[TowerTalk] CMC-230-5K

[Jim Brown]

On Wed,4/20/2016 6:29 AM, Jim Thomson wrote:
> ###  By the time I buy 4 x torroids from one vendor PLUS shipping, then a pair of
> those special one off  SO-239s  he uses, no Z bumps,  silver /teflon /gold...PLUS shipping,
> then double shielded teflon coax, with silver braids + silver center conductor...PLUS shipping,
> then a UV /water proof enclosure... PLUS shipping, then 4 of the one off nylon tie downs, that
> are machine screwed down...PLUS shipping....and assuming I have the SS hardware on hand
> plus the required gear to silver solder and terminate the ends, I decided I will save next to nothing.
> In fact, I would save nothing.

You would save a lot if you did what I recommended about 8 years ago -- 
get together a group purchase and buy in quantity. I've been part of at 
least half a dozen, two of which I've organized. Appendix One of my 
tutorial lists Fair-Rite part numbers of some useful parts and lists 
several good industrial vendors who sell in quantity at great discounts. 
Remember - we need these parts not only for feedline chokes, but also to 
kill the many RFI sources that most of us have in our homes, and that 
are in the homes of our neighbors.

>
> ##  sometimes mucking about, dealing with in this case, at least FIVE  different vendors, and shipping
> on all FIVE, assuming no screw ups, and  hoping it all arrives intact,  I spend more time  rounding this stuff
> up vs  building it. Shipping from USA to canada is not cheap.

I've also organized several group purchases of Amphenol 83-1SPs, and 
assorted audio connectors of the type we use around the shack. I'd be 
very surprised if there are no distributors of Fair-Rite and Amphenol in 
Canada.

>
> ##  I don’t see any  plug and play  cook book designs  by anyone, that  covers the 2-30 mhz
> spectrum, with a sky high  8-12k Z, that  fits into a very compact 6 long x 4.375  wide  x 2  tall box,
> that weighs exactly 1.8 lbs.

Don't you recognize an advertising claim when you see one?  I'm not 
trying to sell you anything, I publish measured data on the chokes, AND 
tell you exactly what's in them and how I measured them. Do you see ANY 
of that in the magic boxes you're buying?
>   
>
> ##  he offered FREE shipping to Canada on a completed, plug and play unit.  It was here real fast.
> I wish I had the megabuck worth of test gear to do my own experimentation on CMC chokes.
> Nobody has managed to overheat a CMC-230-5k....yet.

It's a brand new product, Jim!  And you really believe a mfr is going to 
tell you about his failures?

> You will literally  melt the traps in any
> Mosely pro-96 yagi long b4 the cmc heats up.   Ditto with the xfmr inside the stepir yagi.
>
>
> ##  To increase power handling capability of a CMC, there is a few ways to do it, and that depends on
> how much spectrum it has to cover. More cores + less turns is one technique.

WRONG!

> Cascaded CMCs is another technique.... or a combo of both techniques.    Sky high Z + RS is another concept.

I published my take on this 6 years ago, and what I wrote about it was 
not smoke and mirrors.  I also have written about specific single core 
chokes that failed at high power.

73, Jim K9YC