[MAMS] 24 GHz waveguide filter Yo Dave

[Zack Widup]

I still think the Pyrojoe filters are the best bet. They are already
put together and tuned, they evidently require minimal tuning at 24
GHz (Joe says they only attenuate ~1 dB at 24192) and they're cheap.

They are actually WR-34 filters but you can butt up WR-34 to WR-42 and
they work just fine. The mounting holes on the waveguide for WR-34 and
WR-42 flanges are even the same.

73, Zack W9SZ


On 12/19/10, M Ragouzis <n0obi at yahoo.com> wrote:
> Hi Dave and all
>
> I have a millimeter scale on the digital read out if you need holes drilled
> in
> wave guide / K&S tubing ?
>
> Mike
>
>
>
> ________________________________
> From: Lloyd Ellsworth <l10368r1 at yahoo.com>
> To: MAMS <mams at mailman.qth.net>
> Sent: Sat, December 18, 2010 11:49:56 AM
> Subject: [MAMS] 24 GHz waveguide filter
>
> Dave,
>
> Every now and then, you run into one for sale.
>
> Charles Suckling, G3WDG, has a good construction article on HB one using
> WR42
> waveguide. About 4 inches long as I recall. Alignment is a bit of work. But
> it
> works. I may have a copy of his construction article somewhere. Likely, you
> can
> substitute some K&S hobby brass rectangular tubing and make it work. Early
> experiments ran with WW8M, showed it to work. Nearest K&S Brass size works
> out
> to WR34. But the spacing is the same on the holes and iris. Mounting brass
> screws is tricky because the brass is thin. Does not take much heat. Warps
> easy.
> We made a pile of Home brew waveguide transitions. I wrote up an article on
> that
> for MUD some years ago. Still using them. Still making them. Takes me about
> 4
> hours. W2PED has/had some very nice transitions available.
>
>
> I had some WR42 for sale, and standard 4 hole flanges, but don't know if I
> have
> any waveguide left. I might have a couple extra flanges. WR42 is not as
> common
> as WR90, and it is more expensive. Then the effects of the price of scrap
> copper
> these days.
>
>
> Dayton, and MUD, I have found some extra home brew wave guide filter units
> FS.
> Usually, extra made, then keep the best one.
>
>
> Germany, Henrik the Machineist, and Pale OZ8AFC in Denmark, make some really
> nice professional ones. Silver plated. About $100. Adjustment is pretty
> straight
> forward. Cavity design. Also 47 GHz. That is what I eventually graduated to.
> I
> use them now. Low insertion loss, and performs well.
>
>
> Testing is a bit of a trick. All about the available test equipment.
>
> P.S. Plenty of SMA relays, work on 24 GHz. However, you have to test them
> first.
> Find out if they do, and if the losses and performance are acceptable. Same
> with
> SMA connectors. K type SMA are what you want for 24 GHz. But they are a bit
> scarce and pricey. UT.085 is rated to 65 GHz. I would compare using a SMA on
> 24
> GHz, about like using a PL259 on 2M. Not the best, but it will work. Get you
> on
> and going. Later as the proper surplus, or parts become available, or
> affordable
> then upgrade.
>
>
> Also the Dish Network Dishes. Work just fine. So do the DH dishes. Also
> wrote up
> an article for MUD, for a HB affordable dish feed for 24 GHz. Used a .310
> empty
> brass casing, and solder up a bit of UT.085. Called it the "Detroit"
> special.
>
>
> Big problem you learn about 24 GHz and up. Lead solder absorbs RF. It
> becomes a
> problem. Minimize use.
>
>
> Good luck.
>
> 73, Lloyd NE8I/r
> EN74 etc
>
>
>
>
>
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