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#1
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Hi
I am looking for a supply source for WR430 waveguides (WR340 or WR510 will also do). I need a waveguide with a length of 360 mm but I would buy up to 1000 mm if smaller quantities are not available. Any ideas who supplies such quantities and is willing to ship to Germany? Peter |
#2
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On Sat, 25 Oct 2003 11:17:31 +0200, "Peter Bolch"
wrote: Hi I am looking for a supply source for WR430 waveguides (WR340 or WR510 will also do). I need a waveguide with a length of 360 mm but I would buy up to 1000 mm if smaller quantities are not available. Any ideas who supplies such quantities and is willing to ship to Germany? Peter Why don't you use a language we understand in the civilized world and ask for R22, alternatively R18 or R24 which at the same time indicate the frequency. You seldom see such large dimensions, believe they had waveguide for the over hoizon radio link system on 900MHz, but usually WG is not practical below 3.3GHz, so I would have expected to find any value in collecting such (see conversion table and data in RSGB VHF/UHF Manual) Jan-Martin LA8AK http://home.online.no/~la8ak/ -- remove ,xnd to reply (Spam precaution!) |
#3
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On Sat, 25 Oct 2003 11:17:31 +0200, "Peter Bolch"
wrote: Hi I am looking for a supply source for WR430 waveguides (WR340 or WR510 will also do). I need a waveguide with a length of 360 mm but I would buy up to 1000 mm if smaller quantities are not available. Any ideas who supplies such quantities and is willing to ship to Germany? Peter Why don't you use a language we understand in the civilized world and ask for R22, alternatively R18 or R24 which at the same time indicate the frequency. You seldom see such large dimensions, believe they had waveguide for the over hoizon radio link system on 900MHz, but usually WG is not practical below 3.3GHz, so I would have expected to find any value in collecting such (see conversion table and data in RSGB VHF/UHF Manual) Jan-Martin LA8AK http://home.online.no/~la8ak/ -- remove ,xnd to reply (Spam precaution!) |
#4
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"J M Noeding" wrote in message
... ...... You seldom see such large dimensions, believe they had waveguide for the over hoizon radio link system on 900MHz, but usually WG is not practical below 3.3GHz ....... Nonsense, rectangular waveguide is used quite frequently in UHF television broadcast transmitting installations. Granted it's pretty good sized stuff to get the lower cutoff frequency down where it needs to be in the 450 - 800 MHz range (WR1150, WR1500, and WR1800 for example) .. at least 6" x 12" outside dimensions. But it's definitely practical at those frequencies which are far below 3.3 Ghz. See http://www.dielectric.com/broadcast/...rWaveguide.pdf for full details. 73s |
#5
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"J M Noeding" wrote in message
... ...... You seldom see such large dimensions, believe they had waveguide for the over hoizon radio link system on 900MHz, but usually WG is not practical below 3.3GHz ....... Nonsense, rectangular waveguide is used quite frequently in UHF television broadcast transmitting installations. Granted it's pretty good sized stuff to get the lower cutoff frequency down where it needs to be in the 450 - 800 MHz range (WR1150, WR1500, and WR1800 for example) .. at least 6" x 12" outside dimensions. But it's definitely practical at those frequencies which are far below 3.3 Ghz. See http://www.dielectric.com/broadcast/...rWaveguide.pdf for full details. 73s |
#6
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In article , "Larry
King" writes: "J M Noeding" wrote in message ... ...... You seldom see such large dimensions, believe they had waveguide for the over hoizon radio link system on 900MHz, but usually WG is not practical below 3.3GHz ....... Nonsense, rectangular waveguide is used quite frequently in UHF television broadcast transmitting installations. Granted it's pretty good sized stuff to get the lower cutoff frequency down where it needs to be in the 450 - 800 MHz range (WR1150, WR1500, and WR1800 for example) .. at least 6" x 12" outside dimensions. But it's definitely practical at those frequencies which are far below 3.3 Ghz. Rectangular waveguide below 1 GHz (which is above UHF TV)? Coaxial structures, yes, especially for the visual-aural diplexer. I've walked INTO the channel 13 diplexer for KCOP on Mount Wilson (serving Los Angeles with 50 KW into the antenna). Just open the door in the corner formed by the visual and aural transmitters and one comes upon a massive array of round structures...:-) General Electric used rectangular guide based filters for their 1.8 GHz microwave radio relay diplexer, a 1950 design. Efficient as a multisection pair of narrowband bandpass filters for its time. Big, though, was as long as four racks are wide. At a PGMTT meeting in Santa Monica I once heard an informal chat about three guys using air conditioning duct at high UHF in lieu of buying special waveguide. It worked at low power. Think about it...some standard ducting comes in 2:1 width:height ratios just dandy for TE_1_0 mode. Heckuva lot cheaper than buying specific waveguide at the same size...probably cheaper than used waveguide (if such is available). Len Anderson retired (from regular hours) electronic engineer person |
#7
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In article , "Larry
King" writes: "J M Noeding" wrote in message ... ...... You seldom see such large dimensions, believe they had waveguide for the over hoizon radio link system on 900MHz, but usually WG is not practical below 3.3GHz ....... Nonsense, rectangular waveguide is used quite frequently in UHF television broadcast transmitting installations. Granted it's pretty good sized stuff to get the lower cutoff frequency down where it needs to be in the 450 - 800 MHz range (WR1150, WR1500, and WR1800 for example) .. at least 6" x 12" outside dimensions. But it's definitely practical at those frequencies which are far below 3.3 Ghz. Rectangular waveguide below 1 GHz (which is above UHF TV)? Coaxial structures, yes, especially for the visual-aural diplexer. I've walked INTO the channel 13 diplexer for KCOP on Mount Wilson (serving Los Angeles with 50 KW into the antenna). Just open the door in the corner formed by the visual and aural transmitters and one comes upon a massive array of round structures...:-) General Electric used rectangular guide based filters for their 1.8 GHz microwave radio relay diplexer, a 1950 design. Efficient as a multisection pair of narrowband bandpass filters for its time. Big, though, was as long as four racks are wide. At a PGMTT meeting in Santa Monica I once heard an informal chat about three guys using air conditioning duct at high UHF in lieu of buying special waveguide. It worked at low power. Think about it...some standard ducting comes in 2:1 width:height ratios just dandy for TE_1_0 mode. Heckuva lot cheaper than buying specific waveguide at the same size...probably cheaper than used waveguide (if such is available). Len Anderson retired (from regular hours) electronic engineer person |
#8
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"Avery Fineman" wrote in message
... In article , "Larry King" writes: "J M Noeding" wrote in message ... ...... You seldom see such large dimensions, believe they had waveguide for the over hoizon radio link system on 900MHz, but usually WG is not practical below 3.3GHz ....... Nonsense, rectangular waveguide is used quite frequently in UHF television broadcast transmitting installations. Granted it's pretty good sized stuff to get the lower cutoff frequency down where it needs to be in the 450 - 800 MHz range (WR1150, WR1500, and WR1800 for example) .. at least 6" x 12" outside dimensions. But it's definitely practical at those frequencies which are far below 3.3 Ghz. Rectangular waveguide below 1 GHz (which is above UHF TV)? Sure, take a look at the URL in my original message from the Dielectric webpages :-) And the Andrew Corp. extolls the virtues of its circular waveguide product line for the same application..... http://www.andrew.com/search/docviewer.aspx?docid=398 Coaxial structures, yes, especially for the visual-aural diplexer. I've walked INTO the channel 13 diplexer for KCOP on Mount Wilson (serving Los Angeles with 50 KW into the antenna). Just open the door in the corner formed by the visual and aural transmitters and one comes upon a massive array of round structures...:-) When I first read this, I though you meant that you were ***inside*** of the diplexer [hopefully not while it was 'on the air'] :-) Then I reread it, and understood what you meant. Yes those coaxial cavities can be quite impressive. 73s |
#9
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"Avery Fineman" wrote in message
... In article , "Larry King" writes: "J M Noeding" wrote in message ... ...... You seldom see such large dimensions, believe they had waveguide for the over hoizon radio link system on 900MHz, but usually WG is not practical below 3.3GHz ....... Nonsense, rectangular waveguide is used quite frequently in UHF television broadcast transmitting installations. Granted it's pretty good sized stuff to get the lower cutoff frequency down where it needs to be in the 450 - 800 MHz range (WR1150, WR1500, and WR1800 for example) .. at least 6" x 12" outside dimensions. But it's definitely practical at those frequencies which are far below 3.3 Ghz. Rectangular waveguide below 1 GHz (which is above UHF TV)? Sure, take a look at the URL in my original message from the Dielectric webpages :-) And the Andrew Corp. extolls the virtues of its circular waveguide product line for the same application..... http://www.andrew.com/search/docviewer.aspx?docid=398 Coaxial structures, yes, especially for the visual-aural diplexer. I've walked INTO the channel 13 diplexer for KCOP on Mount Wilson (serving Los Angeles with 50 KW into the antenna). Just open the door in the corner formed by the visual and aural transmitters and one comes upon a massive array of round structures...:-) When I first read this, I though you meant that you were ***inside*** of the diplexer [hopefully not while it was 'on the air'] :-) Then I reread it, and understood what you meant. Yes those coaxial cavities can be quite impressive. 73s |
#10
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In article , "Larry
King" writes: "Avery Fineman" wrote in message ... In article , "Larry King" writes: "J M Noeding" wrote in message ... ...... You seldom see such large dimensions, believe they had waveguide for the over hoizon radio link system on 900MHz, but usually WG is not practical below 3.3GHz ....... Nonsense, rectangular waveguide is used quite frequently in UHF television broadcast transmitting installations. Granted it's pretty good sized stuff to get the lower cutoff frequency down where it needs to be in the 450 - 800 MHz range (WR1150, WR1500, and WR1800 for example) .. at least 6" x 12" outside dimensions. But it's definitely practical at those frequencies which are far below 3.3 Ghz. Rectangular waveguide below 1 GHz (which is above UHF TV)? Sure, take a look at the URL in my original message from the Dielectric webpages :-) And the Andrew Corp. extolls the virtues of its circular waveguide product line for the same application..... http://www.andrew.com/search/docviewer.aspx?docid=398 I'm not going to say it can't be done or even shouldn't. :-) Rectangular guide at TE-sub-10 mode is convenient to use in general applications. Except for the choke-joint flanges, it is fairly easy to fabricate, even in the home workshop; think raw PCB stock for stiffness and easy solderability or other sheet metal joined with a copper-pipe-plumber's torch. The launch probes are also mechanically easy on fabrication. In circular waveguide, there's a different mode choice and you can't fabricate that easily in the home workshop. Also the I/O structures are a bit more difficult for the hobbyist. I'm not going to drag out the Matthei for this but the above is looking at practicality. Andrew is a good company and has been making antennas for a while. I got very intimate with their 10 foot dishes back in 1954...:-) But then they were using 1 5/8" rigid coax feed, pressurized over 250-foot length of terminal to antenna. Coaxial structures, yes, especially for the visual-aural diplexer. I've walked INTO the channel 13 diplexer for KCOP on Mount Wilson (serving Los Angeles with 50 KW into the antenna). Just open the door in the corner formed by the visual and aural transmitters and one comes upon a massive array of round structures...:-) When I first read this, I though you meant that you were ***inside*** of the diplexer [hopefully not while it was 'on the air'] :-) Then I reread it, and understood what you meant. Yes those coaxial cavities can be quite impressive. KCOP does the 24/7 bit now as it did in 1958 when a buddy and I got a tour of it. It was ON when we stepped into the collection of large- scale plumbing. Not a problem. Two transmitters at right angles, diplexer at the corner. At the time their older transmitter was on the other side of the transmitter room, ready to use in case of main xmtr catastrophe...forget how the antenna connection switchover was done although it was explained (I'll blame the altitude...Mt. Wilson is about 5700 feet ASL...:-). Most TV broadcasters don't mind interested viewers visiting their stations if one calls ahead. Remote transmit sites don't get a lot of activity. Mt. Wilson for Greater Los Angeles coverage is an exception with over two dozen transmitters along with a solar observatory, a couple hotel/motels, and the beginning of a national park area. Len Anderson retired (from regular hours) electronic engineer person |
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