From: "Dexter McIntyre W4DEX" <dexter.mc at gmail.com>
> To: "Discussion of the Lowfer (US, European, &amp;UK) and MedFer bands" <lowfer at mailman.qth.net>
> Sent: Friday, March 14, 2014 8:45 PM
> Subject: [Lowfer] 29.499 again tonight-OP2H
> 
> 
>> I'm in receive mode tonight running OP2H and uploading Argo grabs of Bob's big signal at 10 min 
>> intervals:
>> 
>> www.w4dex.com/grabber
>> 
>> I found an antique RF ampmeter which tells me the antenna current was .4 amp with 150 watts 
>> leaving the shack.  Then with an IR thermometer I discovered the stack of three FT-240-77 toroids 
>> that work well for antenna matching on 73, 137 and 500 kc was heating up about 25 deg above 
>> ambient temp.  I've located some J type toroids.  Would I be wasting my time trying those for 
>> impedance matching?
>> 
>> Dex
>> 
>> 
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