[Repeater-Builder] Maybe a strange question...
Our repeater is coordinated on a given two meter frequency. Due to terrain and other factors, we were forced to agree to some interference from a neighboring repeater, on the same frequency. The neighboring repeater is located on a peak roughly 100 miles away from us, and roughly 1800 feet higher in elevation. The repeater owner claims an ERP of 55 watts from an omni, however, I can consistently hear that repeater on my base at my QTH with an s-1 to s-3. I am transmitting 50w, 2dB loss in connectors, about 1.25 dB loss in feedline and about +6.5 dBi in antenna gain. So, I figure my ERP should be about 100 watts (+3dB = double in power, right). My antenna height is about 35 feet. So, as a newbie, I am assuming that if I can hear him at s-3, and he is transmitting 55w ERP, where my ERP is 100w, I should be able to program the radio with the proper offset and PL tone and get into the repeater. Is this a correct assumption? After all, if I can consistently hear him, the path is line of sight, right? Due to the difference in altitude, this would make sense. If all else is the same, I should be able to bring the repeater up. Or, is this repeater putting out much more than 55w ERP? Thanks!
Re: [Repeater-Builder] Maybe a strange question...
Your ERP will be around 55-60 watts given the info provided. I de-rated the dBi by 2 dB to give you dBd. I think that's correct. So your overall gain is only 1.25 dB. Chuck WB2EDV - Original Message - From: Randy Ross To: Repeater-Builder@yahoogroups.com Sent: Thursday, October 15, 2009 9:04 PM Subject: [Repeater-Builder] Maybe a strange question... Our repeater is coordinated on a given two meter frequency. Due to terrain and other factors, we were forced to agree to some interference from a neighboring repeater, on the same frequency. The neighboring repeater is located on a peak roughly 100 miles away from us, and roughly 1800 feet higher in elevation. The repeater owner claims an ERP of 55 watts from an omni, however, I can consistently hear that repeater on my base at my QTH with an s-1 to s-3. I am transmitting 50w, 2dB loss in connectors, about 1.25 dB loss in feedline and about +6.5 dBi in antenna gain. So, I figure my ERP should be about 100 watts (+3dB = double in power, right). My antenna height is about 35 feet. So, as a newbie, I am assuming that if I can hear him at s-3, and he is transmitting 55w ERP, where my ERP is 100w, I should be able to program the radio with the proper offset and PL tone and get into the repeater. Is this a correct assumption? After all, if I can consistently hear him, the path is line of sight, right? Due to the difference in altitude, this would make sense. If all else is the same, I should be able to bring the repeater up. Or, is this repeater putting out much more than 55w ERP? Thanks!
Re: [Repeater-Builder] Maybe a strange question...
--- On Thu, 10/15/09, Randy Ross rr...@librtynet.com wrote: From: Randy Ross rr...@librtynet.com Subject: [Repeater-Builder] Maybe a strange question... To: Repeater-Builder@yahoogroups.com Repeater-Builder@yahoogroups.com Date: Thursday, October 15, 2009, 9:04 PM Our repeater is coordinated on a given two meter frequency. Due to terrain and other factors, we were forced to agree to some interference from a neighboring repeater, on the same frequency. The neighboring repeater is located on a peak roughly 100 miles away from us, and roughly 1800 feet higher in elevation. The repeater owner claims an ERP of 55 watts from an omni, however, I can consistently hear that repeater on my base at my QTH with an s-1 to s-3. I am transmitting 50w, 2dB loss in connectors, about 1.25 dB loss in feedline and about +6.5 dBi in antenna gain. So, I figure my ERP should be about 100 watts (+3dB = double in power, right). My antenna height is about 35 feet. So, as a newbie, I am assuming that if I can hear him at s-3, and he is transmitting 55w ERP, where my ERP is 100w, I should be able to program the radio with the proper offset and PL tone and get into the repeater. Is this a correct assumption? After all, if I can consistently hear him, the path is line of sight, right? Due to the difference in altitude, this would make sense. If all else is the same, I should be able to bring the repeater up. Or, is this repeater putting out much more than 55w ERP? Unless you have a very good receiver and the repeater does not, if you can hear a repeater and your transmitter is running the same or more power, you should be able to bring it up. You normally assume that the repeater is using the same antenna for receiving and transmitting and the loss in the feedline and duplexer is the same for both.
Re: [Repeater-Builder] Maybe a strange question...
Randy, it's pretty common these days for a transceiver in a valley to have much higher useful sensitivity than a receiver at a high repeater site, because your noise floor may be much lower, and the front end of the repeater's receiver may require much higher selectivity. It is also possible that the other repeater is running above its coordinated power level. I believe that many are. Such an accusation is usually unproductive. If you can still hear your own repeater over the distant one when both are active, that is NOT interference, that's users whining. CTCSS works both ways. Put it on your repeater's output, have users use decoders on their receivers, and *-poof-* problem solved. 73, Paul, AE4KR - Original Message - From: Randy Ross To: Repeater-Builder@yahoogroups.com Sent: Thursday, October 15, 2009 7:04 PM Subject: [Repeater-Builder] Maybe a strange question... If all else is the same, I should be able to bring the repeater up. Or, is this repeater putting out much more than 55w ERP? .
