[NLRS] Looking for RF transformer

[Baker, Donn B]

Try:
http://www.amidoncorp.com/aai_productselection.htm

They are VERY "ham-friendly."

220MHz may be "pushing the envelope" a bit.  The site also has a lot of really good background data and information.

73 Donn
WA2VOI/0

> -----Original Message-----
> From: nlrs-bounces at mailman.qth.net
> [mailto:nlrs-bounces at mailman.qth.net]On Behalf Of James Klassen
> Sent: Wednesday, October 27, 2004 1:37 PM
> To: Dan Larson; Jason Godfrey; nlrs at mailman.qth.net
> Subject: Re: [NLRS] Looking for RF transformer
> 
> 
> 
> Hi, I was also looking for an RF transformer, but for 222MHz. 
> What I was
> wondering is where is a good source for the balun/torroid cores?
> 
> Jim Klassen
> KB0UAZ
> 
> On 27 Oct 2004, Dan Larson wrote:
> > Oh, sorry, I forgot to mention, that with two-hole
> > balun cores, each turn must pass through both holes.
> > 
> > With a torroid core each turn passes trough the center 
> > only once. 
> > 
> > That is why you can get half-turns with a two-hole 
> > balun core. (they really *do* look like pig snouts!)
> > 
> > Dan KC0LUY
> > 
> > On Wed, 27 Oct 2004 11:58:09 -0500, Dan Larson wrote:
> > 
> > >You can come very close by winding a transformer
> > >with separate primary and secondary on a Type 43
> > >torroid core or balun core (sometimes called a 
> > >"pig snout")
> > >
> > >Use 10 turns for the 50-ohm primary, and 12 turns
> > >for the 75-ohm secondary. The impedance ratio is 
> > >the square of the turns ratio of the primary to 
> > >secondary. In this case 10t:12t will yield 50ohm:72ohm
> > >which is probably close enough. If you use a two
> > >hole balun core (pig snout) then you can wind with
> > >a ratio of 10t:12.5t to get 50ohm:74.4ohm.
> > >
> > >Hope this helps.
> > >
> > >Dan KC0LUY
> > >
> > >On Wed, 27 Oct 2004 10:57:40 -0500, Jason Godfrey wrote:
> > >
> > >>Hello.
> > >>
> > >>This is not for a ham radio application, but I thought 
> NLRS may be a
> good 
> > >>source for what I am looking for.
> > >>
> > >>I need an RF transformer to go from 50 ohms to a 75 ohm load. The
> > transformer
> > >>needs to be good to 100 Mhz, handle around 30 watts full 
> duty cycle,
> and
> > have
> > >>low Q (good bandwidth.) 
> > >>
> > >>If anyone has one to sell or knows where I could find 
> such a beast,
> please
> > let
> > >>me know.
> > >>
> > >>Thanks
> > >>- Jason, N0RPM
> > >>_______________________________________________
> > >>NLRS mailing list
> > >>NLRS at mailman.qth.net
> > >>http://mailman.qth.net/mailman/listinfo/nlrs
> > >
> > >
> > >
> > 
> > 
> > 
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> > 
> James Klassen
> 
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