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splitter ?
I have used Mini Circut Labs ZFSC-2-1 and a 2 port passive Stridsberg. I
obtained the MCL's at hamfests for $10 and the Stridsberg new Presently I am using a MCL PSC-3-1 to feed 3 receivers. I also got this at a hamfest. My receivers make up the nearly 5 db loss. Charlie "Drifter" wrote in message ... question. anyone recommend the rf-system-SP-1? or the mini-circuits- zsc-2-2? or, what are you using and why? looking for suggestions... thanks... Drifter... |
"Charles W. Hinkle" wrote: I have used Mini Circut Labs ZFSC-2-1 and a 2 port passive Stridsberg. I obtained the MCL's at hamfests for $10 and the Stridsberg new Presently I am using a MCL PSC-3-1 to feed 3 receivers. I also got this at a hamfest. My receivers make up the nearly 5 db loss. How do they make up the loss? Just curious. dxAce Michigan USA |
I have an excellent splitter for sale, please contact me at
I tried emailing you but your email bounced "Drifter" wrote in message ... question. anyone recommend the rf-system-SP-1? or the mini-circuits- zsc-2-2? or, what are you using and why? looking for suggestions... thanks... Drifter... |
In article ,
dxAce wrote: "Charles W. Hinkle" wrote: I have used Mini Circut Labs ZFSC-2-1 and a 2 port passive Stridsberg. I obtained the MCL's at hamfests for $10 and the Stridsberg new Presently I am using a MCL PSC-3-1 to feed 3 receivers. I also got this at a hamfest. My receivers make up the nearly 5 db loss. How do they make up the loss? Just curious. Maybe his radios have pre-amps like the Drakes. When you use a passive splitter the loss is 3dB power and 6dB voltage. I think most radio S meters are responding to the voltage number due to the nature of the AGC circuits. Someone can correct me on this. Should be easy enough to take a splitter in and out of line. -- Telamon Ventura, California |
Telamon wrote:
Maybe his radios have pre-amps like the Drakes. When you use a passive splitter the loss is 3dB power and 6dB voltage. I think most radio S meters are responding to the voltage number due to the nature of the AGC circuits. Someone can correct me on this. Should be easy enough to take a splitter in and out of line. -- Telamon Ventura, California ------------------------------------------------------------ Almost all modern receivers use teh AGC voltage for the "S-meter". And very few have any meaningfull calibration. Terry |
Telamon wrote: In article , dxAce wrote: "Charles W. Hinkle" wrote: I have used Mini Circut Labs ZFSC-2-1 and a 2 port passive Stridsberg. I obtained the MCL's at hamfests for $10 and the Stridsberg new Presently I am using a MCL PSC-3-1 to feed 3 receivers. I also got this at a hamfest. My receivers make up the nearly 5 db loss. How do they make up the loss? Just curious. Maybe his radios have pre-amps like the Drakes. When you use a passive splitter the loss is 3dB power and 6dB voltage. I think most radio S meters are responding to the voltage number due to the nature of the AGC circuits. Someone can correct me on this. Should be easy enough to take a splitter in and out of line. Correct me if I'm wrong... but would it not be better to run some pre-amplification ahead of the splitter rather than try to make up something that has already disappeared? Much the same in say VHF work where it is better to run a receive pre-amp right at the antenna versus running it at the receiver end of the coax? I'd never consider using a passive splitter here, and I rarely if ever engage the pre-amps on the receivers... no need. dxAce Michigan USA |
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On Sun, 17 Apr 2005 18:06:44 -0400, dxAce
wrote: Telamon wrote: In article , dxAce wrote: "Charles W. Hinkle" wrote: I have used Mini Circut Labs ZFSC-2-1 and a 2 port passive Stridsberg. I obtained the MCL's at hamfests for $10 and the Stridsberg new Presently I am using a MCL PSC-3-1 to feed 3 receivers. I also got this at a hamfest. My receivers make up the nearly 5 db loss. How do they make up the loss? Just curious. Maybe his radios have pre-amps like the Drakes. When you use a passive splitter the loss is 3dB power and 6dB voltage. I think most radio S meters are responding to the voltage number due to the nature of the AGC circuits. Someone can correct me on this. Should be easy enough to take a splitter in and out of line. Correct me if I'm wrong... but would it not be better to run some pre-amplification ahead of the splitter rather than try to make up something that has already disappeared? Much the same in say VHF work where it is better to run a receive pre-amp right at the antenna versus running it at the receiver end of the coax? I'd never consider using a passive splitter here, and I rarely if ever engage the pre-amps on the receivers... no need. dxAce Michigan USA Most outboard amplifiers cause more problems than they solve. Listen with your ears, not your S-Meter. |
David wrote: On Sun, 17 Apr 2005 18:06:44 -0400, dxAce wrote: Telamon wrote: In article , dxAce wrote: "Charles W. Hinkle" wrote: I have used Mini Circut Labs ZFSC-2-1 and a 2 port passive Stridsberg. I obtained the MCL's at hamfests for $10 and the Stridsberg new Presently I am using a MCL PSC-3-1 to feed 3 receivers. I also got this at a hamfest. My receivers make up the nearly 5 db loss. How do they make up the loss? Just curious. Maybe his radios have pre-amps like the Drakes. When you use a passive splitter the loss is 3dB power and 6dB voltage. I think most radio S meters are responding to the voltage number due to the nature of the AGC circuits. Someone can correct me on this. Should be easy enough to take a splitter in and out of line. Correct me if I'm wrong... but would it not be better to run some pre-amplification ahead of the splitter rather than try to make up something that has already disappeared? Much the same in say VHF work where it is better to run a receive pre-amp right at the antenna versus running it at the receiver end of the coax? I'd never consider using a passive splitter here, and I rarely if ever engage the pre-amps on the receivers... no need. dxAce Michigan USA Most outboard amplifiers cause more problems than they solve. Listen with your ears, not your S-Meter. I don't use any outboard amplification here 'tard boy, other than that which the Stridsberg uses to overcome the loss to support up to 4 receivers. I'm fairly certain I've done my fair share of listening, you just keep on trying to catch up. Please, get a clue, and try to get a grip. Continue to tote. dxAce Michigan USA |
dxAce wrote:
Correct me if I'm wrong... but would it not be better to run some pre-amplification ahead of the splitter rather than try to make up something that has already disappeared? Much the same in say VHF work where it is better to run a receive pre-amp right at the antenna versus running it at the receiver end of the coax? I'd never consider using a passive splitter here, and I rarely if ever engage the pre-amps on the receivers... no need. dxAce Michigan USA ------------------------------ The results might surprise you. When I received my zfsc-2-1 I expected the addional ~3.5dB loss to be an issue. But after much testing I found that it didn't make that much difference. For the most part any signal I could receive without the addtional loss was still present with the loss. I used a HP step atenuator to check this before going to the trouble of mounting the zfsc. I really expected to need a good low noise, high intercept, preamp before the splitter. If you have a "good enough" antenna the additional loss is of slight concern. Since I have all of my antennas, receivers, RF filters on a patch panel, it allows me to easily move the splitter out of line. I use BNC connectors because I was given a "boat load" of them and find them easier and faster to move then PL/SO-259 connectors. A friend wanted a similar setup and I gave him enough bulkhead mount "F" femalefemale to allow him to bring all of his antenas and both receivers to a panel. He found an "old" TV spliter that works very well to below the MW/BCB band. I bought a bag of over 500 for $1 at the local Goodwill store. Another advantage of a RF patch panel is I can connect my Pro2004 IF out to my R2000 so I can listen to SSB VHF/UFF comms. I do have to be very carefull to insure that I don't connect my ham gear to my receiver inputs. At them moment I have them feeding different RF patch panels and simply don't ever connect my ham gear to a receive antenna. I am considering switching all of my receive RF connectors to "F", at least at the patch panel. I have thought of using TNC but they are expensive and are easier to crossthread then "F". Terry |
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dxAce wrote:
dxAce Apr 17, 3:11 pm show options Newsgroups: rec.radio.shortwave From: dxAce - Find messages by this author Date: Sun, 17 Apr 2005 18:11:26 -0400 Local: Sun,Apr 17 2005 3:11 pm Subject: splitter ? Reply | Reply to Author | Forward | Print | Individual Message | Show original | Report Abuse - Hide quoted text - - Show quoted text - Yes, the calibration may indeed be off with various manufacturers, however all things being equal it should be very easy to determine various antenna changes with a 'particular' receiver. Damn simple. dxAce Michigan USA --------------------------- Sadly very few radios have S-meters that behave in a "correct" way. I have a HP calibrated step attenuator, with .5dB steps. Zin 50Ohm Zout 50 Ohm. When checked at the electronics lab (at UK) the error was less then .07dB worst case. I have a simple crystal osc that is very temp stable. Zout 50 Ohms at .1V. Measured to be 0.10V. I have had chance to check quite a few receivers. From the famous R390, to one of the Lowe 150s. I would have to dig out my notes, if I even still have them, and the R390 was the ony one that tracked 6dB/1S unit. This url has better data then I can dig out out the moment: http://www.ac6v.com/sunit.htm Unless you know, that is have measured, your S-meter, it is only a rough indication. You can clearly use your S meter to compare one antenna to another, but I would be very hesitant to say that "antenna 1 is S2 and antenna 2 is S6, therefore antenna 2 has 24dB more gain then antenna 1." Based on the assumption that 1 S unit equals 6 dB. S6-S2=4 S-units, 4 X6dB = 24dB (Math shown for those new to the hobby) Now if you have a calibrated step attenuator you could show that: Ant 1 gives S2 Ant 2 requires 20dB of attenuation to give a reading of S2. Ant 2 has about 20dB more gain then Ant 1. I bought my Hp attenuator at a surplus store for $5. I bought 2 fox industries 50P-077 +12V BCD attenuators that have a measured error of less then .01dB for $1each! Coupled with some Pasternak PE7101 coaxial relays I hope to be able to some "meaningfull" antenna experiments this summer and next winter. There is a vacant lot caty corner behind us and I have permission from the lot owner, and both my rear and next door neigbors to run an temp antenna to and across that lot. I will be able to get about 300' of wire up in a straight line. I intend to see just how length effect signal strength. Next fall a frined is going to let me spend a few weekends on his fields to check even longer wires. Terry |
sorry Mike, email on the way...
Drifter... |
BNCs are certainly the way to go as opposed to PL-259
If you keep your eyes open, you can get real RF patch bays. I don't know the name of the connector, but they are really patches, i.e. no threads. About the only way to buy these RF patch bays is with the patches at the same time. There seem to be two similar designs, but the dimensions are not quite the same. I ohmed out all the connectors before buying any of the patch cables. The whole deal about about $30 to $40 a few years ago. Mine had the stickers on from a radar company (Whistler), so I'm pretty sure it was 50 ohm. I guess there is a risk you might get a 75 ohm video patch bay. Unless the pre-amp is as clean as your radio, I'd take the loss in the splitter and make it up in the AGC. I wouldn't want to risk intermod in the amp degrading the reception of the signal. Signal strength and quality of the signal are not always related. You can experiment by taking a strong signal and pad it down with an antennuator to the level of some weak signal. The padded down strong signal tends to sound cleaner. I think this is because the pad also reduced the level of the background noise at the same time, while a weak signal has a lower signal to noise ratio "naturally." I hope that makes sense. |
- 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... |
wrote:
BNCs are certainly the way to go as opposed to PL-259 If you keep your eyes open, you can get real RF patch bays. I don't know the name of the connector, but they are really patches, i.e. no threads. About the only way to buy these RF patch bays is with the patches at the same time. There seem to be two similar designs, but the dimensions are not quite the same. I ohmed out all the connectors before buying any of the patch cables. The whole deal about about $30 to $40 a few years ago. Mine had the stickers on from a radar company (Whistler), so I'm pretty sure it was 50 ohm. I guess there is a risk you might get a 75 ohm video patch bay. Unless the pre-amp is as clean as your radio, I'd take the loss in the splitter and make it up in the AGC. I wouldn't want to risk intermod in the amp degrading the reception of the signal. Signal strength and quality of the signal are not always related. You can experiment by taking a strong signal and pad it down with an antennuator to the level of some weak signal. The padded down strong signal tends to sound cleaner. I think this is because the pad also reduced the level of the background noise at the same time, while a weak signal has a lower signal to noise ratio "naturally." I hope that makes sense. http://www.switchcraft.com/products/vpp.html & http://www.switchcraft.com/products/561.html are examples of video patch bays and plugs that work for HF receivers as well. They are used for manual routing of video in some studios and transmitter sites. Western Electric used to use them on their coaxial long lines that fed video cross country before TV satellites were available. If you're old enough to remember the nationwide live video feed after President Kennedy was assassinated, the techs and engineers at ATT patched together the first nationwide feed by connecting the different network's feeds together to provide all network stations with live video and did the same with the audio feeds. -- Former professional electron wrangler. Michael A. Terrell Central Florida |
"dxAce" wrote in message ... "Charles W. Hinkle" wrote: I have used Mini Circut Labs ZFSC-2-1 and a 2 port passive Stridsberg. I obtained the MCL's at hamfests for $10 and the Stridsberg new Presently I am using a MCL PSC-3-1 to feed 3 receivers. I also got this at a hamfest. My receivers make up the nearly 5 db loss. How do they make up the loss? Just curious. dxAce Michigan USA Same question here. Dale W4OP |
On Mon, 18 Apr 2005 02:43:05 GMT, "Michael A. Terrell" wrote: http://www.switchcraft.com/products/vpp.html & http://www.switchcraft.com/products/561.html are examples of video patch bays and plugs that work for HF receivers as well. They are used for manual routing of video in some studios and transmitter sites. Western Electric used to use them on their coaxial long lines that fed video cross country before TV satellites were available. If you're old enough to remember the nationwide live video feed after President Kennedy was assassinated, the techs and engineers at ATT patched together the first nationwide feed by connecting the different network's feeds together to provide all network stations with live video and did the same with the audio feeds. 75 Ohms, if that matters. If you're going to use RG-59/U, you might as well just use ubiquitous and cheap F-Connectors and A/B/C switches. |
David wrote:
On Mon, 18 Apr 2005 02:43:05 GMT, "Michael A. Terrell" wrote: http://www.switchcraft.com/products/vpp.html & http://www.switchcraft.com/products/561.html are examples of video patch bays and plugs that work for HF receivers as well. They are used for manual routing of video in some studios and transmitter sites. Western Electric used to use them on their coaxial long lines that fed video cross country before TV satellites were available. If you're old enough to remember the nationwide live video feed after President Kennedy was assassinated, the techs and engineers at ATT patched together the first nationwide feed by connecting the different network's feeds together to provide all network stations with live video and did the same with the audio feeds. 75 Ohms, if that matters. If you're going to use RG-59/U, you might as well just use ubiquitous and cheap F-Connectors and A/B/C switches. If you want to use 75 ohm cables its your choice. The patch bays are BNC on both halves so you can use 50 or 75 ohm cables with them. These patch bays show up used and surplus along with the plugs. I've used them at several TV stations, a mobile production van I built and in the telemetry package we shipped to Italy. They are a lot better quality than "F" fittings and CATV switches. I used to run insertion loss and other tests on samples for United Video Cablevision and there was more junk submitted than quality parts. Even the better quality switches only lasted a year or so when we used them to reroute video feeds in the L.O. studio. -- Former professional electron wrangler. Michael A. Terrell Central Florida |
On Mon, 18 Apr 2005 13:33:03 GMT, "Michael A. Terrell"
wrote: If you want to use 75 ohm cables its your choice. The patch bays are BNC on both halves so you can use 50 or 75 ohm cables with them. These patch bays show up used and surplus along with the plugs. I've used them at several TV stations, a mobile production van I built and in the telemetry package we shipped to Italy. They are a lot better quality than "F" fittings and CATV switches. I used to run insertion loss and other tests on samples for United Video Cablevision and there was more junk submitted than quality parts. Even the better quality switches only lasted a year or so when we used them to reroute video feeds in the L.O. studio. 75 Ohm BNCs and 50 Ohm BNCs are two different connectors. You can mix them up if you like, but it's lame. |
By advancing the af gain control
"Dale Parfitt" wrote in message news:J7O8e.18054$ox3.16766@trnddc03... "dxAce" wrote in message ... "Charles W. Hinkle" wrote: I have used Mini Circut Labs ZFSC-2-1 and a 2 port passive Stridsberg. I obtained the MCL's at hamfests for $10 and the Stridsberg new Presently I am using a MCL PSC-3-1 to feed 3 receivers. I also got this at a hamfest. My receivers make up the nearly 5 db loss. How do they make up the loss? Just curious. dxAce Michigan USA Same question here. Dale W4OP |
http://www.trompeter.com/assets/prod...itary_Aero.pdf
You can get 50 ohm patchs bays too. The military uses them. Like I said, if you buy them used, make sure you ohm out the connections. There are so many variations that look like they are the same until you plug them in. Make sure you have a can of Caig DeOxit handy. |
David wrote:
On Mon, 18 Apr 2005 13:33:03 GMT, "Michael A. Terrell" wrote: If you want to use 75 ohm cables its your choice. The patch bays are BNC on both halves so you can use 50 or 75 ohm cables with them. These patch bays show up used and surplus along with the plugs. I've used them at several TV stations, a mobile production van I built and in the telemetry package we shipped to Italy. They are a lot better quality than "F" fittings and CATV switches. I used to run insertion loss and other tests on samples for United Video Cablevision and there was more junk submitted than quality parts. Even the better quality switches only lasted a year or so when we used them to reroute video feeds in the L.O. studio. 75 Ohm BNCs and 50 Ohm BNCs are two different connectors. You can mix them up if you like, but it's lame. "N" connectors are the really touchy connectors as far as pin and collet diameters. I would worry more about the intermod problems from worn contacts in cheap A-B switches. I've seen it and had to track it down in places that were too cheap to buy a video router or patch bay. -- Former professional electron wrangler. Michael A. Terrell Central Florida |
"Charles W. Hinkle" wrote in message ... By advancing the af gain control " My receivers make up the nearly 5 db loss. How do they make up the loss? Just curious. dxAce Michigan USA Same question here. Dale W4OP The problem here lies in S/N ratio not loudness. If the 5dB loss places a signal down near the noise floor- NO amount of RF or AF gain in the receiver can restore the S/N. If your assumption were true, there would be no need of LNA's, small signal RF amps, active splitters etc. It's not magic, it's math. Dale W4OP |
In article ,
dxAce wrote: Telamon wrote: In article , dxAce wrote: "Charles W. Hinkle" wrote: I have used Mini Circut Labs ZFSC-2-1 and a 2 port passive Stridsberg. I obtained the MCL's at hamfests for $10 and the Stridsberg new Presently I am using a MCL PSC-3-1 to feed 3 receivers. I also got this at a hamfest. My receivers make up the nearly 5 db loss. How do they make up the loss? Just curious. Maybe his radios have pre-amps like the Drakes. When you use a passive splitter the loss is 3dB power and 6dB voltage. I think most radio S meters are responding to the voltage number due to the nature of the AGC circuits. Someone can correct me on this. Should be easy enough to take a splitter in and out of line. Correct me if I'm wrong... but would it not be better to run some pre-amplification ahead of the splitter rather than try to make up something that has already disappeared? Much the same in say VHF work where it is better to run a receive pre-amp right at the antenna versus running it at the receiver end of the coax? Generally yes. An active splitter would have some matching losses on the input, then amplification, then split the signal, then have a line driver for each output. -- Telamon Ventura, California |
In article ,
"Michael A. Terrell" wrote: David wrote: On Mon, 18 Apr 2005 02:43:05 GMT, "Michael A. Terrell" wrote: http://www.switchcraft.com/products/vpp.html & http://www.switchcraft.com/products/561.html are examples of video patch bays and plugs that work for HF receivers as well. They are used for manual routing of video in some studios and transmitter sites. Western Electric used to use them on their coaxial long lines that fed video cross country before TV satellites were available. If you're old enough to remember the nationwide live video feed after President Kennedy was assassinated, the techs and engineers at ATT patched together the first nationwide feed by connecting the different network's feeds together to provide all network stations with live video and did the same with the audio feeds. 75 Ohms, if that matters. If you're going to use RG-59/U, you might as well just use ubiquitous and cheap F-Connectors and A/B/C switches. If you want to use 75 ohm cables its your choice. The patch bays are BNC on both halves so you can use 50 or 75 ohm cables with them. These patch bays show up used and surplus along with the plugs. I've used them at several TV stations, a mobile production van I built and in the telemetry package we shipped to Italy. They are a lot better quality than "F" fittings and CATV switches. I used to run insertion loss and other tests on samples for United Video Cablevision and there was more junk submitted than quality parts. Even the better quality switches only lasted a year or so when we used them to reroute video feeds in the L.O. studio. I think F connectors are just plain nasty. Pain in the butt getting them started threading. BNC is used on practically any lab equipment in the audio and video range. Most gear operating 1KHz to 500MHz uses BNC. Making up the BNC connector is a little more work than a PL-259 but the push on and twist makes changing patch board connections a snap. Just say no to F connectors unless you are using RG-59, which they are made for and the connections will not be changed often. -- Telamon Ventura, California |
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..... 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. If you plan to use a preamplifier, PLEASE (!) use a low noise model. Often times preamps will raise the noise floor by several dB, which could wipe out some weak DX for you. Purchase (or build) the BEST preampllifier that you can. It should be low noise, and the gain should not be so high that it goes into oscillation (you really just want to overcome the splitter losses). Some preamps will cause trouble with the 3d order intercept points of your receiver by overloading the front end. Every active component plays against every other active component, so be mindful of your trade-offs and gains. Good luck! 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 =---- |
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. 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... -- Telamon Ventura, California |
Telamon wrote:
Another fine example of an intelligent response on Usenet. What else is left after they get done throwing apples at each other while they flame each other? ;-) -- Former professional electron wrangler. Michael A. Terrell Central Florida |
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 |
In article . com,
wrote: 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. Some of the information you posted above is wrong. Please read my post at the top. It does not matter if the passive splitter is resistive or a coupled transformer type the power divides in half otherwise you will violate the laws of conservation. The transformer type will provide some isolation between the ports above what the resistive splitter will provide but that's about it. Sorry that just the way it is as you don't get something for nothing in this world. -- Telamon Ventura, California |
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 =---- |
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 |
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 =---- |
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 |
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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