RE: [Repeater-Builder] Repeater Rebuild Project Input
At 1/9/2010 20:49, you wrote: The GP9 I used on the repeaters was on a hill that was about 900 feet elevation. The problems didn't seem to make any difference regardless if the user was 2 miles out or 10 miles out. Then either you had lots of foliage absorption (lots of trees in Oregon), which affects 440 more than 2 meters, or you just got a bad antenna. The fact that you changed sites along with antennas may have changed the absorption issue. I have 4 GP9s in service then all work very well on 440. The one I have on the 5200' mountain significantly outperforms a DB-420, which is now my backup TX antenna. Bob NO6B
RE: [Repeater-Builder] Repeater Rebuild Project Input
At 1/8/2010 23:39, you wrote: I used a Comet GP9 for about 2 years on a 444 Mhz repeater, then connected a 2 meter repeater to it. The 2 meter system performed FAR better than the UHF system. Both repeaters were nearly identical in performance otherwise, the GP9 simply performed much better on 2 meters. The GP9 does have significant nulls below the horizon on 440, so if your repeater was on a mountain you were trying to access it close-in, it would appear to perform much worse than on 2 meters, where the gain is lower. The only GP9 I have on a mountain is used for TX only, so I don't care about the close-in coverage. At 15 miles away the main lobe hits the ground. Bob NO6B
RE: [Repeater-Builder] Repeater Rebuild Project Input
The GP9 I used on the repeaters was on a hill that was about 900 feet elevation. The problems didn't seem to make any difference regardless if the user was 2 miles out or 10 miles out. I can not recommend a GP9 for UHF. -- Original Message -- Received: Sat, 09 Jan 2010 11:20:21 AM PST From: n...@no6b.com To: Repeater-Builder@yahoogroups.com Subject: RE: [Repeater-Builder] Repeater Rebuild Project Input At 1/8/2010 23:39, you wrote: I used a Comet GP9 for about 2 years on a 444 Mhz repeater, then connected a 2 meter repeater to it. The 2 meter system performed FAR better than the UHF system. Both repeaters were nearly identical in performance otherwise, the GP9 simply performed much better on 2 meters. The GP9 does have significant nulls below the horizon on 440, so if your repeater was on a mountain you were trying to access it close-in, it would appear to perform much worse than on 2 meters, where the gain is lower. The only GP9 I have on a mountain is used for TX only, so I don't care about the close-in coverage. At 15 miles away the main lobe hits the ground. Bob NO6B
RE: [Repeater-Builder] Repeater Rebuild Project Input
Hi John, Happy New Year. If money is an issue, go to your local radio shop and see if they have an old DB or Sinclair antenna laying around. Most likely they will. Mike Mullarkey K7PFJ 6886 Sage Ave Firestone, Co 80504 303-954-9695 Home 303-954-9693 Home Office Fax 303-718-8052 Cellular _ From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of JOHN MACKEY Sent: Saturday, January 09, 2010 9:50 PM To: Repeater-Builder@yahoogroups.com Subject: RE: [Repeater-Builder] Repeater Rebuild Project Input The GP9 I used on the repeaters was on a hill that was about 900 feet elevation. The problems didn't seem to make any difference regardless if the user was 2 miles out or 10 miles out. I can not recommend a GP9 for UHF. -- Original Message -- Received: Sat, 09 Jan 2010 11:20:21 AM PST From: n...@no6b.com mailto:no6b%40no6b.com To: Repeater-Builder@ mailto:Repeater-Builder%40yahoogroups.com yahoogroups.com Subject: RE: [Repeater-Builder] Repeater Rebuild Project Input At 1/8/2010 23:39, you wrote: I used a Comet GP9 for about 2 years on a 444 Mhz repeater, then connected a 2 meter repeater to it. The 2 meter system performed FAR better than the UHF system. Both repeaters were nearly identical in performance otherwise, the GP9 simply performed much better on 2 meters. The GP9 does have significant nulls below the horizon on 440, so if your repeater was on a mountain you were trying to access it close-in, it would appear to perform much worse than on 2 meters, where the gain is lower. The only GP9 I have on a mountain is used for TX only, so I don't care about the close-in coverage. At 15 miles away the main lobe hits the ground. Bob NO6B
Re: [Repeater-Builder] Repeater Rebuild Project Input
From the information you've provided I'm look hard at a Motorola R1225 or a pair of GM300s. The diamond will certialy lower your SWR, but so will a 50 ohm dummy load. Low SWR isn't the only concern any more than antenna gain is. It's likely the Diamond will work, but these ham market antennas have notoriously short lives in full duplex operation. There are exceptions that have been in service a long time, but a large percentage get annual changes. I'd also look hard at a local water tank if you want reliable coverage. ;-) On 1/8/2010 2:08 AM, phantom1071 wrote: Hello All, I am looking to rebuild a 70cm repeater with an output within the ham band. We currently have a non-tunable fiberglass comercial band antenna wich is giving us a SWR of about 2:1. The first piece of advice we are looking for is recomendations for replacing the antena. There are some conciderations to go with this. Since it is a privately owned repeater it is in a back yard and not mounted very high due to lack of an antenna tower or space to put one up on the property. The antenna will be mounted at about 20 feet from ground level and we are looking to maximize coverage area so we are looking at high gain antennas such as the Diamond F718 which would be a step up as it would lower our SWR. What are your thoughts with this antenna or recomendations on other high gain antennas for the 70cm band? Also, we are looking to replace the repeater itself. Right now we have an old Kenwood business band repeater that has been modified to work in the ham band but it is becoming more unstable as time progresses. We want to keep the equipment as back up and would like to look into a new system. We want something that is computer programable if possible. It also should work with an external controller as we are using a CAT-1000 with an attached weather station and CAT weather radio reciever. Right now we are coordinated at 25 watts output but would like to have a repeater that could run 50 watts continuous. Also, we would like to stay away from D-STAR simply because of personal preferance. Any suggestions or reccomendations for the repeater unit? Thanks for your help! Andrew KB8UPB ___ -- mailto:o...@ozindfw.net Oz POB 93167 Southlake, TX 76092 (Near DFW Airport)
RE: [Repeater-Builder] Repeater Rebuild Project Input
Depending on what coverage you are looking to expect, will help you choose the proper gain antenna. A higher gain antenna is not always a good choice and can cause more problems and poor coverage then you would expect nearby the repeater. What is you HAAT? Are most the user going to be fixed station mobile users or HT? if so How far away from the repeater will you users be? If your users are near by the site and you have a erp you do not need to exceed a lower gain antenna or unity gain might do you a great job. SWR 2:1 have you check this antenna with a true 50ohm analyzer, or into the transmitter without the duplexers? Hello All, I am looking to rebuild a 70cm repeater with an output within the ham band. We currently have a non-tunable fiberglass comercial band antenna wich is giving us a SWR of about 2:1. The first piece of advice we are looking for is recomendations for replacing the antena. There are some conciderations to go with this. Since it is a privately owned repeater it is in a back yard and not mounted very high due to lack of an antenna tower or space to put one up on the property. The antenna will be mounted at about 20 feet from ground level and we are looking to maximize coverage area so we are looking at high gain antennas such as the Diamond F718 which would be a step up as it would lower our SWR. What are your thoughts with this antenna or recomendations on other high gain antennas for the 70cm band? Also, we are looking to replace the repeater itself. Right now we have an old Kenwood business band repeater that has been modified to work in the ham band but it is becoming more unstable as time progresses. We want to keep the equipment as back up and would like to look into a new system. We want something that is computer programable if possible. It also should work with an external controller as we are using a CAT-1000 with an attached weather station and CAT weather radio reciever. Right now we are coordinated at 25 watts output but would like to have a repeater that could run 50 watts continuous. Also, we would like to stay away from D-STAR simply because of personal preferance. Any suggestions or reccomendations for the repeater unit? Thanks for your help! Andrew KB8UPB
RE: [Repeater-Builder] Repeater Rebuild Project Input
At 1/8/2010 16:22, you wrote: Depending on what coverage you are looking to expect, will help you choose the proper gain antenna. A higher gain antenna is not always a good choice and can cause more problems and poor coverage then you would expect nearby the repeater. Andrew said he wants to maximize the coverage the antenna will only be 20 feet up. Clearly this calls for a higher gain antenna. I recommend the Comet GP9. It has 11 dBi gain on 440 MHz, on the horizon, also works well on 2 meters in the event you want to add a remote base. Bob NO6B
RE: [Repeater-Builder] Repeater Rebuild Project Input
I used a Comet GP9 for about 2 years on a 444 Mhz repeater, then connected a 2 meter repeater to it. The 2 meter system performed FAR better than the UHF system. Both repeaters were nearly identical in performance otherwise, the GP9 simply performed much better on 2 meters. A couple years later I changed sites and the repeaters each got their own antennas. Then they performed roughly the same. -- Original Message -- Received: Fri, 08 Jan 2010 05:35:36 PM PST From: n...@no6b.com To: Repeater-Builder@yahoogroups.com Subject: RE: [Repeater-Builder] Repeater Rebuild Project Input I recommend the Comet GP9. It has 11 dBi gain on 440 MHz, on the horizon, also works well on 2 meters in the event you want to add a remote base. Bob NO6B
