also: google image search for "waveguide flange" , sort by largest file size, you'll find some excellent annotated references for the different types.
On Mon, Sep 22, 2014 at 8:21 AM, cstanners--- via Af <[email protected]> wrote: > Thanks for all this info! > ------------------------------ > *From: * Chuck McCown via Af <[email protected]> > *Sender: * "Af" <[email protected]> > *Date: *Mon, 22 Sep 2014 13:22:48 +0000 > *To: *<[email protected]> > *ReplyTo: * [email protected] > *Subject: *Re: [AFMUG] Waveguide compatibility info? > > There are two types of grooves, o-ring groove for > pressurization/moisture sealing and choke flange grooves to eliminate > mismatch. Choke flanges are CBR, where moisture sealing are PBR and flat > are UBR. > > You want to use a PBR with a UBR if you can. The UBR gives the O ring a > good flat surface to mate with. > > Not sure how well two PBRs would work against each other. I would not > recommend it if you wanted to pressurize. > > Two UBRs will be fine from an electrical point of view but could not bre > pressurized. > > Choke flanges are more for high power applications. I don’t think I have > ever seen one on lower power comm equipment. > > But for basic signal work, all of this stuff will work if you get them > relatively close to each other. They don’t even have to be fully touching > or perfectly aligned. I have taped them together in a pinch and they have > run for years that way. Two screws and they are good to go for many > applications. It almost seems like the signal is clingy to the inside of > the waveguide like capillary action. Of course if you are trying to get > rid of leakage in or out for extreme weak signal work, you would want to > put in all the screws. > > *From:* Colin Stanners via Af <[email protected]> > *Sent:* Sunday, September 21, 2014 6:25 PM > *To:* [email protected] > *Subject:* Re: [AFMUG] Waveguide compatibility info? > > Can grooved and ungrooved waveguides be safely be used together, e.g. in > outside weather? Like PBR and UBR? > > On Sun, Sep 21, 2014 at 12:10 PM, Chuck McCown via Af <[email protected]> > wrote: > >> Waveguide is a broadband bandpass filter. You can couple one size to >> another as long as there is overlap in the pass band. Go to low in >> frequency and the waveguide just blocks the signal. The cut off frequency. >> It is not a brick wall filter. Normally the cut off frequency is something >> like the 1 dB mismatch loss frequency, go lower and the loss goes up >> quickly. >> >> Different problem in going too high. >> >> To use my photon analogy: >> >> Photons simply will not fit down the tube if they are too large (low >> frequency). Go too high in frequency and you get other than single file >> photons trying to get town the tube. Like two abreast, two rows two >> columns etc etc. >> >> Those are called higher order modes and you can use them if you take care >> of launching and receiving the signal in a low loss high return loss manner. >> >> http://www.rfcafe.com/references/electrical/waveguide-chart.htm >> >> Then there are the non rectangular waveguides. Ridge waveguide is >> physically smaller than rectangular waveguide. Circular is good for dual >> pol and is exceedingly low loss but extra care has to be taken to prevent >> polarization rotation. >> >> -----Original Message----- From: cstanners--- via Af >> Sent: Saturday, September 20, 2014 6:41 PM >> To: Jason McKemie via Af >> Subject: [AFMUG] Waveguide compatibility info? >> >> Does anyone have resources/FAQs/etc to understand Waveguide compatibility? >> >> >> >
