[RFI] New Larger Fair-Rite #31 Toroid

[Roger (K8RI)]

I would think there will  be enough room for a common mode choke  To be 
part of the feedline of RG-8 size coax. even LMR600 for 75 and possibly 160.

I'm going to order enough to do the 75 m slopers and possibly the 160 
half slopers.

The larger cores give us possibilities for increasing the power 
capability of antennas like the AV640 and OCF antennas. Common mode 
chokes as well as step up baluns.

I really think we should buck the trend of calling everything hooking 
the feedline to the antenna as a "BALUN" which has a very specific 
meaning.  Balun is short for Balanced to unbalanced, so the common mode 
choke is not a 1:1 BALUN.

It's likely a losing battle, but With each profaning of terms we are 
dumbing down Ham Radio. Now the League wants an entry level license! 
Entry Level. Compared to the Novice exam I took, all the current license 
tests are entry level.
The # of hams who can design simple circuits is getting to be fewer and 
fewer.  Low power SSB kits are lauded, but what happened to the basic CW 
transmitter from a hand full of parts.  Why do they think we need an 
entry level license compared to what we have now?

It takes very little time to learn how to design a simple bipolar SS 
circuit.  I used to teach Semiconductor circuit design using the 
Heathkit course books.  That was 30 years ago and I'd need to review to 
do it again, but it took less than a week at one hour a day to cover the 
basics.

Computer design was done using machine language (Hexadecimal). for the 
basic digital courses. Assembler was a higher level language. Now days, 
new rigs often need to be debugged as the operation is so 
sophisticated.side effects don't show up until they are being used. Rigs 
give the user so much control that they can really screw up the signal.

Sorry: End of rant!

73,  Roger (K8RI)


On 3/26/2017 7:22 PM, Jim Brown wrote:
> KY8D asked me about a new, larger #31 toroid that has recently been 
> added to the catalog. It's 4-in o.d., 3-in i.d, and 1-inch long.
>
> http://www.fair-rite.com/product/round-cable-emi-suppression-cores-2631814002/ 
>
>
> Note the impedance data for 1, 3, and 5 turns at the bottom of the page.
>
> Gan's email arrived today (Sunday) so I haven't had the opportunity 
> yet to investigate pricing. My guess is at least double the cost of 
> the 2.4-in toroid, but because it's twice the length (1-in as opposed 
> to 0.5-in for the 2.4-in toroid), a single core will likely be 
> equivalent to two of the 2.4-in cores, so fewer cores will be required 
> to achieve the same choking Z. More important, the much larger i.d. 
> will allow more turns and/or larger coax.
>
> 73, Jim K9YC
>
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