| Author |
Message |
    
Tech808
Moderator
Username: Tech808
Post Number: 10519
Registered: 8-2002
| | Posted on Thursday, July 13, 2006 - 3:35 pm: | 
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So the QUESTION is:
Is the Comet CF-360A a DIPLEXER or a DUPLEXER for an ANTENNA?
Comet CF-360A:
Duplexer 1.3-30/49-470Mhz
The CF-360A Duplexer is for transmitting and receiving 1 - 30Mhz and 50Mhz (or 144 & 433Mhz) at the same time. Combined High quality filters help to prevent TVI.
Specification:
* BandPass Frequency & Input Loss:
* 1.3 - 30Mhz / Less than 0.2dB
* 49 - 470Mhz / Less than 0.25dB
* Impedance : 50 Ohms * VSWR : 1:1.2
* Maximum Input Power 1.3 - 250Mhz 600Watts (PEP)
* Maximum Input Power 300 - 470 Mhz 500 Watts (PEP) * Size : W66 x D90 x H26 mm
Connectors:
* Input 1 X SO239 Socket
* Output 2 x Leads with fitted PL259 Plugs
Lon
Tech808
CEF808
N9CEF
CVC#2 |
Rldrake
Intermediate Member
Username: Rldrake
Post Number: 200
Registered: 1-2006
| | Posted on Thursday, July 13, 2006 - 11:55 am: |
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No. What you have pictured there is a DIPLEXER.
NOT A DUPLEXER !
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Eagle_eye
Junior Member
Username: Eagle_eye
Post Number: 35
Registered: 1-2005
| | Posted on Thursday, July 13, 2006 - 5:04 pm: |
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i did not know what the correct terms were so i went to the icom site since icom has made 1000's of radios and other radio equipment for hams over the years
http://www.icomamerica.com/support/manuals/ham_radio_terms.pdf
icom says "duplex" is an operation mode in which the transmit and the receive frequencies are different
icom says a "duplexer" is a device which divides transmit and receive signals
and that is exactly what it does!
since tech 833 is a licensed professional broadcast engineer maybe he can jump in and let us know if it is a duplexer
ee |
Tech833
Moderator
Username: Tech833
Post Number: 1407
Registered: 8-2002
| | Posted on Thursday, July 13, 2006 - 10:16 pm: |
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A duplexer is a filter of sorts that allows a transmitter and receiver to use the same antenna at the same time. This is how repeaters use a single antenna for full or half duplex. Usually, a duplexer is either pass, notch, or pass/notch.
A diplexer is a combiner that allows two or more transmitters to use the same antenna at the same time. A diplexer is sometimes also called a combiner or hybrid combiner or filter combiner, depending on the physical makeup.
So, the answer really depends on the mode the transceiver is in. |
Milkman21218
Member
Username: Milkman21218
Post Number: 77
Registered: 1-2004
| | Posted on Thursday, July 13, 2006 - 10:39 pm: |
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Just a serious question here.
If the Comet CF-360A is not a duplexer as advertised then what is the:
Diamond MX72D/37/62M/214D/610/72D/72H/72N/72A or the MFJ 916?
They are ALL labeled Duplexer's.
If they are not DUPLEXER's then that means that they are all mis-
representing their product's and labeling them incorrectly.
I can see where a single company may mis-lead the ham's into buying
thier product, but having 3 MAJOR Ham Related companies and ICOM trying
to mis-lead or delibertly label the product's incorrectly or put out
false or mis-leading information is a little hard for me to believe.
Why would these companies spend thousand's of dollar's for advertising
on these product's if the information is incorrect or mis-leading to
the
consumer? |
Bruce
Senior Member
Username: Bruce
Post Number: 3961
Registered: 9-2003
| | Posted on Thursday, July 13, 2006 - 11:02 pm: |
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My comet duplexer ( cf-706 ) allows me to use the DIAMOND V-2000 on all 3 bands.it splits the signal by dual bandpass filters one a high one a low pass the IC-706 has 2 antenna inputs and with the CF-706 i don't need to change the antenna from port to port so one antenna can be used on all bands IF it is designed to work them
HF input is 1.3 - 57 mhz VHF input is 75-500 mhz |
Chad
Advanced Member
Username: Chad
Post Number: 988
Registered: 11-2004
| | Posted on Thursday, July 13, 2006 - 10:20 pm: |
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If it isolates the other transmitter instead of offering simultaneous operation.......
I vote duplexer...
Duplexer
From Wikipedia, the free encyclopedia
1) A duplexer is a device that combines two or more signals onto a common channel or medium to increase its transmission efficiency.
In radar systems, it is a device that isolates the receiver from the transmitter while permitting them to share a common antenna.
Note 1: A duplexer must be designed for operation in the frequency band used by the receiver and transmitter, and must be capable of handling the output power of the transmitter.
Note 2: A duplexer must provide adequate rejection of transmitter noise occurring at the receive frequency, and must be designed to operate at, or less than, the frequency separation between the transmitter and receiver.
Note 3: A duplexer must provide sufficient isolation to prevent receiver desensitization.
Source: from Federal Standard 1037C
2) A duplexer is also an add on accessory for printers, and it allows one to print on both sides of the paper automatically.
Also See Diplexer
Retrieved from http://en.wikipedia.org/wiki/Duplexer
Diplexer
From Wikipedia, the free encyclopedia
A diplexer (sometimes called a combiner) is a device that combines the radio frequency output of two or more radio transmitters into a single output. This is extremely useful in reducing the number of radio antennas on a tower, reducing the weight and loading from wind and potential ice, as well as the necessary size of the tower itself. Diplexers must be carefully designed and tuned to prevent intermodulation and keep reflected power (VSWR) to a minimum for each input transmitter and frequency. While diplexers can combine a relatively wide bandwidth, the major limitation comes with the antenna itself, which must be sufficiently wideband to accept all of the signals being passed through it, and transfer them to the air efficiently.
One of the most massive diplexers in use is atop the Empire State Building in New York, where over a dozen radio stations transmit through one four-panel antenna. Diplexers are also used to combine the audio and video carriers for television, and also for non-broadcast stations such as amateur radio.
Small diplexers are also used in the home, allowing direct broadcast satellite TV signals from the dish to the receiver to piggyback on one regular coaxial cable, along with lower-frequency signals from an outdoor terrestrial TV antenna for local channels. This is extremely useful in homes which are already pre-wired, as it eliminates the need for the difficult installation of unsightly extra cables. However, the cables must be the higher-quality RG6, as the less-expensive RG59 will not pass the high intermediate frequency (usually 950 to 1450MHz) which the LNB outputs from the feedhorn.
In this case, one diplexer joins the two signals together. Another diplexer then separates the signals to the receiver of the TV set, and the IRD of the DBS set-top box. More complex systems have a distribution amplifier, which allows each IRD to access multiple LNBs with different antenna polarizations. These usually have an antenna input and a diplexer, so that the antenna signal is also distributed along with the satellite. Diplexers are also commonly used to combine UHF/VHF frequency signals (ie TV/FM radio) onto one downlead which can then be split back into its component parts as required. See also: multiplexing
Retrieved from http://en.wikipedia.org/wiki/Duplexer
Chad |
Hollowpoint445
Senior Member
Username: Hollowpoint445
Post Number: 1299
Registered: 6-2004
| | Posted on Friday, July 14, 2006 - 10:41 am: |
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It's a diplexer. Diplexers allow transceivers of different bands to utilize the same antenna.
Duplexers allow transmitters and receivers that work in the same band to share the same antenna.
I remember it this way - a diplexer di-sects the RX and sends it to the appropriate radio for the appropriate band. |
Tech833
Moderator
Username: Tech833
Post Number: 1409
Registered: 8-2002
| | Posted on Friday, July 14, 2006 - 11:13 am: |
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Milkman- The exact same way Antron, Comet, Diamond, and other antenna makers spend nearly MILLIONS of dollars advertising their antennas with '10 dB gain', about 9 dB more than they really have.
The marketing department and engineering department are almost always in disagreement. The MARKETING depertment labelled your device a duplexer. |
