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Old October 25th 03, 11:17 AM
Peter Bolch
 
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Default Looking for WR430 waveguides

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


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Old October 26th 03, 03:50 AM
J M Noeding
 
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Default

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/

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Old October 26th 03, 03:50 AM
J M Noeding
 
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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!)
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Old October 26th 03, 06:02 AM
Larry King
 
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Default

"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


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Old October 26th 03, 06:02 AM
Larry King
 
Posts: n/a
Default

"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   Report Post  
Old October 26th 03, 06:50 PM
Avery Fineman
 
Posts: n/a
Default

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
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Old October 26th 03, 06:50 PM
Avery Fineman
 
Posts: n/a
Default

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
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Old October 26th 03, 08:06 PM
Larry King
 
Posts: n/a
Default

"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



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Old October 26th 03, 08:06 PM
Larry King
 
Posts: n/a
Default

"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



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Old October 27th 03, 12:42 AM
Avery Fineman
 
Posts: n/a
Default

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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