RE: [Repeater-Builder] Min FREQ Separtation, VHF rep, No Duplexers
as it must be the correct distance between an antenna and another one if I use bansplit of 5MHZ?Joe Montierth <[EMAIL PROTECTED]> wrote: --- Steve Bosshard <[EMAIL PROTECTED]>wrote:> Once upon a time I asked Lloyd Alcorn up at Wacom> that question.> > Best I recall 60 ft is the maximum distance on a> tower that you can> seperate antennas.> > Further seperation will not yield additional> isolation because of the> coupling within the tower itself.> > Number wise memory tells me that the isolation at> 146 Mhz and 60 ft. was> around 60 db - just enough maybe with a clean tube> transmitter and very> selective receiver to get by, and maybe not. > Horizontal seperation was> not nearly as effective.> > Seems like 85 db of isolation was the magic number> at 600 kc.> > Regards,> > Steve> > Isolation wise, vertical is much superior tohorizontal. For the example we're working on, 100 fthorizontal would be the same as about 14 ft vertical.To me, it would be easier to get 14 ft vertical, than100 ft horizontal.Joe__Do you Yahoo!?Yahoo! Photos: High-quality 4x6 digital prints for 25¢http://photos.yahoo.com/ph/print_splashYahoo! Groups Links<*> To visit your group on the web, go to:http://groups.yahoo.com/group/Repeater-Builder/<*> To unsubscribe from this group, send an email to:[EMAIL PROTECTED]<*> Your use of Yahoo! Groups is subject to:http://docs.yahoo.com/info/terms/Do You Yahoo!? Todo lo que quieres saber de Estados Unidos, América Latina y el resto del Mundo. Visíta Yahoo! Noticias. Yahoo! Groups Links To visit your group on the web, go to:http://groups.yahoo.com/group/Repeater-Builder/ To unsubscribe from this group, send an email to:[EMAIL PROTECTED] Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
RE: [Repeater-Builder] Min FREQ Separtation, VHF rep, No Duplexers
Why would you need a repeater to cover an area that simplex would cover? -Original Message- From: Virden Clark Beckman [mailto:[EMAIL PROTECTED] Sent: Tuesday, April 20, 2004 8:53 AM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Min FREQ Separtation, VHF rep, No Duplexers You know I was thinking of any possible way this might work and I remembered something after a club meeting last night, if both antennas were covered with a globe of shielding foil except for 10 degrees facing opposite directions, 10 watts of output with a 100 ft. long rg-58 feedline extension, if all the users were in between the antennas it would work within one 2.0 meg of split and this would work for a family picnic or a hamfest flea market as long as there was no co-ordinated repeaters using the same freqs. There was a young ham from our club who tryed something like this at his farm, it was almost useless but we who saw and used it learned that many walkytalkies had one memory for the uncommon split - like cap or mars uses. courir26 wrote: > > I'll rephrase the question, what is the min frequency separtation for > a 10W repeater with two ants, no vertical separation, horizontal sep > of about 100'. > > I'm guessing it would have to be 2 MHz or more, but that is what I'm > asking. > > Please don't answer .600 and 200' vertical because that is not the > question. > > I'm referring to an emergency or garage repeater with odd split. > > Thanks! > > Tom N5OFF > -- 73...Clark Beckman N8PZD Yahoo! Groups Links Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
RE: [Repeater-Builder] Min FREQ Separtation, VHF rep, No Duplexers
--- Steve Bosshard <[EMAIL PROTECTED]> wrote: > Once upon a time I asked Lloyd Alcorn up at Wacom > that question. > > Best I recall 60 ft is the maximum distance on a > tower that you can > seperate antennas. > > Further seperation will not yield additional > isolation because of the > coupling within the tower itself. > > Number wise memory tells me that the isolation at > 146 Mhz and 60 ft. was > around 60 db - just enough maybe with a clean tube > transmitter and very > selective receiver to get by, and maybe not. > Horizontal seperation was > not nearly as effective. > > Seems like 85 db of isolation was the magic number > at 600 kc. > > Regards, > > Steve > > Isolation wise, vertical is much superior to horizontal. For the example we're working on, 100 ft horizontal would be the same as about 14 ft vertical. To me, it would be easier to get 14 ft vertical, than 100 ft horizontal. Joe __ Do you Yahoo!? Yahoo! Photos: High-quality 4x6 digital prints for 25¢ http://photos.yahoo.com/ph/print_splash Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Min FREQ Separtation, VHF rep, No Duplexers
--- courir26 <[EMAIL PROTECTED]> wrote: > I'll rephrase the question, what is the min > frequency separtation for > a 10W repeater with two ants, no vertical > separation, horizontal sep > of about 100'. > > I'm guessing it would have to be 2 MHz or more, but > that is what I'm > asking. > > Please don't answer .600 and 200' vertical because > that is not the > question. > > I'm referring to an emergency or garage repeater > with odd split. > > Thanks! > > Tom N5OFF > OK, let's just look at theoretical numbers here. 100 ft of horizontal separation between 2 dipoles at 2M would give you 41 dB of isolation. If you have a 10 watt TX, that is putting out +40 dBm, which would put a -1 dBm into your RX (at the TX freq). The further in freq you get from the TX, the more your sideband (or phase) noise will be reduced. Since your RX can probably hear down to -120 dBm, you will need that much TX phase noise suppression at your RX frequency. Most good quality (non-ham) transmitters may acheive this at a 2 to 3 meg separation, some ham models may also do this. Now, your RX front end needs to suppress the TX freq by a certain amount, to avoid overload. Most radios will overload at about a -30 dBm, so your helicals need to suppress the TX freq by at least 30 dB, reference the RX freq. A Micor or MII, or other good RX will probably do OK in that field, since they have "tight" preselectors. Most ham grade radios will not work, since everything in band comes right through. You might be able to put on an external preselector and make a ham RX work. Bottom line, 2 megs might be too close, 3 megs might be where things start to work OK, and further the better. Most of the figures you would need to test this aren't published, and you would have to experiment to find out what did and didn't work. Like I said previously, we had a commercial 161MHz Micor on a 150 KHz split that worked without cavities, and only about 60 ft vert between antennas. If I hadn't seen it working, I would never have beleived it. But 60 ft vertical is 28 dB better than 100 ft horizontal. Joe __ Do you Yahoo!? Yahoo! Photos: High-quality 4x6 digital prints for 25¢ http://photos.yahoo.com/ph/print_splash Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Min FREQ Separtation, VHF rep, No Duplexers
Tom I think if you took two Mitrek units and set one up as a receiver and the other as a transmitter, using two antennas and two feed lines with 600Khz separation and kept the transmitter power at 20 watts or less this would work like you want. In my past memory I once saw this done. I think if you study the specs on the Mitreks you will see this should work. The selectivity of the receivers would allow this if the power was less than 20 watts. 73's de Tom Manning, AF4UG Virden Clark Beckman wrote: > You know I was thinking of any possible way this might work and I > remembered something after a club meeting last night, if both antennas > were covered with a globe of shielding foil except for 10 degrees facing > opposite directions, 10 watts of output with a 100 ft. long rg-58 > feedline extension, if all the users were in between the antennas it > would work within one 2.0 meg of split and this would work for a family > picnic or a hamfest flea market as long as there was no co-ordinated > repeaters using the same freqs. There was a young ham from our club who > tryed something like this at his farm, it was almost useless but we who > saw and used it learned that many walkytalkies had one memory for the > uncommon split - like cap or mars uses. > > courir26 wrote: > > > > I'll rephrase the question, what is the min frequency separtation for > > a 10W repeater with two ants, no vertical separation, horizontal sep > > of about 100'. > > > > I'm guessing it would have to be 2 MHz or more, but that is what I'm > > asking. > > > > Please don't answer .600 and 200' vertical because that is not the > > question. > > > > I'm referring to an emergency or garage repeater with odd split. > > > > Thanks! > > > > Tom N5OFF > > > > -- > 73...Clark Beckman N8PZD > > > Yahoo! Groups Links > > > > Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Min FREQ Separtation, VHF rep, No Duplexers
Title: RE: [Repeater-Builder] Min FREQ Separtation, VHF rep, No Duplexers After some more thought on the situation, and considering we were talking 10 watts at a residential location, what's wrong with using good old fashioned simplex. If the machine was low profile anyway, simplex most likely would work fine. Just another thought, maybe not what the original poster wanted to hear, but a thought. Chuck WB2EDV - Original Message - From: Buley, Kenneth L (GE Consumer & Industrial) To: 'Repeater-Builder@yahoogroups.com' Sent: Tuesday, April 20, 2004 9:03 AM Subject: RE: [Repeater-Builder] Min FREQ Separtation, VHF rep, No Duplexers 100' separation between antennas and all users between the antennas Why not just use tin cans and string LOL ;>) Seriously, ever think about using a simplex repeater ??? One radio, one antenna, no duplexer, can run off of batteries, can run on 1 frequency or 2 if you choose, no retuning or rearranging anything if you need to change frequencies. Ken KE4AWY Yahoo! Groups Links To visit your group on the web, go to:http://groups.yahoo.com/group/Repeater-Builder/ To unsubscribe from this group, send an email to:[EMAIL PROTECTED] Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
RE: [Repeater-Builder] Min FREQ Separtation, VHF rep, No Duplexers
Title: Message Once upon a time I asked Lloyd Alcorn up at Wacom that question. Best I recall 60 ft is the maximum distance on a tower that you can seperate antennas. Further seperation will not yield additional isolation because of the coupling within the tower itself. Number wise memory tells me that the isolation at 146 Mhz and 60 ft. was around 60 db - just enough maybe with a clean tube transmitter and very selective receiver to get by, and maybe not. Horizontal seperation was not nearly as effective. Seems like 85 db of isolation was the magic number at 600 kc. Regards, Steve Yahoo! Groups Links To visit your group on the web, go to:http://groups.yahoo.com/group/Repeater-Builder/ To unsubscribe from this group, send an email to:[EMAIL PROTECTED] Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
Re: [Repeater-Builder] Min FREQ Separtation, VHF rep, No Duplexers
You know I was thinking of any possible way this might work and I remembered something after a club meeting last night, if both antennas were covered with a globe of shielding foil except for 10 degrees facing opposite directions, 10 watts of output with a 100 ft. long rg-58 feedline extension, if all the users were in between the antennas it would work within one 2.0 meg of split and this would work for a family picnic or a hamfest flea market as long as there was no co-ordinated repeaters using the same freqs. There was a young ham from our club who tryed something like this at his farm, it was almost useless but we who saw and used it learned that many walkytalkies had one memory for the uncommon split - like cap or mars uses. courir26 wrote: > > I'll rephrase the question, what is the min frequency separtation for > a 10W repeater with two ants, no vertical separation, horizontal sep > of about 100'. > > I'm guessing it would have to be 2 MHz or more, but that is what I'm > asking. > > Please don't answer .600 and 200' vertical because that is not the > question. > > I'm referring to an emergency or garage repeater with odd split. > > Thanks! > > Tom N5OFF > -- 73...Clark Beckman N8PZD Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Min FREQ Separtation, VHF rep, No Duplexers
I think you are expecting a miracle here and I doubt anyone on this list is going to be able to give you an exact answer. My suggestion is that you take two synthesized rigs and try different frequency separations. If you can accomplish the task with ham rigs, then you should be able to substitute a commercial transmitter and receiver and just, if you're lucky, have enough extra headroom to make it work reliably. My gut feeling is that you won't be able to accomplish what you are setting out to do at that small distance and stay within the ham band without the aid of a can or two. Chuck Kelsey WB2EDV > courir26 wrote: > > > > I'll rephrase the question, what is the min frequency separtation for > > a 10W repeater with two ants, no vertical separation, horizontal sep > > of about 100'. > > > > I'm guessing it would have to be 2 MHz or more, but that is what I'm > > asking. > > > > Please don't answer .600 and 200' vertical because that is not the > > question. > > > > I'm referring to an emergency or garage repeater with odd split. > > > > Thanks! > > > > Tom N5OFF > > > > Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Min FREQ Separtation, VHF rep, No Duplexers
The answer lies along the diagonal lines; http://www.repeater-builder.com/pix/vertsep.jpg and http://www.repeater-builder.com/pix/horizsep.jpg - using the horizontal method you will need so much bandwidth you will be into the next radio band, like 222 and 440 or 146 and 222. This is just one of those things that doesn't work in the same band, period. You need isolation for the rx to hear without being desensed by the adjascent tx, you can get this using bandpass/notch cavity filters to keep one from the other, you could try some notch only filters and check the results but it will be tedious and you may find the loss is more than the gain but if all you have is time build them and give it a try. courir26 wrote: > > I'll rephrase the question, what is the min frequency separtation for > a 10W repeater with two ants, no vertical separation, horizontal sep > of about 100'. > > I'm guessing it would have to be 2 MHz or more, but that is what I'm > asking. > > Please don't answer .600 and 200' vertical because that is not the > question. > > I'm referring to an emergency or garage repeater with odd split. > > Thanks! > > Tom N5OFF > -- 73...Clark Beckman N8PZD Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
