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#1
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I want to run two or even three QRP (200mW) HF beacons to one antenna. Is
it possible to build a duplexer to combine 8M and 40M or 30M and 40M or 30M and 20M. Does anyone have a pointer to a web site where I might get some tips? Dick G4BBH |
#2
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![]() "Richard Ferryman" wrote in message ... I want to run two or even three QRP (200mW) HF beacons to one antenna. Is it possible to build a duplexer to combine 8M and 40M or 30M and 40M or 30M and 20M. Does anyone have a pointer to a web site where I might get some tips? Dick G4BBH Sure you can and the power is not limiated to QRP either. There are two ways to go about it. Band pass filters or low pass/high pass filters. Look up diplexers. Here is an example and may be close to what you want. http://yu1lm.qrpradio.com/HF%20MULTI...S-%20YU1LM.pdf |
#3
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On 07/19/2012 09:39 AM, Ralph Mowery wrote:
Sure you can and the power is not limiated to QRP either. There are two ways to go about it. Band pass filters or low pass/high pass filters. Look up diplexers. Here is an example and may be close to what you want. http://yu1lm.qrpradio.com/HF%20MULTI...S-%20YU1LM.pdf Hello, and I would just add that while hams tend to use "duplexer" a lot of others use "diplexer". Just something to keep in mind for Google et al searches. Sincerely, and 73s from N4GGO, -- J. B. Wood e-mail: |
#4
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On 7/19/2012 11:17 AM, J.B. Wood wrote:
On 07/19/2012 09:39 AM, Ralph Mowery wrote: Sure you can and the power is not limiated to QRP either. There are two ways to go about it. Band pass filters or low pass/high pass filters. Look up diplexers. Here is an example and may be close to what you want. http://yu1lm.qrpradio.com/HF%20MULTI...S-%20YU1LM.pdf Hello, and I would just add that while hams tend to use "duplexer" a lot of others use "diplexer". Just something to keep in mind for Google et al searches. Sincerely, and 73s from N4GGO, They're different animals, http://www.microwaves101.com/encyclopedia/diplexers.cfm http://www.microwaves101.com/encyclopedia/duplexers.cfm |
#5
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![]() "Audio1" wrote in message ... Hello, and I would just add that while hams tend to use "duplexer" a lot of others use "diplexer". Just something to keep in mind for Google et al searches. Sincerely, and 73s from N4GGO, They're different animals, http://www.microwaves101.com/encyclopedia/diplexers.cfm http://www.microwaves101.com/encyclopedia/duplexers.cfm Not picking on you, but here we go again with that damn diplexer\duplexer thing. Even the people that make them will sometimes call the diplexer a duplexer. Just look at the ads in the ham catalogs. I do know the differance, but the terms have been used wrong so much that it is no use trying to correct them here. Maybe we can get Szczepan Bialek to chime in here so the thread can reach about 50 messages about the differance. |
#6
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Ralph Mowery wrote:
Not picking on you, but here we go again with that damn diplexer\duplexer thing. Even the people that make them will sometimes call the diplexer a duplexer. Just look at the ads in the ham catalogs. I do know the differance, but the terms have been used wrong so much that it is no use trying to correct them here. Maybe we can get Szczepan Bialek to chime in here so the thread can reach about 50 messages about the differance. Are the electrons flowing into the diplexer? Do the diplexer have the counterpoise? What did Marconi write about it? |
#7
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"Rob" wrote in message
... Ralph Mowery wrote: Not picking on you, but here we go again with that damn diplexer\duplexer thing. Even the people that make them will sometimes call the diplexer a duplexer. Just look at the ads in the ham catalogs. I do know the differance, but the terms have been used wrong so much that it is no use trying to correct them here. Maybe we can get Szczepan Bialek to chime in here so the thread can reach about 50 messages about the differance. Are the electrons flowing into the diplexer? Do the diplexer have the counterpoise? What did Marconi write about it? Diplexer? Duplexer? Complex-ier? :-) Couldn't resist. It's a dull, damp day here in the UK. Someone will make a lot of money selling souvenir umbrellas to the Olympic crowds. 73, Ian. |
#8
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Jeff wrote:
They're different animals, http://www.microwaves101.com/encyclopedia/diplexers.cfm http://www.microwaves101.com/encyclopedia/duplexers.cfm That site is wrong!! What they describe as a 'duplexer' in radar is in fact a circulator, although it is acting as a duplexer. The term duplexer is generally used for a device that permits simultaneously transmission and reception on a single antenna, but a duplexer can be a diplexer where the transmit and receive bands differ. That is, a diplexer that splits an antenna into 2 isolated ports at different frequencies is being used as a duplexer. A circulator that isolates a transmit and receive port at the same or similar frequencies is also a duplexer but not a diplexer. Jeff The definitions I've found generally seem to say a duplexer isolates two ports on the same, or very close to the same, frequency and that a diplexer isolates two ports on different bands. The definitions I've found also generally seem to say a circulator is a 3 or 4 port device in which a signal to a port is directed to only the next port in order and says nothing about frequencies. And, as you said, is often used at microwave to act as a duplexer. I would guess the definative definitions would be what the IEEE dictionary says, but I don't currently have access to that. |
#9
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On Thu, 19 Jul 2012 13:49:48 +0100, "Richard Ferryman"
wrote: I want to run two or even three QRP (200mW) HF beacons to one antenna. Is it possible to build a duplexer to combine 8M and 40M or 30M and 40M or 30M and 20M. Does anyone have a pointer to a web site where I might get some tips? If you check the web sites for the various beacon networks, NONE of them transmit on more than one frequency at a time. The transmissions on each band are done in rotation. You do NOT need a duplexer, diplexer, perplexer, or antenna tuner. The danger in transmitting simultaneously on multiple bands at the same time is intermod mixing generated in the final stages of your transmitter. Ask Field Day operators for how that works. For a beacon, all you need is a multiband antenna of some sorts and a uP controller to change bands and frequencies according to a set pattern. http://www.ncdxf.org/beacon/photos/index.html Contact anyone involved in the network for details and horror stories. http://www.ncdxf.org/beacon/beaconcontact.html -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
#10
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![]() "Ralph Mowery" napisa³ w wiadomo¶ci m... "Audio1" wrote in message ... Hello, and I would just add that while hams tend to use "duplexer" a lot of others use "diplexer". Just something to keep in mind for Google et al searches. Sincerely, and 73s from N4GGO, They're different animals, http://www.microwaves101.com/encyclopedia/diplexers.cfm http://www.microwaves101.com/encyclopedia/duplexers.cfm Not picking on you, but here we go again with that damn diplexer\duplexer thing. Even the people that make them will sometimes call the diplexer a duplexer. Just look at the ads in the ham catalogs. I do know the differance, but the terms have been used wrong so much that it is no use trying to correct them here. Maybe we can get Szczepan Bialek to chime in here so the thread can reach about 50 messages about the differance. For me it is enough the difference Hertz dipole/radio amateur dipole. "diplexer\duplexer" continue without me. Anyway, do you know the difference Hertz dipole/radio amateur dipole" S* |
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