Re: [Repeater-Builder] Re: Repeater Antenna Question
The Telewave unit is a tuned circut type too (low pass VHF / high pass UHF), just much more robust. They are capable of running at a much higher power level than the Amateur type. They are also weather proof (with proper connector sealing) if you want to "break out" your feedline at the top of the tower into a seperate VHF/UHF antennas. I have an application where a long run of 1 1/4" LDF was more cost and DB effective than two (2) runs of smaller cable by using a "cross band coupler" both top and bottom. Now i have lower loss, one less run of feedline on the tower and mono band perfromance with dedicated antennas on 2 meters and 440. crackedofn0de <[EMAIL PROTECTED]> wrote: --- In Repeater-Builder@yahoogroups.com, [EMAIL PROTECTED] wrote: > > In a message dated 4/26/2007 4:39:57 P.M. Eastern Daylight Time, > [EMAIL PROTECTED] writes: > > cross band coupler > > > Thanks that sounds like the ticket. Seems like the way to go > > > JA How about a diplexer from Comet or Diamond? I looked into this recently for a similar application and couldn't tell the difference between the expensive Telewave crossband couplers and the dime-a-dozen amateur diplexers. The specs given for the diplexers even indicate about twice the isolation compared to the crossband couplers. While the designs appear to be different (tuned "cavity" vs. tuned circuit), I can't find any information that would indicate any pros or cons between the two in practice. Anybody? Both Comet and Diamond call their diplexers duplexers. I have no idea why. They get it right when they call their triplexers triplexers. I was thinking about going with a Diamond product (they at least have a metal housing) and swapping out any UHF connectors for N types. http://www.rfparts.com/diamond/Product_Catalog/plexers.html http://www.cometantenna.com/products.php?CatID=1&famID=6&childID=0 - Ahhh...imagining that irresistible "new car" smell? Check outnew cars at Yahoo! Autos.
Re: [Repeater-Builder] Re: Repeater Antenna Question
I have been building my own cross-band couplers for years. Two meters and 440 work fine as long as you stay away from harmonically related frequencies. My cross band coupler consists of a standard Tee section tuner for 440 with a series cap on the input, a shunt inductor, and a series cap on the output. The two caps are tuned for the best SWR on the input into the existing antenna system - even if there is some SWR. For two meters I use a series inductor, a shunt capacitor, and a series inductor. The two meter output inductor is connected in parallel with the 440 output cap, and again the two meter section is tuned for best SWR back to the two meter load. Tune the 440 section first, and you will find that the very small capacity on the output of the two meter section is no problem. Likewise, the inductor back to the two meter section poses no problem to the 440 output. Spreading or compressing the turns on the two meter coils will allow a good match when tuning the two meter capacitor. This system provides a two band to one band combiner, along with antenna matching for each band. The 440 section is hi pass while the two meter section is low pass, and each band is actually tuned to resonance Z matcher style. We operated a 440 repeater through one of these combiners to a GP-9 type antenna along with a two meter remote base. An MVP at 12 watts was the 440 repeater, and an Icom 22S was the remote base. It worked great with no interaction that we could tell. I added six meters to one of these couplers by simply putting a capacitor and inductor in series with no ground connection with the inductor connected to the output side of the combiner and had good operation on all three bands at the same time. The capacitor stator was connected to the six meter input. 73 - Jim W5ZIT -Original Message- From: [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Fri, 27 Apr 2007 8:58 AM Subject: RE: [Repeater-Builder] Re: Repeater Antenna Question I don't think any of them have cavities in them. I would suspect that the telewave is built very similar to the diamond etc. Mostly lumped circuit tuning (capacitor and coils) and maybe some 1/4 wave stub tuned coax rolled up inside. For a long time most commercial manufactures like telewave Sinclair etc. stayed away from cross band couplers between 150 and 450 bands but readily did it between 800 and 450 or 800 and 150. The problem with 150 and 450 is that they are harmonically related. A quarter wave length cavity on 150 is a three quarter wave length cavity on 450. A three quarter wave cavity resonates just as well at three quarter wave as it does at a quarter wave but of course has more selectivity as a three quarter wave. Most of the better transmitter combiners for 800 and 900 MHz used three quarter wave length cavities in them. Most of the cross band couplers use capacitors and inductors to form low and high pass filters to get around the 3rd resonance mode of cavities. Cross band couplers open the door for intermode problems as those 3rd harmonics are not attenuated all that much in the couplers. They do work but sometimes may cause problems. DUPLEXER / DIPLEXER A duplexer and diplexer are very similar. A diplexer is what it is usually called when two transmitters are combined together. If a transmitter and receiver are combined then it is called a duplexer. The cross band couplers I suppose could be called either as they do combine two transmitters but they also combine two receivers and allow duplex operation. You could have a 450 receiver working at the same time as a 150 transmitter so that would be a duplex situation. Maybe they should be called duo-duplexers. :>) 73 Gary K4FMX > -Original Message- > From: Repeater-Builder@yahoogroups.com [mailto:Repeater- > [EMAIL PROTECTED] On Behalf Of crackedofn0de > Sent: Friday, April 27, 2007 9:34 AM > To: Repeater-Builder@yahoogroups.com > Subject: [Repeater-Builder] Re: Repeater Antenna Question > > --- In Repeater-Builder@yahoogroups.com, [EMAIL PROTECTED] wrote: > > > > In a message dated 4/26/2007 4:39:57 P.M. Eastern Daylight Time, > > [EMAIL PROTECTED] writes: > > > > cross band coupler > > > > > > Thanks that sounds like the ticket. Seems like the way to go > > > > > > JA > > How about a diplexer from Comet or Diamond? I looked into this > recently for a similar application and couldn't tell the difference > between the expensive Telewave crossband couplers and the dime-a-dozen > amateur diplexers. The specs given for the diplexers even indicate > about twice the isolation compared to the crossband couplers. While > the designs appear to be different (tuned "cavity" vs. tuned circuit), > I can't find any information that would indicate any pros or cons > between the two in practice. Anybody? > &g
Re: [Repeater-Builder] Re: Repeater Antenna Question
Quoting [EMAIL PROTECTED]: > At 4/27/2007 06:34, you wrote: > >> How about a diplexer from Comet or Diamond? I looked into this > > They work fine provided you use the model WITHOUT the pigtail leads, IOW > all connectors must be directly on the diplexer. Use only coax with > silver-plated braid (RG-214, 223, 142 or 400) or hardline to connect to > it. Also be careful with how much power to run to it. My systems that use > crossband diplexers all run relatively low power (no more than 30 watts); > others have reported problems with component overheating & failure at > higher power levels. If you plan on running 100 watts through it you > should test on the bench by running continuous higher power through it for > several hours. > > Bob NO6B > > > About a year ago we diplexed a Daniels VHF repeater (30 watts) with a GE master UHF repeater (15 watts) into a Sinclair 210 C4. Install went well and worked good with reasonable antenna paterns. Recently we upgraded the UHF repeater to another Daniels (25 watts). The new repeater did not like the diplexer. The TX went into SWR shutdown and was not happy at all. Solution was to install a UHF 4 pole without the diplexer and life became good. We are not sure if we were being had or not, but we now are sucpicious of diplexers. I guess we did not re invent the wheel. Roger VA7RS
RE: [Repeater-Builder] Re: Repeater Antenna Question
I don't think any of them have cavities in them. I would suspect that the telewave is built very similar to the diamond etc. Mostly lumped circuit tuning (capacitor and coils) and maybe some 1/4 wave stub tuned coax rolled up inside. For a long time most commercial manufactures like telewave Sinclair etc. stayed away from cross band couplers between 150 and 450 bands but readily did it between 800 and 450 or 800 and 150. The problem with 150 and 450 is that they are harmonically related. A quarter wave length cavity on 150 is a three quarter wave length cavity on 450. A three quarter wave cavity resonates just as well at three quarter wave as it does at a quarter wave but of course has more selectivity as a three quarter wave. Most of the better transmitter combiners for 800 and 900 MHz used three quarter wave length cavities in them. Most of the cross band couplers use capacitors and inductors to form low and high pass filters to get around the 3rd resonance mode of cavities. Cross band couplers open the door for intermode problems as those 3rd harmonics are not attenuated all that much in the couplers. They do work but sometimes may cause problems. DUPLEXER / DIPLEXER A duplexer and diplexer are very similar. A diplexer is what it is usually called when two transmitters are combined together. If a transmitter and receiver are combined then it is called a duplexer. The cross band couplers I suppose could be called either as they do combine two transmitters but they also combine two receivers and allow duplex operation. You could have a 450 receiver working at the same time as a 150 transmitter so that would be a duplex situation. Maybe they should be called duo-duplexers. :>) 73 Gary K4FMX > -Original Message- > From: Repeater-Builder@yahoogroups.com [mailto:Repeater- > [EMAIL PROTECTED] On Behalf Of crackedofn0de > Sent: Friday, April 27, 2007 9:34 AM > To: Repeater-Builder@yahoogroups.com > Subject: [Repeater-Builder] Re: Repeater Antenna Question > > --- In Repeater-Builder@yahoogroups.com, [EMAIL PROTECTED] wrote: > > > > In a message dated 4/26/2007 4:39:57 P.M. Eastern Daylight Time, > > [EMAIL PROTECTED] writes: > > > > cross band coupler > > > > > > Thanks that sounds like the ticket. Seems like the way to go > > > > > > JA > > How about a diplexer from Comet or Diamond? I looked into this > recently for a similar application and couldn't tell the difference > between the expensive Telewave crossband couplers and the dime-a-dozen > amateur diplexers. The specs given for the diplexers even indicate > about twice the isolation compared to the crossband couplers. While > the designs appear to be different (tuned "cavity" vs. tuned circuit), > I can't find any information that would indicate any pros or cons > between the two in practice. Anybody? > > Both Comet and Diamond call their diplexers duplexers. I have no idea > why. They get it right when they call their triplexers triplexers. > > I was thinking about going with a Diamond product (they at least have > a metal housing) and swapping out any UHF connectors for N types. > > http://www.rfparts.com/diamond/Product_Catalog/plexers.html > > http://www.cometantenna.com/products.php?CatID=1&famID=6&childID=0 > > > > > > > > > Yahoo! Groups Links > > >
Re: [Repeater-Builder] Re: Repeater Antenna Question
At 06:34 AM 4/27/2007, you wrote: >I was thinking about going with a Diamond product (they at least have >a metal housing) and swapping out any UHF connectors for N types.
Re: [Repeater-Builder] Re: Repeater Antenna Question
At 06:34 AM 4/27/2007, you wrote: >How about a diplexer from Comet or Diamond? I looked into this >recently for a similar application and couldn't tell the difference >between the expensive Telewave crossband couplers and the dime-a-dozen >amateur diplexers. <---I'm using a Diamond one on one of my systems but one without the pigtails (don't want leaky coax do we?!). Just make sure whichever one you get can handle the COMBINED power on both ports. I have used it quite successfully for the past 5 years on a 90 watt UHF repeater with a 60 watt 2 meter remote base. Ken -- President and CTO - Arcom Communications Makers of the world famous RC210 Repeater Controller and accessories. http://www.arcomcontrollers.com/ Coming soon - the most advanced repeater controller EVER. Authorized Dealers for Kenwood and Telewave and we offer complete repeater packages! AH6LE/R - IRLP Node 3000 http://www.irlp.net
Re: [Repeater-Builder] Re: Repeater Antenna Question
At 4/27/2007 06:34, you wrote: >How about a diplexer from Comet or Diamond? I looked into this They work fine provided you use the model WITHOUT the pigtail leads, IOW all connectors must be directly on the diplexer. Use only coax with silver-plated braid (RG-214, 223, 142 or 400) or hardline to connect to it. Also be careful with how much power to run to it. My systems that use crossband diplexers all run relatively low power (no more than 30 watts); others have reported problems with component overheating & failure at higher power levels. If you plan on running 100 watts through it you should test on the bench by running continuous higher power through it for several hours. Bob NO6B
[Repeater-Builder] Re: Repeater Antenna Question
--- In Repeater-Builder@yahoogroups.com, [EMAIL PROTECTED] wrote: > > In a message dated 4/26/2007 4:39:57 P.M. Eastern Daylight Time, > [EMAIL PROTECTED] writes: > > cross band coupler > > > Thanks that sounds like the ticket. Seems like the way to go > > > JA How about a diplexer from Comet or Diamond? I looked into this recently for a similar application and couldn't tell the difference between the expensive Telewave crossband couplers and the dime-a-dozen amateur diplexers. The specs given for the diplexers even indicate about twice the isolation compared to the crossband couplers. While the designs appear to be different (tuned "cavity" vs. tuned circuit), I can't find any information that would indicate any pros or cons between the two in practice. Anybody? Both Comet and Diamond call their diplexers duplexers. I have no idea why. They get it right when they call their triplexers triplexers. I was thinking about going with a Diamond product (they at least have a metal housing) and swapping out any UHF connectors for N types. http://www.rfparts.com/diamond/Product_Catalog/plexers.html http://www.cometantenna.com/products.php?CatID=1&famID=6&childID=0
Re: [Repeater-Builder] Re: Repeater Antenna Question
In a message dated 4/26/2007 4:39:57 P.M. Eastern Daylight Time, [EMAIL PROTECTED] writes: cross band coupler Thanks that sounds like the ticket. Seems like the way to go JA ** See what's free at http://www.aol.com.
[Repeater-Builder] Re: Repeater Antenna Question
JA, Since you have good quality duplexers already, i would go with the "cross band coupler" that Telewave makes. This is a very good commercial grade product, reasonably priced and is designed for repeater applications. I am using similar duplexers, a cross band coupler and a Diamond X- 500HNA on one of my sites due to limited available tower space. Not being a fan of duel band antennas, i'll have to admit, the combo performs quite well. :) 73, Steve / K6SCA --- In Repeater-Builder@yahoogroups.com, "jhccradio" <[EMAIL PROTECTED]> wrote: > > I am not sure if we ever visited this question before, If we have > sorry... > > Here is the story, I have a Comet Dual Band Antenna GP9 VHF/UHF, > works for me and I like the quality and price. I have a UHF Repeater > and soon to have a VHF Repeater at the same location. I have no more > space or money to run the cable for another antenna, to the top. How > could I run both repeaters off the same antenna, I have a wacom > duplexer 4 can base type (not the cheap mobile kind) for one and the > other is a Telewave VHF 4 can (same type but VHF). Is it possible? > Could I use one of those splitters (450/150 mini duplexers) attached to > both duplexers? Or would I need something else? This is probably > simple I just am not sure? Thanks in advance? > > JA >
