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Re: [Amps] 2 x 3-500Z filament choke + 30/60/80A fil chokes

To: "Jim Thomson" <jim.thom@telus.net>, <amps@contesting.com>
Subject: Re: [Amps] 2 x 3-500Z filament choke + 30/60/80A fil chokes
From: "Carl" <km1h@jeremy.mv.com>
Date: Mon, 5 Dec 2011 13:22:23 -0500
List-post: <amps@contesting.com">mailto:amps@contesting.com>
----- Original Message ----- 
From: "Jim Thomson" <jim.thom@telus.net>
To: "Carl" <km1h@jeremy.mv.com>; <amps@contesting.com>
Sent: Monday, December 05, 2011 4:19 AM
Subject: Re: [Amps] 2 x 3-500Z filament choke + 30/60/80A fil chokes


>
>
> --------------------------------------------------
> From: "Carl" <km1h@jeremy.mv.com>
> Sent: Sunday, December 04, 2011 6:04 PM
> To: "Jim Thomson" <jim.thom@telus.net>; <amps@contesting.com>
> Subject: Re: [Amps] 2 x 3-500Z filament choke + 30/60/80A fil chokes
>
>> The 33 Mix is what gets you down to 160 without having to get fancy with 
>> using the choke as part of the input network. The network programs dont 
>> calculate for the hammy hambone "engineering".
>>
>> Carl
>> KM1H
>>
>
> ###  say what?   33 mix is low freq stuff...and will also work just fine. 
> It has a mu of
> 600.   Type 43 has a mu of 800.    I had zero access to type 33 material 
> in rod form.
> What you don't want is  type 61, with it's  mu=125.   It won't provide 
> enough uh
> on the low bands at all.  If type 61 is used, the type 61 rod can be 
> removed, and type
> 33/43 slid into place.

** I dont know where you are getting 43 mix rods Jim since Fair-Rite doesnt 
make them.
The 33 mix is the choice plus it is temperature stable to a high degree.

>
> ##  The only place where you will ever see the fil choke being part of the 
> tuned input
> is on Rich measures 160m SB-220 conversion article.   The stock heath fil 
> choke is just
> 9 uh per winding.  Instead of installing a bigger one, he instead adds an 
> additional 900 pf in parallel
> to the  C2 cap [closest to the cathode]  of his  new 160m tuned input  PI 
> net.
> That extra 900pf  cap will parallel resonate  with the 9uh fil choke on 
> 160m only.  That makes the
> sb-220 fil choke look like a High Z on 160m.  That was a one off unique 
> method to get around
> installing a  bigger fil choke for the 160m mod.  What's slick about his 
> mod is... the extra 900 pf
> is only added in..via the 160m tuned input.   It's out of the circuit on 
> all other bands.

** Rich must have copied that from Dentron which used a 4" 33 mix down to 
160.


>
> ## The story I got was the fil chokes XL  should be  4 x  the   cathode Z. 
> With a 50 ohm input Z,
> that equates to 200 ohms of XL on the lowest freq... which equates to  9 
> uh on 80m....and 18 uh
> on 160m.
>
> ##  what's  hammy hambone engineering, your typ arrl  fubar handbook ?

** Also a lot of the garbage called engineering on many web pages.


>
> ##  hey carl,  what was that giant rod you used to sell  way back in the 
> 80's ?    It was
> 12"  long x 1"  diam.   I kicked myself for not stockpiling a few of em. 
> Thought it was
> type 33 ?

** R33 -75-1200. I saved a few for myself but finally put them on Fleabay 
back when I told you I was going thru old stock here. I dont build 3X3's any 
longer.



     I see you can get 6-8-10 ga magnet wire easily  like from
> planet wire etc.


** I still have a lot of 10, 12 and 14.


> Apparently you can get 4 ga magnet wire in chile.
>
> later... Jim  VE7RF



Carl 

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