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#31
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On Apr 19, 7:38 pm Telamon wrote:
Snip There are passive and there are active splitters. Passive can be transformer or resistive it does not matter. If the splitter is one port to two ports then the power is going to divided in half between the two output ports. It is that simple. Half the power is 3dB and half the voltage is 6 dB. That's all there is to it. Active splitters can be anything because you can have any amount of amplification to to make up for the division in power. Same story with one to four ports where the power out is 1/4 the power in. Same story with any other division splitter. Now if you force me to I WILL resort to an analogy where you have this bushel of apples you want to divide in half and... -- Telamon ---------------------------------------------------------------- Please review the information at: http://www.microwaves101.com/encyclo..._splitters.cfm And note that a resistive splitter has: "Resistive power dividers are easy to understand, can be made very compact, and are naturally wideband, working down to zero frequency (DC). Their down side is that a two-way resistive splitter suffers 3 dB of real resistive loss, as opposed to a lossless splitter like a hybrid. Accounting for the 3 dB real loss and the 3 dB power split, the net power transfer loss you will observe from the input to one of the two outputs is 6.04 dB for a two-way resistive splitter. (Thanks, Dr. BKS, for helping us clarify that point!)" I own a Mini Circuits ZFSC-2-. It has a measured insertion loss of less then 3.5dB for 100KHz through 30MHz Another strength of tranformer based hybrids/power splitters is the greater isolation between power out ports. The Mini circuits ZFSC-2-1is rated for: 5 MHz 25dB isolation midband (~450MHz) 20dB isolation 500MHz 20 isolation These are minimum not typ[ical. My unit has been measued to have better then 25dB isolation between the power out ports from ~250KHz to above 30MHz. The isolation start to creep up below 250KHZ reaching a minimum of ~21dB at 100KHz. Below 100KHz the loss starts increasing and by 10KHZ the loss is just over 9dB and the isolation is down to just less then 15dB. The "roll your own splitter" page gives some real world loss and isolation data: http://www.dxing.info/equipment/roll...own_bryant.pdf MiniCircuits isloation PDF http://www.minicircuits.com/appnote/pwr2-4.pdf MiniCircuits hybrid/power splitter PDF http://www.minicircuits.com/appnote/psc2-2.pdf Quoting again frm the article on resistive splitters: "To put it simply, the resistive splitter has double the dBs compared to a lossless splitter's insertion loss. Thus a two-way resistive splitter transfers -6.04 dB power to each arm, a three-way splitter transfers -9.44 dB, a four-way transfers -12.08 db, etc." And: "The isolation of a resistive splitter is equal to its insertion loss." I hope that we can all agree that 3.5 dB loss is much better then 6dB loss and that 20dB isolation is better then 12dB isolation. I ued the wort case bad specs from minicircuits for loss and isolation. In the microwave world resitive splitters are the rule. In HF/VHF/UFH transformer splitters appear to dominate. Sorry for the dublicate posting under two threads. I feel this is a very important concept and wanted to make sure my position is clear. Terry |
#33
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Here's a website for making a transformer type HF splitter.
http://www.geocities.com/n2uhc_2/hfsplitter.html ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
#34
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In article , starman
wrote: Here's a website for making a transformer type HF splitter. http://www.geocities.com/n2uhc_2/hfsplitter.html That is not a very good design but it will work. It would probably be best to grab a toroid out of the EMI section of a power supply. A toroid from that area would have the proper characteristics. -- Telamon Ventura, California |
#35
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On Wed, 20 Apr 2005 02:38:40 GMT, Telamon
wrote: In article , Tebojockey wrote: On Mon, 18 Apr 2005 00:12:32 GMT, Drifter wrote: - Hide quoted text - - Show quoted text - ************************ thanks to one and all for some great info. i need to study on this. i found an old article in the july/04, NASWA Journal. get my facts together here, and move to there. would be fun to build when i find the time. thanks again... Drifter... Now that the dust has settled a little bit and the belligerents are hopefully being triaged..... Not a chance! I have to give you a hard time. You don't. One-upmanship has no place here. Please read the spec sheets on the prospective splitter you intend on using or, if rolling your own, look at the design. Many splitters claim to have "only" a 3 or 5 dB loss, but that's only "best case." Often times, the loss will vary greatly across the operating range of the splitter (and sometimes the impedance!). For HF and MF, the losses are usually not too bad. Snip There are passive and there are active splitters. Passive can be transformer or resistive it does not matter. If the splitter is one port to two ports then the power is going to divided in half between the two output ports. It is that simple. Half the power is 3dB and half the voltage is 6 dB. That's all there is to it. Active splitters can be anything because you can have any amount of amplification to to make up for the division in power. Same story with one to four ports where the power out is 1/4 the power in. Same story with any other division splitter. Now if you force me to I WILL resort to an analogy where you have this bushel of apples you want to divide in half and... You are arguing points that I did not even discuss. What you are describing is the standard "Wilkinson" splitter or combiner. We could also discuss 90 degree splitters and other variants, but that would be beyond the ascope of what I was trying to impart to the person I was trying to help. Your assertion that they may be active or passive is correct. Loss implies a passive splitter (be it resistive or reactive), while the other part of my dissertation (as far as raising the noise floor, etc.) implies an active splitter. Perhaps it was not clear to you, but perhaps the person who it was posted for understood what I was saying. I should have also given him information on port to port isolation as well as the effect upon his 3d order intercept points that active splitters can cause, but I didn't feel it would benefit him. My intent was to be as layman as possible to assist the person asking the question. Al in CNMI ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
#36
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In article ,
Tebojockey wrote: On Wed, 20 Apr 2005 02:38:40 GMT, Telamon wrote: In article , Tebojockey wrote: On Mon, 18 Apr 2005 00:12:32 GMT, Drifter wrote: - Hide quoted text - - Show quoted text - ************************ thanks to one and all for some great info. i need to study on this. i found an old article in the july/04, NASWA Journal. get my facts together here, and move to there. would be fun to build when i find the time. thanks again... Drifter... Now that the dust has settled a little bit and the belligerents are hopefully being triaged..... Not a chance! I have to give you a hard time. You don't. One-upmanship has no place here. You have no sense of humor. Please read the spec sheets on the prospective splitter you intend on using or, if rolling your own, look at the design. Many splitters claim to have "only" a 3 or 5 dB loss, but that's only "best case." Often times, the loss will vary greatly across the operating range of the splitter (and sometimes the impedance!). For HF and MF, the losses are usually not too bad. Snip There are passive and there are active splitters. Passive can be transformer or resistive it does not matter. If the splitter is one port to two ports then the power is going to divided in half between the two output ports. It is that simple. Half the power is 3dB and half the voltage is 6 dB. That's all there is to it. Active splitters can be anything because you can have any amount of amplification to to make up for the division in power. Same story with one to four ports where the power out is 1/4 the power in. Same story with any other division splitter. Now if you force me to I WILL resort to an analogy where you have this bushel of apples you want to divide in half and... You are arguing points that I did not even discuss. That happens on Usenet when more than 2 people participate in a discussion. What you are describing is the standard "Wilkinson" splitter or combiner. We could also discuss 90 degree splitters and other variants, but that would be beyond the ascope of what I was trying to impart to the person I was trying to help. Sorry I messed up your message. Your assertion that they may be active or passive is correct. Loss implies a passive splitter (be it resistive or reactive), while the other part of my dissertation (as far as raising the noise floor, etc.) implies an active splitter. Perhaps it was not clear to you, but perhaps the person who it was posted for understood what I was saying. I should have also given him information on port to port isolation as well as the effect upon his 3d order intercept points that active splitters can cause, but I didn't feel it would benefit him. My intent was to be as layman as possible to assist the person asking the question. Yeah, it's a balancing act all right. -- Telamon Ventura, California |
#37
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On Tue, 26 Apr 2005 06:09:00 GMT, Telamon
wrote: In article , Tebojockey wrote: On Wed, 20 Apr 2005 02:38:40 GMT, Telamon wrote: In article , Tebojockey wrote: On Mon, 18 Apr 2005 00:12:32 GMT, Drifter wrote: - Hide quoted text - - Show quoted text - ************************ thanks to one and all for some great info. i need to study on this. i found an old article in the july/04, NASWA Journal. get my facts together here, and move to there. would be fun to build when i find the time. thanks again... Drifter... Now that the dust has settled a little bit and the belligerents are hopefully being triaged..... Not a chance! I have to give you a hard time. You don't. One-upmanship has no place here. You have no sense of humor. Well, yeah I do...maybe I overreacted to your post. Please read the spec sheets on the prospective splitter you intend on using or, if rolling your own, look at the design. Many splitters claim to have "only" a 3 or 5 dB loss, but that's only "best case." Often times, the loss will vary greatly across the operating range of the splitter (and sometimes the impedance!). For HF and MF, the losses are usually not too bad. Snip There are passive and there are active splitters. Passive can be transformer or resistive it does not matter. If the splitter is one port to two ports then the power is going to divided in half between the two output ports. It is that simple. Half the power is 3dB and half the voltage is 6 dB. That's all there is to it. Active splitters can be anything because you can have any amount of amplification to to make up for the division in power. Same story with one to four ports where the power out is 1/4 the power in. Same story with any other division splitter. Now if you force me to I WILL resort to an analogy where you have this bushel of apples you want to divide in half and... You are arguing points that I did not even discuss. That happens on Usenet when more than 2 people participate in a discussion. Been on Usenet a long, long time. You're right there! What you are describing is the standard "Wilkinson" splitter or combiner. We could also discuss 90 degree splitters and other variants, but that would be beyond the ascope of what I was trying to impart to the person I was trying to help. Sorry I messed up your message. "Fuhgeddaboutit" (I do a lousy Sopranos imitation). Your assertion that they may be active or passive is correct. Loss implies a passive splitter (be it resistive or reactive), while the other part of my dissertation (as far as raising the noise floor, etc.) implies an active splitter. Perhaps it was not clear to you, but perhaps the person who it was posted for understood what I was saying. I should have also given him information on port to port isolation as well as the effect upon his 3d order intercept points that active splitters can cause, but I didn't feel it would benefit him. My intent was to be as layman as possible to assist the person asking the question. Yeah, it's a balancing act all right. And when I drink too much I list badly to port..... LOL Al in CNMI ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
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