Re: [Repeater-Builder] Question on portable repeaters
At 10/8/2009 06:04, you wrote: Possible options ? I decided to poke around on the Bird TX/RX website and found this little guy ( relatively speaking :-) ) Probably more command post sized than SUV sized but hey.. how big is that SUV :-)??? http://birdtechnologies.thomasnet.com/item/all-categories-duplexers-and-triplexers/duplexers-2/28-37-04c?seo=110 At 9.5 x 19 x 10.5 inches, COULD fit in a car.. It is rated at 65db at .5mhz so would be a bit better at .6mhz and as I recall many of the little mobile duplexers are typically 65db to 80db at bestso would be in the neighborhood of lowest useable isolation figures, depending on how quiet the TX is to start with. It looks like it gets to 70db at 1 mhz with less insertion loss so .6 mhz would likely be somewhere in between... if you do not mind the insertion loss... Not enough isolation. With most equipment you need at least 80 dB. Possibly with a very low noise (PLL exciter) TX you could get away with a few dB less but ~67 dB isn't enough. But as you say, using this split antennas just a few feet apart might yield sufficient isolation. Bob NO6B
Re: [Repeater-Builder] Question on portable repeaters
At 10/9/2009 06:32, you wrote: I applaud the desire to build a special event 2-meter portable repeater. I honestly think that most well-intentioned groups don't understand the technical difficulty to accomplish this task without spending a lot of money. However, it begs the question -- isn't there an existing, nearby 2-meter repeater that could be used? Chuck WB2EDV In my case, sadly, no. Yeah, you'd think in the heart of the 2nd largest city in the US that there'd be a lot of HT-accessible repeaters to use. But at the time I set out to build my first 2 meter portable system, only ONE 2 meter repeater had adequate coverage along the 26.2 mile LA Marathon course. ONE! At the time, the course roughly ran a circle with its eastern-most point in downtown LA. So we needed HT coverage in downtown, Hollywood, the Fairfax district, the Coliseum. Aside from the high building density in a few areas (not many - we don't have lots of highrises like NYC Chicago), this shouldn't have been a difficult area to cover. Certainly there were a lot of repeaters that could be HEARD in the target area, but most were not HT-accessible. The situation is a little better now on 2 meters but still to this day there is a 220 repeater that should cover the whole course, in fact can be heard solidly along the whole route, but has a deaf RX apparently the owner doesn't want to fix it. So we ignore it use our own system installed specifically for the event. Bob NO6B
Re: [Repeater-Builder] Question on portable repeaters
Yeah, Much lest costly to build a suitcase salellite receiver... - Original Message - From: n...@no6b.com To: Repeater-Builder@yahoogroups.com Sent: Saturday, October 10, 2009 1:00 PM Subject: Re: [Repeater-Builder] Question on portable repeaters At 10/9/2009 06:32, you wrote: I applaud the desire to build a special event 2-meter portable repeater. I honestly think that most well-intentioned groups don't understand the technical difficulty to accomplish this task without spending a lot of money. However, it begs the question -- isn't there an existing, nearby 2-meter repeater that could be used? Chuck WB2EDV In my case, sadly, no. Yeah, you'd think in the heart of the 2nd largest city in the US that there'd be a lot of HT-accessible repeaters to use. But at the time I set out to build my first 2 meter portable system, only ONE 2 meter repeater had adequate coverage along the 26.2 mile LA Marathon course. ONE! At the time, the course roughly ran a circle with its eastern-most point in downtown LA. So we needed HT coverage in downtown, Hollywood, the Fairfax district, the Coliseum. Aside from the high building density in a few areas (not many - we don't have lots of highrises like NYC Chicago), this shouldn't have been a difficult area to cover. Certainly there were a lot of repeaters that could be HEARD in the target area, but most were not HT-accessible. The situation is a little better now on 2 meters but still to this day there is a 220 repeater that should cover the whole course, in fact can be heard solidly along the whole route, but has a deaf RX apparently the owner doesn't want to fix it. So we ignore it use our own system installed specifically for the event. Bob NO6B
Re: [Repeater-Builder] Question on portable repeaters
On Wed, 7 Oct 2009, Paul Plack wrote: It's hard to beat 440 for a mobile or portable repeater. Tiny duplexers work, surplus commercial gear is cheap and plentiful, and many hams have radios for it. The repeater part is easy on 900 MHz and 1.2 GHz, but almost nobody has radios for those bands outside a couple big cities. 73, Paul, AE4KR There are small cities that have a 900MHz presence as well. If you have wide open space and line of sight, 900MHz would be a good choice for this. You would be able to put a radio in each ham's hands that was already on the right channel and setup with no dinking required. 440MHz is another good choice if you want to do it with everyone supplying thier own gear. In my current area, I have no reason to carry a 70cm HT as there is no activity on 70cm despite eight repeaters. In my last town there was quite a bit of 440MHz activity, and still is. 2M is often best used as a simplex net, provided everyone can hear Net Control and Net Control can hear everyone. Radio discipline is a must however. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Question on portable repeaters
On Fri, 9 Oct 2009, Chuck Kelsey wrote: I applaud the desire to build a special event 2-meter portable repeater. I honestly think that most well-intentioned groups don't understand the technical difficulty to accomplish this task without spending a lot of money. I think that a vast number of groups don't consider *where* they need communications and drop the repeater transmitter power accordingly while raising the antenna gain and directionality. If you're trying to talk up a mountain road, you can put the repeater at ground level and point it up the mountain with a small Yagi. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Question on portable repeaters
On Sat, 10 Oct 2009, WA3GIN wrote: Yeah, Much lest costly to build a suitcase salellite receiver... I've suggested this a few times to a local group before a large service event, but priorities get juggled every year and it falls off the mental map. Or the voter shelf saves the repeater from being rained on by functioning as a pail. If you've got a voter already set up and don't need the second receiver or have a tertiary input, setup an omnidirectional antenna at the repeater site and send audio back over a link frequency with a beam. The commercial FM guys have been doing this for years and calling it a remote. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Question on portable repeaters
When I was in college and had a part time job in the summer for a local radio station, we did many remotes using the 150 Mhz range. We had Marti broadcast equipment. Being in northern Wisconsin, it was challenging at times to go out to a resort in the Nicolet National forest and try to get a good signal back to the station. I'll never forget the day that I had to climb up an evergreen tree and hang the antenna up around 75 feet before the station got a good signal. The station manager told me later that if you didn't do that remote, you wouldn't be working here anymore. BTW, that's how I got into ham radio. Don, KD9PT - Original Message - From: Kris Kirby To: Repeater-Builder@yahoogroups.com Sent: Saturday, October 10, 2009 7:53 PM Subject: Re: [Repeater-Builder] Question on portable repeaters On Sat, 10 Oct 2009, WA3GIN wrote: Yeah, Much lest costly to build a suitcase salellite receiver... I've suggested this a few times to a local group before a large service event, but priorities get juggled every year and it falls off the mental map. Or the voter shelf saves the repeater from being rained on by functioning as a pail. If you've got a voter already set up and don't need the second receiver or have a tertiary input, setup an omnidirectional antenna at the repeater site and send audio back over a link frequency with a beam. The commercial FM guys have been doing this for years and calling it a remote. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Question on portable repeaters
At 10/7/2009 16:15, you wrote: Morning, We are looking at building a portable repeater for special even use. This will be mobile mounted and 2M. My questions is this: If we are using two radios (one for TX one for RX) then what does the antenna separation have to be for all of this to work? Use a wide (2.5 MHz or greater) split a mobile duplexer. Then the antenna separation becomes 0. Bob NO6B
Re: [Repeater-Builder] Question on portable repeaters
I applaud the desire to build a special event 2-meter portable repeater. I honestly think that most well-intentioned groups don't understand the technical difficulty to accomplish this task without spending a lot of money. However, it begs the question -- isn't there an existing, nearby 2-meter repeater that could be used? Chuck WB2EDV - Original Message - From: n...@no6b.com To: Repeater-Builder@yahoogroups.com Sent: Friday, October 09, 2009 8:48 AM Subject: Re: [Repeater-Builder] Question on portable repeaters At 10/7/2009 16:15, you wrote: Morning, We are looking at building a portable repeater for special even use. This will be mobile mounted and 2M. My questions is this: If we are using two radios (one for TX one for RX) then what does the antenna separation have to be for all of this to work? Use a wide (2.5 MHz or greater) split a mobile duplexer. Then the antenna separation becomes 0. Bob NO6B
Re: [Repeater-Builder] Question on portable repeaters
Possible options ? I decided to poke around on the Bird TX/RX website and found this little guy ( relatively speaking :-) ) Probably more command post sized than SUV sized but hey.. how big is that SUV :-)??? http://birdtechnologies.thomasnet.com/item/all-categories-duplexers-and-triplexers/duplexers-2/28-37-04c?seo=110 At 9.5 x 19 x 10.5 inches, COULD fit in a car.. It is rated at 65db at .5mhz so would be a bit better at .6mhz and as I recall many of the little mobile duplexers are typically 65db to 80db at bestso would be in the neighborhood of lowest useable isolation figures, depending on how quiet the TX is to start with. It looks like it gets to 70db at 1 mhz with less insertion loss so .6 mhz would likely be somewhere in between... if you do not mind the insertion loss... Assuming we could split, it at worst case, 10-20db of antenna isolation in a mobile environment might be possible, and/or some additional notching...all this may make a low power 2m portable duplexer plausible without filling a whole car:-) Our club uses a 300khz 6 can TX/RX for our 2M repeater that was rated at ~100db at 600khz.. but when we had it set up for 600khz spacing it yielded in excess of 120 db TX to RX as delivered from TX/RX. From a practical perspective small 2M duplexers seem to start at about 2Mhz split... but hey size is relative Doug KD8B Morning, We are looking at building a portable repeater for special even use. This will be mobile mounted and 2M. My questions is this: If we are using two radios (one for TX one for RX) then what does the antenna separation have to be for all of this to work? Planning on mounting this in a SUV so roof space can be adjusted if need be. Thanks Peter Dakota Summerhawk Laramie County ARES
Re: [Repeater-Builder] Question on portable repeaters
If you are serious about keeping it at 600KHz separation ten you will need to have real duplexors. You can get them in an enclosure with the three required connectors. The biggest issue other than their size will be possible de tuning when transporting. 440 is a better choice. Another option is to make a 440 repeater and connect it to a VHF simplex radio, this would allow you to put it at a remote location that is high and talk to all of the other users. You would also have a cross band repeater as well since a lot of people now have dual band hand held radios.. Stan --- On Thu, 10/8/09, Doug Bade k...@thebades.net wrote: From: Doug Bade k...@thebades.net Subject: Re: [Repeater-Builder] Question on portable repeaters To: Repeater-Builder@yahoogroups.com Date: Thursday, October 8, 2009, 8:04 AM Possible options ? I decided to poke around on the Bird TX/RX website and found this little guy ( relatively speaking :-) ) Probably more command post sized than SUV sized but hey.. how big is that SUV :-)??? http://birdtechnolo gies.thomasnet. com/item/ all-categories- duplexers- and-triplexers/ duplexers- 2/28-37-04c? seo=110 At 9.5 x 19 x 10.5 inches, COULD fit in a car.. It is rated at 65db at .5mhz so would be a bit better at .6mhz and as I recall many of the little mobile duplexers are typically 65db to 80db at bestso would be in the neighborhood of lowest useable isolation figures, depending on how quiet the TX is to start with. It looks like it gets to 70db at 1 mhz with less insertion loss so .6 mhz would likely be somewhere in between... if you do not mind the insertion loss... Assuming we could split, it at worst case, 10-20db of antenna isolation in a mobile environment might be possible, and/or some additional notching...all this may make a low power 2m portable duplexer plausible without filling a whole car:-) Our club uses a 300khz 6 can TX/RX for our 2M repeater that was rated at ~100db at 600khz.. but when we had it set up for 600khz spacing it yielded in excess of 120 db TX to RX as delivered from TX/RX. From a practical perspective small 2M duplexers seem to start at about 2Mhz split... but hey size is relative Doug KD8B Morning, We are looking at building a portable repeater for special even use. This will be mobile mounted and 2M. My questions is this: If we are using two radios (one for TX one for RX) then what does the antenna separation have to be for all of this to work? Planning on mounting this in a SUV so roof space can be adjusted if need be. Thanks Peter Dakota Summerhawk Laramie County ARES
Re: [Repeater-Builder] Question on portable repeaters
Perhaps you need two Ford Explorers? :) Theres a lot of them to be found dead for scrap prices. Delete the driveshaft(s) and add a tow bar. Nice inconspicuous repeater platform! 2m RX - 900/1.2 link to other SUV - 2M TX If the link radio TX was very low (few hundred mW?) a smallish deep cycle (SLA) battery should run the RX and link TX for quite a while, and all you'd need then is a notch of some sort to keep the across-the-parking-lot-or-whatever signal from slipping into the 2M RX. Of course, a backpack, ammo box, ice chest or even a small trailer may be an easier solution to work with. I suggest the second Explorer to possibly increase the value of my own dead Ford Exploder. Maybe you could start a trend! JS Peter Dakota Summerhawk wrote: Morning, We are looking at building a portable repeater for special even use. This will be mobile mounted and 2M. My questions is this: If we are using two radios (one for TX one for RX) then what does the antenna separation have to be for all of this to work? Planning on mounting this in a SUV so roof space can be adjusted if need be. Thanks Peter Dakota Summerhawk Laramie County ARES
Re: [Repeater-Builder] Question on portable repeaters
300 feet. On Wed, Oct 7, 2009 at 4:15 PM, Peter Dakota Summerhawk commcon...@gmail.com wrote: Morning, We are looking at building a portable repeater for special even use. This will be mobile mounted and 2M. My questions is this: If we are using two radios (one for TX one for RX) then what does the antenna separation have to be for all of this to work? Planning on mounting this in a SUV so roof space can be adjusted if need be. Thanks Peter Dakota Summerhawk Laramie County ARES Yahoo! Groups Links
Re: [Repeater-Builder] Question on portable repeaters
No worries. They have an SUV roof. Vertical and horizontal distance with be significantly different, with vertical being smaller. You should look onto a mobile duplexer. They are relatively cheap. Michael -Original Message- From: DCFluX dcf...@gmail.com Date: Wed, 7 Oct 2009 16:18:32 To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Question on portable repeaters 300 feet. On Wed, Oct 7, 2009 at 4:15 PM, Peter Dakota Summerhawk commcon...@gmail.com wrote: Morning, We are looking at building a portable repeater for special even use. This will be mobile mounted and 2M. My questions is this: If we are using two radios (one for TX one for RX) then what does the antenna separation have to be for all of this to work? Planning on mounting this in a SUV so roof space can be adjusted if need be. Thanks Peter Dakota Summerhawk Laramie County ARES Yahoo! Groups Links
Re: [Repeater-Builder] Question on portable repeaters
About 30 feet vertical, depending on filtering and the antennas. You'd probably be better going on UHF with a mobile notch duplexer.
Re: [Repeater-Builder] Question on portable repeaters
You won't find a mobile duplexer for 600 kHz spacing. Chuck WB2EDV - Original Message - From: michaelh...@gmail.com To: Repeater-Builder@yahoogroups.com Sent: Wednesday, October 07, 2009 7:36 PM Subject: Re: [Repeater-Builder] Question on portable repeaters Vertical and horizontal distance with be significantly different, with vertical being smaller. You should look onto a mobile duplexer. They are relatively cheap. Michael
Re: [Repeater-Builder] Question on portable repeaters
Two antennas on 2-meter isn't exactly doable, the vertical and horizontal spacing issues would make it prohibitively undoable for a mobile repeater platform. You might find a mobile duplexer with 1.2mhz spacing (I remember someone here on RB talking about such a unit some time ago), but like Chuck said... 600khz is going to be a hard if not near impossible find. That is if you don't mind four normal duplexer cans taking up the entire back seat of your vehicle. -Brian / KF4ZWZ On Wed, Oct 7, 2009 at 4:55 PM, Chuck Kelsey wb2...@roadrunner.com wrote: You won't find a mobile duplexer for 600 kHz spacing. Chuck WB2EDV - Original Message - *From:* michaelh...@gmail.com *To:* Repeater-Builder@yahoogroups.com *Sent:* Wednesday, October 07, 2009 7:36 PM *Subject:* Re: [Repeater-Builder] Question on portable repeaters Vertical and horizontal distance with be significantly different, with vertical being smaller. You should look onto a mobile duplexer. They are relatively cheap. Michael
Re: [Repeater-Builder] Question on portable repeaters
Don't even try doing a portable repeater on 2 meters. Do it on 440 MHz or 900 Mhz. -- Original Message -- Received: Wed, 07 Oct 2009 04:15:29 PM PDT From: Peter Dakota Summerhawk commcon...@gmail.com To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Question on portable repeaters Morning, We are looking at building a portable repeater for special even use. This will be mobile mounted and 2M. My questions is this: If we are using two radios (one for TX one for RX) then what does the antenna separation have to be for all of this to work? Planning on mounting this in a SUV so roof space can be adjusted if need be. Thanks Peter Dakota Summerhawk Laramie County ARES
Re: [Repeater-Builder] Question on portable repeaters
Because the spacing between antennas is minimal at 440 and 900 megs and you can buy a duplexor for roughly the same cost as a good mobile antenna. If you want this to be an easy set up 44O is the way to go. Might also want to look for some used 2 meter stuff with duplexors ready to go. The seperate antenna and radios add to the work but can be done. for special events the less that can go wrong the better. --- On Wed, 10/7/09, JOHN MACKEY jmac...@usa.net wrote: From: JOHN MACKEY jmac...@usa.net Subject: Re: [Repeater-Builder] Question on portable repeaters To: Repeater-Builder@yahoogroups.com Date: Wednesday, October 7, 2009, 6:17 PM Don't even try doing a portable repeater on 2 meters. Do it on 440 MHz or 900 Mhz. -- Original Message -- Received: Wed, 07 Oct 2009 04:15:29 PM PDT From: Peter Dakota Summerhawk commcon...@gmail.com To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Question on portable repeaters Morning, We are looking at building a portable repeater for special even use. This will be mobile mounted and 2M. My questions is this: If we are using two radios (one for TX one for RX) then what does the antenna separation have to be for all of this to work? Planning on mounting this in a SUV so roof space can be adjusted if need be. Thanks Peter Dakota Summerhawk Laramie County ARES Yahoo! Groups Links __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com
RE: [Repeater-Builder] Question on portable repeaters
1.2gHz ! Chris Kb0wlf -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:Repeater- buil...@yahoogroups.com] On Behalf Of JOHN MACKEY Sent: Wednesday, October 07, 2009 8:17 PM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Question on portable repeaters Don't even try doing a portable repeater on 2 meters. Do it on 440 MHz or 900 Mhz. -- Original Message -- Received: Wed, 07 Oct 2009 04:15:29 PM PDT From: Peter Dakota Summerhawk commcon...@gmail.com To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Question on portable repeaters Morning, We are looking at building a portable repeater for special even use. This will be mobile mounted and 2M. My questions is this: If we are using two radios (one for TX one for RX) then what does the antenna separation have to be for all of this to work? Planning on mounting this in a SUV so roof space can be adjusted if need be. Thanks Peter Dakota Summerhawk Laramie County ARES Yahoo! Groups Links No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.5.421 / Virus Database: 270.14.1/2407 - Release Date: 10/07/09 05:18:00
RE: [Repeater-Builder] Question on portable repeaters
Peter, The only viable solution for a portable repeater on 2m is to use two widely-spaced frequencies, low power, and a compact base-station duplexer. Here in Central and Southern California, TASMA has wisely set aside two frequencies (144.930 input and 147.585 output) exclusively for temporary portable repeaters. The 2.655 MHz separation means that a small duplexer such as the Celwave 5085-1 can be used at low power, say 10 watts. I have just such a repeater in the final stages of construction, using a Motorola R1225 VHF duplex radio running about 8 watts- more than enough for emergency communications. The complete repeater is in a Pelican-style case that is about one cubic foot and weighs about 15 pounds. Separate antennas is really not an option here. Even with just 10 watts of power, the horizontal separation needed to avoid desense is over 9,500 feet horizontally or 150 feet vertically. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Peter Dakota Summerhawk Sent: Wednesday, October 07, 2009 4:15 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Question on portable repeaters Morning, We are looking at building a portable repeater for special even use. This will be mobile mounted and 2M. My questions is this: If we are using two radios (one for TX one for RX) then what does the antenna separation have to be for all of this to work? Planning on mounting this in a SUV so roof space can be adjusted if need be. Thanks Peter Dakota Summerhawk Laramie County ARES
RE: [Repeater-Builder] Question on portable repeaters
Maybe the gentleman wants a VHF portable repeater for commercial channels, so the offset will be a lot more than 600KHz..? JT Don't even try doing a portable repeater on 2 meters. Do it on 440 MHz or 900 Mhz. -- Original Message -- Received: Wed, 07 Oct 2009 04:15:29 PM PDT From: Peter Dakota Summerhawk commcon...@gmail.com http://us.mc456.mail.yahoo.com/mc/compose?to=commcon...@gmail.com To: Repeater-Builder@yahoogroups.com http://us.mc456.mail.yahoo.com/mc/compose?to=repeater-buil...@yahoogroups.c om Subject: [Repeater-Builder] Question on portable repeaters Morning, We are looking at building a portable repeater for special even use. This will be mobile mounted and 2M. My questions is this: If we are using two radios (one for TX one for RX) then what does the antenna separation have to be for all of this to work? Planning on mounting this in a SUV so roof space can be adjusted if need be. Thanks Peter Dakota Summerhawk Laramie County ARES . Web Bug from http://geo.yahoo.com/serv?s=97359714/grpId=104168/grpspId=1705063108/msgId=9 4809/stime=1254965424/nc1=1/nc2=2/nc3=3 http://www.mailscanner.info/images/1x1spacer.gif
RE: [Repeater-Builder] Question on portable repeaters
How big is the SUV? --- On Wed, 10/7/09, Eric Lemmon wb6...@verizon.net wrote: From: Eric Lemmon wb6...@verizon.net Subject: RE: [Repeater-Builder] Question on portable repeaters To: Repeater-Builder@yahoogroups.com Date: Wednesday, October 7, 2009, 6:42 PM Peter, The only viable solution for a portable repeater on 2m is to use two widely-spaced frequencies, low power, and a compact base-station duplexer. Here in Central and Southern California, TASMA has wisely set aside two frequencies (144.930 input and 147.585 output) exclusively for temporary portable repeaters. The 2.655 MHz separation means that a small duplexer such as the Celwave 5085-1 can be used at low power, say 10 watts. I have just such a repeater in the final stages of construction, using a Motorola R1225 VHF duplex radio running about 8 watts- more than enough for emergency communications. The complete repeater is in a Pelican-style case that is about one cubic foot and weighs about 15 pounds. Separate antennas is really not an option here. Even with just 10 watts of power, the horizontal separation needed to avoid desense is over 9,500 feet horizontally or 150 feet vertically. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Peter Dakota Summerhawk Sent: Wednesday, October 07, 2009 4:15 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Question on portable repeaters Morning, We are looking at building a portable repeater for special even use. This will be mobile mounted and 2M. My questions is this: If we are using two radios (one for TX one for RX) then what does the antenna separation have to be for all of this to work? Planning on mounting this in a SUV so roof space can be adjusted if need be. Thanks Peter Dakota Summerhawk Laramie County ARES Yahoo! Groups Links
RE: [Repeater-Builder] Question on portable repeaters
--- On Wed, 10/7/09, Juan Tellez xe...@grupocimsa.com wrote: From: Juan Tellez xe...@grupocimsa.com Subject: RE: [Repeater-Builder] Question on portable repeaters To: Repeater-Builder@yahoogroups.com Date: Wednesday, October 7, 2009, 9:43 PM Maybe the gentleman wants a VHF portable repeater for commercial channels, so the offset will be a lot more than 600KHz……? JT Don't even try doing a portable repeater on 2 meters. Do it on 440 MHz or 900 Mhz. -- Original Message -- Received: Wed, 07 Oct 2009 04:15:29 PM PDT From: Peter Dakota Summerhawk commcon...@gmail.com To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Question on portable repeaters Morning, We are looking at building a portable repeater for special even use. This will be mobile mounted and 2M. My questions is this: If we are using two radios (one for TX one for RX) then what does the antenna separation have to be for all of this to work? Planning on mounting this in a SUV so roof space can be adjusted if need be. Thanks Peter Dakota Summerhawk Laramie County ARES The 2M is usually taken to be the 2 meter ham band around 146 mhz. Also the ARES is a ham shortcut.
RE: [Repeater-Builder] Question on portable repeaters
Ford Explorer if that helps. And yes I was looking for a 2M repeater even if the spacing does have to be more than 600Kh just curious if its doable. Thanks Peter From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Chris Quirk Sent: Wednesday, October 07, 2009 8:07 PM To: Repeater-Builder@yahoogroups.com Subject: RE: [Repeater-Builder] Question on portable repeaters How big is the SUV? --- On Wed, 10/7/09, Eric Lemmon wb6...@verizon.net wrote: From: Eric Lemmon wb6...@verizon.net Subject: RE: [Repeater-Builder] Question on portable repeaters To: Repeater-Builder@yahoogroups.com Date: Wednesday, October 7, 2009, 6:42 PM Peter, The only viable solution for a portable repeater on 2m is to use two widely-spaced frequencies, low power, and a compact base-station duplexer. Here in Central and Southern California, TASMA has wisely set aside two frequencies (144.930 input and 147.585 output) exclusively for temporary portable repeaters. The 2.655 MHz separation means that a small duplexer such as the Celwave 5085-1 can be used at low power, say 10 watts. I have just such a repeater in the final stages of construction, using a Motorola R1225 VHF duplex radio running about 8 watts- more than enough for emergency communications. The complete repeater is in a Pelican-style case that is about one cubic foot and weighs about 15 pounds. Separate antennas is really not an option here. Even with just 10 watts of power, the horizontal separation needed to avoid desense is over 9,500 feet horizontally or 150 feet vertically. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com http://us.mc456.mail.yahoo.com/mc/compose?to=repeater-buil...@yahoogroups.c om [mailto:Repeater-Builder@yahoogroups.com http://us.mc456.mail.yahoo.com/mc/compose?to=repeater-buil...@yahoogroups.c om ] On Behalf Of Peter Dakota Summerhawk Sent: Wednesday, October 07, 2009 4:15 PM To: Repeater-Builder@yahoogroups.com http://us.mc456.mail.yahoo.com/mc/compose?to=repeater-buil...@yahoogroups.c om Subject: [Repeater-Builder] Question on portable repeaters Morning, We are looking at building a portable repeater for special even use. This will be mobile mounted and 2M. My questions is this: If we are using two radios (one for TX one for RX) then what does the antenna separation have to be for all of this to work? Planning on mounting this in a SUV so roof space can be adjusted if need be. Thanks Peter Dakota Summerhawk Laramie County ARES Yahoo! Groups Links roups.com mailto:repeater-builder-fullfeatu...@yahoogroups.com http://us.mc456.mail.yahoo.com/mc/compose?to=Repeater-Builder-fullfeatured@ yahoogroups.com ahoogroups.com
Re: [Repeater-Builder] Question on portable repeaters
Peter, I haven't seen this mentioned, but perhaps you could do a split-site repeater, with a 2m rcvr, basic controller, low-power UHF transmitter and small solar panel ready to hang on a utility pole somewhere, then park the SUV with a UHF link receiver and 2m transmitter a half-mile away but line-of-site. More pieces, a little tougher to set up, but much more compact than using a 2m duplexer. It's hard to beat 440 for a mobile or portable repeater. Tiny duplexers work, surplus commercial gear is cheap and plentiful, and many hams have radios for it. The repeater part is easy on 900 MHz and 1.2 GHz, but almost nobody has radios for those bands outside a couple big cities. 73, Paul, AE4KR - Original Message - From: Peter Dakota Summerhawk To: Repeater-Builder@yahoogroups.com Sent: Wednesday, October 07, 2009 5:15 PM Subject: [Repeater-Builder] Question on portable repeaters Morning, We are looking at building a portable repeater for special even use. This will be mobile mounted and 2M. My questions is this: If we are using two radios (one for TX one for RX) then what does the antenna separation have to be for all of this to work? Planning on mounting this in a SUV so roof space can be adjusted if need be. Thanks Peter Dakota Summerhawk Laramie County ARES
